Journal and Proceedings
of the
Royal Society

of
New South Wales

Volume 146 Part 2

Numbers 449 and 450

“*... for the encouragement of stucies and investigations in Saence Art Literature and Philosophy ..”

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Hon. Secretary (Ed.)
Hon. Secretary (Gen.)
Hon. Treasurer

Hon. Librarian

Councillors

Southern Highlands
Branch Representative
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Chair

Executive Office

THE ROYAL SOCIETY OF NEW SOUTH WALES

OFFICE BEARERS FOR 2013-2014

Her Excellency Ms Quentin Bryce AC CVO

Governor-General of the Commonwealth of Australia.

Her Excellency Professor Marie Bashir AC CVO

Governor of New South Wales.

Dr Donald Hector BE (Chem) PhD (Syd) FIChemE FIEAust FAICD

Mr John Hardie BSc Syd) FGS MACE MRSN

Em. Prof. David Brynn Hibbert BSc PhD (Lond) CChem FRSC FRACI

Em. Prof. Heinrich Hora DipPhys Dr.rer.nat DSc FAIP FInstP CPhys

Prof. Michael Burton BA MA MMaths (Cantab) PhD (Edin) FASA FAIP

Mr Colin Bradley BBus MA (Bus Res) MHA GAICD

Mr Shakti Ram BComm (Macq) MBA (Deakin) CPA GAICD

(vacant)

Prof. Richard Banat) MD PhD

Mr David Beale BSc (Tech) (NSW) FIEAust

Mr Brendon Hyde BE (Syd) MEngSc (UNSW) MICE (Lon) FIEPak
FIEAust CPEng

Em. Prof. Roy MacLeod AB (Harv) PhD (Cantab) LittD (Cantab) FAHA
PASSA

Dr Frederick Osman BSc (Hons) PhD (UWS) FACE MAIP MRSN

Mr Clive Wilmot

Ass. Prof. Maree Simpson BPharm (UQ) BSc(Hons) (Griffith) PhD (UQ)
Ms Emma Dallas DipHR BComm (UWS) LLB (UWS)

EDITORIAL BOARD

Prof. Michael Burton BA MA MMaths (Cantab) PhD (Edin) FASA, FAIP — Honorary Editor
Dr David Branagan MSc PhD(Syd) DSc (Hon) (Syd) FGS

Dr Donald Hector BE(Chem) PhD Gyd) FIChemE FIEAust FAICD

Prof. David Brynn Hibbert BSc PhD (Lond) CChem FRSC FRACI

Dr Michael Lake BSc (Syd) PhD (Syd)

Dr Nick Lomb BSc (Syd) PhD (yd)

Em. Prof. Roy MacLeod AB (Harv) PhD (Cantab) LittD (Cantab) FAHA FASSA

Prof. Bruce Warren MB BS (Syd) MA DPhil DSc (Oxon) FRCPath FRSN

The Society traces it origin the Philosophical Society of Australasia founded in Sydney in 1821. The Society exists for “she
encouragement of studies and investigations in Saence Art Literature and Philosophy’: publishing results of scientific
investigations in its Journal and Proceedings; conducting monthly meetings; awarding prizes and medals; and by
laison with other learned societies within Australia and internationally. Membership is open to any person whose
application is acceptable to the Society. Subscriptions for the Journal are also accepted. The Society welcomes, from
members and non-members, manuscripts of research and review articles in all branches of science, art, literature and
philosophy for publication in the Journal and Proceedings.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
ISSN 0035-9173/13/02

Journal and Proceedings of the Royal Society of New South Wales, vol. 146, nos. 449 & 450, pp. 74.

ISSN 0035-9173/13/020074-1

Editorial

This special issue of the Jomnal and
Proceedings provides a tribute to the memory
of Jak Kelly, a past President of our Society.
Jak was an experimental physicist who spent
the greater part of his career at the
University of New South Wales, including
serving as the Head of School for Physics.
We hear in this issue from colleagues and
former students about the influential role
Jak played in mentoring their own careers,
of work that Jak led them into, of the
essential elements of physics that he instilled
in them at formative stages in their lives —
the arts and skills of problem solving, of
looking at the big picture and thinking
beyond the constraints — all hallmarks of
good science and good scientists.

Richard Newbury, the current Head of
Physics at UNSW, begins, comparing the
School today to how it was in Jak’s time,
and musing at how the world of academia
had changed, not necessarily for the better.
David Mills describes how Jak led him into
the world of solar collectors -— an
unfashionable field at the tme — and to the
development a new type of surface for the
efficient collection of radiation, one which
later became the key technology behind
millions of solar hot water systems in China.
We have three articles from former PhD
students of Jak. Patrick Krejcik learnt the
tools of the trade of particle accelerators
under Jak in the High Voltage Accelerator
Laboratory at UNSW. He ended up
working with Stanford’s Linear Accelerator,
where many fundamental discoveries
underlying our current understanding of
particle physics have been made. Patrick
writes on the history of particle accelerators
at Stanford. Zoltan Kerestes is now a
medical physicist at Sydney’s Royal North

74

Shore Hospital, practising a different kind
of physics to that he learnt under Jak. But
the lessons Jak instilled 1n him have played
an essential part in developing his career.
Zoltan espouses some of these lessons for
us, along the way giving us insights into
Jak’s irrepressible character and his sense of
humour. Jim Williams was enticed by Jak
into a PhD using the soon-to-be installed
Cockcroft-Walton accelerator at UNSW.
That experiment didn’t quite go the way 1t
was planned, or at least to schedule — not an
unusual story with frontline science, but one
that provided an invaluable lesson into how
science actually works and led Jim into the
new field of ion channelling. He recounts
some of the experiences, and the influence
of Jak, which has underpinned his own
successful career that has ended up at the
Australian National University. Heinrich
Hora was a fellow academic at UNSW with
Jak, heading theoretical physics while Jak
was the driving force behind experimental
physics. Heinrich describes some of the
research avenues that his interactions with
Jak led him into. The final contribution for
this special edition comes from Andrew
Ong, also at UNSW, but having just
completed his PhD — he was the Society’s
Jak Kelly Award winner in 2012. We begin
the edition by reprinting Jak’s Obituary, as
published in [o/ 745 of this Journal.

Michael Burton
Hon. Secretary (Editorial)

This spectal issue of the Journal has been supported
by both the School of Phystes and the Faculty of
Sctence at the University of New South W ates.

Journal and Proceedings of the Royal Soctety of New South Wales, vol. 146, nos. 449 & 450, pp. 75-76.

ISSN 0035-9173/13/020075-2

Obituary

Professor Jak (John Charles) Kelly FRSN
(14 February 1928 — 11 February 2012)

Re-printed from Vol 145, Part 1, Nos. 443 & 444, pp 101-102.

Jak was born John Charles Kelly in 1928, in
Borenor, about 30 km west of Orange in
New South Wales. The son of a contract
wheat harvester, he obtained a scholarship
to the De La Salle Bros. school in Armidale
and progressed to the University of Sydney,
where he fell in love with physics and
caving.
Sydney University Speleological Society in
1948 and became a local caving icon.
Opening the 50% SUSS meeting in 1998, he
recalled running out of oxygen: “People
were unable to strike matches for their
cigarettes. It took 45 minutes to get down

>

Jak was founding President of

and 5 minutes to get out

Graduating in 1950, Jak worked at the
National Standards Laboratory in Sydney,
publishing his first paper in Nature in 1950
on his invention of vibration measurement

ibe:

using multiple beam interferometry. In
1953, he married Irene Traub, who
remained at his side for the next 59 years
and is known to many in the Society.

In 1955 Jak moved to the University of
Reading to complete a thin film PhD
project under O.S. Heavens. In order to
create better quality thin films, he invented
Electron Bombardment Deposition using a
pendant droplet of melted metal heated by
an electron beam. It became a standard
high temperature metal
evaporation. Graduating in 1958, he
worked at Harwell on radiation damage in
crystals, grown using his single drop
method.

method = of

Jak returned to Australia in 1961 to the
UNSW School of Physics, where he
remained for the rest of his salaried career,
writing more than 150 papers. He
specialised in 1on beam _ deposition,
patenting several improvements, and co-
authored three books. He served as Chair
of the Australian Institute of Physics in
1965-66, became a Fellow of the Australian
and UK Institutes of Physics, and in 1975
was created a Doctor of Science for his
body of work. His curiosity was broad and
his subsequent cooperation with other
eroups included thermoluminescent dating,
using 1on implantation to improve the
attachment of bone cells to prosthetic
surfaces, the modelling and deposition of
thin film solar energy absorbers, irradiation
of wool using tion beams to improve wool
properties, studying low energy nuclear

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills, Hardie, Hora — Obituary of Jak Kelly

reactions, and proposing laser fusion
improvements.

At UNSW Jak served as Head of School
and Science Faculty Chairman (1985-89),
and Chairman of the Australian Academy of
Science Section A and other committees.
He retired in 1989, remaining a visiting
professor, and became Editor of Australian
Physics (1992-98), Honorary Professor of
Physics at Sydney University in 2004, and
subsequently President of the NSW Royal
Society (2005 and 2006). He was appointed
an Inaugural Fellow of the Society in 2009.

Jak was an outstanding ambassador tor
Physics. His flamboyance, fluency, and
sense of humour found a ready audience in
younger students and drew many into

Physics as a career. Many still remember
him playing the scientific sage in 1980 in a
Robin Williams ABC Science Show spoot
about the discovery of a 60,000 year old
fossilised beer can. He also supervised
many PhD students who became friends
and remained so.

Jak died with his family around him, 3 days
before his 84'* birthday. Fle is survived by
Irene, who for vears assisted the Sydney
RSNSW office; their daughter and former
science broadcaster Karina Kelly, who
preceded Jak as President of the Society;
and sons Michael and Julian.

David Mills
John Hardie
Heintich Hora

s

a

.

if P
@
a
we
ps

Journal and Proceedings of the Royal Soctety of New South Wates, vol. 146, nos. 449 & 450, pp. 77-82.

ISSN 0035-9173/13/020077-6

Jak Kelly — Peerless Head of the School of Physics,
UNSW 1985-1989

Richard Newbury
Head, School of Physics, UNSW

School of Physics, University of New South Wales, Sydney, NSW 2052, Australia

Abstract
Jak Kelly served as the Head of the School of Physics at the University of New South Wales from 1985 to
1989. This article provides a perspective of life in the School of Physics in Jak’s day compared to 2013, as

seen and experienced by the current Head of School.

I have been asked to write something about
Jak Kelly. My instructions are to write
something about Jak Kelly the man and the
scientist and something also from a Head of
School perspective, the suggestion being to
contrast the job as it was in Jak’s time as
Head (1986-1988) with the nature of the job
today. Actually this is a little difficult
because I came to Australia only in 1991
(jak had by then already retired), I didn’t
know Jak and, although I did see him in the
corridors of the School from time to time,
we never spoke. However a little informed
guesswork is possible and a sketch of things
as they were then can be gleaned from the
recollections of staff who have been with us
in the School since the 80s. One thing I am
sure about ts that the job, in some respects,
is very different today.

I attended Jak’s funeral in 2012 and met
many of his family and friends. It was
obvious as we heard from the many in
attendance that Jak was a very special man,
a talented researcher and teacher and a man
with wonderful family and many devoted
friends, colleagues and students he’d taught
and supervised.

So let’s look back a bit to the earlier days of
the School, 20-25 vears back.

77

When I arrived at the School in February
1991, Bob Starrett, a Professional Officer in
the School since time immemorial, took me
to a (very) dusty room half way along the
Lower Ground Floor of the Old Main
Building and said “I want to show you
something, I think you'll find it interesting”.
Half an hour later with Bob still fiddling
with diecast boxes and BNC cables I was
becoming quite impatient when a rotating
globe icon appeared in the corner of the 10
inch black & white monitor and Bob said:
“that’s the internet, it’s great isn’t itl”
Fascinating, Bob. What does it do?” After
a 10-minute briefing from Bob I remained
unconvinced, couldn’t see any potential in
the daft distraction Bob called the Internet,
and we went off to lunch.

It’s quite likely that Jak wouldn’t have been
able to anticipate either — who could have
guessed? — the impact the internet would
have on so many things, changing the
nature of work, leisure and things one could
put in the category “irritations”.

I say irritations because, once upon a time,
to request that someone at the other end of
campus, or further afield, do something
required a phone call or often a letter. In

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Newbury — Jak Kelly: Peerless Head of School

Jak’s time a letter would be drafted, typed,
proofed, put into an envelope and posted.
‘The recipient would receive the instruction
up to a week later. The advantage of the
inertia build into this system of
communication, aside from the extra work
required is that people issued less requests
for action or for compendious data sets ete.
An even bigger advantage was that people
probably thought more carefully about the
reason for their requests for action and
information. Perhaps with the time saved
people were able to engage in more
profound activities and not the “thought
bytes” that we must sometimes be content
with nowadays?

So what was Jak doing back then, BT
(Before The Internet)? One of Jak’s earliest
papers was a nice piece of work published
in Nature in March 1950 and concerned the
use of interferometry for
measurements of vibration — for example
vibration of buildings. This work was
performed at the National Standards
Laboratory, CSIRO. By the mid-50s Jak
was at the University of Reading studying
for his PhD and had moved on to thin film
physics, radiation detectors and the
properties of molten metals, work which
Jak continued until the early 1960s, firstly at
Reading, then the Atomic Energy Research
Establishment, Harwell and then at the
School of Physics, UNSW, having taken up
a permanent academic position in the
School in 1961.

sensitive

I am fortunate to have to hand a copy of
Jak’s D.Sc. thesis from 1972, a collection of
some 39 papers that form a very nice
“roadmap” for Jak’s research directions.

A key development in Jak’s “Materials
Irradiation Laboratory” in the School of
Physics was the availability of a 1.2

78

Meegavolt accelerator, a machine “inherited”
from ANU = and installed on UNSW’s
Randwick Campus. This machine became
the workhorse for much of Jak’s subsequent

research. Jak worked on_ sputtering,

particularly of the Alkali Halides, and on the
interaction of energetic electrons with
crystal lattices, particularly channelling in
crystals.

Figure 1. A thoughtful looking Jak in front of the high
voltage stacks of the 1.2 megavolt accelerator at Randwick
campus. Photo couriesy of Patrick McMillan.

At this time Jak also co-authored a series of
very nice theory papers. The series on
“Wave Theory of — Lattice-Directed
Trajectories”, written with Hans Nip, which
appeared in Physical Review B are a good
example of this work.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Newbury — Jak Kelly: Peerless Head of School

Figure 2. Jak with bis research Bab. rots circa 1989, TF rom left to abe David oie (+ “NST O) PhD dude OiChu
Phang (UNSW) PhD student, Zoltan Kerestes (UNSW PhD student, Bruce Beilby (UNSW) PhD student, Jak Kelly,
Eric Clayton (ANSTO) PhD student, Mathew Borland (UNSW) PAD student, Bob Dalglish (UNSW) PhD student,
Jules Yang (UNSW) Jak’s Technical Officer, Rolf Howlett, Jak’s ARC Co-investigator. Many thanks to Patrick
McMillan for tdents ‘in these people and to Ranji Batalla for supphing the picture from ber personal album.

Pieure 3. Ubustrions company! Wak shakes hands vib so0n-Lo- ni; i Fea of Vio of Physics Tein cre "Wee | ifs "Tee of
Science at UNSW Ted (Viliam Teodor) Buchwald, Professor of Applied Mathematics and Dean of Science 1980-88, and
right, the late Gavin Brown who was Dean of Science at UNSW 1989-1992 and then Vice Chancellor of the University of

Adelaide and of the University of Sydney.

19

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Newbury — Jak Kelly: Peerless Head of School

The work at the Materials Irradiation
Laboratory led to international recognition
for Jak for his lab and work on ton
implantation and defects in materials.

Jak became Head of the School of Physics
in 1985 and served a 3-year term. During
this period he was also elected Chair of the
Faculty of Science. Jak took over the
headship from Ken ‘Taylor and was
succeeded in 1988 by John Storey.

In 1985 some aspects of School life were
quite different. The academic and general
staff complements were larger. All senior
members of academic staff had a personal
secretary — unthinkable today as this would
be prohibitively expensive — but essential
because everything formal would be typed,
usually on an IBM “Golfball” typewriter.
Typing anything with a significant amount
of mathematical would — be
excruciating because the golfballs would
need to be continuously switched in and out
to provide the range of symbols and fonts
required.

content

Nowadays academics type practically
everything themselves but in the 1980s a
professor would work closely with her or
his secretary and a mistake on an ARC
application requiring re-typing would surely
have put some serious strain on_ this

working relationship and presumably
needed the odd lunch to restore
equilibrium.

There is a handy segue here. I have talked
to half a dozen people in the School who
knew Jak and there its a constant theme in
their remarks: Jak was a kind and most
generous Head of School, he was always
extremely supportive of junior staff.

80

i 4

wth his Head of School PA (1986-
88) Ranji Balalla at Jak’s retirement party. Ranji is an
excellent source of anecdote from that time (and is stil in
the School). One winter day Ranji told Jak that she'd
never seen snow. The next morning Jak put some Keys on

Figure 4. Jak Kelly n

Ranjt’s desk and said: you and your family should go
down to stay at my iabin in Lake Excumbene, you'll see
some snow’ there! Typical Jak Kelly thoughtfulness and
generosity.

Furthermore, Jak was a terrific lecturer,
universally appreciated and much liked by

students. He had a wonderful sense of
humour, often more than a_ little
mischievous. One colleague commented

that Jak would enjoy “stirring the pot’, this
done, of course, without mal-intent.

Talking to two senior colleagues who knew
Jak well and were in the School when he
was Head has provided an_ interesting
perspective — no names here for obvious
reasons!

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Newbury — Jak Kelly: Peerless Head of School

‘There was, apparently, regular and “robust”
discussion about who should have which
space in the School and how much of it. So
no change there, space has always been one
of the most challenging of all tssues and a
perennial headache for heads.

I am sure Jak managed space issues with
aplomb and probably used humour, quite
liberally, to defuse potentially explosive
situations. I say potentially explosive
situations because it would seem there have
always been one or two people in the
School burdened with an
unrealistic view of their own co-ordinates
and are surprised to be told that they are
not, in fact, at the centre of the Universe.
With what P’ve discovered about Jak I think
also dealt with

characters with composure and style.

who are

he would have these

Today I asked a former Head of School for
his view of how the job has changed over
the past ~30 years, particularly with regard
to changes in the nature of the job and
changes in workload due to the information
technology and communications revolution
that’s taken place in the intervening years. I
was stunned to be told that a Head of
School in the 1980s and early 1990s could
contain a full year’s School correspondence
in a single manila folder containing a stack
of sheets approximately one centimetre
thick! ‘That sounds like a party trick; today
the correspondence accumulated in a few
days would exceed that, if printed out.

Many other things have changed, too. OHS
was no more than an acronym in the 1980s.

Reichard Newbury

Received 15 November 2013, Accepted 18 November 2013.

81

Now it is a vast, consuming activity with
truly byzantine intricacies. Key
pertormance targets (KPTs aka KPIs) were
unknown. Human Resources was
“Personnel” and a staff appointment could
be made by mailing a single sheet of paper.

But let’s be clear about one thing here,
Physics at UNSW has always been strong,
the School having both strength and depth,
and in Jak’s time the quality of teaching and
research was just as good, if not superior to,
what it is today.

So what does this all add up to? For you,
dear reader, who has passed the point in life
at which one starts to acquire wisdom more
rapidly, you will say: I know this already,
many things in the life of the School have
changed, some tor the better, and some not.

So its one step forward and two back?
Possibly. It is tempting to wonder whether
or not we are achieving more these days.
Not greater numbers of this and that as
measured by bare metrics but profound
discoveries, things that are of genuine
benefit humanity, things that will help us
solve some of the challenges facing the
planet and persuade naysayers that now 1s
the time for action.

So what would Jak do? Well I think he’d
manage things the way he did back then,
with clear and thoughtful leadership and
with kindness, generosity and a good dose
of humour about it all — and I think he

would manage rather well.

Ic JURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Newbury — Jak Kelly: Peerless Head of School

Richard Newbury has been at the School of Physics, UNSW since 1991. He is a condensed
matter experimentalist and has a keen interest in learning and teaching. He was Director of First
Year Studies in Physics 1999-2005 and has been Head of the School of Physics from 2006.

Soi

Journal and Proceedings of the Royal Soctety of Nen South Wales, vol. 146, nos. 449 & 450, pp. 83-90.

ISSN 0035-9173/13/020083-8

A Timely Intervention — Jak Kelly and Solar

David Mills”

Formerly Dept. Applied Physics, University of Sydney, Sydney, Australia

* Corresponding author.
E-mail: davidmills1946@gmail.com

Abstract
‘This ts a personal recollection of my cooperation with Prof. Jak Kelly, who was a friend before he became
my father-in-law. Only once did we cooperate scientifically, with an outcome that that we could not have

predicted.

Introduction

Jak Kelly and T met in 1977 in the UNSW
School of Physics. I was born in Canada,
and immigrated into Western Australia
after travelling for two years in Africa and
Asia. As a graduate student in Physics at
WATT, now Curtin University, I had soon
developed an unrefined concentrator
concept called the prism concentrator for
PV cells (developed three decades later
into a ten million dollar start-up in
California by people who discovered my
work, but that is another story). In 1976,
my supervisor suddenly pulled up stakes
and departed for Fiji, leaving me without
a supervisor experienced in solar energy.
After writing to all of the Universities in
Australia with solar programs, I joined the
UNSW School of Physics as a Master’s
student under John Guitronich, who had
done pioneering experiments with a solar
furnace in the 1960s and was trying to set
record for
John

an optical concentration
parabolic trough concentrators.
kindly agreed to supervise me as a
Master’s programme even though my area
of interest, called “non-imaging optics”,

was distant from his own.

I began to publish papers in my own little
field, with John as co-author, and I soon
upgraded to a PhD programme. We
received some federal energy research
money and populated the solar lab with
some bright young researchers. Our lab
was opposite the hall from Jak Kelly’s
office and I found Jak very welcoming
and interesting, so I occasionally popped
in to chat about the world at large and the
microcosm of departmental politics. We
had little in common in research terms —
he was a materials experimentalist with an
emphasis on ion implantation techniques,
while I was interested in the limits of
geometrical optics. However, my new
University programme demanded some
course work, so I[ attended his
postgraduate materials science course and
found him to be a remarkable teacher.

In 1980, I was invited to Jak’s home and
met his daughter Karina, a student in
English and Archaeology Sydney
University. We both graduated in 1980
and were married in 1983. Karina went
on to forge a career in TV at SBS,
Channel 7 and science broadcasting at the

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills — A timely intervention: Jak Kelly and Solar

ABC, and I moved to the University of
Sydney Department of Applied Physics,
run by Richard Collins under Head of
School Harry Messel. Both Karina and
Jak were to become Presidents of the
Royal Society many years later, with
Karina masterminding the move of that
Society from Macquarie University to
Sydney University and Jak being made a
Fellow of the Society late in his life.

An Unwelcome Project

Upon landing in the University of Sydney
in 1981, I
materials-oriented group, justly famous
for developing evacuated solar absorber
tubes using spectrally selective coatings

found myself in a_ very

under very capable — experimental
researchers like Brian Window, Jett
Harding, David McKenzie, and the

theorist Ross McPhedran. I became
interested in using such tubes to develop
simple solar collectors with non-tracking
mirrors, but enough optical concentration
to be capable of producing high
temperature steam for electricity
generation industrial thermal applications.
However, to generate power efficiently,
we would need a more efficient absorber
coating than had so far been developed.

In 1952, an Israeli researcher Harry Tabor
had shown that it was best to design solar
absorber surfaces that are highly
absorbing (black) in the short wavelength
solar spectrum to maximise — the
absorption of solar energy, and highly
reflective (“silvery”) in the long
wavelength thermal re-radiation spectrum
because highly reflective surfaces emit
very poorly, so minimal heat is lost (Fig.
1). Tabor designed such a surface called
Chrome Black, which was used for many
years by the solar water heater industry,
but is no longer produced because of

84

environmental concerns about the heavy
metal Chromium.

The general view by the early 1980s was
that selective coatings were not likely to
function well at higher temperatures
required for thermal power generation,
about 500°C. Jeff referred me to recent
papers by D. M. ‘Trotter and A. J. Sievers
(1979, 1980). Solar wavelength selective
absorber coatings turned out to be a very
active topic with hundreds of papers
being published every year.
specialist in materials, 1t was daunting and
I had a lot to learn.

For a non-

Figure 1: A diagram of the solar selective coating
action taken from the author's presentations in
the early 1990's. AM2 is the solar radiation
spectrum and mountain-like wave forms to the
right are spectra for black surfaces at different

temperatures. The “tdeal” selective absorber
surface is shown in black and rises from O%
reflectivity to 100%. The vertical section of the
line ts called the ‘edge’. Complete separation of
the solar and re-radiation spectra is impossible,
but a near-vertical edge maximises solar collection
and minimises thermal loss. Real surface edges
produced back in the 1980's were not very
vertical and were situated at about 2 microns
wavelength.

My department head Richard Collins was
of the view that solar systems only had
value at low temperatures such as for

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills — A timely intervention: Jak Kelly and Solar

water heating and perhaps process heat
Having come from a
nuclear energy background, he was in

and refrigeration.

favour of nuclear systems for electricity
generation.

My ignorance of the materials field caused
me to ask questions that others found
trivial, but I found some interest from a
colleague in the School, Lindsay Botten. I
increasingly felt that the conventional 2
micron edge position seemed more like an
faith than an optimal
positioning. In 1983 we published a
paper (Mills and Botten, 1983) which
suggested that the position and steepness
of the edge were critically important to
performance. We showed that if we
changed the edge position to below 1.8
microns and made it steeper, the ratio of
energy absorbed to energy lost could be

article of

much improved up to 700°C, well into
the realm of high temperature thermal
generation. We suggested a surface called
the “SIM” and composed of three layers,
a semiconductor layer atop an insulating
dielectric layer, with a reflector layer at the
bottom. The top layer would be more
porous going upward so as to_ better
refractive of the air
above it and thus reduce reflection losses.
‘The paper noted that “Se/ecdive surfaces of the

match the index

SIM type would....require concentrations of ~6-7
limes at 300°C and ~25 times at 700°C. The
former figure can be attained by relatively
inerpensive adjustable
concentrators, while the latter tracking paraboliw

non-ltracking
trough arrays.”

However, there were no such ‘steep edge’
surfaces yet available. Two years later |
published another paper (Mills, 1985) that
refined the theoretical analysis and
suggested a possible approach that might

be able to use SIM Germanium or

85

Silicon-Germanium cermets (ceramic
metal mixtures) as a basis for surface
coating with emittance.
Unfortunately, our Department Head
remained strongly opposed to developing
high temperature solar energy for
electricity production. In a conference
paper (Collins, 1986) he wrote that!

very low

“The intrinsic nature of the |renewable) resource
make it uncompetitive with fossil fuels in most
applications.”

and

“Society is unlikely to be dependent on renewable
energy in a major way in Australa for many
decades, even centuries.”

It didn’t look promising. Clearly, I would
not be able to count on Departmental
financial or infrastructure support to get
this idea to the experimental stage.
Fortunately, my non-permanent position
continued to be supported by School
Head Prof. Harry Messel, who presciently
saw value in the work. However, this
much appreciated encouragement did not
extend to funds for the research. I
needed a way to develop the project
departmental
resources or even intimating a link to high

basics without — using

temperature solar.

The Dad and Dave Grant

As I had done previously when problems
arose at the UNSW, I dropped over to my
old department and = discussed the
situation with Jak Kelly. Quite by chance,
I had just come across a paper about ton
implantation forming waveguides of
germanium oxide in germanium. I asked
Jak if ion implantation could be used to
allow the production of optical layers of
Si/Ge within a dielectric matrix so that

Jc IURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills — A timely intervention: Jak Kelly and Solar

information on optical constants might be
obtained. He said it could. We began to
wonder if there was a workaround for the
financial problem. Jak expressed
sympathy for my political problems and
suggested that we might be able to do
some basic experimental work at his
UNSW lab in a joint project. We
sketched out a joint project with Jak as a
lead researcher. It would be a grant for
basic optical studies of layers deposited by
an ion beam machine. That came under
basic science funding rather than energy
funding, and incurred no costs in my
Department except some of my time. Jak
wanted to involve an unusual scholarship
student from China called Qi-Chu Zhang.
Zhang had survived the Cultural
Revolution, was older than I was — about
40 — and had a long background in
materials experimentation.

Jak and I jointly applied to the Australian
Research Council, and our project, Jon
Implanted Optual Muttiiayers — received
exactly $82,059. Karina was amused by it
all and nicknamed it the “Dad and Dave
Grant” 1930's radio

in homage to the

soap opera and later films. We were also
successful in a follow-on grant that took
the project to 1989. As a first step, the
project developed surfaces based on pure
Germanium instead of the preferred Si-
Ge mixture, and the UNSW part of the
team demonstrated very favourable
absorptance in the surfaces that was
unexpected according to current theory
(Zhang, Kelly and Kenny, 1990). By
1989, Jak was approaching retirement and
the money was drying up, but by then
encouraging lab results provided enough
justification for me to apply _ tor
NERDDC (energy research) funding,
with the research to be carried out back at
my base in Applied Physics at Sydney

86

University using sputtering deposition
equipment in that department.

The new grant now clearly emphasized

the intention of producing surtaces for a
more efficient and
higher temperature solar evacuated tubes.
This time there opposition;
parabolic troughs with chrome black
coatings evacuated had
in California for
300°C.
Similar systems with more efficient tube
coatings should be able to achieve 500°C.

new generation of
was no

inside tubes
to be

operation

started used

thermal just above

The grant application was successful and
the project was called High Temperature
Solar Evacuated Tube and provided
$96,705. I duly hired Zhang immediately
after he had successfully completed his
doctorate.

The initial emphasis of our project was on
developing = Germanitum-based = SIM
surfaces using the Sydney University
sputtering equipment, and then moving to
sputtered Si-Ge surfaces which might
yield a better-placed edge position. The
first sputtered results were excellent with
the deposited surfaces having very low
thermal loss by emittance. Fig. 2 shows a
comparison of modelled and experimental
data from the work. The measured and
calculated reflectivity curves were similar
for a layered structure of a Ge and GeO,

mixture on Ge on a Cu substrate shown

in Fig. 2(a) and 2(b),
experimental worked optically very well,
with an emittance of 0.073 at 500°C,
much lower than previous surfaces in the
literature. Zhang was able explain the
results using experimental — optical
constants he had and

and the surtace

measured
theoretical improvements derived in his

PhD thesis.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills — A timely intervention: Jak Kelly and Solar

The original SIM surface concept was
finally validated, as was Zhang’s newer
modelling. We were of course, very

happy.

©
22
oh once vitriccae!
amen ST =
rear
——
em

Reflectivity

Wovelength (urn)

(a)

Reflectivity

4+ 45 6769 2
Wavelength (um)
(b)

Figure 2: Modelled (a) and experimental (b)
reflectivity spectra of SIM Ge/GeO2 surfaces on
a Cu substrate. Note the very steep edge
behaviour. These figures were are from Zhang,
Kelly and Mills (1991). The conference paper
published in 1991 included Jak’s name as a co-
author in recognition of his extensive work with
Zhang on earlier ton beam samples which was
reported.

34 86709 2 3

But science rarely runs exactly to plan;
just the act of investigating something in
great detail often produces more than you
had ever imagined. I had purchased a

87

faster desktop computer for Zhang’s
modelling and during a delay in the
delivery of Ge material, he used his new
machine to perform more than 1000 runs
using his methodology, allowing optical
constants and surface thicknesses to be
varied to converge on an optimal optical
configuration. It was a brute force
calculation that took many days, but the
result was a big surprise.

Germanium was very expensive and the
SIM layers were relatively thick (about 2
microns), increasing sputtering time
greatly. What Zhang showed me were
modelled surface performance results that
approximately equalled the performance
of an SIM surface, but used much thinner
layers. Furthermore, the new surfaces did
not employ expensive thick
semiconductor layers at all. The new
layers could be made by co-sputtering
common inexpensive metals ofr
dielectrics. The new surfaces were very
different; instead of a gradual variation in
refractive index in the top layer to
promote high solar absorption, as was
standard in the field, the new surface used
two very thin homogenous cermet layers,
each with a different refractive index as
illustrated in Fig. 3.

We hadn’t finished our Ge work, but we
knew this discovery was very important. |
applied to NERDDC to change the
technical direction of the project and the
funders agreed that the new surface
should be a better candidate for low cost
high volume production.

The new surface was named the “Double
Cermet” coating and it was first
announced at the Conference of the
Australian and New Zealand Solar Energy
Society (Zhang Kelly and Mills, 1991),

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills — A timely intervention: Jak Kelly and Solar

followed by a paper in Applied Physics
Letters (Zhang and Mills, 1991a) and later
papers (Zhang and Mills, 1991b, 1992 and
1996) as the idea developed.

Anti-reflection

gathnorts HMVF or LMVF cerme!

ee LMVF or HMVF ceme

Metal reflector

erry rere

Figure 3: The new film structure was composed
entirely of homogeneous layers. T'rom the top
downward, a thin anti-reflective coating using a
low refractive index material is followed by two
cermet layers of differing refractive indices and
then a reflective layer underneath. It didn’t much
matter whether the high metal volume fraction
(AMV EF) cermet layer was above or below the
low metal volume fraction (LMIVF) cermet layer;
the refractive indices could be adjusted to make
them work similarly. It was also found that three
cermet layers could improve performance slightly,
but would probably not be cost-effective, and four
or more gave no improvement. The figure is the
original from Zhang and Mills (1990).

Fig. 4 shows calculated and experimental
reflectance spectra for a surface using Cu-
SiO» cermets on a Cu reflector layer. The
steepness of the edge in Fig. 4 1s apparent;
it could be improved further as well, as
shown by the gold line in Fig. 1 for a later
experimental surface using a gold reflector
layer. Many variants of the surface were
prepared in the lab and a_ practical
sputtered version using stainless _ steel
carbide cermet became popular for
commercial water heating applications.

88

Reflectivity

0.1 4 10 100
Wavelength (am}

Figure 4: The experimental absorption and
emittance of O.911 and 0.0594 compared quite
well nith an ideal surface (edge at 1.8 micron)
having values of 0.959 and 0.0275, and the
double cermet emissivity was lower than the
previous Ge/ GeO surface value of 0.073. The
small absorption reflectivity in the visible shown
decreases absorption compared to the ideal of xero,
and the experimental surface edge was closer to 2
rather then the desired 1.8, but the results are in
reasonable agreement. This figure is from Zhang

and Mills (1991).

A Fortunate Intervention

The double cermet surface and
university evacuated tube technology were
licensed to the Chinese companies
Turbosun in 1996 and Tlimin in 2004.
The technology soon spread to other
companies in China. Today, the number
of evacuated tubes produced each year in
China for hot water is in excess of 100
million, and many premium tubes use the
double cermet surface. Well over 100
million people use Sydney Unirversity-
derived solar hot water systems, which in
China had a thermal capacity of 118,000
MW’ in 2012. A large number are now
imported to Australia for water heating as

other

well.

In addition to hot water applications, the
double cermet surface coating provided a
new inspiration for coatings used in high
temperature evacuated tubes for parabolic
trough and = linear Fresnel systems

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills — A timely intervention: Jak Kelly and Solar

developed in the last decade, as we had
hoped in the 1980s. Parabolic trough
collectors now use evacuated tubes with
temperatures of operation of 500°C, and
even higher temperatures are now being
investigated. ‘Their spectrally selective
absorber coatings use additional adjacent
anti-diffusion layers to preserve the
integrity of the basic surface structure at
such temperatures, but optically they
operate similarly to the 1991 laboratory
double cermets. Trough concentrating
mirrors provide in excess of 25 times
concentration, higher than we suggested
in early days, but the commercial surfaces
used aren’t quite as efficient as the
theoretical surfaces that we proposed
back in 1983 and 1985 so higher
concentration is needed at 500°C
Whatever the reflector system, high
temperature i

selective coatings in

evacuated tube receivers have become
commercial reality. It is extraordinary to
think that such a tiny team not only
solved the seemingly intractable problem
of how to make high highly selective solar
absorbers once, but twice.

Looking back, the important decision by
Jak Kelly to host development at a critical
time in undoubtedly saved the project.
Jak was a nuclear fusion advocate in his
years, but his almost limitless
enthusiasm embraced many fields. In this
solar project, his immense experience in
materials

later

science, provided excellent

guidance and an ideal experimental
platform for his brilliant PhD student, Qi-
Chu Zhang. Even though Jak was not
directly involved in the later double
cermet work, the UNSW-based ion beam
effort proved a firm grounding for the
Zhane’s later computer simulation and
using sputtered

surfaces at the University of Sydney.

experimental work

89

Zhang later returned to China as the CSO
of Himin and oversaw for many years the
development of that company’s tube
coating facility. He is semi-retired and
remains a citizen of Australia. His family
lives in Sydney.

Jak passed away in 2012, but lived to hear
of the impressive commercial results of
his timely contribution and was always
very chuffed that many millions of people
were using this low thermal emissions
technology every day.

References

Collins, R. E. (1986) Strategic Solar Research and
Development in Australia. Proc. Solar 86
Conference, Australian and New Zealand Solar
Energy Society, Adelaide, Nov. 13-15, 36-42.

Mills, D. R. and Botten L. C. (1983). Lower
emissivity limits indicated for high
temperature sclective surfaces, Applied Optics,
22, 3162*3190.

Mills, D. R. (1985) Limits of solar selective
surface performance. Applied Optics 24 (20),
3374-3380.

Trotter, D. M. and Stevers, A. J. (1979)
Thermal emissivity of selective surfaces: new
lower limits, Applied Physics Letters, 35, 374-
378.

Trotter, D. M. and Sievers, A. J. (1980)
Spectral selectivity of high-temperature solar
absorbers, Applied Optics. 19, 711-728.

Zhang Q.-C., Kelly J. C. and Kenny M. J.
(1990) Germanium implanted with High Dose
Oxygen and its optical properties, Nuclear
Instrum. Methods B47, 257-262.

Zhang Q-C, Kelly J. C, and Mills D. R. (1990),
Possible high absorptance and low emittance |
selective surface for high temperature solar

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Mills — A timely intervention: Jak Kelly and Solar

thermal collectors. Appied Optics, 30(13),
1653-1658.

Zhang Q-C and Mills D. R. (1991), New
cermet film structures with excellent solar
performance, So/ar 91 Conference, Australian
and New Zealand Solar Energy Society, 2, 586
— 593.

Zhang Q-C and Mills D. R. (1992a), Very low

emittance solar selective surfaces using new

David Mills

film structures, J. Applied Physics, 72(7), 3013-
3021.

Zhang Q-C and Mills D. R. (1992b), High
solar performance selective surface using bi-
sublayer cermet film structures, So/ar Energy
Materials and Solar Cells, 27, 273-290.

Zhang, Q-C., Yin, Y., Mills, D.R. (1996). High
efficiency Mo-AbO; cermet selective surfaces
for high temperatures applications. So/ar
Energy Materials ¢& Solar Cells, AO(1), 43-53.

Manuscript received 18 October, 2013. Accepted 21 October 201 3.

90

Journal and Proceedings of the Royal Soctety of New South Wakes, vol. 146, nos. 449 & 450, pp. 91-102.

ISSN 0035-9173/13/020091-12

The Development of Modern Particle Accelerators at the
Stanford Linear Accelerator Center

Patrick Krejcik

SLAC National Accelerator Laboratory, Menlo Park, California, U.S.A.

E-mail: pkr@slac.stanford.edu

Abstract
The development of high-energy accelerators at the Stanford Linear Accelerator Center has closely
paralleled the advances in high-energy physics over the last fifty years. From its original conception as the
world’s largest linear accelerator for fixed target experiments, the facility evolved over the years with various
colliding beam configurations in the quest for higher collision energies. An offshoot of the high-energy
physics program was the synchrotron radiation from accelerators that proved a useful tool for x-ray studies.
Photon science has since become the major thrust of the laboratory with the construction of LCLS, the

world’s first free electron x-ray laser.

Introduction

Particle accelerator technology had already
developed to a sophisticated level by the time
the Stanford Linear Accelerator was proposed
in the late 1950’s and early sixties. The
origins of the particle accelerator and the
desire of physicists to study the behaviour of
fundamental particles beyond that revealed in
cosmic rays and the emissions from natural

socio SEATON BS -9
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i. NearHall ..
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radioactivity have been extensively chronicled
in the past. This review focuses on those
developments that took place at the Stanford
Linear Accelerator Center (SLAC) and how
they have led to the rise of The Standard Model,
the birth of new accelerator technologies and
the burgeoning of synchrotron radiation
physics that followed.

Damping
Rings

Nipsczae ite
Sa

Ae
Mairnlinac - <_< Cone PU pesc y

a

ind a

-

Pioure 1: Aerial view of SL_AC nestled in the Stanford foothills, hichlightine some of the accelerator facilities. (SLLAC photo)

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Krejcik — Development of particle accelerators at SLAC

Figure 2: The Cockeroft-Walton accelerator that was
moved from the Australian National University to the
Physics Department at the University of New South
Wales where it was used by Jak Kelly. It is an example
of an early high-voltage accelerator. (ANU photo)

1000 TeV F
100 TeV j—
1 TeV |.
1 TeV >
2 100GeV
x
rr]
=
=
c 10 GeV
=
a vo Bectron Linas
_~ Synchrocye lotrans
1 GeV a
p _ooee Proton Linacs
Sector-Forused
100 Me\ Cyclotrons
Blectrostathe
Generates:
1 MeV
oss Rectifher
1 Mev Generators
1930 1S Ly 1)

Year of Comrnissicss ny
Figure3: A plot, styled after Livingston of the change in
accelerator technology that allowed awelerators to increase
in energy.

The machines at SLAC, shown in Figure 1,
have always been used to accelerate electrons,
or their antimatter counterparts, positrons.
The dogged adherence to lepton machines is
based on the premise that leptons are a point-
like particle, with no constituent parts and
therefore the study of collisions with leptons
should be the least ambiguous to interpret.
While other high-energy physics laboratories
delved into the complexities of protons and
the structure of even heavier nuclei in ton
beams, SLAC made the first of its Nobel
Prize winning discoveries to support its
original premise: the discovery, described in
more detail in the following — sections,
demonstrating that protons and neutrons
were indeed made of smaller, constituent
parts, quarks, and that only an electron beam
could reveal that fine detail.

Figure 4: A viens inside the tyo-mile SLAC accelerator
tunnel showing the linac mounted above the alignment light

pipe

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Krejcik — Development of particle accelerators at SLAC

The driving technology behind the SLAC
accelerators is the use of very high power
radio frequency (RF) fields. The earliest

i Cont |

1 inch (approx.)

Figure 5: The SLLAC linac structure is shown in a
cutaway view and comprises roughly 80,000 copper cells.

accelerators used dc voltages to accelerate a
particle just once across a fixed potential, as in
Figure 2, but the energy is limited to a few
MeV before high voltage breakdown
becomes a problem. High energies can only
be achieved by repeated application of a time-
varying electric field. § The — successful
confluence of high power microwave
technology in the development of klystrons at
SLAC together with particle accelerator
design put SLAC at the forefront of high
energy physics.

The quest for higher energy accelerators is
driven by both the need to resolve smaller
detail and to be able to create exotic new
particles of heavier mass out of the collision
energy. In the wave-particle duality view of
nature a higher energy particle beam has
shorter wavelength and therefore can probe
smaller detail in scattering experiments. The
mass-energy equivalence tells us that the mass
of any new particle created in a collision ts
limited by the centre-of-mass energy available
in the collision.

The early high voltage acceleration technique
would only ever be used at SLAC to power
the electron gun used to inject electrons into
the main linear accelerator (or linac, as it is
commonly abbreviated). ‘The electrons in the

SLAC linac, Figures 4 and 5, are accelerated

93

instead by high frequency waves using a
technique pioneered by William W. Hansen at
Stanford. The microwave power is delivered
by klystron tubes, Figure 6, also developed at
Stantord by the brothers Russell and Sigurd
Varian.

The Early SLAC Linac
The physics motivation for building a 20

GeV electron linac was born out of the
success of Robert Hofstadter’s experiments
on the elastic scattering of 188 MeV
electrons. The experiments were performed
on the main Stanford campus in the Hansen
Experimental Physics Laboratory using the
University's 220-foot long Mark III electron
accelerator. These Nobel Prize winning
experiments determined the precise size of
the proton and the neutron and provided the
first reasonably consistent picture of the
atomic nucleus.

Figure 6: Cutaway view of one of the 240 S-band
klystrons delivering up to 65 MW’ each of peak power
at 2856 MHx,

A team in the Stanford Physics department,
led by Wolfgang “Pief’ Panofsky envisaged a
machine 100 times larger that was destined to
reveal not just the structure of the nucleus,

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Krejcik — Development of particle accelerators at SLAC

Stanlerd's Linear Accelerator
Dupical Cross-Section

Figure 7 Whimsical view of the SLAC tinac as
depicted by Bob Gould the chief civil engineer during the
construction phase.

but of the nucleons themselves. Dubbed
Project M, where M stood for monster, it was
completed in 1966 at a cost of $120M and
represented the largest publicly funded, pure
research project of its time.

The project was not without controversy and
caused a split in the Stanford Physics
department because some of the faculty
believed that the accelerator facility should be
for the exclusive use of Stanford research
departments. Panofsky, on the other hand
believed that such a large facility should be
open to the public, and invited proposals
from around the world to participate in
experiments at SLAC. A separate SLAC
faculty was created and the two Departments
went their separate ways.

The early experiments at SLAC were

designed to extend elastic scattering of

electrons from the proton and the neutron (in
the deuteron) to higher energies, and then to
extend this work to inelastic scattering,
leading to the known “resonances” or excited

94

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810°
° We2 Gev
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4a ~~ W*3.5 GeV
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z 2 \ :
5 9 x,
1073 ELASTIC
\. SCAT TERING
be
= 0 | 2 3 4 5

q® (GeV/c)*
Figure 8: Exvidence of the quark. structure came from
the ratio of deep imelastic scattering (DIS) cross-section
of electron scattering in hydrogen to the theoretical Mott
scattering cross-section from a point charve, plotted as a

Junction of the square of the four-momentum transfer.

The elastic scattering cross-section is plotted for
comparison. (From Hoddeson et al., Pig 32.2.)

states of the nucleons, essentially extending
the previous work of Robert Hofstadter to
much higher momentum transters. However,
there was a growing interest in explaining the
“strange” behaviour of new _ particles
discovered at other laboratories and the
conjecture by Gell-Mann and Zweig that
nucleons were combinations of “quarks” of
charge + 1/3 or + 2/3. The new research
groups began examining “deep inelastic
scattering” (DIS) which left the nucleons
fragmented in a continuous set of energy
states. The results had tremendous
implications since the DIS cross-section
turned out to be much larger than previously
believed. The ratio of DIS, as a function of
the momentum transfer to the nucleons, to
scattering from a charged point particle,

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Krejycik — Development of particle accelerators at SLAC

Figure 9: View of the Eend Station A spectrometer and
detectors used to measure scattering from quarks within
the proton and neutron. The scale is apparent from the
human figure in the centre foreground.

exhibits a very slow variation, shown in
Figure 8, in contrast to the very steep
decrease with momentum transfer exhibited
by elastic scattering.

The scattering experiments required the
detectors to be moved through large angles to
observe both the forward and back-scattered
electrons. For 20 GeV electrons the
spectrometer magnets ate formidable and
resembled locomotives on tracks, as seen in

Figure 9.

Richard ‘Taylor, Henry Kendall, and Jerome
Friedman recetved the 1990 Nobel Prize in
Physics for this work, which established the
foundation of the physical reality of the quark
components of the Standard Model.

Colliding Beams at SLAC

In striving for higher energies to extend the
reach of scattering experiments, one must
realize that the centre of mass collision
energy, F:.,, is reduced by the recoil of the
target atom of mass 7.
Em = §2m,E,

whereas much higher centre-of-mass energies
can be attained by colliding two beams of
energy f:, and Ep.

95

Figure 10: The Princeton-Stanford Colliding Beam
Experiment used a figure eight confieuration to collide
5OOMeV electrons.

The colliding beam concept was first
envisaged for hadron machines but was soon
taken over by the lepton community. Unlike
protons, an electron will radiate away its
energy if made to follow a circular path, and
this dissipative process causes the electrons to
naturally converge to the axis of the beam
pipe. This makes the injection process into
an electron storage ring much easier.

Several design proposals were made around
the world using counter rotating beams of
oppositely charged particles that could
economically make use of one vacuum
chamber tn a single ring. The availability of
an electron linac to inject the beams made
Stanford an obvious choice for a
demonstration experiment. An_ electron
storage ring was proposed at Princeton by
Gerry O’Neil in 1956 and the Colliding Beam
Experiment (CBX) began construction in
1959 at Stanford. The figure-eight ring,
shown in Figure 10, collided 500 MeV
electrons with currents up to 50 mA in each

beam.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Krejcik — Development of particle accelerators at SLAC

Figure 11: An early photograph of the SPELAR storage
ring before it was surrounded by synchrotron radtation
huteches.

The CBX revealed three major limitations
that would prove essential in future storage
ring design. In spite of being the largest ultra-
high vacuum system constructed for an
experiment, with a base pressure of 10° Torr
in the 2 m’ volume, the pressure would rise
by a factor 300 when higher beam currents
were stored. Desorption from synchrotron
light impinging on the chamber walls caused a
pressure spike that severely limited the stored
beam lifetime. The synchrotron light power
scales as the 4" power of beam energy and
required a re-evaluation of the vacuum system

design.

The second limitation observed during
operation was a transverse resonant instability
caused by the tmage charge wall currents
causing wakefields in the vacuum chamber.
Resonant coupling could be suppressed by
separating the betatron tune of the two rings,
and further damping was observed due to rest
gas ionization effects.

The fundamental limit affecting all future
storage rings was found in the beam-beam
tune shift, Av. This is the transverse focusing
of one beam upon the other and increases as

96

the interaction density, or luminosity,
increases according to
Nr, By,
Av, = ae
2ny/ o,(a, + o,)

for N electrons at an energy E=y m, e, with

m ;
transverse beam sizes Oxy =v B ane 3

where fy are the lattice functions, & the
beam emittances and yr, the classical electron
radius. Tune shifts above 0.025 typically
caused beam degradation and
luminosity due to resonance induced by the
beam-beam interaction.

loss of

New energy scale EF... (GeV)

3.000 3.060 3.3100 3755 3.200
10,000 ln teers girs be ee gee eae = pais (eos 3
o (et om = HADRONS) x
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c is J
| y ‘
100 a ' ,
F i 4
— 4
rs T, -e 44
: ? ; 330%
egreseerr ere cs® sweewen st is es ey - a" aeomenaoeen +
| GED “Background
ti ee Sree: We ee Een One nner eee t (mero aee al
3.000 3.050 3.100 3.150 3.200
Ecm (Ge'v) Now. 104 meme
‘
aoe 200 Mew} acedncnesoscasicntanasctnintly

Figure 12: A historic plot marking the discovery of the

J/® particle at SPEAR.

The lessons learned proved invaluable for
future storage ring designers, particularly one
collaboration member, Burton Richter who
went on to lead the effort to design the
Stanford Positron Electron Asymmetric
Rings (SPEAR). This collider began
operation in 1972 and proved to be the most
prolific of all the SLAC accelerators tn
providing physics results per dollar spent on
their construction.

At the time of its inception, the SPEAR

project was competing with more

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Kreycik — Development of particle accelerators at SLAC

conservative upgrade projects that would
raise the main linac energy by at most a factor
two. ‘These projects eventually also proved
successful and led to the success of the linear
collider described in the section.
However, the physics motivation of being
able to raise the centre-of-mass energy by an
order of magnitude over the CBX machine
spur the laboratory
management fund the SPEAR
construction out of operating funds without
obtaining direct government funding agency

next

was enough to

to

approval.

Funding was not available for a new building
to house the new machine so it was literally
constructed on the parking lot adjacent to
End Station A and covered over with
concrete radiation shielding blocks, as seen in
Figure 11. The design was simplified to a
single ring with counter rotating electron and
positron beams of 3 GeV energy. Unlike the
electron-electron collisions in CBX, the e*
and e can annihilate each other producing an
intermediate state with enough energy, and
according to conservation laws, to
spontaneously produce massive new particles.
Studying how these particles are produced
proves to be the ideal tool for learning about
their structure.

The gamble paid off handsomely with the
observation of a resonance in the event rate at
a centre-of-mass energy of approximately 3.1
GeV, shown in Figure 12. This was
attributed to the production of a new particle
the ]/ Y which could only be explained as a
tightly bound pair of charmed quarks. ‘The
laboratory director announced the discovery
to the Atomic Energy Commission with the
statement: “I would like to report the
discovery of an unauthorized particle on an
unauthorized colliding beam facility’. In
1974 it heralded what is now referred to at

The

SLAC as the November Revolution.

aT

Figure 13: A view inside the PEP tunnel showing two
rings stacked on top of each other for the PEP-IT
asymmetric B Factory.

discovery resulted in a Nobel Prize for
Burton Richter and Samuel C. C. ‘Ting, and
was followed by a rich study of charmonium
physics revealing the spectroscopy of various
bound states of charm-anticharm quarks.

The SPEAR ring yielded yet another Nobel
Prize to Martin Perl for his discovery of the
tau lepton, the third of the three families of

leptons, the electron, the muon and the tau.

At this point in SLAC’s history funding
became available to build upon this success
and construct an even larger collider, the
Positron Electron Project (PEP) able to attain
15 GeV with a ring 1.4 miles (2.2 km) in
circumference. This was the largest ring that
would comfortably fit on the SLAC site. A
large ring 1s necessary at high energies because
the energy loss per turn due to synchrotron
radiation increases as the 4% power of the
energy while it only decreases linearly with
machine radius.

During the PEP era at SLAC Burton Richter
spent a sabbatical period at CERN in
Switzerland where he entertained the idea of
designing the maximum energy storage ring
feasible on an unlimited site. CERN went on
to build the Large Electron Positron project
(LEP), a 27 km circumference ring capable of
attaining 50 GeV beam energies.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Krejcik — Development of particle accelerators at SLAC

North Damping 200 MeV
ring (NDR) Positron
e@ Gun Accelerator

Positron Return Line

ie aac me a

rng (NDA)
Tale 1: Ibe Standard Mode! can be thought of as a Figure 14: The SLAC Linear Collider accelerated

hype of Periodic Table from which all the known sub-

bunches of electrons and positrons to 50 Gel” which
atomic particles can be constructed.

were deflected in opposite directions around an aré to
collide at the detector.

Richter, on the other hand, returned to SLAC
| proclaiming that we must return to linear
accelerator technology for colliding beams in
order to overcome the energy limitations of

Bang, by which there is more matter than
antimatter in the universe. A key factor in
these observations was to make the collisions
asymmetric in energy so that the centre-of-

storage rings. mass frame would be moving during the

collision and allow the lifetime of the
Before turning our attention to the linear different decay channels to be identified by
collider project at SLAC we should jump virtue of the distance of the new particle

ahead to SLAC’s final endeavour with storage
rings, and the construction of an asymmetric
collider known as the PEP-I] B-Factory.

vertices from the collision point.

Two tings were constructed inside the PEP The SLAC Linear Collider

tunnel, stacked one on top of the other, as The discoveries at SLAC gave strong support
shown in Figure 13, to store 9 GeV electrons to the quark model, and the “eight fold way”
in the high-energy ring and 3.1 GeV positrons was enhanced to become “The Standard
in the low-energy ring, with one intersection Model” and is summarized 1n ‘Table 1.

point where the beams would be allowed to
collide. The rings began operation in 1999 The quarks and the leptons appeared to be

and eventually reached a luminosity of around divided into three families of matter and all
MES cr? «tat astonishing beam ‘cuitente or the particles that had been discovered
approximately 1.5 A of electrons and 2.5 A of SLAC and elsewhere could be accounted for
positrons. in this framework. The vector bosons in the
Standard Model, or force carriers had also
The centre-of-mass collision energy was been observed. The next step was to confirm
tuned to the Upsilon 4S resonance to that there were indeed only three families of
produce a flavourless meson formed from a matter, not more, and this could be
bottom quark and its antiparticle that then confirmed by measuring the resonance width
decays into a pair of B mesons. It allowed the of the Z boson, the carrier of the weak force.
first observation of charge-parity violation Both CERN and SLAC proposed _ the
outside of the kaon system and helps explain construction of an ete collider with a roughly
the mechanism, at the instant of the Big 100 GeV centre-of-mass energy at the Z

98

(nb)

o,

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Krejcik — Development of particle accelerators at SLAC

Fei ee nee einen! Oe) MO Oe Sa i eee ee We
88 89 90 91 92 93 + 94
E (GeV)

Figure 13: The SLLAC measurement of the width of
the Z,, resonance at 91.4 GeV" confirmed the Standard
Model prediction that there were only three families of

matter.
resonance to make this precision
measurement. CERN proposed the 27 km
LEP ring, and SLAC proposed using the 3
km long linac to reach the same energy.
SLAC was able to raise the energy of the linac
from its original 20 GeV to 50 GeV through
the invention of the SLED device (SLAC
linac Energy Doubler). It uses RF pulse
compression to deliver four times the peak
RF power in a shorter pulse to the linac
structure thereby increasing the accelerating
field gradient.

SLAC would have to perform an extra trick
accelerating consecutive bunches of
electrons and positrons and deflecting them
around two opposite arcs, as shown in Figure
14, to bring them into collision in the centre
of the SLD detector.

ot

The LEP storage ring would collide the
bunches ten thousand times per second as
they went round and round, so the SLAC
Linear Collider (SLC) would have to focus
the beams to micron size diameters in order
to get the same luminosity in the detector.
This was possible at SLC by making very
small emittance beams in the damping rings

99

and then keeping the emittance under control
as the beam was accelerated in the linac.

The storage ring was a more conservative
approach and ultimately reached a_ higher
luminosity, but the linear collider was also a
test experiment for future colliders. Clearly,
the next generation of colliders operating at
10!2 or Terra electron volt (TeV) energies
would be impractically large if built as rings,
so it was important to test the linear collider
concept whose size would still be manageable
when scaled to a TeV.

The SLAC measurement of the Zo resonance,
shown in Figure 15, was still sufficient to
prove beyond a doubt that the Standard
Model held true and that only three

generations of matter could exist.

Synchrotron Light Sources

Already during the heyday of particle physics
at the SPEAR machine another group of
Stanford physicists was lobbying for access to
the photon radiation generated by the beam
circulating in the ring. Synchrotron radiation
was regarded with disdain by the machine
builders because it limited the energy of a
storage ring and it produced unwanted
heating and outgassing of the vacuum
chamber. The photon users persisted with
their claims that the synchrotron light was the
brightest source of x-rays in the world, by
orders of magnitude, and would allow
revolutionary new science to be done.

The director of SLAC reluctantly allowed one
photon beam line to be added to the SPEAR
ring, worried that it would take away precious
beam time from the high-energy physics
program. ‘The rest is history, as they say, and
the number of synchrotron radiation beam
lines grew rapidly. When SPEAR reached the
end of its useful life as a high-energy physics
machine it became the world’s first dedicated

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Krejcik — Development of particle accelerators at SLAC

Wavelength (nm)
124.0 1.24 0.0124

, SLAC
/7 LcLs

=
=)

_-*” DESY
TTF-FEL

-_
°o

LCLS |.
Spont.-*
(100 m)

SPPS 28 GeV <=

ESRF/APS 7 GeV
Undulator (max)

=
oO

ALS 1-2 GeV
07 Undulators

Peak Spectral Brightness
[photons = s-1= mm ?= mr? (0.1% bandwidth)-*]

ah

APS 6-8 GeV
Wigglers

oak
©
=

107

10°

Photon Energy (keV)
Figure 16: The peak brightness from linac-based light
sources exceeds storage rings by many orders of
magnitude over a range of wavelengths.

107

synchrotron light source. It has been
upgraded several times and stil operates
today as a 3% generation light source,

SPEARS.

Many dedicated synchrotron light source
laboratories have now been built around the
world, numbering more than sixty, including
the Australian Synchrotron built in 2007 in
Melbourne. These modern storage rings use
insertion deviesto wiggle the beam in an
undulator section to produce extremely bright
x-ray beams. The brightness of the x-rays ts
ultimately limited, though, by the equilibrum
electron bunch dimensions in the storage
ring.

The light source designers enviously looked at
the extremely small electron bunches that the
linear collider was producing and calculated
they could create a free electron laser (FEL) at
x-ray wavelengths using a very long undulator

100

. ie acl ses ‘
{
* ih

: , *
Figure 17: view of the 100 m long undulator of the
Linac Coherent Light Source.

at the end of the linac. The linear collider
project was not about to give up any of tts
precious beam time to the light source users,
but we were able to do a proof-of-principal
experiment to demonstrate the teastbility of
x-ray production with the linac.

An electron bunch compressor chicane was
installed in the linac in 2002 which would
compress the bunches to a pulse as short as
80 femtoseconds duration. ‘The bunch
compressor chicane worked by putting an
energy chirp on the electron bunch, giving the
head of the bunch a higher energy, and then
sweeping the bunch around a chicane so that
the low energy tail would catch up with the
head of the bunch.

A 2.4 m long undulator borrowed from the
Argonne Advanced Photon Source was
installed on a beam line at the end of the linac
and the compressed 28 GeV electron bunch
produced a blinding flash of x-rays at 1.5 A
wavelength.

At this time the linac was primarily being used
as an injector for the PEP-I collider, but tt
was possible to parasitically deliver 10 Fz
repetition rate beams to this new photon
facility, the Sub-Picosecond Photon Source
(SPPS). Numerous experimental techniques

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Krejcik — Development of particle accelerators at SLAC

Figure 18: The LCLS undulator is made up of
thousands of permanent magnet wigoler magnets.
« « Lo 3 «

for linac-based light sources were able to be
tested with the ultra-fast pulses at this facility.

For a time the SPPS held the record for peak
brightness for any x-ray source, as seen in
Fioure 16. The radiation, however, was still
incoherent, as it is in storage ring light
sources. The bigger prize was yet to come
with the installation of a linac-driven FEL.

The Linac Coherent Light Source LCLS

The LCLS produced its first x-ray beam in
2009, and uses a 100 m long undulator,
shown in Figure 17, at the end of the linac to
produce Self Amplified Stimulated Emission
(SASE) at x-ray wavelengths. The undulator
is assembled in 3 m long modules made up of
hundreds of permanent magnet dipoles, as
shown in Figure 18. The incoherent
synchrotron radiation generated as the beam
wiggles back will amplify in one selected
mode and produce fully coherent x-rays that
are 10 orders of magnitude brighter than a
storage ring light source.

Such an increase tn brightness over existing
machines has required the invention of a
whole new science in analysing x-ray
diffraction. It is now possible, for example,
to image a single molecule in a single shot. It
will no longer be necessary to crystallize
complex organic molecules such as proteins

in order to image their structure. Enough

101

photons can impinge on a single molecule
that the diffraction image can be collected
from a single molecule. The downside is that
of course the molecule does not survive the
onslaught of such a bright beam of x-rays.
However, the pulse duration from the LCLS
can be as short as a few femtoseconds so it is
possible to capture the image before the
molecule flies apart. The extremely short
duration of the pulse also allows ultra-fast
phenomena to be captured in the strobed
images. <A technique referred to as pump-
probe allows the molecule to be stimulated
and then observed with the x-ray strobe at
sub-picosecond intervals after the stimulus

has been applied.

Conclusion
SLAC has had a rich history, playing a

significant role in the development of
accelerator technology and the understanding
of modern particle physics. SLAC continues
to play a role in the development of new
technology for future colliders and
participates in international collaborations to
build a Linear Collider and Higgs factory.
The SLAC campus, however, may become
more recognized in the future for its role as
the world’s leading photon science laboratory
with its unique facilities for x-ray laser
production.

Acknowledgements

This article is written in fond memory of my
mentor and thesis advisor, Professor Jak
Kelly, who instilled in me a suitable awe for
large accelerators and high-energy physics. I
am happy to sav that this fascination with
accelerators has stuck with me at SLAC. In
preparing this article I am also grateful to the
SLAC Archive Office for their extensive
collection of photographs and articles
chronicling the history of SLAC.

JOURNAL AND PROCEEDINGS OF ‘THE ROYAL SOCIETY OF NEW SOUTH WALES
Krejcik — Development of particle accelerators at SLAC

References P. Krejcik et al., “Commissioning of the SPPS
linac bunch compressor” - Conf. Proc. C030512
(2003) 423 PACO3-WOAC005, SLAC-PUB-
9858.

G. S. Abrams et al., ““Measurements of 7-Boson
Resonance Parameters in e*e Annihilation’,
Physical Review Letters, Volume 63, Number

9 5173 917 7 : ae a
20, pp. 2173 - 2176. R. W. McAllister & Robert Hofstadter, “Elastic

Scattering of 188 MeV Electrons from Proton
and the Alpha Particle”, Physical Review, 102,
pp. 851 - 856 (1956).

K. L. Brown, “Luminosity and Tune Shift in e+e-
Storage Rings”, SLAC-PUB-4366 (1987).

P. Emma et al., “First Lasing and Operation of an
Angstrom-Wavelength Free-Electron Laser’’,
Nature Photonics 4, pp. 641 - 647 (2010).

Wolfgang K.H. Panofsky, “Panofsky on Physics,
Politics, and Peace: Pief Remembers” Springer,

New York (2007).

L. Hoddeson (Editor), “The Rise of the Standard
Model: Particle Physics in the 1960's and
1970's,” Cambridge University Press (1997).

J. Seeman et al., “Performance of the Pep-IT B-
Factory Collider at SLAC”, Proceedings of 2005
Particle Accelerator Conference, Knoxville,
Tennessee (2005).

Patrick. Krepetk

Received 8 September 2013, Accepted 14 September 201 3.

Patrick Krejcik graduated from the University of New South Wales with a PhD in 1980, where
his supervisor was Professor Jak C. Kelly at the High Voltage Accelerator Laboratory in the
School of Physics. Jak instilled in his students not only an awe for physics, and that it could be
good fun, but also that it was part of a bigger adventure that was going on in laboratories around
the world. Patrick pursued accelerator research at the German heavy-ion laboratory, GSI, then at
the proton-antiproton collider at CERN in Switzerland, before finally moving to SLAC in
California, where he now resides.

In later years, Jak wryly observed that there was an alarming trend in Patrick’s career moving
from heavy tons at GSI to smaller protons at CERN, then to tiny electrons at SLAC and finally

to massless photons in the FEL laser, suggesting that there may only be the vacuum energy of
virtual particles left to speculate on. Jak’s energy and wit remains with us.

Tad)

102

Journal and Proceedings of the ne: sig of Neu South Wales, vol. 146, nos. 449 & 450, pp. 103-109.

ISSN 0035-9173/13/020103-

Paper clips, rubber bands and satay sticks

Zoltan Lewis Kerestes

Northern Sydney Cancer Centre, Medical Oncology Department, Royal North Shore Hospital,
St Leonards, Sydney NSW 2065

Abstract
This is a personal article about the lasting influence the late Professor Jak Kelly has had over the course of

the author’s varied career. Fis influence was especially pronounced when the author was under pressure
and had to confront a difficult and unusual situation. Some of these situations are illustrated in this article.

It is hoped that the article showcases in parts Professor Jak Kelly's sense of humour. Professor Jak Kelly

was a mentor and a long term friend of the author.

“Most people say that it ts the intellect which makes a great scientist. They are wrong: it ts character.”

Introduction

The day I met Professor Jak Kelly was the

day I did something that was totally out of

character: I declined an offer to have
graduation drinks at the ‘White Horse’ with
fellow students from Sydney University.
Instead, I headed to the School of Physics
at UNSW to enquire teaching
position with postgraduate research work.

about a
In those days it was a ‘buyers market’. You
went around to all the departments, had a
Heads and then decided
which group to join. On first meeting, Jak
enthusiastic and passionate about
science. He also seemed to have a wicked
sense of humour and the research work he

chat with the

Was

was engaged in was of a vision with an
exciting and useful future. The decision to
join his group was a foregone conclusion
when he took me to view the impressive
1.25Mev Cockcroft-Walton accelerator,
standing a storey high inside a former
Electrical Transformer Building.

Every Friday afternoon Jak made it a focus
for all his postgraduate students to gather
together on the grounds of the Accelerator
to present our progress of the week. We

103

Allbert Einstein

discussed problems we had encountered
and freely shared ideas. These discussions
were always accompanied by great food and
increasingly better quality wines. It was at
these meetings with Jak and fellow students
that Jak inspired in me to look at the world
not just with a scientific eye but with a
broad vision; to try to think differently, to
challenge accepted dogma, and to consider
historical perspectives. Jak’s great strength
and drive was to apply ideas across many
disciplines. Jak was also a great orator and
showman and his formal lectures were
legendary.

Lesson 1: “Curb your enthusiasm!”

Jak valued genuine intention first and

foremost. If then the result turned out
disastrous his Irish humour helped to ease
the pain and embarrassment.

My PhD project involved the study of
sputtering. ‘This is the process of ejection of
atomic material from the surface of solids
during bombardment by energetic atomic
particles. ‘The experimental setup that I
used to study the phenomenon had a small
oven that produced the energetic particles.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Kerestes — Paper clips, rubber bands and satay sticks

This oven was cooled by water. It was
easier to connect the water to the mains
than to the 2000 litre storage on the root.

One late Saturday night, after completing a
full day’s experimental run, IT headed home,
forgetting to switch off the water cooling. |
was barely awake the next morning, when I
received the call, “You better come right
now. The School of Physics is flooded.” I
was ina nightmare. It was not until I drove
down High Street that I saw a triangle of
water spanning two floors — at its apex, the
window of my lab. After I entered the
School of Physics, reality very quickly
asserted itself. As I rushed in to go up the
main staircase, a _ perfectly formed
waterfront cascaded down over the stairs.
On the First floor, the Head of the School’s
dog darted out at full speed towards me. It
immediately registered the mini lake in front
of it and with a terrified, desperate look in
its eyes, it tried to stop. You could even
pick up the Doppler shift in its desperate
cry and yelp as it water-skied past me,
haunches on the ground, front
outstretched, forming a perfect wake.

leg

Next I entered the library and there an
equally surreal image confronted me: the
School of Physics’ librarian holding an
umbrella in the downpour from the ceiling
above, desperately trying to save as many
books as he could. I felt bad about the
disaster I caused but I felt worse about the
books. They took months to dry out.

At the end of that Sunday, with as many
helpers as we could muster, we managed to
clean up the water. We all then gathered at
the Head of School’s campus residence for
a beer. Jak knew that his group would
receive a fine for the downpour and the
damage it caused. As was his way though,

104

he pulled me aside and said, “Zoltan, my
boy, you must curb your enthusiasm!”

I believe that in the vears that tollowed
there were a few ‘enthusiasts’ like myself.

Lesson 2: “Have you done your
experiment correctly?”

This was the question that Jak always
drummed — into even when the
experimental results seemed to confirm our

us,

expectations and especially when faced with
an anomalous results.

The first terme I heard him ask me this
question, he followed it as usual with an
anecdote about the tme he was working at
Harwell Atomic Energy Establishment tn
the UK. He noticed that experimental
results taken betore lunch were quite
different to those taken after lunch. Could
it be that when he, Paul Chatterton and
other members from the lab would go out
to lunch, which would of course have
included some ale or wine with the meal,
this may have somehow influenced the
measurements? Jak being a true scientific
sceptic, dismissed this hypothesis on the
grounds that in his experience, up tll then,
he found that insights and experimental
measurements usually were improved by a
glass or two but only when not imbibed in
excess of course. He then noted that not all
laboratory members joined them on their
usual lunch break. In fact there was a
young technician, a teetotaller who never
joined them. On questioning the young
man, the mystery was solved when it
became evident the he used the vacuum
chamber to warm up his curry at lunch
time. ‘Thus the experimental anomaly was
not due to the effect of wine but rather due
to the left over residue from curry vapours.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Kerestes — Paper clips, rubber bands and satay sticks

After completing my PhD thesis in 1979, I
worked for a brief period at Sydney
Hospital with Dr Leopold Dintentass. His
interest was studying the factors affecting
the viscosity and aggregation of red blood
cells. Efe was preparing an experiment to
go aboard the space shuttle ‘Discovery’ as at
the tme NASA was also interested in red
blood cell aggregation under zero gravity,
ageregation being the process whereby red
blood cells stack together to form linear and
structures. Dr
the time, the first
Australian scientist to have an experimental
project accepted by NASA. ‘The proposed
experiment used an automated slit-capillary
photo-viscometer. ‘Uhis instrument consists
of a set of two highly polished glass plates,
with a gap of 12.5um. Using an infusion
pump, blood samples could be introduced
into the © slit-capillary. types of
experiments were planned. ‘The first was to
take micro and macro photographs of static
blood in the slit. In this case, the pump
introduces the sample into the slit and then
is stopped to allow for the formation of
ageregates. Photographs were then taken.
‘The second experiment was to take blood

three dimensional

Dintenfass, was at

‘Two

viscosity measurements. I was asked to
investigate the anomalies found within these

measurements.

One day when I was in the workshop with
the polisher, I noticed — the
monochrome light source he had to check

glass

the flatness of the glass plates he was
polishing. I instantly had a hunch. I went
back to him with one of our slit viscometers
and put it under the light. I used water to
the slit and the resultant
interference pattern showed that the glass
plate assembly deforming under
pressure of the liquid being injected into the
slit. A quick high school calculaton from

inject into

Was

the measurement of the fringes, revealed

105

that the gap between the plates near the
centre, more than doubled. The main
the anomaly was found.
Unfortunately it was too late to redesign the
glass plate and assembly and to resubmit the

proposal to NASA.

source of

There were two NASA shuttle flights in
1985 and 1988 where the equipment was
only used to obtain photographs of red cell
ageregation. The results of both flights
showed significant changes in red blood cell
morphology and a reduction in the size of
agoregates in native plasma.

Lesson 3: How useful is a paper clip
and rubber band?

There are times when an urgent solution
necessitates unorthodox methods and tools.

After working with Dr Dintenfass I was
offered a contract with the CSIRO’s
Mineral Physics and Nuclear applications
group facility in North Ryde. My work
included working in the field in Western
Australia, at Kalgoorlie, and at a remote
station at Yeelirrie, where the nearest town,
Waluna, was 70 kms away. I learned in Jak’s
lab the importance of self reliance and of
having a detailed knowledge of your
experimental equipment. These skills were
paramount in my success in that isolated
environment.

In 1983 near the end of my four year term
with the CSIRO, I was involved with the

assembly and testing of the recently
acquired 2.7Mev ‘Tandem accelerator. The

accelerator was to be used as a
microanalytical system in geochemical and
geochronologic studies. The accelerator
was thoroughly tested the night before the
facility was due to be officially launched. In
the control room, The Honourable Minister

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Kerestes — Paper clips, rubber bands and satay sticks

for Science Barry Jones was to push a big
red button which would turn on_ the
accelerator. An ton beam would be
produced that travelled down inside a
vacuum tube be bent around by an
electromagnet. It would then travel down a
straight section of the vacuum tube into a
small chamber. The chamber contained a
remotely controlled mechanism with a small
target that would flip into and intersect the
beam showing a glowing spot. This
glowing spot was picked up by a video
camera and would then show up on a
television screen next to the red button that
initiated the whole sequence. The glow was
a visual confirmation that the accelerator
worked.

The Minister, along with dignitaries from
the Government and the CSIRO and a
news crew had been invited to witness and
record the event. All tested well the night
before the launch but the situation changed
by morning. We all showed up early and
everything was working, except for the
target which would not flip into the beam.
We 1solated the target chamber, brought it
up to atmosphere, opened it, tested the
remote signal all okay. I had a very careful
look and used my finger to flip the target
holder and noticed that a fine spring got
caught in the mechanism and had twisted
and finally had broken loose. There was no
time to take it out and repair it. Again |

drew on Jak’s teachings, think the
unthinkable. =A paperclip and a rubber
band. ‘The shape of the paper clip was

reconfigured to fit into the mechanism with
a slight counter tension and the rubber band
supplied the opposing tension. Within five
minutes the target was working again, more
smoothly than ever before. In the jubilation
some exclaimed ‘“‘we should patent this”.

106

The chamber’s top was quickly bolted
down, the vacuum pump turned on and
when its gauge showed the required vacuum
had been reached tor operations the final
thumbs up signal was given just as everyone
entered the control room. ‘There were only
three of us who knew about the fix. We
quickly left the experimental hall where the
accelerator and the beam tubes were housed
and joined the dignitaries in the back of the
throng, with our hands behind our backs,
fingers crossed. Judging from the applause,
as we couldn’t see from the back, we
figured that my “low tech” solution must
have worked.

Lesson 4: How to change careers and
survive

My association and friendship with Jak and
his family had continued over the years.
During our association Jak advised and
helped me greatly in making a major shift in
my career path.

I had an offer from the Department of
Medical Oncology to work in Clinical Trials
at Royal North Shore Hospital.
though I knew the work would be
interesting, challenging and rewarding the
fact was that I was no longer going to be

liven

practising Physics. Jak helped me over
some of my doubts by having faith in my
abilities and by pointing out that just
because he is working in another area a
Physicist never stops practicing the methods
and attitudes that he has been trained with.
He also pointed out that succeeding and
finding reward in another area ts in fact the

ultimate endeavour.
He was right.

The Head of the Department of Medical
Oncology was Professor John Levi, who

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Kerestes — Paper clips, rubber bands and satay sticks

was a founding father of chemotherapy
trials in Australia. He wanted someone
from pure research, outside of Medicine, to
help with the design of the trials, to ensure
the trials’ data integrity and quality and to
provide help in statistical analysis of results.
Software and hardware support for his
Department was also a requirement.

During my first six months of probation I
had a challenge that I never expected to
face: a visiting doctor who was involved in a
chemotherapy trial was attempting to apply
‘what-if-scenarios’ to the data. I could not
understand this. In trials, there 1s always a
strugele with patient recruitment. It ts
critical because, with small numbers, the
statistical power is weak. Furthermore, the
patients are usually further divided by
different treatment modalities thus further
diminishing the statistical power. I found
that Medicine is so much more difficult
than Physics because individual humans are
varied in their biological responses and
genetic makeup. All one can do in a clinical
trial is to identify as many patient factors
that may be of relevance and to then analyse
the response of the cohorts. In this case
there are no ‘what-it-scenarios’. I explained
the situation to the doctor but he kept
insisting that what he was attempting to do
was valid. I felt that my new career was
going to finish even before it started. The
doctor hadn’t actually crossed the line of
‘changing data integrity but I felt very
uncomfortable with his attitude. ‘The tssue
of intellectual honesty never really came up
in our research in Physics, since we spent so
much time ensuring that we had all the
factors effecting measurements identified
their importance — evaluated. A
measurement was only real if tt could be

and
reproduced. In clinical trials I have seen
now that a statistically sionificant result in
one trial was quite often nullified by a

107

similar trial at another centre. Many years
later, by pooling results from many centres
and applying methods of meta-analysis,
helped to firm up results.

In my situation with this doctor, I had no
other course except to defend my stand and
to ensure that the ‘line’ was never crossed. I
kept my job and I have been with the unit
now for almost thirty years, he left medicine
a tew years later after this incident.

Lesson 5: Unconventional Solutions

Clinical trials are now conducted by the
drug companies and my interest turned to
the use of information systems in Medicine.

When Internet technology began to mature
in the mid 90s I rapidly saw just how useful
it could be to disseminate information
efficiently. In a hospital setting what was
required was to set up an Intranet. I also
realised that quality and version control of
documents were crucial to its successful
implementation. ‘The final tool to make the
process useful was software that became
available to convert word processing files
into HTML. If those documents were
properly styled, then those styles could be
turned into a linked table of contents. I was
seconded to the Information Technology
Department of the Hospital to lead a team
to develop an Intranet as well as policies
and procedures for document authoring
and version control. The project was highly
successful and I was asked to give a
presentation of our work to the
Department of Health. The night before
my talk, I was going to put the final touches
to my PowerPoint presentation. To turn
my laptop on, I pushed on the sliding
power switch located on its side. It broke.
I couldn’t turn the power on and to my
horror, I didn’t have a backup. It was at

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Kerestes — Paper clips, rubber bands and satay sticks

this desperate point that again the
experiences and attitudes I gleaned tn Jak’s
lab illuminated me: do not give up, examine
the problem thoroughly and most of all of
seek answers the
realm. There was a small opening where
the switch broke that I could push some
pointed tool in and possibly throw the
power switch on. However in this situation,
I could not use my all purpose paper-clip
tool as I might short the laptop and make a
bad situation even worse. Light bulb
moment, a satay stick! A mad dash to the
kitchen drawers and within minutes I had
the laptop come alive, made a quick backup
and finished the presentation and backed
that up also. As the talk took place early on
in the morning, I didn’t have time to get
another laptop. I had to use the one I had.
I didn’t feel too good about using a satay
stick at a presentation where I knew there

outside conventional

were going to be some senior members
from Health Department of Health. Even
though I came up with a working solution
and practiced turning the laptop on and oft
so at least it looked like a smooth operation,
I still thought it was tacky but there was
nothing to be done.

Once again finding myself in an unusual
circumstance Jak’s influence helped. Next
morning I turned up to give my talk. [|
pulled out my laptop, placed it on the
lectern and made sure that my audience
could see that I had used a 5 cm long
transparent tape to stick two satay sticks to
the cover. I could see that most people
were quite intrieued. They have never seen

anything quite like it.
Don’t hide the facts, emphasise them.

I began my talk by explaining what occurred
the previous night and how I came up with
the solution. I then took one of the satay

108

sticks and, with a confident flourish, |
turned on my laptop. <A few people
applauded. I then asked the audience
whether anyone could tell me why I had
two satay sticks. “No idea? No guesses?” I
teased. “Clearly ...the second satay stick 1s

for backup.”

That bought the house down.

Conclusion: “People in the cheap
rows, at the back, can you hear me?”

A week after my presentation with the satay
oftered the
rewarding projects of my career. A project
that especially help all
professionals in NSW in the far flung areas
of the west of the state. At the time,
Broken Hill Hospital did not even have a
medical library.

sticks I was one of most

would health

The Clinical Information Access Program
(CIAP) was a project of the NSW
Department of Health, initiated in 1997 and
driven by the Clinical Systems Steering
Committee. Its principal aim was to use the
Internet to bnng to the point of care,
clinical information for all health
professionals working within the NSW
public health The

information and resources

system. clinical
the

support clinical best practice, education and
research.

was [to

I was asked to make the CIAP a reality by
identifying and purchasing an initial pool of
data sources and associated search engines,
to contact every major medical library in the
state and inform them of this soon to be
delivered resource, and to obtain feedback
and create the web structure for delivering
the information resources purchased.

JOURNAL AND PROCEEDINGS OP THE ROYAL SOCIETY OF NEW SOUTH WALES

Kerestes — Paper clips, rubber bands and satay sticks

The website was launched on July 4, 1997
and the year after the CIAP received the
Data Management Associaton (DAMA)
Australia Achievement Award for
Excellence in Information Management and
the Australian Library and Information
Association (ALLA) NSW = Branch Merit
Award tor Services to Rural and Remote

Users and the Community.

Zoltan Kerestes

Received 31 October 2013, Accepted 11 Noveniber 2013,

109

After the launch one of the many emails |
received from the rural doctors was, ““This
is the best thing that has happened since a

bail of clover ina drought.”

Thus, thanks to Jak’s legacy, I too managed,
in my own way, to get the message to the
“people at the back”.

Journal and Proceedings of the Royal Soctety of New South Wales, vol. 146, nos. 449 & 450, pp. 110-115.

ISSN 0035-9173/13/020110-6

Ion beams and channelling: the early days with Jak Kelly

Jim S Williams®

Research School of Physics and Engineering, Australian National University, Canberra ACT 0200

* Corresponding author.
E-mail: jimavilliams(@anu.edu.au

Abstract

This paper contains some personal perspectives of the lessons learnt during my PhD studies with Jak Kelly

at UNSW. Jak was passionate about science, had boundless enthusiasm, was an eternal optimist, was an
‘ideas’ person and innovator, as well as a superb motivator for his students and co-workers. I owe him

much for his impact on my career in science.

t

Introduction

I first encountered Jak Kelly as an
undergraduate student at UNSW in the
mid-1960s. He was clearly the most
enthusiastic and passionate lecturer in my
early undergraduate years. His lecturing
style decidedly theatrical
compelling. It was not a surprise to me that

was and
his daughter Karina showed much of that
style in her media successes years later.
During my Physics Honours year I was
called up for national service. I sought Jak
out for advice on whether a PhD might be a
viable choice to keep me out of the army!
Jak and Bnan Lawn, another impressive
academic member of staff at that time,
suggested an intriguing topic for a PhD that
brought together their individual research
interests: 1on channelling in Jak’s case and
brittle fracture in Brian’s case. Jak explained
that the phenomenon of ion channelling
had only been discovered a few vears earlier
and the field was ripe for the picking. I was
impressed and signed up for a PhD. The
topic turned out to be a bizarre and,
ultimately, an incompatible union of
research directions, but more about that
later.

110

There were four attributes of Jak that stood
out during my PhD time: 1) he was a
fantastic ‘ideas’ person but I learnt early that
some filtering was necessary to give a reality
check and pick those directions that were
feasible given our meagre resources at
UNSW; 1) he was an eternal optimist and
always saw opportunity in adversity; 11) he
was a fabulous motivator and his boundless
enthusiasm helped me face the most
daunting of problems with confidence; and
tv) he was a superb innovator and taught
me to improvise with what was available to
achieve an important research goal. I have
chosen three examples or stories from my
PhD time that illustrate these attributes.

The 1.2 MV Cockcroft-Walton
accelerator

Part of Jak’s motivation for suggesting my
thesis topic, built around ton channelling,
was that he was in the process (in early
1969) of negotating the purchase of the
ANU Cockcroft-Walton accelerator.
typically naive student, I believed Jak when
he said that the accelerator should be fully
running within about 6 months and | could

As a

c JURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Williams — Ion beams and channelling

plan to do my channelling measurements
across fracture interfaces in silicon on that
machine. Little did I know at that time that
a suitable home for this machine had not
been found, and that was only the start of
the problems that needed to be solved
before the machine was usable! In truth
even Jak didn’t realise the enormity of the
task. Anyone that has worked with
accelerators will know that, when they are
left idle, (essential) bits are progressively
cannibalised. It was no different with the
ANU machine that was decommissioned in
1967. Jak managed to convince the
University to buy an old tram maintenance
shed opposite Randwick racecourse. It was
an ideal location, with very solid walls and a
ceiling high enough to house the very
impressive Cockcroft-Walton accelerator
shown in its glory days at ANU in Fig.1.
The charging system and the three stack
configuration of the machine created a sight

to behold.

When the accelerator arrived at UNSW
there were many parts missing and the
electrical wiring, vacuum system, beam lines
and data collection needed to be completely
rebuilt. Undaunted, Jak set about mobilising
a team to work on it. Bob Dalgleish, a very
talented PhD student who had a strong
electronics background from an earlier life,
played a major role in finally getting it
operational by the end of 1972. Alas, too
late for my own PhD! Nevertheless, the
accelerator was a major focus of Jak’s group
activity at the time and its successful
installation was a huge achievement, a
testimony to improvisation that brought
great credit to Jak and those who worked
on tt.

111

Faoure 1x) The 7.2

MV Cockeroft-Walton
accelerator as installed at the ANU in the early
1950s. The high voltage generator stack ts at the
right. A uniform voltage gradient is applied to the
acceleration tube via the central condenser stack.

The ion source ts located in the left side ‘bun’ at the
top of the acceleration column.

I can well remember the occasion of the
first time voltage was obtained on the ton
source ‘bun’. We were all awestruck! Jak
had to demonstrate that high voltage was
‘safe’ if there was no path to ground. He
proceeded to climb into the ‘bun’, the
ladder was removed and he asked Bob to
wind up the voltage. I believe we reached
50,000 volts with Jak up there, his head and
shoulders visible above the bun. Jak’s hair
was extended in all directions, like Einstein,
and one of my co-students called out: ‘Jesus
Christ’, and at that moment, to all of us, Jak
was!!

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Williams — Ion beams and channelling

Ion channelling at AAEC: the early
days

Although the Cockcroft-Walton was not

operational in time, not all was lost for my

thesis. Jak had already established a

successful collaboration with Roger Bird at

the Australian Atomic Energy Commission

(AAEC) at Lucas Heights and a
‘channelling beam line had been

constructed by PhD student Murray Hollis.
When I started Murray had not obtained
any channelling data but with the help of
Pat Price, a PhD student who followed on
from Murray, he managed to achieve
channelling in gold foils and completed his
thesis by early 1969. To achieve channelling
Murray needed to construct a goniometer!
in a vacuum chamber that had 5 degrees of
freedom, all controlled from outside the
vacuum. It was a beast of a system and held
together just long enough for Murray to
complete!

Pat and I were forced to build another
scattering chamber and goniometer to have
any hope of — further channelling
experiments. I remember talking to Jak at
the time and asking him how we could get a
system up and running in a reasonable time.
I had been doing X-ray experiments on
fractures in using a simple
goniometer in air and wondered how this
would go in vacuum with flexible angle and
translation through
feedthroughs. Jak’s immediate response
was: ‘try it and I think I have just the
chamber for it. I dusted off an ancient
chamber that Jak had used years earlier at
Sydney University and within two weeks we
had a very inelegant looking, but workable,
goniometer in a vacuum chamber that could

silicon

control vacuum

| An

orientation of faces of a crystal with respect to some

instrument used for the precise angular
reference direction; eg. the incoming ion beam

direction.

112

hold a reasonable vacuum despite the
lubricants on the goniometer drives. It was
connected to the channelling line at AAEC
and we were off and running. ‘This was
symptomatic of the type of improvisation
that Jak encouraged in the group. It ts a
skill that has held me in good stead over my

career 1n science.

The experiments that Pat and I did at Lucas

Heights were the first Rutherford
backscattering and channelling

measurements in Australia.
papers on radiation damage build up in
alka halides (Price et al, 1973) and
radiation effects in quartz (Williams and
Lawn, 1973). The chamber, beam line and
analysis system at AAEC remained in use
until the early 1980s, servicing many other
students and
replaced by a
commercial system.

They led to

researchers, until itt was

more — user-friendly

As an aside, Murray Hollis went oft to
Chalk River laboratories in Canada and
returned to the ANU, and became the
laboratory manager of the Research School
of Physical Sciences, the very School of
which I became Director a couple of years
after Murray retired. Pat Price came from a
sugar cane farm in North Queensland to do
his PhD with Jak. He also went off to
Canada on a_ post-doctoral fellowship,
before returning to Australia as an engineer
in industry.

Channelling without an accelerator:
the pinhole camera

I realised about 6 months into my PhD that
I was very unlikely to be able to achieve my
original goal of ion channelling across a
fracture interface to dynamically measure
crack tip separation. I can remember the
first ttme I went to talk to Jak about this

problem I was quite depressed. [| also

JOURNAL AND PROCEEDINGS OP THE ROYAL SOCIETY OF NEW SOUTH WALES

Williams — lon beams and channelling

remember coming out of that meeting
totally energised and enthusiastic again. So,
what did Jak say? I honestly can’t
remember but there was certainly no ready
solution to my dilemma. That was the
effect Jak had on his students: he could
motivate and encourage them simply by his
positive attitude and passion. What I do
remember is that he gave me a paper by a
French group, Yves Quere and co-workers,
and said I should read it as it may lead to
something useful for my project.

The said paper was in French (Quere, 1968)
and described how a radioactive source
C1Am, which produced 5.46 MeV a-—
particles) could be used to obtain
channelling patterns by inserting thin
samples between it and a track-recording
cellulose film. I discussed this paper with
another of Jak’s PhD students, Hans Nip,
and the two of us decided to try a twist on
the French method. We built a pinhole
camera that is shown in Fig. 2. We figured
that it could be used for observing
channelling phenomena. We actually built
the camera and obtained channelling
patterns before we told Jak anything about
it. When he saw the results he was
delighted and told us that this was just the
sort of innovation he wanted to see from
his students. The trick with these
experiments was to polish the single crystal
sample to a precise thickness that was too
thick for a—particles that entered the crystal
in a random direction to penetrate through
it but thin enough for easy penetration of
well-channelled particles. The distances
between sample and source (d,) and sample
and film (d;) could be varied in our vacuum
camera as well as the penetration angle (by
viewing different distances from the film
centre). A magnification can be defined as
d;/Rr and adjusting the various spacings
allows a range of channelling phenomena

113

(and defects which inhibit channelling) to be
observed. Fig. 3 shows channelling
transmission patterns for 3 different
oriented single crystal silicon samples. The
width of the bright lines allows the
channelling critical angles to be measured.
At the time, these patterns had only
previously been obtained by expensive high
energy particle accelerators.

=. eo oo ae

aperture

source

rR,

a

Figure 2: A schematic of the vacuum pinhole
camera arrangement whereby O—particles passed
through an aperture and sample and impinged onto
a cellulose nitrate film. E:xtching the film revealed the
individual O—particle tracks and the channelling
directions in the crystal. From Nip and Wilkams
(1972).

Both a conference presentation and a
journal paper (Nip and Williams, 1972) were
obtained from this work. I presented the
paper at a conference in Oslo in 1971 which
was very well received. In fact, I was
congratulated on the innovative method
and had three post-doctoral offers, one of
which I accepted at the University of
Salford in the UK working with George
Carter. Again, this type of innovation was
strongly encouraged by Jak: I owe him
much for the training in his group that set
up my future career in science.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Williams — Ion beams and channelling

Figure 3: Pinhole channelling patterns from a)
<111>, b) <100> and c) <110> orented silicon
thin samples, mith the respective stereographic
projections in d), e) and f). From Wilkams (1972).

Very sadly, Hans Nip committed suicide
around the time I presented the Norway
paper. It was not known by any of our
rather close group that Hans was struggling
with ‘demons’ that he could ultimately not
overcome. Outwardly he appeared a happy
go lucky person, who liked to share jokes
and perspectives on life, including his very
insightful poems of the week, with his
friends and colleagues.
affected by this sad event, chastising himself
that he did not detect a problem within
such an otherwise caring group of people.
For my part, I have become very friendly
with Hans’s sister Renee and family in the
Netherlands. A few years ago she visited
Australia and Sydney to see for herself what
Hans had described to her as a geteat
country.

Jak was strongly

114

Perspectives

‘Towards the end of my PhD I was married
to my wife Ros of over 40 years now. Jak
and Irene were at the wedding, as were
many of my UNSW colleagues. At events
such as this Jak would be excellent value,
with an endless number of very witty stories
and anecdotes. Years later during my post-
doctoral fellowship at the University of
Salford in the UK, the Kelly family visited
us. They crammed into our very small flat
and I can remember that Karina (at about
age 14) babysat our two small children while
we went out for a meal.

If I look back at where my career has gone,
I have a lot to thank Jak for. In my early
days in the UK and Denmark, I quickly
realised that improvisation and adaptability,
the ability to think laterally and problem
solving, attributes that I had learnt from Jak,
were highly valued by my new colleagues. |
was given a problem when I arrived in
Salford to measure the range distributions
of various ions in materials. I realised that
the depth resolution of the Rutherford
backscattering method I was using was
barely sufficient. It needed to be improved
but what to do? After a little thought about
how the resolution was improved in the
channelling pinhole camera I decided to
dramatically change the entrance and enit
angle of the analysis beam, calculating a
large enhancement in effective depth
resolution. It worked better than I
imagined. In fact, this simple twist to the
Rutherford backscattering technique to
improve its depth resolution, a small step
learnt quite naturally tn working with Jak,
helped establish my scientific credibility. It
led to collaborative and job opportunities
and a very enjoyable life in science. I thank
you Jak for giving me the chance to work
with you, for what you taught me that not
only enriched my career but engendered in

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Williams — Ion beams and channelling

me a passion and enthusiasm for science Quere, Y. (1968) Journal de Physique, 29 215-
that I have endeavoured to pass on to 219.
others. Williams, J. S. (1973) Some properties of open
structured brittle single crystals, PhD thesis, UNSW.
References Williams, J. S. and I awn, B. R. (1973) Slow crack
Nip, H. C. H. and Williams, J. S. (1972) A pinhole growth in proton and deuteron irradiated

camera for the observation of channelling phenomena, quartz, Journal of Materials Science, 8 1059-

Radiation Effects 12, 171-174. 1061.
Price, P. B., Williams, J. S. and Kelly, J. C. (1973)

Deuteron induced damage in alkatt halides, Radiation

Effects 19, 203-204.

Jim Willams
Received 19 December 2013, Accepted 20 December 2013

Protessor Williams obtained his BSc (1969) and PhD (1973) degrees from the University of New South
Wales before moving to Europe and North America for a series of research and industry appointments,
including a member of technical staff at Bell Telephone Laboratories, New Jersey, USA. He returned to
Australia to take up an academic post at the Royal Melbourne Institute of Technology in 1978 and became
Director of the Microelectronics and Materials Technology Centre in 1982. In 1988 he moved to the
Research School of Physical Sciences at ANU as Foundation Professor of the Department of Electronic
Materials Engineering. Both of these R&D efforts involved leading large research teams focussed on
innovative materials and devices research covering aspects of both fundamental interest and applicability to
industry. In 1997 he assumed the additional role of Associate Director of the Research School of Physical
Sciences & Engineering at ANU and took up the Directorship of the School in 2002. In 2012 he retired
and is now an Emeritus Professor of Electronic Materials Engineering at the ANU.

Protessor Williams has carried out research in diverse areas of materials science, nanotechnology, 1on-solid
interactions and semiconductors for over 40 years. He has published over 450 refereed papers and five
books in a broad spectrum of sub-fields within semiconductors, materials science and processing, device
fabrication and engineering. His papers are well cited with an h-index of 50 and over 8,000 citations in
total. He is particularly well known internationally for his pioneering work on ion implantation into
semiconductors, solid phase epitaxial growth of silicon, innovative development of ton beam analysis
methods, impurity gettering in silicon and nanoindentation of semiconductors, the latter area leading to
prospects for novel patterning of silicon at room temperature. Over the past 20 years he has had an
average of 5 invitations per year to deliver keynote plenary or invited papers at major international
conferences. He has served on the editorial board of ten international journals and three international
conference series. He was awarded the Boas Medal of the Australian Institute of Physics in 1993 and the
Thomas Rankin Lyle Medal of the Australian Academy of Science in 2011. He is a Fellow of the
Australian Academy of Science, the Australian Academy of Technological Sciences and Engineering, the
Materials Research Society, American Physical Society, is President of the Australian Materials Research
Society and is an IEEE distinguished lecturer. He has served on the MRS Council and has been a Vice
President of the International Union of Materials Research Societies. He has been the founding director or
initiator of two spin off companies, Acton Semiconductors and WRiota, in 1999 and 2004, respectively.

Soap

115

Journal and Proceedings of the Royal Soctety of New South Wales, vol. 146, nos. 449 & 450, pp. 116-135.

ISSN 0035-9173/13/020116-20

Research Cooperation with Past President Jak Kelly

Heinrich Hora

School of Physics, University of New South Wales, Sydney 2052
h.hora@unsw.edu.au

Abstract
A review of research work done in collaboration with Jak Kelly between 1975 and 2012 at the University of
New South Wales requires a rather detailed explanation of the subjects covered. ‘These begin with the
pioneering work on very high intensity electron beams of energy ranging between 10 and 200 keV as well as
ion beams and their defect generation in solid material. Combination with lasers led to the whole range of
ion generation from few eV to GeV including the need for changing Maxwell’s stress tensor of plasma

optical properties.

This led to the discovery of relativistic self-focusing and subsequently to joint

applications based on papers covering solar cells and the reduction of friction in motor engines together
with patents. With nuclear energy being 10 million times more efficient than chemical energy there 1s the
possibility that lasers might lower the most dangerous levels of radioactive radiation to the point that it can

be neglected.

Introduction

An indication of the importance of my
collaboration with Jak Kelly 1s an obituary
we prepared as fellows of the Institute of
Physics (London) for its magazine, on
Professor Christopher Milner, Head of the
School of Physics at the University of New
South Wales, and his long years of service
(Hora et al. 1998). Milner was highly
regarded tor establishing the very successtul
School of Physics and for becoming the
only physicist as Dean of Science. No
doubt Jak Kelly was very appreciative when
Kit Milner academic
position in Sydney following the exciting
work he had been doing at the Harwell
Research Establishment in England. Jak’s
new position led to his appointment as

oftered him = an

professor and later to Head of the School of
Physics and Chairman of the Faculty of
Science of the UNSW.

Research in physics has numerous instances
of adversity that cause fricton and hamper
progress. Never when working with Jak
Kelly did I experience such negativity. Ifa

116

researcher claimed to have measured
velocities faster than c of light in a vacuum,
Jak would a prion not take a negative stand
and would first look into details tor the

claim.

Jak’s interests followed many directions
such as applying his profound knowledge to
ton implantation or to defect generation in
solids. Other directions were to investigate
alternatives for energy generation and to
deliberate on nuclear energy. During the
times I collaborated with Jak there were
many examples of the positive side to
research. Although personal
reflections do include —_fak’s
contributions to areas such as solar-thermal
production, — or

these
not
energy luminescence
methods for measuring the age of pottery in
archaeology, they do include F:éetron Beam
Treatment of Materials, Low E:xnerey Nuclear
Reactions, laser interaction nith plasmas, and
Nuclear E:xnerey without Problems of Radioactive
Radiation that I have covered below.

Jak’s positive attitude emerged at times

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Hora — Research cooperation with past president Jak Kelly

when organisational decisions had to be
made. For example the University of New
South Wales was oftered the purchase of
the
Australian National University when it
purchased a new accelerator. It took Jak
less than a second to accept the offer
although there had to be a lot of work done
before rich fruits of his decision could be
harvested.

the wan-de-Graaf accelerator trom

The following is a summary of results of
our collaborative research. They reflect
Jak’s exceptional ingenuity and attitude to
solving problems and even though not all
problems were solved, in most cases the
research helped to open new doors to

knowledge.

Electron Beam Treatment of Materials

Electron beams could be seen long before
the year 1900 in the electric discharges
within low pressure Geifler tubes before
knew Using
electron beams became more common in
Braun’s television tubes and by the wave
properties in electron microscopes from
about 1930. But to get the electron beams

one what an electron 1s.

at such high intensities that these could melt
materials, cut or weld them, came along
only just around 1950. Jak Kelly’s first
publication was in Nature (Bruce et al.
1951) from work in Sydney about wave
properties, and when he joined the
University of Reading in England for his
Ph.D. project, this was the place where the
very intense electron beams were used.
Metals highest — melting
temperatures above about 2000 centigrade
could be heated up and liquid droplets
could be studied. Kelly’s paper (1959)
described the “Electron bombardment
apparatus for vacuum evaporation” leading
to the first possibility to measure the surface
tension of these matertals (Tille et al. 1963)

with the

117

as basis of surface potential measurements
(lownsend et al. 1967). On top it was
highly important to study the crystal defects
in materials by this bombardment of the
electrons and also by beams of intense ions
of similar high energies and = current
densities. | About the crystal defects, a
standard book was published by Kelly
(lownsend et al. 1976, cited 350 times) and
he became a leading authority in this field of
high importance for material research when
he was leading an international conference.

Similar but independent studies with high
intensity electron beams came from another
side tor cutting and welding of metals under
extreme conditions in Germany
(Steigerwald 1961; Hora 1961). It was even
possible that the basically fixed optical
fundamental absorption of silicon could be
changed (Hora 1961a). On top it could be
shown that the very intense electron beams
could produce detects in silicon for
changing n-conducting crystals into p-
conducting states producing diodes (Hora
1962) for later use for transistors at electron
energies of 50 keV, while the established
value by Lark-Horowitz from simplified
crystal theory needed more than 200 keV.

Another result with homogeneous
semiconductors (GaAs) led to the
calculation of the laser threshold at

pumping with electron beams _ predicted
(Hora 1964) exactly in agreement with
subsequent measurements (Hora 1965a;

1965b; 1965c).

When I accepted the offer of the
Foundation Chair in Theoretical Physics at
the University of new South Wales in
Sydney/ Australia in 1975, I brought in this
background for cooperation with Jak Kelly,
though my appointment was based on my
achievements of purely theoretical results.
the clarification of the

These were

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

Richardson equations for electron emission
where the analysis on the basis of an integral
equation led to the general spectral response
theory of photoelectric electron emission
(G6rlich et al. 1957; 1957a; 1958) with the
result that the general response function ts
given by a volume process in contrast to the
established theory of the surface effect
(Herbert Frohlich; Igor Tamm). This was
clarifying the unique property of the Cs;Sb
photocathode, discovered by Gorlich 19306.
This and similar compounds substituted
soon all earlier emitters of photocells with
the instabilities and low efficiencies. As
another mathematical achievement, I had
discovered the mechanical forces in plasmas
by irradiation of light, if the correct
dielectric optical properties were used (Hora
et al. 1967) leading then to the exact
modification of Maxwell’s stress tensor in
plasmas (Hora 1969).
coupled nonlinear differential equations for
the complete relativistic motion of electrons
in laser fields (Hora 1973) permitting the
general solution of relativistic laser beams
for self focusing in plasmas (Hora 1975).

I solved the two

This
harmonizing with the interests of Jak Kelly

though | with

research background) was well

was mostly involved
establishing lectures in higher mechanics,
electrodynamics based on Maxwell’s theory
and the mathematical foundation
solving the Schrodinger and the Dirac
equation for undergraduates, where I
profited especially on my mathematical and
theoretical German

universities.

tor

education from

The sub-threshold energies of electrons for
producing n- into p-conducting silicon was
the first joint project to be studied with Jak
Kelly, especially after I just got granted a
patent (Hora 1977) how to produce solar
cells by much lower costs and avoiding

118

ageressive and poisonous chemicals. I had
to win with a patent process against the
AKG in Germany. This work was the topic
of a Honour’s thesis of Hinckley et. al.
(1979; 1980) supervised together with Kelly
student received

where the a first class

honours and the University Medal.

Using the direction of crystal detect
generation by ion implantation in silicon —
pioneered by Kelly (fownsend et al. 1976) —
I spend a study semester with the Siemens
research laboratory in = Munich-Perlach
(Hora 1983) which results were then further
studied at UNSW in cooperation with Julian
Goldsmid and with using laser annealing by
George Paul (Goldsmid et al. 1984) in
cooperation with E.F. Krimmel (Siemens
Research Munich-Perlach)
measurement of thermal conductivity. It
should be mentioned that Goldsmid’s work

about — laser

led to a widely used instrument for

identifying diamond crystals.

For the 1on implantation, it was interesting
to use laser irradiated targets as sources
about which I had experience from the
laser-plasma interaction. In cooperation
with Jak Kelly, J. Len Hughes from the
Australian National University et al. we got
eranted a US-Patent (Kelly et al. 1980;
1981). This was then used for studies how
to reduce the friction of iron after intensive
and high energy implantation of tin tons.
These studies were performed after I had
become Emeritus Professor at the UNSW
and had a Konrad-Zuse-Protessorship in
the Faculty of Electrical Engineering in
Regensburg, Germany. These — results
(Boody et al. 1996) received more than 100
citations and through my contacts from the
Rotary Club with the Regensburg plant of
BMW, our research found interest by the
R&D Chief, Dr.-Ing. Wolfgang Reitzle
(BMW, Munich). The tin implantation

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Hora — Research cooperation with past president Jak Kelly

reduced the friction in steel by a factor up
to ten which result was measured by Savage
(1984) at the University of Wollongong in
contact with Jak Kelly. It was considered to
improve motor engines for racing cars. The
unique measurement by Savage (1984) led
to the result, that when the tron surface was
scratched oft by friction under long use, the
implanted tin ions are moving to the inner
We had no further
information the interest
stopped when BMW withdrew from car

volume of the iron.
whether was
racing or due to the fact that Reitzle had
changed to become the CEO of Jaguar in
England.

The production of very low cost solar cells
with electron beam generated p-n junction
was reported (Ghoranneviss et al. 2006) and
an efficiency of about 10% at not optmized
parameters was measured. ‘This may open
the production of solar cells in plastic foils
of organic materials for an economic
contribution to © solar The
commercial level of present silicon solar
cells is mostly determined by the high
equipment and connections costs to be

energy.

added to the present comparably high costs
of the silicon cells. Kelly as the Editor-in-
Chief of the Journal and Proceedings of the
Royal Society of New South Wales during
this time was interested and involved in
reports and publications of related topics
(Osman et al. 2007).

Low Energy Nuclear Reactions

This topic needs some introduction and
explanation because this is related to the
widely criticized “cold fusion”. More than
95% of all what has been published since
1989 ts unacceptable for physicists and it ts
important to select the few facts which may
be taken seriously. ‘The whole development
came from a very important line of
research, from the muon-catalysed fusion

119

(Jones 1986; Rafelski et al. 1987). Along
these lines of research, the incorporation of
very large densities of deuterium in
palladium resulted in the measured emission
of neutrons (Jones et al. 1989). The
confusion about these facts resulted from a
press conterence of Fleischmann and Pons
on 23 March 1989 at Bingham Young
University in Utah (Miley, see Hora 2011).

Jak Kelly’s attention to these developments
followed the results of Jones et al. (1989) by
being involved from the early stages (Hora
et al. 2001; Miley et al. 2009). Following the
line of Jones and Rafelski,
interesting physics approaches by
Parmenter and Lamb jr. analysed Debye-
length influences by the Thomas-Ferm-
Mott model including the Oppeneheimer-
Phillips process (Parmenter et al. 1989;
1990) and it may not have been a
coincidence, that the evaluation of
Coulomb screening was a key point of the
work with Jak Kelly (Hora et al. 1993)
which was later confirmed by ab initio
quantum mechanics by Czerski et al. (2001)
and Huke et al. (2008).

serious

The present situation was summarized by a
media source (Krivit 2013) in the following
way: “The older researchers who have
fought the battle for ‘cold fusion’ for 24
vears have, sadly, found themselves with
increasingly less funding, research, and
mainstream media coverage. Their
conference papers, for the most part, repeat
the research they have done for many years.
In some cases, they have presented the
same experiments for a decade. During this
time, they have made little progress, both in
the expansion of scientific knowledge and

toward commercialization of LENR
technologies. On the other hand,

something fascinating is taking place. As a
result of slow but steady mainstream

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Hora — Research cooperation with past president Jak Kelly

acceptance of LENR (by Royal Dutch Shell,
Toyota Motor Corp., CERN, ANS, Boeing,
ST Microelectronics, Elsevier, and Wiley

ee

1.E+03

Secondary lon Counts

100

and Sons), mainstream science and industry
are taking notice.”

150 200
Mass (anu)

Figure ta. Abundance of elements in palladium before loading nith deuterium (Miley et al. 1996).

1.£+03

Secondary ton Counts

1.602 |

1E+01 |

In this situation it is necessary to give more
detailed explanation to a rather complicate
but completely solid basis for confirming
the nuclear reaction mechanism when high
densities of deutertum are incorporated in
palladium or in comparable metals as nickel

120

Mass (arr)

Fioure 1b. The elements detected in palladium after electrolytic loading of deuterium.

etc. before talking about the results
established with Jak Kelly (Hora et al. 1993).
The solid basis of the phenomena was given
by Miley’s et al. (1996) unique measurement
of a Maruhn-Greiner Maximum (Hora et al.

2007). This can be mentioned as a well

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Hora — Research cooperation with past president Jak Kelly

elaborated proof of the generation of nuclei
from the whole list of stable nuclei up to
lead, Figs. la and 1b. This discovery by
Miley et al. (1996) has been documented as
a “Low Energy Nuclear Reaction” LENR
process. The distribution of the generation
probability of the generated nuclei G(Z) on
the nucleon proton number as discovered
by Miley (1996), Fig. 2, which is similar to
SAD (standard abundance distribution of
elements in the universe, Rauscher et al.
1994; Hora et al. 1998) with a relation to the
nuclear magic numbers (Hora 1998).

if ne aia a ae cies faa
i" “Vg |

é "

- | f |} ae

io | be

re Ay

4 i % j i.

210} iy | ON

e \ | > i ‘Te ‘ ‘

5 oni Ny H ; | hy

{ | # e a’ he é <a |

at | | 1
3 esa aes a a"

Alomec number (2!

igure 2. Generation probability G(Z) of elements
nith proton number Z after the reaction of the
deuterium in the palladium (Miley et al. 1996,
2002).

When listing the distribution G/(A)
depending on the nucleon number A the
minimum for A between 125 and 175, Fig.
3, this has a similarity to the distribution
G(A) for the fission of uranium shown in
Fig. 4. For Uranium 236 there is a large-
scale minimum at A=118, just the half
nucleon number of the Uranium nucleus
(Feltus 2002). The splitting of Uranium
nuclei is there from an unexcited state.
However, if the heavy nucleus has been
excited to energies around MeV, a local
maximum appears for uranium as a local
peak (Fig. 5 at A = 118) as it was

121

theoretically explained by Maruhn et al.
(1974).

Production Rate (atoms! s-cc)

Mass No. (A)

Frgure 3. Measurement of Low Energy Nuclear
Reactions (LEENR) resulting in the distribution
G(A) of the generation probability of nuclei of
nucleon number A for the range between 125 and
185. Detailed nuclear mass spectrum of the
LENR generation probability at the highest A-
minimum with a tocal (Marubn-Greiner)
maximum at A = 155.

Puaion yield, percent

0.001

Mast number 4

Figure 4. Distribution G(A) of the generation
probability of nuclei of nucleon number Aas
measured from the nuclear fission of 7??U, 7? U and
239Py (Feltus 2002).

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora —

l0q,9 Fission Yield {7

pees EEE See Saeeey Mane Senree

78 98 118 BS 158
Mass No.

Figure 5. Fission mass distribution curves for °°U
calculated when the nucleus, at the time of fission, ts

excited to a temperature 0, 0.5, 1, and 7 Me\~

(upward sequence of Ref. Maruhn et al. 1974).

It is important to note for the case of

deuterium in palladium, that a similar local
maximum peak was seen in the
measurement of the distribution G(A).

LENR (Miley et al. 1996) ts a similar large-

scale minimum at A = 155, Fig. 3 and ako a

local maximum as a peak similar to the case of

This fact of the
observed = Maruhn-Greiner
(Maruhn et al. 1974) corresponds to a
compound nuclear fission reaction (Hora et
al. 1997; 1998a; 1998b; 1999; 1999a; 2000a;
2001) through a nucleus *Xj2, with Z =
126 protons and 310 — 126 = 184 neutrons.
Both numbers 126 and 184 are magic
nuclear numbers (Hora et al. 2001) and it ts
significant, that the evaluations of super
heavy nuclei with Z between 116 and 120
have both numbers for well pronounced
energy minima at 126 and 184 (Kuzmina et

al. 2012).

uranium fission of Fig. 5.
Maximum

Before Miley’s discovery of the LENR
process and how this was ascertained by the
Maruhn-Greiner maximum, an important
step was that with Kelly about the

evaluation of the plasma screening process for

Research cooperation with past president Jak Kelly

deuterons in palladium crystals (see Fig. 1 in
Hora et al. 1993) where the numbers tor the
reaction probabilities of Ratelski (see Jones
et al. 1989) were completely fitting with a
deuterium pm
Different to most of the experiments with
electrolytes, the measurements by Prelas et

(1990) were loading palladium with
deuterium in the gas phase or by plasma
mechanisms.

reaction in 2 distance.

‘This permitted an evaluation
by assuming that the deuterons in the
palladium crystal were behaving like a
Maxwellian gas and the theory of screening
of Coulomb repulsion could be described in
the same way as in the theory of Ichimaru
(1994) for high temperature plasmas. In his
case the Coulomb repulsion arrived at a
reduction factor of 5. In our case (Hora et
al. 1993) the screening has a factor of 13
according to the evaluation of experiments
of Prelas et al. (1990). The Maxwellian
deuterium tons are then, for distances down
to 2 pm, behaving similarly to neutral
particles. ‘This agrees then to a reaction

probability similar to the well-known
inverse K-electron capture — radioactivity.
This reasonable property allowed

considering that the deuterons can stick
together at 2 pm distance as a Bose-Einstein
of the
deuterons is possible (flora et al. 2007).
The 10 pm diameter cluster reacts then with
a palladium nucleus via a compound
nucleus *!’Xy. to fit with the measured
Maruhn-Greiner local This
result 1s based on the evaluation of the
results of Rafelski (1987) and Jones et al.
(1989) where Fig. 1 of Hora (1983) shows
the reaction probabilities of Ratelsk1 on
which basis Kelly could evaluate reactions
for D-D in 2 pm distance.

cluster within which no_ locality

maximum.

The phenomenologically derived screening
by the factor 13 derived with Kelly in 1993
(Hora. et. al. 1995; 1996; 1998a). was

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

confirmed from a complete quantum
mechanical derivation (Czerski et al. (2001);
Huke et al. (2008)). The long time uncertain
question whether the LENR reactions emit
neutrons of more than MeV energy from
nuclear reactions was measured with
recently developed diamond detectors
(Prelas et al. 2012) resulting in a neutron
emission of considerably more than one
million within five minutes. ‘These results
led to the recent activites in industry
for clarification of — the
mechanisms with the potential of far

laboratories
ranging applications.

Brian Josephson was interested in the
physics of LENR and visited the UNSW
2005 after he had several tmes discussed
these activities at the Nobel-Laureate
meetings in Lindau/Germany. Attention
was given by the team with Jak Kelly
(Osman et al. 2005; Hora et al. 2005). He
was at this time President of the Royal
Society of New South Wales and arranged
the then scheduled Pollock Lecture to be
presented by Nobel Laureate Josephson
and celebrated as a highly visited event.

Kelly’s involvement in laser interaction
with plasmas

Jak Kelly had joined the research team of
including relativistic

laser interactions,

and ion acceleration
mechanisms, described in granted patents
(Kelly et al. 1980; 1981) that were assigned
to UNISEARCH, the commercialisation
branch of the UNSW. This resulted in the
first derivation of electric double layers in
plasmas (Hora et al. 1984) and surtace
tension (Hora et al. (1989). The theory of
relativistic self- focusing of laser beams in
plasmas (Hora 1975) was the starting point
for a number of studies. A further point of
joint interest arrived about the topic of laser

conditions

driven ton sources about which Jak was well

Le)

familar through his — van-de-Graaf
accelerator after it was successfully working.
I had for more than one year a position as
Attache Remuneree at the CERN
Laboratory in Geneva/Switzerland with the
aim, what can be done that the ton sources
of accelerators may be improved by using
lasers (Haseroth et al. 1993, 1996; Hora et
al. 1992). Pioneering experiments were
done before at the Russian high-energy
physics research centre in Dubna well
following the general developments on the
main stream of laser-plasma_ interaction.
This is the reason why it is necessary to
summarise the related research in the
following.

During my time at CERN, I was in close
contact with Jak who had prepared laser
work at his accelerator in combination to
study the problems of laser driven ion
sources. He had also prepared PhD
students to contribute to this problem in
cooperation with CERN, well following the
concept of the earlier granted patents to
UNISEARCH (Kelly et al. 1980, 1981).
After successful experiments at CERN by a
very experienced Postdoc from Munich
(Hora et al. 1992) the later work by Russian
colleagues did not lead at the expected
results.

This research work on laser interaction with
plasmas for ion generation is needed in the
following to explain the development of
ultrahigh acceleration of plasma blocks and
of ultrahigh ion currents generated by
nonlinear — eftects. The — ultrahigh
acceleration of macroscopic objects by
more than 10?) cm/s? was the result of
theory and computations at the UNSW
(Hora et al. 1979a; Hora 1981) and was first
measured by Sauerbrey (1996) who
underlined that these acceleration were
100,000 times higher than ever produced in

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

a laboratory before. ‘The generated space
charge neutralized ion macroscopic blocks
had above 10!
Amps/ em? (Hora et al. 2002) that were
much higher than a million times than
produced in classical accelerators. All these
developments were considered in some
contact with Jak Kelly leading then to his
aspects (Hora et al. 2009) of a new scheme
of laser driven nuclear fusion where the very

ion current densities

dangerous radiation problems of

radioactivity may be eliminated.

After these results with very energetic ion
acceleration for all kinds of applications, it 1s
necessary to differentiate against the
basically different ultrahigh acceleration of
plasma blocks by avoiding relativistic self-
focusing. ‘These are becoming important
also for the application on laser driven
fusion energy and are to be developed now
for hadron therapy of cancers and other
applications. This type of acceleration goes
back to the early cooperation of the team
including Jak Kelly as shown by his co-
authorship for a scientific magazine (Hora
et al. 2009) where theoretical-numerical
predictions of 1977 from the UNSW (Hora
1991), however, needed a long time before
the experimental verification was reached by
Sauerbrey (1996). This was possible only
after the radical new discovery (Strickland et
al. 1986) of CPA (Chirped Pulse
Amplification) permitted the generation of
laser pulses with less than picosecond (ps)
duration (down to attoseconds, Krausz et al.
2009) and with powers above petawatt
(PW) (Mourou et al. 2006).

The developments go back to the effect
discovered by Linlor (1963) of the crucial
difference between thermal-chaotic
hydrodynamic processes and the contrary
basic nonlinearity determined mechanisms
just opened by the laser leading to collective

effects (Hora 2013). ‘This touches the
fundamental — problems

Edward Teller and are going to become

expressed — by

under control by damping and stabilization
of complex systems by Lord Robert May of
Oxtord (2011) following his Dirac Lecture
in May 2011 which was supported by the
RSNSW. For the stabilization mechanisms
see the discussion about Edward ‘Teller and
Lord May in a recollection of Hora (2011).
Before Linlor’s discovery, laser pulses up to
MW power when hitting targets in vacuum
heated these up to plasmas of about 20,000
centigrade by classical — thermokinetic
pressures and fluid-dynamics, seen c.g.,
from the emission of tons of the
corresponding energies if few eV. When
Linlor applied very smoothly produced laser
pulses of about 10ns duration by Q-switch
the
jumped from few eV to several thousand
eV by changing the laser power by a factor
of about fife only. The hope that then the
laser driven thermonuclear fusion enerey
generation, however, could not be fulfilled,
because the keV tons were not thermal but
were linearly increasing on the charge
Thermal

techniques, measured ion energies

would
The Z-

dependence of the energy indicated an

number Zz. processes

results in ions of same energy.
electrodynamic acceleration
ditterent from thermal action.

process,

The action of electrodynamic forces goes
back to the discovery by William Thomson
(Lord Kelvin) who in 1845 discovered, that
an electrical charge-free medium can be
accelerated by divergent electrostatic fields.
After discovery of Maxwell’s equations, this
ponderomotive force appeared also beyond
electrostatics in time dependent
electromagnetic fields, discovered by Weibel
(1958) when electrons tn vacuum could be
confined within the nodes of standing
waves of microwaves, and later by laser

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

fields. ‘The same could be concluded for
space-charge neutral plasmas — similar to
Kelvin’s uncharged dielectric materials. ‘The
new situation for plasmas is due to the
eradients of the optical dielectric and
absorption constants (Hora et al. 1967)
which were then just derived. The optical
constants could be used for describing
inhomogeneous
This can be
seen when a laser pulse penetrates a slab of
plasma (Fig. 6) where the negative gradient

spatial variations ot
dielectric plasma properties.

of the optical constant results in forces
moving the plasmas towards lower density.

|
Nix)
|
|
|

Ive. 6. Plasma layer between depths x, and x1
nith electron density N(x) and optical refractive
index n(x). The negative gradient of n causes
nonlinear (ponderomotive) forces (arrows) in the

space charge neutral plasma (Hora et al. 1967).

The force density f in a plasma ts given by
the classical thermal gas-dynamic pressure
p=3nRT/2 where m is particle density, & is
Boltzmann’s the
temperature, and given by the nonlinear

constant and = 7
force fx), due to electro-dynamic interaction

f= Vp + fy (1)

The nonlinear (optical corrected) nonlinear
force was derived from Maxwell’s stress
tensor with the optical refractive index n for
the stationary conditions from momentum
conservation (Hora 1969) and for the
general transient case with the unity tensor 1
and the electric E and magnetic field H of
the laser:

fy. = Ve(EE + HH — 0.5(B?+ H?)1 +
(1+(0/dt)/W0)(n2-1)EE]/(41T) — (0/dt)E
x H/(4TTc) (2)

from symmetry results (Hora 1985) for
the final equation of motion (1) being
Lorentz and gauge invariant (Rowlands

1990).

For simplified geometry with plane wave
laser interaction, Eq. (2) can be reduced to

fu). = — (/dx)(E2+H2)/(8TT)

— (W),/09)2(0/x)(E,2/n)/(16TT) (3)

For high accuracy evaluations following
the nonlinearity principle (Hora 2000) all
components of the stress tensor need to
be included (Cicchitelli et al. 1990). The
first expression is the basic relation with
the gradient of the electromagnetic energy
density and the second expression 1s
formally related to Kelvin’s
ponderomotive force, which was derived
for electrostatics without magnetic fields
and not for plasma properties. Following
Eg. (2), the nonlinear force dominates
over the thermal pressure, when the non-
relativistic oscillation (quiver) energy of
the electrons in the laser field exceeds the
thermal energy

Eosc = E?/(8T1x,.) > (3/2)a4T (4)
where E its the electric laser field and 7,,is

the critical electron density #, using the
real part of the refractive index in the

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

plasma n = (1 — W?/W,’)!/? which is zero
when the laser radian frequency W 1s
equal to the plasma frequency W),

(411 17,.e7/ m)'/? with the charge e and mass

m of the electron.

Cm Sec

VELOCITY

10°

E +H 8&2 [ces]

(
/
ee ee ee eee eee

-5O -30 -10 10 cf] 50 7)

— INTENSITY THICKNESS [um]

ome VELOCITY

Fig. 7. 10'° W/ cnr neodymium laser incident from
the right hand side on an initially 100 el hot very
low reflecting bi-Rayleigh deuterium plasma profile,
showing after 1.5ps interaction the electromagnetic
energy density (Lig. 3). The dynamic development
had accelerated the plasma block. of 20 vacuum wave
length thickness moving against the laser nith
velocities above 10° cm/s? and another into the

plasma (combining results from p. 178 &* 179 of

Ref Hora (1981)) nith > 10-%cm/& ultraligh

acceleration.

Using a general fluid-dynamic plasma-code
with collisions, — thermal — equipartition
between electron and ton temperature and
with pressures with inclusion of — the
nonlinear force, the numerical result of Fig.
7 was achieved (Flora et al. 1979a; Hora
1981, p. 179) showing an acceleration of
more than 10°? cm/s? of deuterium plasma
against the laser light. In 1980, ps laser
pulses with the high intensity were by far
not available. But there was another reason
that any experimental proof was impossible.
The computations were performed with
ideal plane geometry of the plasma target at
plane wave laser incidence. Just at the time

a ee ae ee Speen Sern Tver.

6

of the computations, the relativistic self-
focusing was discovered (Hora 1975) such
that any laser prepulse produced a plasma
plume which squeezed the intense laser
pulse to less than wave length diameter by
relativistic self-focusing with subsequent
very high ton acceleration into all directions
(Basov et al. 1986; Hauser et al. 1988).

The situation changed drastically after the
discovery of CPA (Strickland et al. 1986)
when ps and shorter laser pulses above ‘TW
(Mourou et al. 2006) or 2 PW power
(Cowan et al. 1999) were available. For
technical reasons to produce the pulses
without pre-pulses, their suppression by a
very high contrast ratio was necessary to
avoid the plasma plume. ‘his led to the
measurement of strange plasma
acceleration (alashinkov et al. 1994). A
very convincing clarification by Sauerbrey

some

(1996) was the measurement with similar
pulses from very high quality Krk laser of
10'S W/cm? laser intensity, where the
Doppler effect for the plasma front moving
against the laser beam perpendicular to the
target surtace showed an acceleration of
2x10 cm/s?. This was in the range of the
similar computer results with accelerations
of Fig. 6 (Hora 1981), the more detailed
evaluations (Hora et al. 2007a) were exactly
reproducing the measurement of Sauerbrey
if a dielectric swelling of the laser field ot a
factor 3 could be concluded, very similar to
the comparable results by Badziak et al.
(1999). The role of eliminating the pre-
pulse was measured in a splendid way by
Zhang et al. (1998) from the fact that the
usually observed very high intensity hard x-
rays at relativistic self-focusing were absent
when using extremely high contrast. But it
a ps pre-pulse was irradiated 70 ps betore
the main pulse, the x-rays were same as
usual. The 70ps were calculated for the
time to produce the plume. The repetition

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

of the Doppler-etfect measurement by
Sauerbrey needed extremely sophisticated
techniques and succeeded by Féldes et al.
(2000).

Sauerbrey (1996) underlined in the summary
of his paper in order not to be missed, that
his measurement of the nonlinear force
driven plasma block — as_ theoretically-
numerically expected since 1978 — was
100,000 times higher than any acceleration
measured before in a laboratory. On top of
the ultrahigh acceleration, a further result
was (Hora et al. 2002) that the space-charge
neutral plasma block consisted in an
ultrahigh ton current density, more than
million times higher than any accelerator
could produce. This plasma block had the
origin in the dielectrically strongly increased
skin depth of the interaction by the
nonlinear force. Its highly directed motion
was in contrast to the ion acceleration by
relativistic self-focusing which 1s going into
all directions (Basov et al. 1986; Hauser et
al. 1988). The directivity of the plasma
blocks was experimentally confirmed as well
as the plasma block behind the critical
density (see Fig. 6) moving into the laser
pulse direction (Badziak et al. 2004; Badziak
et al. 2004a).

This overview of the general physical
development of laser plasma interaction —
as topic of discussions with Jak Kelly —
explains not only how the points of
applications had been developed, beginning
with the work of radiation interaction
(Hhnckley etal 1979.7) 19c0) Voeine
generation of energetic tons (Kelly et al.
1979; 1980) by laser interaction with targets,
or the continuation for using as laser driven
ton sources of accelerators at CERN
(Haseroth et al. 1993; 1995). This was the
about the
worldwide large-scale developments how

topic of the discussions

127

lasers can lead to solve the problem of
alternative energy generation without
polluting the atmosphere with carbon
dioxide CO>. After years
developments, the just described discovery
of the ultrahigh acceleration of plasma
blocks led to an alternative method which
was summarized in cooperation with Jak
Kelly in a general article in a physics
mapazine (Hora et al 2009), are
summarized in the following section with an
update for the recent developments.

long

Prospects of Nuclear Energy without
Problems of Radioactive Radiation

‘The result of the ultrahigh acceleration of
plasma blocks offered the possibility for a
basically new scheme of generating low
cost, unlimited, safe nuclear fusion energy
and without the problems of generating
most dangerous nuclear radiation as
summarized by Jak Kelly (Hora et al. 2009).
This was explained in more details in due
course (Hora 2009; Hora et al. 2010; Miley
et al. 2011) and follows the attempt to use
the 10 million times more efficient nuclear
energy production than available by
chemical energy e.g., by burning coal,
however with the goal that the emission of
radioactive radiation including neutron
generation per gained energy has to be of a
lower value than from burning coal. This
goal of ignoring the problem of dangerous
radioactive radiation can be ignored, when
burning protons with the boron isotope 11
(HB11) as fusion fuel in contrast to the
usual fusion fuel of heavy and superheavy
deuterium D and trittum T (DT).

In view that the emission of carbon dioxide
into the atmosphere should be reduced by
more than 80% of the present value, the
need for alternative energy sources is of
highest priority. Nuclear energy from the
presently developed fission reactors 1s at

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

present the second largest energy source
while the managing of the radiation
especially of the waste from the reactors
and safety against unexpected incidents ts
solved to a very high degree but just not at a
total 100% solution. On the other hand,
energy from nuclear reaction processes 1s
extremely interesting because the gained
enetgy is more than 10 millon times higher
compared exothermal chemical
reactions. Despite an enormous amount of
research, the aim of a fusion power station

trom

with controlled generated nuclear fusion ts
not yet at the level of break-even, even not
yet for a power station with the easiest
fusion of (DT).

The most advanced DT fusion process 1s
that with nanosecond lasers pulses. If the
lasers are heating and compressing the fuel
to densities about 1000 times of the solid
state, the thermal based process involves
numerous losses and difficulties. The laser
energy conversion into electrons is delayed
by the collisions; then the thermal energy of
the electrons has to be transferred by
delaying equipartition processes into ton
energy whose pressure its then determining
the plasma dynamics. Instabilities and
radiation losses are unavoidable (Hora et al.
1998c, 1998d). Nevertheless, the extension
of all experiments with direct laser driving
and adiabatic volume ignition led to the
highest fusion gains (Hora 2013) and the
extension of the results to nanosecond laser
energy inputs of few megajoule from the
largest laser on earth (Moses et al. 2008;
Lind] et al. 2011; Haan et al. 2011) indicated
that breakeven may be reached where the
main advantage is the self-heat by the
generated alpha particles and some self
absorption of bremsstrahlung resulting in a
jump of the volume ignition (Hora et al.
1978; 1998). ‘The most studied indirect
drive spark ignition has still nearly 1000

8

times too low gains (Hora 2013) and the
self-heat is aimed tor a solution. But even tf

this would be

consider the completely harmless

solved and one would
final
reaction products, the intermediary large
amounts of neutrons, decaying with a half
life of 12 minutes into stable end-products
(electrons and water) have the problem of
handling the tritium in the reactor and what
during the 12 minutes life tme is happening
producing radioactive nuclei in the
environment (Vahir et al. 1999),
A dream reaction is known from the
beginning from the reaction of protons with
the boron-11 isotope as being absolute
clean. For the performance of laser driven
fusion by the mentioned thermal processes
by nanosecond laser pulses, compression to
100,000 times solids ts necessary and_ all
together this 1s about 100,000 times more
difficult than the just not yet achieved
thermal reaction with ns laser pulses.

The conditions are changing as it was
shown at least from several computations
from ditterent
advent of the

with about same _ results
approaches. With the
nonlinear force driven ultrahigh acceleration
of plasma blocks using ps laser pulses of
PW power, the side-on ignition of a fusion
flame in solid density fuel is possible now
after the development of the CPA
technique (Strickland et al. 1986; Mourou et
al. 2006). The side-on ignition was the
study by Chu (1972) and Bobin (1974)
where a laser pulse irradiating solid density
DT ts leading to ignite a fusion flame. The
computations of Chu resulted in the need
of a minimum energy flux of 4% 10% J/cm?
This condition was — far
possibilities in 1972 and laser driven fusion
energy followed the thermal compression
and ignition of DT by nanosecond laser
pulses (Moses et al. 2006; Lindl et al. 2011;

above — the

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Hora — Research cooperation with past president Jak Kelly

Haan et al. 2011). The conditions of
breakeven can well be reached by direct
drive volume ignition (Hora 2013) with 2
MJ nanosecond laser pulses due to a jump
in gain by the self-absorption of alphas
particles and by partial re-absorption of
bremsstrahlung. ‘This may now be a way
also for indirect drive spark ignition (Haan
et al. 2011).

Max lon Temperature with inhibition Factor

on

Collective Effect

0.15x10'° erg/em*

& ) er 2
¥ 0.1x10°~ ergcm
ic Soles Effec
Fis
- 415 2
0.05x10°~ erg/cm*
0
0 2 3 4 5 6 7 8

t in nsec

Figure 8. Dependence of DT plasma temperature T
on time ¢ after igniting by a ps deposition energy flux
F:* given as the parameter to produce a fuston flame,
generalizing the computations of Chu (1972) by
using the collective effect for the alpha particle
stopping and the inbibition factor for varying
parameter of input energy flux density E*. lenition
is reached only above such E:* where the temperature
T does not decay on time t (Hora et al. 2008)

An improvement of the flame ignition
following Chu (1972) with updating of later
discovered phenomena (Hora et al. 2008)
(Fig. 8), arrived at the improved threshold
for ignition of solid density DT-fusion of

B* > 2X10" J/om? (5).
The result of the ultrahigh acceleration of

plasma blocks (Hora 1981) when using
CPA generated ps high intensity laser pulses

129

(Sauerbrey 1996) led to the possibility (Hora
2009) to ignite solid density DT with laser
energy fluxes above __ petawatt/cm?,
calculated for plane geometry (about other

geometries, see below).

Max ton Tem peraure without intibition factor and Collective effect
2x10" ergiom

TinkeV

8 8 6 $$ 8 32 8 8

a 5 at) 15
Lin nsec

Eieure 9. Tensperature dependence on time t of the

Juston flames for p-'B (HB11) under the same

assumptions of Chu (1972) for comparison mith
DT fusion. The 20-times reduction of E:* (Hora et
al. 2008) is not included and the alpha stopping ts
as in the DT case only by electrons (Hora et al.
2009). The ton stopping with an avalanche of
secondary production of alpha particles will lead to a
much higher fusion gain for L1B11 (Hora 2012).

When the positive result for DT was
applied to compute the case of HB11, it was
rather surprising, Fig. 9, that the threshold
for the side-on ignition was only 5 to 10
times more difficult than for DT (and not
100,000 times) (Hora 2009, Hora et al.
2009, 2010; Li 2010; Miley et al. 2011). On
top, these computations were based on the
Gabor collective alpha-stopping powers
with electrons only as in the case of DT.
The fusion gains will be dramatically
increased if the alpha stoping includes the
secondary ion interactions, where the
resulting alpha particles all had the same
energy of 2.88 MeV. When these alphas are
colliding with boron nuclei, central
collisions transfer 630 keV energy. This
energy is in the wide range of an exceptional

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Hora — Research cooperation with past president Jak Kelly

very large reaction cross section leading to a
second boron reaction with a_ proton
nucleus to produce three new alphas.

This multiplying avalanche reaction of the
alphas can produce a gain very much higher
than the gain from DT with the possibility
to lead to an ideal burning of the fuel until
exhaustion, depending of the detailed
plasma fluid dynamics of the fuel after the
ps-laser-pulse initiation of the fusion flame.
The only bottleneck ts the ignition by a laser
fusion energy flux density of which at
present it can be assumed that this 1s in the
range of that for DT, Eq. (5), because this is
a 2-dimensional process while the avalanche
process is 3-dimensional.

er

~
AG

Figure 10. For a new desien ICAN (Mouron et al.
2013) of a CPA laser for pulses shorter than 1 ps
and with powers of Petawatt to E:xawatt and
higher, the use of fibres is being designed with an
initial partial section for demonstration of highest
quality laser pulses on comparably low casts. The
beam output of the fibre bundle irradiating a
Jocusing mirror 6 has diffraction limited quality for
focusing to highest intensities. It is expected
(Mourou 2013) that a cross section of 100 cnr ps
laser beam may be produced nith k] energy pulse
corresponding to a Petawatt power.

The comparison between DT and HB11
for plane geometry and without the alpha-
avalanche was only a first step of the
computations (Hora 2009, Hora et al. 2009).
What has not been included is that in the
case of a fusion power station, only a
(comparably large) section of plane
geometry can be used for the interaction. A

130

cylindrical section will suffer from lateral
losses of energy and_ particles.
possibility to overcome this ts to confine the
cylindrical reaction by very large cylindrical
magnetic fields (Moustaizis et al. 2003) after
the shock processes in the fuel got under
control in details from general plasma-
hydrodynamics (Lalousis et al. 2013). This
may be possible with the now available
cylindrical magnetic fields above 10 kilotesla
(Fujioka et al. 2013).
change from plane into spherical irradiation
fronts (Hora et al. 2012; Moustaizis et al.
2013). In this case, however, ps laser pulses
with a power above 100 PW are needed. 2
PW were achieved in 1999 (Cowan et al.
1999) and the level of 7 PW was reached in
2013. After the new scheme with fibre-
optics accelerators ICAN (Mourou et al.
2013) in Fig. 10 can produce PW highest
quality laser pulses at a cross section of 100
cm’, a spherical irradiation of one meter
radius may produce more than 900 PW
laser pulses of 1 ps duration spherically
propagating to extreme high intensities, see
Fig. 11.

One

Another way is to

The conditions for initiating a spherical
HB11 reaction depend on the result of Eq.
(5) where a possibility may be to work with
lower energy flux densities due to a small
degree of avalanche alpha processes. ‘The
chance for this reduction, however, may be
rather limited, because the initiation process
in the ps range may be too short. ‘The
following evaluations are realistically based
on the limit of Eq. (5) needing the operation
with Exawatt laser pulses, though the total
reaction efficiencies can be considerably
much better than for DT. First evaluations
resulted in gains of about 80 when
generating 100 MJ fusion energy that up to
95% of which electrostatic conversion into
electric power may be used. GW power
stations may operate with less than about 15

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Hora — Research cooperation with past president Jak Kelly

Hz sequence of shots. ‘The main advantage
of working with sub-ps laser pulses consists
in the collective conversion (Hora 2013a) of
laser energy into macroscopic motion of the
plasma blocks nearly without thermal losses
in contrast to the spherical thermal
compression and ignition of DT plasma
being close to break-even (Hora 2013, Hora
et al. 2013).

Figure 11. Combining the fibre output of an
ICAN laser (Fig. 10) to a sphere (1) of more than
1m radius may produce a converging spherical laser
pulse of Tps duration and Exawatt power for
interaction on a sphere 3 in the centre. Apart from
diffraction limited beams mith intensities above 10°
W/cm for the application of HB11 fusion, the
radius of sphere 3 can be in the range of 0.1
millimetre for producing nuclear energy in the range
of 100 M] free of neutrons and with less
radioactivity per gained energy than from burning
coal.

This is the present status for potential
realization of BH11 power stations as
envisaged by Jak Kelly (Hora et al. 2009)
following the comment of an expert in
nuclear fusion at the Lawrence Livermore
National Laboratory in California, S.W.
Haan (2010) “This has the potential to be
the best route to fusion energy”.

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131

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Hora — Research cooperation with past president Jak Kelly

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SSrS5

135

Journal and Proceedings of the Royal Soctety of New South Wales, vol. 146, nos. 449 & 450, pp. 136-141.

ISSN 0035-9173/13/020136-6.

Jak Kelly Award Winner, 2012

Highly Charged Ions and the Search for the Variation of

Fundamental Constants

Andrew Ong’

School of Physics, University of New South Wales, Sydney, NSW 2052, Australia

* Corresponding author.
E-mail: ong.andrew(@email.com

Abstract

We discuss the search for a variation in the fine-structure constant & using highly-charged ions. In

particular, we examine how highly-charged ions could be used to construct highly-accurate atomic clocks

that could be used to detect the terrestrial variation of & due to the motion of the solar system relative to

the observed “Q-dipole”’.

Furthermore, we show that highly-charged Fe and Ni tons in G191-B2B, a

white-dwarf star could be used to probe non-linearities in the possible coupling of Q&-wariation to the

gravitational scalar potential.

Introduction

The idea to search for a variation in the
constants of physics is not a new one. In
fact, Dirac’s Large Number Hypothesis was
probably the progenitor of our fascination
with the possible non-constancy of our
physical constants (Dirac, 1937).

A measured variation in a constant with
dimensions (units) 1s impossible — to
distinguish from a variation in the
dimensions themselves. Therefore, we will
limit our discussion to the dimensionless
constants, namely, the _ fine-structure
constant, a =e /hc ~ 1/137. Here e@ is
the electron charge, fi is the reduced
Planck constant, and ¢ 1s the speed of light.

The fine-structure constant is a physical
constant that characterises the strength of
the electromagnetic interaction. Analogies
exist, such as a, ~107*, which characterises
the strength of the gravitational interaction.
As gravity is a much weaker interaction

136

compared to electromagnetism, we see that
a, is very much smaller than @ .

‘The quasar absorption spectra analysed by

Webb et al. (2011) using data collected from
the Keck and Very Large Telescopes (King
et al., 2012) suggests that the fine-structure
constant @ takes on a gradient of values
across the sky. This result has come to be
known as the “Australian dipole” (Berengut
and Flambaum, 2012).

Due to the motion of the Sun relative to the
measured dipole (towards a region of larger
X), the spatial gradient translates to a
temporal variation ot around
ala~1l0°™-10°" yr! to an Earth-based
observer, with a further small modulation
incurred by the annual motion of the Earth
around the Sun.

In order to detect this possible temporal
variation, we turn to the most accurate
instruments ever built — atomic clocks. The

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Ong — Variation of fundamental constants

best current limit on terrestrial Q-wvariation
of ala ~ (1.6 +2.3)x 10 yr"!
obtained by Rosenband et al. in 2008 by
comparing Hg* and <Al* optical atomic
clocks. In their experiment, the transition
used in the Hg* clock is strongly dependent
on the value of @ , whereas the transition
used in the Al ts relatively insensitive.

Was

As we note, their experimental result still
falls about two orders of magnitude short of
detecting the level of Q-variation as
predicted trom astronomy. To confirm the
dipole model of Q-variation thus requires
finding more sensitive systems, which ts
parameterised for an energy level within an
atom or ion by

dw

ans (1)

G=
/ dx

where y=(a/a,) -1 is the (small)

fractional change in @* from its present
value of a. Systems known to have large
q values include optical clocks in Yb"
(Porsev et al., 2009) and Th** (Flambaum
and Porsev, 2009). In: sfact, can
approximation for the sensitivity in Eq. (1)
may be written as (Dzuba et al., 1999)

(Za) 2)

where Z is the charge of the atom or ton,
Pons the

the 1onization energy, v ts

effective principal quantum number, and

is the angular momentum of the energy
level.

From Eq. (2), we see quickly why tons such
as Yb* and Th** would be more sensitive to
a variation in @ — they possess combination
of a larger nuclear charge and ionization

137

energy compared to lighter ions such as Al*
and Hg*. In general, the more highly-
charged the ton, the greater its sensitivity to
a variation in @ — a guiding principle we
will use when searching for the most
sensitive system later.

Eq. (2) can also be applied to searches for
Q-variation in astrophysical systems. By
using spectral lines of highly-charged ions,
we should be able to place more stringent
limits on Q-variation.

Flambaum and Shuryak (2007) suggest that
the underlying mechanism for the variation
of fundamental constants may be the
coupling of the constants to scalar fields.
An example of scalar fields is the
gravitational potential. Highly-charged ions
observed in systems with a much different
gravitational potential than that available on
Earth, such as white-dwarf stars, could be
used to investigate such theories.

Level Crossings

As electrons are removed from atoms, the
energy of transitions usually quickly grows
out of the range of optical lasers. This
necessitates the use of different types of
spectroscopy, which can be up to 10 orders
of magnitude less precise than optical
spectroscopy, simply because optical
spectroscopy is well-studied and widely used
in the large majority of existing atomic
clocks. Any gains in sensitivity to the
variation of constants by using highly
charged ions would quickly disappear unless
a way to mitigate this problem ts found.
Thankfully, the phenomenon of level
crossings may be used to solve this tssue
(Berengut et al., 2010).

A level crossing is the energy-reordering of
two or more atomic levels within an atom

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Ong — Variation of fundamental constants

or ion when one or more parameters are
changed. This occurs because the ordering
of energy levels initially follows the
Madelung (periodic table) filing order. As
electrons are removed from the atom, it
begins to increasingly resemble atomic
hydrogen, albeit with a larger nuclear
charge. However, the order of energy levels
in atomic hydrogen differs from that
predicted by the Madelung filling scheme.
This implies that upon removing a sufficient
number of electrons from an atom, its
energy levels will be reordered so as to
reflect the energy level ordering in atomic
hydrogen — a level crossing!

For ions near such level crossing points, the
energy of transition of electrons between
the crossing levels is small, and we find that
optical transitions exist even in these highly-
charged ions (see Figure 1). ‘Therefore, by
identifying ions near level crossings, we are
able to preserve the gains in sensitivity to O-
variation from using highly-charged tons
and at the same time, retain the use of
highly accurate optical spectroscopy.

-1000000

-3000000
~4000000

-5000000

60
Charge

50 55 65

Figure 1: The energy of the 4f and 5s atomic
orbitals for a 62 electron system against nuclear
charge Z. The ordering of the energy levels switch
near Z='77.

70

138

Systematic effects in highly-charged
ions

To achieve high-accuracy using atomic

clocks in laboratories, experimentalists need

to account for the systematic effects that

affect the their
transitions very carefully. I ixamples of such

frequency of atomic
effects that are routinely taken into account
are the blackbody radiation shift, which
accounts for the non-zero temperature of
the system, and clectromagnetic
which cause Stark and Zeeman shifts.

fields

There are two good parameterizations to
describe a system’s evolution from and
towards the regime of highly-charged tons:
isonuclear sequences (the number
electrons changes) — or
sequences (the number of protons changes).

ot

isoelectronic

Whilst isonuclear sequences are how such
1ons would be produced tn a laboratory, we
find isoelectronic — sequences
convenient for — they
straightforward comparisons of fixed energy
levels.

more

allow more

One further point to note is that the while
the 1on charge Z, is a whole number, the

external electrons that we are interested in
“see” a screened (etfective) charge Z_,
instead. Relativistic effects would instead
depend on the unscreened nuclear charge

Z. One may turn to tables for values of
Z. to obtain estimates tor these
systematics.

The general trend is that the size of
systematics tends to be much smaller than
they would be for neutral atoms. This ts
because the electrons are more tghtly
bound to the nucleus, resulting in the
relative size of external effects being much
smaller when compared to the tighter
binding.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Ong — Variation of tundamental constants

‘Table 1: Scaling laws for highly-charged tons
for various sources of systematic shifts 1n
atomic clocks.

Eftect Scaling
2.4 order Stark shift Po Are,
a
Blackbody shift a Ae
° a

2"! order Zeeman shift — Suppressed
Electric quadrupole Pita BW Aa
a

shift
Fine-structure

~Z°Z? (Z, +1)
~ ZZ (Z, +1)

I lypertine A coetf.

Californium — the basis for a
superior atomic clock

Based on our findings, we have identified
highly-charged calitorntum tons, Cf! and
Ct'"*, as the most promising candidates for
building atomic clocks that are both highly
accurate and sensitive to the variation of &
(Berengut et al., 2012). Californtum is one
of the heaviest elements with relatively long-
lived isotopes that can be practically utilized
in an atomic clock — this assures us the large
charge and tonization energy as required for
a large sensitivity in accordance with Eq. (2).

The lowest-lving energy levels as calculated
using configuration interacton and many-
body perturbation theory for Cf are
presented in Table 2. We see that the ion ts
near the 5f-6p level crossing, as the energies
of the transitions between the two orbitals
are well within the range of optical lasers.
‘Table 2 also reveals that the transitions with
the largest sensitivities to Q-variation are
two electron transitions between 5f states
and 6p? (the g value of a transition ts simply
the difference between the g values of the
upper and lower levels) — of which the
strongest are E2 and M1 transitions (QJ is at
most 2). For comparison, the sensitivities
of the transitions used in the Hg+ clock is ¢

139

~ 50000 cm', thus Cf! can potentially
provide a factor of 13 improvement over
the current-day best limits on Q-variation.

‘Table 2: Selected energy levels of Cf!®+ and
their sensitivities to &-variation g.
Configuration Energy

q [cm
[cm]

5£6p! 3 0 0
6p 0 5267 370928
5£6p! 2 6104 106124
5 4 9711 414876
5£6p' 4 24481 162126
5f 2 24483 354444
5f6p' 3 25025 59395
5f 5 29588 451455

Fe" and Ni** in White Dwarves

In this section, we will examine how highly-
charged tons can be used to probe the
relationship between the — gravitational
potential and the variation of & (Maguijo et
al., 2002). Theories (Berengut et al. 2013)
write

Ag =k: Al elie 20)
a rc.

for a dimensionless gravitational potential

A@ and a proportionality constant K,, .

Existing studies of the relationship between
the variation of constants and their coupling
to the gravitational scalar potential has been
liamited to LE arth-based studies. These
studies rely on the ellipticity in the Earth’s
orbit, which gives a 3°% seasonal variation in
the potential at Earth due to the Sun. Due

to the high precision of atomic clocks, k a

can be determined despite the small
variation in the gravitational potential @ .

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Ong — Variation of fundamental constants

The observation of Fet* and Ni** spectral
lines in G191-B2B using the Hubble Space
Telescope Space ‘Telescope Imaging
Spectrograph presents an opportunity to
probe Eq. (3) in the regime of a much
stronger gravitational potential — about 5
orders of magnitude larger.

This not only allows us to verify the
coupling as described by Eq. (3), but it also
allows us to probe any non-linearities that
may atise in the coupling of @ to @ which
certain models predict (Bekenstein, 1982).

Fe*+* and Ni** also have relatively high ton
charges — referring against to Eq. (2), any
limits we place on Q-variation using these
ions would have an advantage over other
spectra due to the innately higher
sensitivities these transitions have to @. At
the moment, our analysis of the results has
been mainly limited by the lack of accuracy
in the laboratory-measured spectra for these
ions, which are needed to provide a
reference for calculating the shift in relative
positions of the lines in the astronomical
spectra. The results as shown tn Figure 2
reveal that the Q-variation in G191-B2B its
consistent with zero at the 1.050 level.

Conclusion

The use of highly-charged tons in the search
for the variation of fundamental constants
has been shown to have much potential.
Atomic clocks based on highly-charged tons
would not only be highly-sensitive to a
variation in the fine-structure constant, but
would also result 1n more accurate clocks
with smaller systematic errors. — Highly-
charged iron and nickel tons in white-dwarf
stars also have the potential to probe the
telationship between the gravitational
potential and the variation of constants.

140

enna

squares). The slope of the lines give
Aa/a =(4.2 1.6) x 10” for Fe and
Aala =(-6.1+5.8) x10” for Ni, respective.

References

Berengut, J. C., Dzuba, V. A., and Flambaum, V.
V. (2010) Enhanced Laboratory Sensitivity to
Variation of the Fine-Structure Constant using
Highly Charged Ions; Physiwal Review Letters,
105, 120801.

Berengut, ]. C., Dzuba, V. A., Flambaum, V. V.,
and Ong, A. (2012) Optical Transitions in
Highly Charged Californium Ions with High
Sensitivity to Variation of the Fine-Structure
Constant; Phystal Reriew Letters, 109, 070802.

Berengut, ]. C. and Flambaum, V. V. (2012)
Manifestations of a spatial variation of
fundamental constants in atomic and nuclear
clocks, Oklo, meteorites, and cosmological
phenomena; Exrop/ysics Letters, 97, 20000.

Berengut, J. C., Flambaum, V. V., Ong, A.,
Webb, J. K., Barrow, J. D., Barstow, M. A.,
Preval, S. P., and Holberg, J. B. (2013) Limits
on the Dependence of the Fine-Structure
Constant on Gravitational Potential from
White-Dwarf Spectra; Physical Revien Letters,
111, 010801.

Bekenstein, ]. D. (1982) Fine-structure constant:
Is it really a constant?; Physical Revie D, 25,
1527-1539.

Dirac, P. A. M. (1937) The Cosmological
Constants; Natwe, 139, 323.

Dzuba, V. A., Flambaum, V. V., and Webb, J. K.
(1999) Space-Time Variation of Physical

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Ong — Variation of fundamental constants

Constants and Relativistic Corrections in
Atoms; Physical Review Letters, 82, 888-891.

Flambaum, V. V. and S. G. Porsev (2009)
Enhanced sensitivity to the fine-structure-
constant variation in the Th IV atomic clock
transition; Physical Rertew A, 80, 064502.

Flambaum, V. V. and Shuryak, E. V. (2007)
How changing physical constants and violation
of local position invariance may occur?; AIP
Conference Proceedings, 995, 1-11

King, J. A., Webb, J. K., Murphy, M. 'T.,
Flambaum, V. V., Carswell, R. F., Bainbridge,
M. B., Wilezynska, M. R., and Koch, F. E.
(2012) Spatial variation in the fine-structure
constant — new results from VLT/UVES;
Monthly Notices of the Royal Astronomical Society,
42?) 3370-3412.

Magueyjo, J., Barrow, J. D., and Sandvik, H.
(2002) Is it e or is it c? Experimental tests of
varying alpha; Physis Letters B, 549, 284-289.

Andrew One

Received 16 July 2013, Accepted 8 August 2013.

Porsev, S$. G., Flambaum, V. V., and Torgerson,
J. R. (2009) Transition frequency shifts with
fine-structure constant variation for Yb II;
Physical Review A, 80, 042503.

Rosenband, T., Hume, D. B., Schmidt, P. O.,
Chou, C. W., Brusch, A. Lorini, L., Oskay, W.
H., Drullinger, R. E., Fortier, T. M., Stalnaker,
J. E., Diddams, S. A., Swann, W. C., Newbury,
N. R., Itano, W. M., Wineland, D. J. and
Bergquist, ]. C. (2008) Frequency Ratio of Al+
and He+ Single-lon Optical Clocks;
Metrology at the 17th Decimal Place; Science,
319, 1808-1812.

Webb, J. K., King, J. A., Murphy, M. T.,
Flambaum, V. V., Carswell, R. F., Bainbridge,
M. B. (2011) Indications of a Spatial Variation
of the Fine Structure Constant; Physical Review
Letters, 107, 191101.

Andrew Ong is a PhD student at the School of Physics, University of New South Wales.
He earned a Bachelor of Science (Adv. Science) at the same university and was also awarded
the University Medal for achieving excellence in his undergraduate career. In his Honours
year he studied the charge density of the neutron, proving it to be non-zero. His current
interests lie in the field of Atomic Physics. Andrew was the Society’s Jak Kelly award winner
for 2012, awarded to the best student physics presentation at a joint meeting with the

Australian Institute of Physics (AIP).

14]

Journal and Proceedings of the Royal Soctety of Nem South Wales, vol. 146, nos. 449 & 450, pp. 142-152.

ISSN 0035-9173/13/020142-11.

Some aspects of the scientific development and
astronomical research of Penny Sackett

Ragbir Bhathal”

School of Computing, Engineering and Mathematics, University of Western Sydney, Locked Bag 1797,
Penrith South NSW 2751.

* Corresponding author.
E-mail: r.bhathal(@uws.edu.au

Abstract
Penny Sackett was the Director of the Research School for Astronomy and Astrophysics at the

Australian National University from 2002 to 2007 and 1s currently an Adjunct Professor at the same

institution. She has made several significant contributions to dark matter in galaxies, galactic structure,

microlensing and the search and characterisation of extrasolar planets. This paper looks at some

aspects of the trajectory that led her to being appointed the Director of Mount Stromlo Observatory,

one of Australia’s internationally well known scientific institutions.

Keywords: Extrasolar planets, dark matter, galaxies, large optical telescopes

Introduction
Penny Sackett had a remarkable career that
spanned three continents, viz: America,
Europe and Australia. She belongs to a
select group of scientific nomads who cross
national
intellectual pursuit of the moving frontiers
of astrophysics. She was the first woman

borders seamlessly in the

scientist to become the Director of a major
astronomical institution in Australia. She
took over the Directorship of Mount
Stromlo Observatory in July 2002. She was
no stranger to Australia, as she had visited
the country previously on her observation
runs associated with her projects at the
Anglo-Australian Observatory. What
prompted her to apply for the Directorship,
she said, “was the reputation of the people
that worked there and also because of the
place it held in world astronomy”. She
came with a vision. According to her, “The

142

faculty that I inherited was stunning. You
know, Bessell, Freeman, Peterson, Norris,
Dopita and Schmidt. They were absolutely
first rate, splendid teachers almost to a
person and so really it was a matter of
trying to reinvigorate that with some
younger blood as well and watch the
tradition continue”.

Tragedy

However, even before she had time to
settle down into her new job, tragedy
struck. It was on a hot summers day on 18
January 2003 that fires engulfed Mount
Stromlo and the Observatory. It was the
most terrible catastrophe to befall the
institution. ‘The fires were so severe that
they left a trail of devastation that had
never been seen before. Only the charred
remains of the once magnificent telescopes
stood as silent witnesses in their burnt out
domes including the $4 million Near Intra-

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red Field Spectrograph (NIFS) that was
undergoing final testing before being
shipped to the Gemini North Telescope in
Hawait had been turned into a blackened
melted mass. According to Sackett, “When
the damage was assessed it was clear that
we had lost all our research facilities — that
is, all of our research telescopes on the
mountain, all of our library facilities, and

our workshop where we had built
instruments for our telescopes and
telescopes for other organisations”. It was

for Sackett and a lesser
probably
his/her hat in and walked away. She stood
her ground and began the rebuilding
process with great determination and
courage. She had to deal with a number of
challenging and frustrating issues that not

a difficult time

person would have thrown

only involved the recalcitrant insurers, the
keepers of the national heritage and statf
morale. “The university put up some of its
funds promptly, and the — Federal
government also gave $7.3 million to help
us rebuild the workshops. So we were very
eratetul for that. That was probably the
biggest issue, at least at the beginning’, she
said. The heritage issues were resolved
with “really excellent compromises” so that
a modern institution could operate within
the constraints of a heritage listed building.
As tor staff morale, she continued, “TI think
as time went on, what became difficult was
managing staff morale, because after the
fire most people had, this sense of fight in
them, that no, we’re not going to let this get
us down. No, this is not the end of Mount
But
rebuilding began to take much longer than
people had anticipated, and when the
insurance agencies were recalcitrant, it
became a little bit harder to keep staff
morale up”.

Stromlo C )bservatory. when the

143

Nevertheless, she pushed on. After the
fires Sackett drew up a strategic plan for the
years 2003 to 2007 in consultation with the
staff to decide where the Observatory
should be heading. This included, she said,
“things like developing new leadership roles
in the next generation of telescopes,
increasing the number of graduate students
that came to Mount Stromlo, increasing the
efficiency of the telescopes at Siding Spring
and supporting those that were most
productive, expanding the breadth of the
knowledge of the faculty, and maintaining
and growing our instrumental and astro-
engineering capacity”.

Finding an astronomical niche

Sackett had arrived at Mount Stromlo with
a track record of astronomical research and
highly cited publications. Born in the small
town of Lincoln, Nebraska she excelled in
her studies at school and according to her,
her secondary school physics teacher, “was
instrumental in opening my eyes to the
beauty and ubiquity, I would say, of
physics, and without him I certainly would
not have trained in physics later. He in fact
taught us calculus just as a means to
understand more physics”. Her parents
had only been trained at a vocational level
and as they had not attended a university
they were of not much help in guiding her
in her career choice. However, her mother,
she said, “was adamant about one thing,
and that was that I should be trained in a
way that I could earn my own living” and
there was an expectation on the part of her
parents that she would go to university.
Having won a scholarship she attended the
University of Nebraska in Omaha and as
she went through university her “physics
instructors became adamant that I should
pursue a higher degree, which I hadn’t
thought of when I entered university”, she
said. After completing her undergraduate

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studies she enrolled for a PhD at the
University of Pittsburgh which, according
to Sackett, “was particularly well known at
that time for its program in relativity and it
had some very high powered general
relativists”. After graduating with a PhD in
theoretical physics in 1984 from the
University of Pittsburgh, it took her
sometime to find a niche for herself. She
completed her postgraduate studies at a
time when there were very few women
physicists in the US. It was difficult for
women physicists to get jobs. Linda
Schiebinger, a historian of science at
Pennsylvania University notes that even as
late as 1996 in the US the unemployment
rate for women PhD physicists remained
twice that of male peers (3.8°% compared
with 1.9%) after controlling for job
experiences (Schiebinger 1999). According
to Sackett, “It was difficult because there
weren't very many women in physics. I
think too that the networking opportunities
simply weren’t there. In general women
were not mentored in the same way that
men were mentored with respect to finding
a job”. There also seems to have been
some prejudice against women in a highly
male dominated discipline. The
locker room mentality was still prevalent in
the US academic circles. In fact, this was
also the case in Australian academic circles
in the 1980s (Bhathal 1999). Sackett gives
us a classic example of this. According to
her, “I remember particularly once a
famous scientist coming to visit when I was

male

in graduate school, and the male graduate
students were asked to go out to dinner
with him, but I was asked to babysit one of
the faculty’s children so that he could go. I
didn’t do the babysitting, but then I didn’t
go to dinner either”.

She worked at a number of jobs, viz: as a
science journalist for Science News, as a

144

teacher at Amherst College — a privately

funded college attended by many of
America’s privileged minority, as a
researcher at the Biological Sciences

Department at the University of Pittsburgh
and as a Program Officer at the National
Science Foundation. Her breakthrough
came when she won a small grant to study
at the Kapteyn Astronomical Institute in
the Netherlands, one of the major centres

of — astronomical research in the
Netherlands. Some of the well known
astronomers when she was there were

Stuart Pottasch who was known for his
work on planetary nebulae, and Renzo
Sancisi and ‘Tjeerd van Albada who were
internationally recognised for their work on
the distribution of dark matter in galaxies.
The short stint provided her with the
transition from being a theoretical physicist
to becoming an observational astronomer.

Later her two years (1992 — 1994) at the
Institute of Advanced Study at Princeton
helped her to begin tying together several
elements that she was interested in, viz: the
structure and dynamics of galaxies which
were related to dark matter. “And one
way’, she said, “to study dark matter ts
through microlensing. So all of
connections were sort of forged while I was
at the Institute for Advanced Study in
Princeton”’. Princeton was
“extraordinarily important to me”. It
provided her with a springboard for the
work she was going to do at the Kapteyn

these

she — said

Institute where she worked for the next
The work she did
centred exclusively around microlensing. It
was during her time at Princeton that she
realized “through the work of Bohdan
Paczynski and Andy Gould _ that
microlensing could be a way to look for
planets, and only — the

MACHOS Compact

seven vears. there

so-called

Halo

noc
(Massive

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Objects) that [were thought to] make up
dark matter’. So this was the direction she
began to increasingly explore when she was
at the Kapteyn Institute.

Extrasolar planets

Extrasolar planets around a Sun-like star
were first y the Swiss
astronomers Michel Mayor and Didier
Queloz in 1995. Mayor and Didier were
hailed as the Galileo’s of the 20% century
and they opened up an area of research
which and
competitive. The method they had used ts
called the radial velocity or the Doppler
technique. The more direct method is
called the transit technique. In this
technique the astronomers look for planets
that partially eclipse the star that they are
orbiting. This causes a temporary but
periodic dip in the brightness of the parent
However, Sackett employed the
gravitational microlensing technique to
search for extrasolar planets. It is based on
the tact that eravity affects light, an idea
Unlike the
microlensing method which is a statistical
technique that can tell you about the planet
population the Doppler
technique is a better method for studying
individual planets. This is also true of the
transit technique.

discovered by

has become very active

Star.

that originated from Einstein.

as a_ whole,

According to Sackett, “Gravity not only
attects objects with mass, but it affects
light. It can actually cause light to bend.
And so when a massive object sits between
a luminous object that’s emitting light and a
detector (an astronomer with a telescope) it
can change the path of that light in such a
way that more light reaches the observer
than otherwise because
there’s some massive object. sitting in-
between. And that massive object is called

would, simply

a microlens, and you can think of it most

145

often as just a normal star somewhere in
the galaxy. It might be a star we can see, or
it might be one we can’t. If that star has a
planet orbiting it, then the gravitational
field will not just be the gravitational field
of the star but the gravitational field of the
star plus the planet. It’s not so important
that the field is stronger, because after all
the planet is just a tiny fraction of the total
mass of the star, but the distribution of that
gravitational field is different. And that
means that as a bright object such as a
background star sends its light to the
telescope, and it’s moving as it does so
because everything in the galaxy moves, it
probes different parts of this gravitational
field, which looks different in different
places because of the presence of the
planet. We can do what’s called ‘inverting’
that problem by taking the light curve that
we observe with the telescope and deducing
what the gravitational field must have been,
and in particular whether it was due to a
planet orbiting a star. The remarkable thing
about microlensing is that you don’t even
have to see the star that the planet is
orbiting in order to detect planets. You're
using the natural effect of the lensing that
Einstein talked about to create a telescope
that 1s more powerful than the ones you

actually have available to you here on
Earth’’.

In the same year (1995) that Michel Mayor
and Didier Queloz discovered the first
planet going around a normal star, Sackett
formed the PLANET collaboration which
consisted of astronomers from various
parts of the world to provide continuous
time coverage. One of her motivations for
forming this team was the “possibility of
being the first to detect an extrasolar
planet”, Sackett, said. However, the
honour was to go to Mayor and Didier.
Her second reason for getting involved in

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this venture was the fact that through
studying dark matter she and _ her
collaborators were confident that they
could understand the microlensing signal.
The chance to find out whether they
understood the microlensing technique in
their search for extrasolar planets came
from their observations of the binary
microlens MACHO-1997—BLG-—41.
According to Sackett, when they analysed
their data they found that what they were
seeing was “not a planet and a star but a
double star system” (Albrow et al. 1998).
By itself this was not extraordinary. What
was extraordinary was the fact that they

could “deduce this just from the
microlensing light curve alone”. This gave
them confidence in their ability to

understand and use the technique.

Ten years after she founded the PLANET
collaboration, Sackett and her colleagues
discovered a cool planet 5.5 Earth masses
through gravitational lensing (Beaulieu et al.
2000). This discovery, she said, took them
ten years rather than the five that she had
hoped. It was an exciting discovery since
up to that time no planet that was more like
an Earth-like planet had been found. Most
of the planets that had been discovered up
until this time, she said, “were 100 to 300
times the Earth’s mass”. With the advent
of the Kepler mission many more potential
planets have been found that are more
Earth-size. Since the last Kepler catalogue
2012 the |
candidates discovered in the Kepler data
now totals 2740 potential planets orbiting
2036 stars. The most dramatic increases
are seen in the number of Earth-size and
super Earth-size candidates discovered,
which grew by 43% and 21% respectively.

was released in number

Dark matter
Her observations of MACHO-98-SMC-1 in

of

146

the Small Magellanic Cloud provided an
interesting insight into MACHO (Massive
Compact Halo Objects) events and dark
matter. At the time they were doing this
research, one of the big questions that
microlensing was expected to answer was
whether the dark matter was made up of
small, compact objects, such as dead stars
or Jupiters or some unknown objects that
could cause a microlensing event. Many
astronomers at that time were looking at
stars in the Magellanic Clouds and secing
whether the light from them exhibited a
microlensing curve as if there was a dark,
unseen microlens between the observer and
the Clouds. | Whenever they recetved
warning from microlensing teams that a
microlensing event was in progress, they
could immediately turn their telescopes to
it. In the case of MACHO-98-SMC-1, they
obtained an absolutely stunning light curve,
Sackett said. According to her, “this was
good enough for us to detect small things
in this light curve that weren’t (at least at
that time) typically observed. And _ those
included being able to tell when one part of
the background star passed a_ particular
point in the gravitational pattern, compared
different
This allowed them to measure

to when a part of the. star
crossed”’.
among other things the proper motion of
the microlensing event. What they found,
she said, “that alas, in this particular event,
it wasn’t some mysterious dark matter that
was causing the microlensing, it was in fact
a typical star in the Magellanic Clouds”

(Altonson et al. 2006).

A lot of hard work goes on into researching
a problem. Quite often one goes down
wrong paths and dead ends. However,
sometimes one is rewarded like Archimedes
with a Eureka or “aha” moment. ‘This
happened to Sackett. According to her, “‘it
relates back to this problem of dark matter

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— it had been suggested by some that
indeed the dark matter in our Galaxy must
be form of these MACHOs
(Compact Halo Objects) — that
microlensing, and that in fact a colour

in the

cause

magnitude diagram would actually show the
population of these objects, some of which
were stars. Now, what I mean by a colour
magnitude diagram is that you plot the
brightness of the star on one axis and the
colour on the other, and if the objects are
all the same age and same distance, then
there’ll be a pattern that develops on this
plot that’s quite characteristic. But if some
of the stars are a little bit closer, and
therefore, say, not in the Magellanic Clouds
but between us and the Magellanic Clouds,
then they would show up at a slightly
different place on the colour magnitude
And it was proposed that
something like this was actually seen’.
There
suggestion bothered Sackett. “It was such a
simple idea. It seemed to be there for all to
see, this extra little addition in the colour
magnitude diagram”, she said. She was
working at the Kapteyn Institute at the
time, and in order to go up to the second

diagram.

were several reasons why this

floor where she worked she had to walk by
the rack of new journals that had just come
in. And on the cover of one of them was
new data from the Hipparcos satellite
showing the colour magnitude diagram not
of the Large Magellanic Cloud but of the
nearby stellar neighbourhood. And in that,
she saw the very same additional feature.
And that, she said, “was my aha moment,
because I realised, this has nothing to do
with the Large Magellanic Cloud. It has
nothing to do with intervening objects that
are in-between us in the Cloud. Nothing to
do with dark matter. It actually has to do
with stellar evolution. There is a period in
stars’ lives when they occupy this particular
part of the colour magnitude diagram, and

147

how many stars are there depend on how
old the different populations are. And so
with a postdoc we took many colour
magnitude diagrams that he already had for
the Large Magellanic Cloud. We analysed
them this way, we showed that this extra
feature was exactly where you would expect
it to be, and it was occupied with precisely
the number of stars you would expect it to
be given the LMC’s star formation history”
(Beaulieu and Sackett 1998). “That aha
moment’, she continued, “was seeing in a
completely different context the same
signal, and therefore immediately knowing
that this explanation was different than
what had been originally proposed”.

Galaxies

Over the last two decades, several studies
have been conducted to understand the
evolution of galaxies. For example, there
has been a realisation that interactions
between galaxies may play an important
role, and observations have also been made
of shells and rings around elliptical galaxies.
Sackett and her colleagues carried out new
observations and produced a photographic
atlas of polar ring galaxies (Whitmore et al.
1990). Some astronomers were interested
in the history of these galaxies and wanted
to know what happened to these odd
looking objects. Her interest in these
fascinating galaxies arose from her desire to
study the shape of dark matter haloes and
how dark matter was distributed. The way
astronomers deduced the presence of dark
matter in galaxies was largely through
rotation curves. They measured the speed
of individual stars in the galaxy as a
function of how far away they are from the
centre, and this told them how much force
they were experiencing and therefore how
much mass the galaxy has that is acting
upon that particular star or set of stars.
This is how astronomers became confident

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that there must be more mass in the galaxy
than we can see and there must be dark
matter. With Linda Sparke, Sackett studied
the polar ring galaxy NGC 4650A. She did
this study when she was at the Kapteyn
Institute for the first time on a small grant
from the National Science Foundation.
NGC 4650A is a strikingly beautiful object
which has a central body of older stars in
the middle, somewhat flattened into an
elliptical shape. This is surrounded by a
gigantic ring of gas and much newer stars
that are orbiting in a completely
perpendicular plane to the way the stars
were orbiting in the central object.

They studied this galaxy because they could
measure the rotation curve not only in the
plane of the central body where there were
stars but also in a plane perpendicular to it
where there were stars and gas they could
use for their analysis. According to Sackett,
by studying these “you could ask the
question: Do these two curves look the
same because the distribution of matter 1s
spherical? If this was the case it would not
matter in which direction looked
because the gravitational field would be
spherical. Or does the polar ring have a
different rotation curve that of the
central body, which might indicate that the
dark matter preferentially lies in one plane
or the other” (Sackett and Sparke 1990).

you

to

From a more detailed analysis of the
motions of the stars in this galaxy, Sackett
said, “we found, after taking into account
that the rotation curve of the stars and gas
in the polar ring is different than that in the
central region. That immediately tells you
that the total gravitational mass is not
spherically distributed”. They knew that
some of the matter is not spherically
distributed because the galaxy’s flattened

elliptical orbits and all sorts of other things

148

and it has a ring. So one had to be more
careful than that and they needed to
subtract the effects of the mass they could
see, and then ask themselves, of the mass
that is left over, how ts it distributed? ‘And
the answer’, Sackett said, ““was as near as
we could tell within the precision of our
measurements that the dark matter was also
flattened — not as thin as a stellar disk, but
sort of as flat as a rugby ball or something
like that”. This work was important for
those astronomers who were trying to
understand what dark matter was made of,
because certain proposals for dark matter
were calling tor a very flattened disk while
others were calling for an absolutely
spherical distribution. She said, they gave
them “something in-between” (Sackett et
al. 1994).

In her study of the spiral galaxy NGC 5907
she found a faint luminous halo around the
galaxy. What surprised her and her
colleagues was that the distribution of this
light was more extended than had been
previously recognised. It did not fall off as
sharply as one typically expected in stellar
haloes. According to her, “we asked the
obvious question — 1s the light distributed
the way we think dark matter is distributed?
Because if it was, maybe there was a
connection between this light we were
seeing and dark matter”. Nature, the British
scientific journal decided to make it the
cover story (Sackett et al. 1994) and it
landed them in a controversy. ‘Their critics
began saying that Sackett and her colleagues
were claiming that they had “found what
dark matter was”, despite the fact, she said,
“that they were as cautious as they could
possibly be in the write up of their
abstract”. Nevertheless, one of the benefits
of this controversy was that it prompted
other astronomers “to look for faint light
around other galaxies, and it was found in

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Bhathal — Astronomical research of Penny Sackett

many other galaxies as well’, Sackett said.
According to Sackett, “when people looked
deeper, what they discovered was that it
wasn’t smoothly distributed but was often
on streamers that were at great distance
from the primary galaxy. And some of the
new thinking (and no doubt this will be
moditied in time as well) is that this faint
distributed light is in the outskirts of
galaxies where the dark matter is because
it’s caused by satellite galaxies that have
dropped into the potential well of the
primary galaxy and slowly over time have
had their stars stripped away into beautiful
long tails that surround the primary galaxy”.

Instruments for Studying the Universe
One of the major agenda items on Sackett’s
plate after the fires was to rebuild the
workshops. [rom its beginnings in the
1920s, the workshops had always been an
integral part of Mount Stromlo. Many of
the instruments that had been used to make
sionificant astronomical discoveries were
based on the instruments that were
designed and constructed in the workshops
which has excellent technical staff. A
Advanced
Centre
Sackett was

modern up-to-date

Instrumentation Technology
(AITC) was built in stages.
responsible for the building of Stage 1
which was opened in 2006. According to
Sackett, “the goal of the Centre was to
replace the activities that took place in the
workshops at Mount Stromlo that were
Furthermore, she

It had a

destroyed in the fire.
built the Centre for the future.
large integration and assembly hall attached
to the electrical and mechanical design

workshops and __ laboratories. The
integration hall and the laboratories have
been designed to cater for the next

generation of instruments expected to be
installed on Extremely Large Telescopes

149

currently being planned by international
consortia”.

The Observatory had acquired a contract to
build the Near-infrared Integral Field
Spectrograph (NIFS) for the Gemini North
telescope. However, as mentioned earlier,
it was completely destroyed by the fires just
before it was to leave the workshops for
NIFS 2 was rebuilt by the
Canberra based aerospace company,
Auspace Ltd, in collaboration with Mount
Stromlo designers and engineers. The
completed instrament was shipped to
Hawaii in August 2005 and installed on the
Gemini North 8.1 metre telescope in
October. Jan van Harmelen, the NIFS
Project Manager and Peter McGregor, the
Project Scientist spent a month at the
Gemint North Observatory supervising the
the initial observations. First
observations on the Gemini North
telescope, she said, “showed unprecedented
spatial and spectral detail in otherwise dust-
obscured regions, allowing young: stellar
wind speeds and black hole masses to be
measured. The whole project was a great
success and a credit to the technical and
scientific staff Mount Stromlo
Observatory”.

Hawatt.

tests and

at

The Observatory also secured a contract to
build the Gemini South Adaptive Optics
Imager (GSAOJI) for the Gemini 8 metre
telescope in Chile. This is a near-infra-red
camera which is being used with Gemini’s
flagship Multi-Conjugate Adaptive Optics
(MCAO) system on the Gemini South 8 m
diameter telescope in Chile. The MCAO
system corrects the blur due to the Earth’s
atmosphere over a wide field than has
previously been possible. GSAOI records
diffraction-limited images of astronomical
objects with 0.02 arcsecond sampling over
its full 85 x 85 arcsecond field of view.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Bhathal — Astronomical research of Penny Sackett

“The GSAOI was designed and built by a
team of engineers led by Peter McGregor.
The team included John Hart, Dejan
Stevanovic, Gabe Bloxham, Damien Jones,
Jan van Harmelen, Griesbach,
Murray Dawson, Peter Young and Mark
Jarnyk. The camera was shipped to the
Gemini South telescope in Chile in October
2006”.

Jason

Another instrument that was approved for
construction in December 2005 was the
Wide Field Spectrograph (WiFeS). — It
provides 950 simultaneous — spectra
throughout the optical frequency range. It
has been installed on the 2.3 m telescope at
Siding Spring. It has a data gathering
capability of 10 to 100 umes the rate of
conventional spectrographs. In the same
year Brian Schmidt’s highly innovative
telescope called the SkyMapper
approved for fabrication. wilt 46 4°155
metre diameter telescope located at Siding
Spring Observatory. It is a new breed of
dedicated survey telescopes that will
conduct the Stromlo Southern Sky Survey
which will produce the first deep digital
map of the entire southern sky. The design

Was

was produced by Conroy, Granlund and
Oates”, according to Sackett.

After the fires the astronomers had a long
and hard think about what they wanted in
terms of telescopes for the future. It would
have been an easy exercise for them to go
down memory lane and recreate what they
But Sackett had rather bold ideas
about what they should be looking for in
terms future telescopes for Mount Stromlo.

had lost.

According to Sackett, “we thought that one
of the legacies we would like to leave 1s that
the future generation would have a facility
that was to them what the AAT (Anglo-
Australian Telescope) was in the 1970s and
1980s, namely, of the

one biggest

150

telescopes in the world that would be
capable of doing things that otherwise
weren't possible, but also a telescope that
was reasonably versatile, that could have a
variety of instruments and do different
sorts of astronomy”.
was to get Mount Stromlo involved tn
planning the world’s next generation very

Her biggest coup

large optical telescopes, called the Giant
Magellan Telescope (GMT). ‘The building
to enclose the telescope will be as high as a
23-story sky scraper. The instrument will
have ten times the resolution of the images
from the Hubble Space Telescope. It will
be a time machine will
astronomers to probe the darkest reaches
of the universe and ask questions such as,
when did the first stars, galaxies and black
holes form?

which allow

Sackett had the audacity and courage to
propose Mount '
becoming involved in the effort to build the
GMT.
decision she made for the future of Mount
Stromlo Observatory and Australian
She signed the Memorandum
of Understanding in Texas on behalt of the

Stromlo Observatory

It was the best and far reaching

astronomy.

Australian National University. By signing
the document, Mount Stromlo joined an
elite group teaching
institutions in the US (Carnegie Institution
of Washington, Harvard
Massachusetts Institute of Technology, the
University of Arizona, the University of
Michigan, the Smithsonian Institution, the

otf and research

University,

University of Texas at Austin and the Texas
A& M University) to undertake the detailed
design of the telescope. It will have six
sepments, each 8.4 metres
surrounding a seventh mirror of the same
size. ‘The total light gathering power will be
nearly seven times that of the Gemini

in diameter

telescopes.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Bhathal — Astronomical research of Penny Sackett

The science objectives, Sackett, said, “will
be many, because it 1s meant to be a multi-
But in particular, the
image quality of this telescope is something

purpose telescope.

that is of prime concern, so that using a
method called adaptive optics, which can
undo the blurring caused by movement in
the atmosphere, this telescope should be
able to not only take pictures that are as
crisp Hubble Space
Telescope but in fact much crisper. That

as those of the
means seeing more detail. It means being
able to pull out faint, very distant objects
from the background or from brighter
foreground objects. ‘That means finding
more distant stars in the early universe. It
means being able to actually see those
planets orbiting other stars, detecting the
light from the planets themselves, and
thereby being able the
atmosphere, for example, of those planets,
which I think be
exciting”. She hopes that construction may
begin as early as 2014, assuming adequate
funding becomes available.

to analyse

will tremendously

Funding and research output

2002 was the first full year that astronomers
from the Research School for Astronomy
and Astrophysics were able to compete for
ARC tunding. “They were very successful
in their grant applications winning over
Over 50% of the School’s
funding was derived from the increasing
success of the School’s astro-engineering
design and tabrication teams”. The arrival
of Sackett at the Observatory in 2002 also

$2.7 million.

brought in the new field of extrasolar
the traditional astronomy
programs pursued by the Observatory.
Together with the Research School of
Earth Sciences, Sackett established a new
Planetary Science Institute in 2002.
According to Sackett, the Institute was

planets into

“designed to cultivate a research program

151]

of planetary science combining the detailed
studies possible in our Solar System with
the recent wealth of information from the
young field of extra-solar planets”.

Despite the fires the Observatory
“remained very active in tfeseatch,

publishing over 500 papers in refereed
international journals”, according to
Sackett. ‘he research effort spread over a
number of speciality areas, viz: solar and
extrasolar planetary systems, stars and
stellar populations, the Milky Way and
galaxies, dark energy and dark matter,
gamma ray bursts, interstellar medium and
galactic feedback, and adaptive optics.

Conclusion

Sackett achieved most of what she had set
out to accomplish in her five year term.
She had, as she planned reinvigorated the
institution and continued the growth of the
tradition of excellence. She steered the
Observatory for a new beginning. Her
decision to embark on the Great Magellan
Telescope was the boldest, audacious and
most visionary decision she made. She will
be remembered in ages yet to come for her
future for Mount Stromlo
Observatory and Australian astronomy in

vision

the era of very large telescopes that will
provide us with discoveries that we have yet
to imagine. In 2007 Sackett completed her
term as the Director of Mount Stromlo
Observatory to take up in 2008 the position
of Chief Scientist for Australia.

Acknowledgements

The author thanks the National Library of
Australia for sponsoring the National Oral
History Project on Significant Australian
Astronomers and Physicists. The interview
with Penny Sackett was conducted on 15
January 2013. All quotations used in the
paper are from the interview that the

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Bhathal — Astronomical research of Penny Sackett

author conducted with Penny Sackett. The
full transcript of the interview 1s held in the
archives of the National Library
Australia (Bib. ID 6183715). The author
thanks Penny Sackett for agreeing to be
interviewed for the Project and reviewing
the paper and providing useful comments.

References

Albrow, M., et al. (1998) “The 1995 Pilot
Campaign of PLANET: Searching for
microlensing anomalies through precise, rapid,
round-the-clock monitoring” Asfrophysical
Journal, 509, 687-702.

Alfonson, C., et al. (2000) “Combined analysis
of the binary lens caustic-crossing event
MACHO 98-SMC-1”) Astrophysical Journal, 532,
340-352.

Beaulieu, J. P. and Sackett, P. D. (1998) “Red
clump morphology as evidence against a new
intervening stellar population as the primary
source of microlensing toward the Large
Magellanic Cloud” Astrophysical Journal, 116, 209
aos

Raebir Bhathal

Received 10 July 2013, Accepted 30 July 2013.

ot

Beaulieu, J. P., et al. (2006) “Discovery of a cool
planet 5.5 Earth masses through gravitational
lensing” Nature, 439, 437-440.

Bhathal, R. (1999) Profiles: Australian women
scientists, National Library of Australia,

Canberra.

Sackett, P. D, et al. (1994) “The flattened dark
halo of polar ring galaxy NGC 46350A2 A conspiracy
of shapes?” Astrophysical Journal, 436, 629-641.

Sackett, P. D. and Sparke, L. S. (1990) The dark
halo of the polar-ring galaxy NGC 46504,
Astrophysical Journal, 361, 408-418.

Sackett, P. D., et al. (1994) “Al facut luminous halo
that may trace the dark. matter around the spiral galaxy

NGC 5907", Nature, 370, 441-445.

Schiebinger, L. (1999) Has feminism changed
science’, Harvard University Press. Cambridge.

Massachusetts.

Whitmore, B. C., et al. (1990) “New
observations and a photographie atlas of polar
ring galaxies” Astrophysical Journal, 100, 1489 —

1522.

Dr Ragbir Bhathal is the Director of the National Oral History Project on Significant
Australian Astronomers and Physicists. He is a Visiting Fellow at the Research School of

Astronomy and Astrophysics, Australian National University. He has published 15 books,
eight on astronomy including two on Aboriginal Astronomy.

Journal and Proceedings of the Royal Society of New South Wales, vol. 146, nos. 449 & 450, pp. 153-154.

ISSN 0035-9173/13/020153-2

Thesis abstract

The flow around a fish-inspired heaving and pitching
hydrofoil ©

Timothy Lau

Abstract of a thesis for a Doctorate of Philosophy submitted to
The University of Adelaide, Adelaide, Australia

An extensive investigation into the flow
around a fish-inspired heaving and _ pitching
hydrofoil was performed using a combination
of two dimensional digital particle tmage
velocimetry (PIV), direct strain gauge force
and moment measurements, dye visualisation
and hydrogen bubble visualisation. The
intention of this investigation was to study the
eftect of the foil dynamics on the foil wake
structure and hydrodynamic forces, with the
ultimate goal of determining if the oscillating
foil, and by implication, fish, employ unsteady
flow mechanisms to generate optimal thrust.

The experiments were performed — by
systematically varying the foil non-
dimensional heave-amplitude-to-chord ratio,
hy /=0.25-0.75, the foil pitch amplitude,
)=0-45°, and the free-stream velocity, Us.
The phase difference between the pitching
and heaving motion was fixed at w=90°
(heave lagoine pitch). Experiments consisted
of 113 ‘different flow «cases “for aye
visualisation, 38 flow cases for hydrogen
bubble visualisation and 108 flow cases for
simultaneous PIV and torce measurements.
‘The resultant Strouhal numbers, based on the
heave amplitude, fall into the range 0.155431
while the Reynolds numbers, based on the
toil chord length, were approximately
Re=500-12,500.

The experimentally measured time-averaged
thrust coefficient, C,, obtained independently
using PIV and = direct strain gauge
measurements, shows excellent agreement,
and indicates that very large values of C,>10
can be generated by the foil, particularly when
the non-dimensional heave amplitude 1s large
relative to the pitch amplitude, and St, is
large. ‘The results also indicate that in all
investigated cases, there is no sign of a
sudden loss in lift that is associated with the
“stall” phenomenon usually seen in steady
foils, even when the unsteady foil achieves
very large instantaneous angles of attack
(Omax>60°).

To obtain a context for comparison, a quasi-
steady model (Q-S model) of the oscillating
hydrofoil was developed, based on_ the
assumption that the flow around the unsteady
foil at any given instant ts equivalent to the
flow around an identical steady foil with the
same angle of attack. For most foil dynamic
parameters and flow conditions, the value of
C, predicted by the Q-S model shows
excellent agreement with the results obtained
experimentally. However, when /y/c is large
compared to @, the experimentally measured
values of C, far exceed the theoretical
predictions. ‘This suggests that the oscillating
foil employs unsteady flow mechanisms to
augment thrust production when /y/c is large
relative to

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Lau — Flow around a heaving and pitching hydrofoil

Flow visualisation of the foil wake indicates
that different wake patterns are produced,
depending on the flow conditions. ‘The
observed wake patterns are interpreted as a
combination of “primary” vorticity, which ts
associated with the production of lift (and
hence thrust) by the foil, and “secondary”
vorticity, which is associated with the drag
produced by the foil. During each foil half-
cycle, secondary vorticity manifests itself as
multiple vortical roll-ups (“S” vortices),
whereas the primary vorticity sheds as a
single, typically large vortex, which combines
with adjacent “S” vortices to form one “P”
vortex. When /p/c is large compared to Oy,
these “P” vortices are obsetved as very large
leading edge vortices with strong spanwise
flow (towards the foil centreline). These
leading edge vortical structures are further
evidence that the foil employs unsteady flow
mechanisms large thrust
coefficients.

to generate
«

Based on the positions of these “P” and “S”
vortices in the wake, we define three distinct
wake regimes, a) “Drag regime’’, occurring at
St,<0.15, b) “Transitional regime”, occurring
at 0.15<St,S0.3 and c) “Thrust regime’,
occurring at St,>0.3, whereby each regime
produces subtly different wake patterns.

The wake behind the toil was also analysed
quantitatively by measuring the first moment
of circulation of the foil wake, which 1s

defined as the product of the total circulation
generated by the foil (of any given sign) per
cycle and the wake width based on_ the
centroids of the
important finding, it is shown that the data

shed vorticity. In an
for C, vs. the first moment of circulation
collapse onto a single curve, regardless of
flow conditions and foil dynamic parameters.
For most (~95°%) of the cases measured, it 1s
shown that C, 1s approximately linearly
proportional to the moment of circulation,
indicating that the thrust produced by the foil
can be increased by generating large vortical
structures and/or increasing the wake width.

Based on these results, we therefore conclude
that the foil employs
mechanisms only when /y/¢c 1s large relative to
Oy.

coetticients are generated by the toil due to

unsteady flow

Under these conditions, large thrust

the generation of leading edge vortical
structures with large circulation, which are
positioned far away from the foil tme-
averaged centreline.

Dr ‘Timothy Lau,

School of Mechanical Engineering,
The University of Adelaide,
Adelaide SA 5005
AUSTRALIA

F-mail: tmothy.lau@adelaide.edu.au

Soa

154

Journal and Proceedings of the Royal Soctety of New South Wales, vol. 146, nos. 449 & 450, pp. 155-157.

ISSN 0035-9173/13/020155-3

Thesis abstract

Ontogenetic ecophysiology of secondary hemi-epiphytic

vines

Yansen

Abstract of a thesis for a Doctorate of Philosophy submitted to
James Cook University, Townsville, Australia

Secondary hemi-epiphytes start their lite
as ground-dwelling plants. Like other
vines, the plant then climbs the host, but
when the plant reaches maturity, the
The
plant then loses its stem connection to
the soil and becomes semt-epiphytic.
true secondary hemi-
epiphytism 1s probably not as common as

oldest portion ot the stem dies.

However,

thought, since, in most cases semt-
epiphytic vines reconnect to the soil
through aerial roots. The change in soil
connection during the ontogeny of these

species may have physiological and
anatomical consequences. As they
eventually live in the canopy

environment, it is feasible that secondary
hemi-epiphytes might develop
adaptations to cope with the stressful
canopy environment, especially water
stress during dry periods. However,
there is a lack of understanding on the
ecophysiology of secondary hemi-
epiphytes in rainforests.

There 1s a paucity of information on the
anatomy and physiology of secondary
hemi-epiphytes, once they lose their stem
connection to the soil, compared with
the terrestrial early stage of development.
To this gap,
characteristics of stem water transport,

address knc mwledge

ln

leaf anatomy and physiology, and soil
resource _ partitioning were
examined in this research. Two species

water

were selected for the study: Freycinetia
excelsa’ F. Muell (Pandanaceae) and
Rhaphidophora australaswa ¥.M. Bailey
(Araceae), which occur naturally in the
Wet Tropics area of north Queensland.
The general objective of this research is
to better understand the ecophysitology
of secondary hemi-epiphytes during their
ontogenetic development.

The capacity of F. exvela and R. australasica
stems to conduct water differed between
plants of different developmental phases.
Adult individuals of F. excefa and R.
australasica had wider vessels than younger
plants. Hydraulic architecture parameters,
1c. hydraulic conductivity, stem specific
conductivity and leaf specific conductivity,
were also higher in adult plants than for
intermediate and juvenile individuals. These
results indicate that adult plants had a higher
capacity to conduct water through the stem
to the leaves than did individuals at an
earlier stage of development.

As the plants became more mature and
longer, they tended to have low hydraulic
conductivity at the stem base. This finding
is supported by the fact that the size of

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Yansen — Ontogenetic ecophysiology of secondary hemi-epiphytic vines

xylem vessels was found to decrease in the
basipetal direction: the base of the stem had
narrower vessels than the middle part of the
stem. the
conductivity at the base of the stem may
also be the fact that
monocotyledonous plants lack secondary
development. Therefore, the stem base
contains the oldest shoot tissues and the
vessels might be less functional. Wider
vessels and higher hydraulic conductivity in
adult individuals of FI. exvefia and R.
australasica show that the change 1n plant-soil
connectivity during ontogeny of these
species does not physically restrict water
transport.

However, low hydraulic

related to

excelsa
stomata

Adult individuals of I. and R.
australasca had larger than
conspecific juveniles. However, adult plants
also had more stomata per unit area, which
gives them more control of the opening and
closing of stomata in certain areas of the
leaves. These characteristics of leat
anatomy suggest that secondary hemt1-
epiphytes are well-adapted to the canopy
environment.

Juvenile plants of these two study species
appear to be more sensitive to the onset of
drought than plants of later developmental
stages. Within each drv and wet season, the
water potential of leaves from all growth
forms were similar but the patterns of daily
CO? exchange differed, with COz uptake by
juvenile plants most affected by dry season
conditions. Hlowever, the CO2 exchange
rates were similar for adult, intermediate
and juvenile plants during the wet season.
High water availability in the wet season and
relatively low evaporative demands provide
excellent conditions for plants to absorb
CO. The significant down-regulation of
CO, exchange in the dry season in the
juveniles is related to the lower hydraulic

156

conductivity of their stems. Water supply to
juveniles may be restricted during the dry
season, such that down-regulation of CO>
uptake and stomatal opening are necessary
to diminish water loss and maintain water
potential. Water supplied to intermediate
and adult plants by aerial roots growing
from a number of places along the stem is
evidently sufficient to sustain higher rates of
COz exchange and water loss.

Plants of different ontogenetic stages had
different behaviours towards soil water
resources. Based on the hydrogen stable
isotopes of water derived from different
layers of the soil profile, matched with
isotope signatures of the stem water, water
uptake by juvenile individuals was limited to
the area near the soil surtace; on the other
hand, adult plants utilized water from all soil
lavers studied. ‘This consequently affects the
capacity of plants to exploit all available soil
water sources across seasons, which
influences the performance of individuals ot
different ontogenetic stages in response to
environmental conditions.

Variations 1n the ecophystological attributes
of the secondary hemi-epiphytes I. excedva
and R. austrafasica indicate differences 1n the
ability of these plants to survive during their
development. This study showed that
smaller size juveniles may have a higher

potential = susceptibility to stressful
environmental conditions compared to
larger adult congeners. Based — on
ecophysiological characters, these two

secondary hemi-epiphytic have not adapted
especially to the epiphytic habit as_ they
climb the host and live in the canopy. ‘The
plants’ soil connections through aerial roots
provide access to soil, avoid the stem basal
hydraulic bottle neck and contribute to
more options for soil water resource
acquisition.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Yansen — Ontogenetic ecophysiology of secondary hemi-epiphytic vines

Dr. Yansen,

Department of Forestry,
University of Bengkulu,
Bengkulu, Sumatra, 38371,
INDONESIA

E-mail: y.yvansen@ymail.com

=e

157

Journal and Proceedings of the Royal Society of New South Wales, vol. 146, nos. 449 & 450, pp. 158-168.
ISSN 0035-9173/13/020158-11

Proceedings of the Royal Society of New South Wales

The 2013 programme of events — Sydney

The venue for Society meetings is the Union University and Schools Club, 25 Bent Street,

Sydney unless noted otherwise.

Wednesday 6 February 2013 at 6:30 pm.
1207th Ordinary General Meeting — Scholarship Presentations
Speakers: Ms Jendi Kepple, Ms Anwen Hrause-Heuer and Ms Helen Smuth

Wednesday 27 February 2013 at 6:00 pm.

The Four Societies Lecture
Going low carbon — the approach of the International F:nerzy Policy Institute

In conjunction with the Nuclear Engineering Panel of the Sydney Branch of
Engineers Australia, the Australian Nuclear Association and the Australian
Institute of Energy.

Professor Stefaan Simons

Venue: Harricks Auditortum [Engineers Australia, 8 Thomas Strect,
Chatswood

Wednesday 6 March 2013 at 6:30 pm.

1207th Ordinary General Meeting
The evolution of galaxies
Dr Ray Norns
Ray Norris ts an astronomer with CSIRO Astronomy & Space Science who
researches how galaxies formed after the Big Bang. He leads an international
project to image the faintest radio galaxies in the Universe which will use the
new ASKAP radio telescope, currently being built in Western Australia.

Wednesday 3 April 2013 at 6:00 pm.
Annual General Meeting

Dr Donald Hector was re-elected President of the Society.

Wednesday 3 April 2013 at 6:30 pm.

1209th Ordinary General Meeting — Royal Society of NSW 2013 Fellows Lecture
An evolutionary history of Australia
Professor Mike Archer AM FAA FRSN
Michael Archer is a distinguished biologist and palaeobiologist. A vertebrate
palacontologist and mammalogist, he was closely involved with the
exploration of the Riversleigh fossil site in Queensland, one of the richest

158

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Proceedings — 2013

fossil discoveries in Australia. He became Director of the Australian
Museum in Sydney and returned to the University of NSW in 2004, first as
Dean of the Faculty of Science and, since 2009, a Professor in the Faculty.
He was awarded the Society’s Clarke Medal in 1984 and was one of the first
Fellows of the Society appointed in 2009.

Friday 19 April 2013 at 7:00 pm.

Annual Dinner and presentation of Awards
The 2012 Clarke Medal, Edgeworth David Medal and the Royal Society of
NSW Medal were presented by Ms Judith Wheeldon AM, educator and
trustee of the Powerhouse Museum.
Judith Wheeldon is one of Australia’s best-known educationalists. She
worked for some years in the Western Australian Department of education
and then was appointed principal of Queenwood School for Girls at
Mosman. Later, she became headmistress of Abbotsleigh. Queenwood and
Abbotsleigh are among Australia’s finest girls’ schools.

Wednesday 1 May 2013 at 6:30 pm.

1210th Ordinary General Meeting
Paul Otlet and the beginnings of modern information scence
Em. Professor W. Boyd Rayward

Thursday 6 June 2013 at 6:30 pm.

Royal Society Forum 2013

(1211th Ordinary General Meeting)
Professor Brian Schmidt AC FRS FRSN, Professor Steven Schwartz AM,
Professor Merlin Crossley and Ms Judith Wheeldon AM. Moderated by
Andrew Funnell of Radio National.
The Forum was broadcast on Radio National Big Ideas on Monday 17 June
2013 and again on Friday 21 June 2013.
Venue: Coles Theatre, Powerhouse Museum, 500 Harris Street, Ultimo
The Forum may be downloaded from the Big Ideas page at the ABC Radio
National web-site.

abc.net.au/radionational/ programs /bt ideas / maths-and-
8).

dee
(http: / Awww

science-education-in-australia /473013

Wednesday 3 July 2013 at 6:30 pm.

1212th Ordinary General Meeting
Caring for highly processed wood pulp? The role of the State Library in the 21st century
Dr Alex Byrne, State Librarian & Chief Executive, State Library of NSW

Wednesday 7 August 2013 at 6:30 pm.

1213th Ordinary General Meeting
How numbers came to rule the world: Luca Pactoli, Leonardo da Vint and the merchants
of \ enice on Wall Street

159

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Proceedings — 2013

Jane Gleeson-White, author of Double Entry: how the merchants of \ entce shaped
the modern world — and how their invention could make or break. the planet

Jane Gleeson-White argued that double-entry book-keeping fuelled the
rise of the West and effectively gave birth to the entire modern scientific
capitalist world and that today it holds the key to sustainable economics
for the 21st century. Jane is recognised as one of Australia’s best
emerging women writers and gave the prestigious keynote address to the
2012 Emerging Writers Festival in Sydney and (alongside Geordie
Williamson) she keynoted a 2012 Stella Prize event entitled “Australia’s
Sleeping Beauties: Reviv ing Australia’s Forgotten Women Writers”.
Venue: Coles Theatre, Powerhouse Museum, 500 Harris Street Ultimo.
The Forum may be downloaded from the Big Ideas page at the ABC Radio
National web-site.

, . . / i . . /
:-//www.abe.net.au/radionational/ programs /bigideas/ numbers-rule-
the-world/ 4881098)

Tuesday 13 August 2013 at 6:30 pm.

Poggendorff Lecture 2013

In conjunction with Charles Sturt University
Biodiversity and the future of agriculture
Professor Geoff Gurr, Professor of Applied Ecology at Charles Sturt
University
Professor Gurr addressed one of the world’s most urgent challenges when he
answers the question: Can we feed 9 billion people by 2050? Not only do we
have to meet that challenge, we have to do it in the face of declining
availability of good-quality land and water, and the need to preserve
biodiversity to provide critical ecosystem services. Professor Gurr drew on
his international research program to explain how biodiversity can be
harnessed to provide effective pest suppression and illustrate how on-farm
biodiversity can advantage growers and the wider community.
The Poggendorff Memorial Lecture honours Walter Hans George
Poggendorff, the eminent Australian agriculturalist and former Hon.
Librarian of the Society, and covers agriculture in its broadest sense.
Venue: Lecture Theatre 3, Charles Sturt University, Leeds Parade, Orange.

Wednesday 4 September 2013 at 6:30 pm.
1214th Ordinary General Meeting
Open science
Dr Matthew ‘Todd, University of Sydney

Wednesday 2 October 2013 at 6:30 pm.

1215th Ordinary General Meeting
“Astrobiology: the latest from ‘Curiosity’ “
Professor Malcolm Walter UNSW

160

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Proceedings — 2013

Wednesday 23 October 2013 at 6:30 pm.

Pollock Memorial Lecture 2013

In conjunction with the School of Physics, University of Sydney
“Onantum computing in silicon and the limits of silicon miniaturisation”
Professor Michelle Simmons FRSN
Director, ARC Centre of Excellence for Quantum Computation and
Communication Technology, University of New South Wales
Professor Simmons is the Director of the Australian Research Council
Centre of Excellence for Quantum Computation and Communication
Technology, a Federation Fellow and a Scientia Professor of Physics at the
University of New South Wales. Following her PhD in solar engineering at
the University of Durham in the UK she became a Research Fellow at the
Cavendish Laboratory in Cambridge, UK, working with Professor Sir
Michael Pepper FRS in quantum electronics. In 1999, she was awarded a
QEII Fellowship and came to Australia where she was a founding member,
and now the Director of the Centre of Excellence. Since 2000 she has
established a research group dedicated to the fabrication of atomic-scale
devices in silicon using the atomic precision of scanning tunnelling
microscopy. Her group has developed the world’s thinnest conducting wires
in silicon and the smallest transistors made with atomic precision. She has
published more than 300 papers in refereed journals and presented over 80
invited and plenary presentations at international conferences. In 2005, she
was awarded the Pawsey Medal by the Australian Academy of Science and in
2006 became the one of the youngest elected Fellows of this Academy. In
2008 she became a dual citizen of Australia/UK and she was awarded a
second Federation Fellowship by the Australian Government and was
named the NSW Scientist of the Year in 2011.
Venue: Eastern Ave Auditorium, University of Sydney.

Wednesday 6 November 2013 at 6:30 pm.

1216th Ordinary General Meeting
Re-thinking science education in Australian schools: development and implementation of the
National Science Curriculum
Dr Mark Butler, Department of Education and Communities

Tuesday 19 November 2013 at 6:30 pm.

AIP Postgraduate Awards Day and judging of the Jak Kelly Award
The Physics of High E:fficiency Photovoltaic Solar Exnergy Conversion
In conjunction with the Australian Institute of Physics
Professor Martin Green, University of New South Wales.
Venue: Room 273, Carslaw Building, University of Sydney.

161

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES
Proceedings — 2013

Thursday 21 November 2013 at 6:00 pm.
The Dirac Lecture 2013
In conjunction with the University of New South Wales and the Australian
Institute of Physics
Professor Sir Michael Pepper RS, University of Cambridge
Venue: Leighton Hall, University of New South Wales

Wednesday 18 December 2013 at 6:30 pm.
A Special Meeting of the Society was held at which the Rules and By-Laws of
the Society were changed.

Wednesday 18 December 2013 at 6:30 pm.

1217th Ordinary General Meeting and Christmas Party
Presentation of the Jak Kelly Award and a brief seminar by the winner,
Xavier Zambrana-Puvyalto.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Proceedings — 2013
SSIS

The 2013 programme of events — Southern Highlands
The usual venue for Southern Highlands branch meetings is the Performing Arts Centre
Chevalier College, Bowral.
Thursday 21 February 2013 at 6:30 pm.
Different depressive and bipolar mood disorders
Professor Gordon Parker, University of New South Wales

>

Thursday 21 March 2013 at 6:30 pm.
King Akhenaten: pharoah, fanatic or freak?
Dr Michael Birrell

Thursday 18 April 2013 at 6:30 pm.
Climate Adaptation Flagship
Dr Andrew Ash, CSIRO

Thursday 16 May 2013 at 6:30 pm.
Advances in aviation
Dr Rik Heslehurst, ADFA, University of New South Wales

Thursday 27 June 2013 at 6:30 pm.
Household sustainability: challenges and dilemmas in everyday life
Professor Chris Gibson

Thursday 18 July 2013 at 6:30 pm.
Nuclear power in Australia
Mr ‘Tony Irwin

Thursday 8 August 2013 at 6:30 pm.

Climate Science Forum
Dr Michael Raupach and William Kintnmonth
Moderator: Ken McCracken

Thursday 12 September 2013 at 6:30 pm.
Dark matter
Professor Ken Freeman, Australian National University

Thursday 17 October 2013 at 6:30 pm.
The dynamic brain
Dr Peter Robinson, University of Sydney

Thursday 21 November 2013 at 6:30 pm.

Superbugs
Professor Liz Harry, University of Technology, Sydney

163

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Proceedings — 2013

The Fellows Lecture 2013

Wednesday, 3 April 2013

Ain evolutionary history of Austraha

Professor Michael Archer Dist FRSN

Professor Michael Archer deliverng the inaugural
Fellows Lecture.

The Society was proud to have Professor
Michael Archer AM present the inaugural
Fellows Lecture on Wednesday, 3 April 2013.
Professor Archer was one of the first Fellows
appointed by the Society, recognising his
outstanding work as a_ palaeontologist,
particularly in relation to the Riversleigh fossil
find in Queensland, one of the richest fossil
deposits in the world.

Until about 50 years ago, only about 70 fossil
mammals had been found in the whole
Australian continent, compared to about
50,000 in North America. The geology of the
Riversleigh area, in northern Queensland, 1s
unusual. ‘There are large expanses of very old
(1.6 billion years) Precambrian rock and more
recent Cambrian deposits (500 million years
old) that contain rather unremarkable fossils
of the era. But there are pockets of more
recent geological deposits, 10-25 million years

old, that have been found to contain

164

extraordinarily well-preserved fossils. There
are about 40 sq. km of these deposits. A wide
range of unusual animals have been found:
five kinds thylacine, giant,
platypus, flesh-eating kangaroos and ancient
birds. Some of the birds are the biggest ever
discovered and would have weighed up to
400 kg. Also, huge fossilised snakes,
importantly, a diverse range of ancient bats
and a great variety of trees and plants have
been discovered.

of toothed

How did this extraordinary preservation take
place? Professor Archer explained that there
were two phenomena that together resulted
in this remarkable deposit. Water that
percolated up from subterranean deposits
were saturated in calctum carbonate and this
quickly precipitated around any dead animals
that fell into the water. This was responsible
for preserving skeletons intact and 1s easily
removed using weak acid such as acetic acid
that quickly dissolve the calcium carbonate,
exposing a well-preserved fossilised skeleton.
But in addition, another phenomenon called
“bacterially-mediated phosphatisation”” means
phosphates from bat droppings
preserved soft tissue, resulting in remarkably

have

complete fossils betng found in many areas.
In a process known as “tufagenic barrage”,
calcium carbonate deposits formed dams that
allowed fossilisation to take place.
dams were ultimately breached but the fossils
were preserved. At the time, Riversleigh area
was covered with rainforest but this has
gradually receded to coastal zones.

‘These

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Proceedings — 2013

The Riversleigh deposits cover five phases
from 25 million years ago to 1.5 million years
ago and is the richest sequence in Australia.
(There is only one other similar deposit in the
world — this is in France.) The Riversleigh
find has completely changed perceptions
about Australia's past. It 1s now clear that
there is a diversity in the fossil record
suggesting an environment that was as rich at
the time as Borneo and the Amazon regions
are today. About 15 million years ago
Australia started to dry out, yet it was not
until about 3 million years ago that extensive
erasslands tormed.

Professor Archer pointed out that the fossil
record gives us a very rich understanding of
the way in which current species have evolved
from which we can deduce how habitat
change can be managed and to protect
species that might be at risk of extinction as
climate change takes place. We can also gain
insight into which species are at threat by
understanding the extent to which their
populations have increased or declined over
long periods of time.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Proceedings — 2013

The Poggendorff Lecture 2013

Tuesday, 13 August 2013

Biodiversity and the future of agriculture

Professor Geoff Gurr

ae EP lain as,

Professor Geoff ‘Gurr delivering the Poggendorff Lecture
2013.

After a hiatus of 20 years, the Poggendortf
Lecture was delivered in conjunction with
Charles Sturt University, Orange, on Tuesday,
13 August 2013. The lecture was delivered by
Professor Geoff Gurr, a biologist and
entomologist and Professor of Applied
Ecology at Charles Sturt University, where he
specialises in the utilisation of natural
solutions to control agricultural pests to
partially or completely replace synthetic
pesticides.

The population of the world is increasing by
170,000 souls per day. Currently, 40% of
land ts used for some agricultural purpose and
the demand for agricultural products ts

oe

166

expected to increase not only
consequence of population growth but by the
increasing living standards of people in the
developing world. For example, the growth
in meat demand 1s very strong and it takes 10
ke of grain to produce 1 kg of animal protein.
This leads to the conclusion that

production needs to double by 2050. ‘The so-

as oa

food

called “green revolution” of the last few
decades has enabled the increase in tood
production to largely match population
growth, largely through the application of
nitrogen, phosphorus, some trace elements,
water and the wide-scale use of pesticides.
But this revolution truly “‘green’’?
Human inputs are largely non-renewable but,
importantly, do not actually address the root

Was

cause of the problem — pest outbreaks are not
due to a lack of pesticide, they are due to
other imbalances in the environment. So the
world ts faced with a “wicked problem” of
seeking food security, having finite renewable
resources, a declining availability of
agricultural land, changing climate and a
moral obligation to preserve biodiversity
(human activity, including agriculture, causes
biodiversity loss at a rate about 10,000 times
greater than the background rate).

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Proceedings — 2013

The Pollock Memorial Lecture 2013

Wednesday, 23 October 2013

Quantum computing in silicon and the limits of silicon miniaturisation

Professor Michelle Simmons Dist FRSN

Professor Michelle Simmmions.

Professor Simmons commenced her address
by overviewing the advances of the now
conventional semiconductor industry. From
the first, famously crude, transistor, through
discrete silicon devices in “transistor radios”
through to modern day integrated circuits
composed of billions of devices. <A point,
well made, was that there were a full ten years
between the laboratory transistor and the first
integrated device and yet another 15 years
before mass products flooded into the
market. It has been a technology that has
revolutionised — the live, but
remarkably still has not deviated from
Moore’s Law. Prof. Simmons described the
basics of what the term “quantum computer”
means and the various characteristics a device
must exhibit to comprehensively qualify as
Although scientifically advanced, the
area is in its infancy analogous to the time of
the first transistor, when the plethora of

way we

such.

167

future applications could not have been
conceived — and that is just how it ts now
with quantum computers — we cannot begin
to estimate their future impact.

Some problems scale exponentially — like the
‘Travelling Salesman problem where the task
is to calculate all possible alternative routes of
a salesman visiting N cities in any order. As
N is increased the number of options
explodes, quickly outstripping the capacity of
even a supercomputer. Other such problems

are many-body models for simulating
molecules and materials. Whereas
conventional “serial” computers become

overwhelmed, quantum computers mirror the
exponential character of these problems with
the exponential number of possible quantum
states held in superposition across the qubits
of the quantum computer. Indeed, with only
300 qubits, a quantum computer would
possess more processing power than all of the
computers currently in the world.

They are known to be suited to particular
niche problems such as decryption, but they
may be combined in many architectures to
perform different logical operations, some of
which Prof. Simmons described using truth
tables and quantum mechanical notation.
The latter may have left behind anyone
without degree level physics, but it was
fascinating to many that do.

JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY OF NEW SOUTH WALES

Proceedings — 2013

Finally, Prof. Simmons gave an overview of
the different research approaches being
applied around the globe towards realizing
the first true quantum computer — elucidating
the strengths and potential issues with each of
the categories. ‘The work at UNSW involves
excavating a surface of silicon atom by atom
and then placing and burying a single dopant
atom to form a qubit, betore covering it over

Her
group is the only group world-wide that can
make such atomically precise devices in

with silicon and attaching electrodes.

silicon: they have developed the world’s
thinnest conducting doped wires in silicon,
the — ability manipulate — and
electronically measure devices with atomically
precise dopant placement.

and to

168

The Royal Society of New South Wales

The Clarke Medal 2013
Professor William Griffin

The Clarke Medal was established to acknowledge the contribution by the Rev William
Branwhite Clarke MA PRS PGs, Vice-President of the Royal Society of New South Wales from
1866 to 1878 The Medal is awarded annually for distinguished work in a natural science done in
Australia and its Territories.

The Medal ts awarded by rotation in the tields of
is in the field of geology tn all its aspects.

geology, botany and zoology. ‘This year’s award

c

The Clarke Medal for 2013 in the field of Geology has been awarded to Professor William
Griffin of Macquarie University.

Professor Griffin came to Australia in 1986 to join the CSIRO, where he rapidly became Chief
Research Scientist. He then helped to establish the ARC Key Centre for Geochemical Evolution
and Metallogeny of Continents (GEMOC) and, subsequently, part of the new ARC Centre of
Excellence for Core to Crust Fluid Systems. He has worked there ever since, first on
secondment from CSIRO and, since 2007, as a CoRE Professor at Macquarie University. He
pioneered (in partnership with Prof Suzanne O'Relly) a world-leading interdisciplinary approach
to mapping the inaccessible deep Earth. The results have increased our fundamental
understanding of Earth's 4.6 billion year evolution, and delivered widely adopted new tools to the
mineral exploration industry. His leadership at Macquarie University has delivered major
breakthrough developments in geochemical analysis that have revolutionised methods for
determining the timing of geological events.

The Medal will be presented at the Annual Dinner of the Royal Society scheduled to be held in
2014.

169

The Royal Society of New South Wales

The James Cook Medal

Professor Brien Holden

The James Cook Medal was established in 1947 with funding by Henry Ferdinand Halloran.
Halloran, who had joined the Society in 1892 as a 23 year-old, was a surveyor, engineer and town
planner. He did not publish anything in the Society’s Journal but he was a very enthustastic
supporter of research. Halloran funded what were to become the Society’s two most prestigious
awards, the James Cook Medal and the Edgeworth David Medal, the latter being the medal tor
young scientists.

The James Cook Medal is awarded at intervals for outstanding contributions to science and
human welfare in and for the Southern Hemisphere.

The 2013 James Cook Medal has been awarded to Professor Brien Holden of the University of

New South Wales.

Professor Holden 1s a distinguished researcher with an international reputation in optometry, in
particular, relating to corneal physiology and contact lenses. Ile pioneered new lens designs to
reduce near-sightedness (myopia) in children and ts considered one of the top vision scientists in
the world. Professor Holden recognised that in developing countries, particularly East Asia,
myopia is one of the leading causes of permanent blindness. ‘The first generation of lenses
designed by Professor Holden reduce myopia progression by up to 50%. Extending this
technology to non-contact lenses 1s also expected to slow myopia progression.

Professor Holden’s work has been recognised by the World Health Organisation as it has
brought world-wide attention to preventable blindness. The Society recognises the outstanding
contribution to science and humanitarian values in awarding the James Cook Medal for 2013 to

Professor Holden.

The Medal will be presented at the Annual Dinner of the Royal Society scheduled to be held in
2014.

=

170

The Royal Society of New South Wales

Walter Burfitt Prize 2013

Professor Michelle Simmons

The Walter Burfitt Prize was established as a result of a generous gift to the Society by Dr W.F.
Burfitt BA MB ChM BSc of Sydney, which was augmented by another gift from Mrs W.F.
Burfitt when Dr Burtitt died in 1957. The Prize was further augmented in 2004 by a gift from Dr
Burfitt’s grand-daughter Mrs A. Thoeming.

The Prize is awarded at intervals of three years to a worker in pure or applied science, resident in
Australia or New Zealand, and whose papers and other contributions published during the past
six years are deemed of the highest scientific merit. Account is taken only of investigations
described for the first time, and carried out by the author mainly in these countries.

The 2013 Walter Burtitt Prize has been awarded to Professor Michelle Simmons of the
University of New South Wales.

Professor Simmons is a pioneer in atomic electronics and engineering. Her vision and leadership
have engendered a radical new technology for fabricating electronic devices with atomic-precision
accuracy — a capability that 1s now proving pivotal for both classical and quantum computing. By
manipulating matter at the atomic scale, she led the team that created the world’s first single atom
transistor and the world’s narrowest conducting wires in silicon — results of truly global
sienificance.

Professor Simmons’ major discoveries have positioned Australia at the forefront of modern
experimental physics. Her vision, her empirical attitude, her determination and her ability to lead
teams working across multiple areas of expertise have created a new, powerful, proven approach
for analysing and manipulating nature at the atomic scale. Professor Simmons has become a
pivotal figure globally in both the fundamental and industrial development of atomic-scale
technologies.

The Medal will be presented at the Annual Dinner of the Royal Society scheduled to be held in

2014.

171

The Royal Society of New South Wales

The Edgeworth David Medal 2013

Associate Professor David Wilson

The Edgeworth David Medal, established 1n memory of Professor Sir ‘Vannatt William
Edgeworth David FRS, a past President of the Society, is awarded for distinguished contributions
by a young scientist.

The conditions of the award of the Medal are:

¢ The recipient must be under the age of thirty-five years at 1st January, 2012.
e ‘The Medal will awarded be for work done mainly in Australia or its ‘Territories or
contributing to the advancement of Australian science.

The 2013 Edgeworth David Medal has been awarded to Associate Professor David Wilson of
the University of New South Wales for his exceptional contributions to the mathematical
modelling of HIV/AIDS epidemics, as well as to the evaluation and strategic planning of global,
regional and country-level responses to this disease.

The Medal will be presented at the Annual Dinner of the Royal Society scheduled to be held in
2014.

icaesy

The Royal Society of New South Wales

Royal Society of NSW Scholarships 2013
The Jak Kelly Award 2013

The Royal Society of NSW Scholarships are funded by the Society to recognise outstanding
achievements by early-career individuals working in a science-related field.

The Jak Kelly Award is awarded jointly with the Australian Institute of Physics to the best PhD
student talk presented at a joint meeting with the AIP.

Three Royal Society of NSW scholarships were awarded in 2013, to Jiangbo Zhao of Macquarie
University, John Chan of the University of Sydney and Jessica Stanley of the University of
Sydney.

The Jak Kelly Award was made to Xavier Zambrana-Puyalto of Macquarie University.

The Jak Kelly Award winner presented at the Society’s meeting on 18 December and the other

three winners will be invited to make a presentation on their work at the first Society’s first
meeting in 2014, to be held in Sydney on Wednesday, 5 February 2014.

173

Archibald Liversidge:
Imperial Science under the Southern Cross

Roy MacLeod
Royal Society of New South Wales, in association with Sydney University Press
ISBN 9781-9208-9880-9

When Archibald Liversidge first arrived at the
University of Sydney in 1872 as Reader in |
Geology and Assistant in the Laboratory, he had | . Archibald
about ten students and two rooms in the main
building. In 1874, he became Professor of
Geology And Mineralogy and by 1879 he had

Liversidge

Im pe rial

persuaded the University Senate to open a 4 i FY Science
Faculty of Science. He became its first Dean in fg _ under the
cs Southern
In 1880, he visited Europe as a trustee of the . Cross

Australian Museum and his ‘report helped to
establish the Industrial, Technological and
Sanitary Museum which formed the basis of the
present Powerhouse Museum’s _ collection.
Liversidge also played a major role in establishing
the Australasian Association for the Advancement of
Science which held its first congress in 1888.

This book is essential reading for those
interested in the development of science in
colonial Australia, particularly the fields of
crystallography, mineral chemistry, chemical
geology and strategic minerals policy.

‘To order your copy, please complete the form Liversidge Book Order Form available at:
http:/ /royalsoc.org.au/ publications /books/ McLeod_Liversidge_Order_Form.pdf and return it together
with your payment to:

The Royal Society of NSW,

(Liversidge Book),

121 Darlington Road,

Darlington NSW 2006,

AUSTRALIA

or contact the Society:
Phone: +61 2 9036 5282
Fax: +61 2 9036 5309
Email: info@royalsoc.org.au

a

Re

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eet
TYE e ed
yyy ane
heey

The Royal Society of New South Wales

INFORMATION FOR AUTHORS

Details of submission guidelines can be found in the on-line Style Guide for Authors at:
http://royalsoc.org.au/ publications /author_info.htm.

Manuscripts are only accepted in digital format and should be e-mailed to: editor@royalsoc.org.au
The templates available on the Journal website should be used for preparing manuscripts.
If the file-size is too large to email it should be placed on a CD-ROM or other digital media and posted to:

The Honorary. Secretary (Editorial),
The Royal Society of New South Wales,
121 Darlington Road,

DARLINGTON NSW 2000.

Manuscripts will be reviewed by the Editor, in consultation with the Editorial Board, to decide whether the
paper will be considered for publication in the Journal. Manuscripts are subjected to peer review by at least
one independent reviewer. In the event of initial reyection, manuscripts may be sent to other reviewers.

Papers (other than those specially invited by the Editorial Board) will only be considered if the content is
either substantially new material that has not been published previously, or is a review of a major research
programme. In the case of papers presenting new research, the author must certify that the material has not
been submitted concurrently elsewhere nor is likely to be published elsewhere in substantially the same
form. In the case of papers reviewing a major research programme, the author must certify that the
material has not been published substantially in the same form elsewhere and that permission for the
Society to publish has been granted by all copyright holders. Letters to the Editor and short notes may also
be submitted for publication. Invited discourses may also be published on topics of broader interest; please
contact the Editor to discuss prospective topics.

The Society does not require authors to transfer the copyright of their manuscript to the Society but authors
are required to grant the Society an unrestricted licence to reproduce in any form manuscripts accepted for
publication in the Journal and Proceedings. Enquiries relating to copyright or reproduction of an article
should be directed to the author.

Volume 146 Part 2

Burton, Michael

MQW LUN
3 9088 01681 2935

JAK KELLY SPECIAL EDITION

Mills, David;
Hardie, John &
Hora, Heinrich
Newbury, Richard
Mills, David
Krejcik, Patrick

Kerestes, Zoltan
Williams, Jim
Hora, Heinrich
Ong, Andrew

REFEREED PAPERS
Bhathal, Ragbir

THESIS ABSTRACTS
Lau, Timothy
Yansen
PROCEEDINGS

AWARDS

INFORMATION FOR AUTHORS

Web: www.royalsoc.org.au

9 | 770035 917000

Numbers 449 and 450

CONTENTS
Editorial 74
Obituary of Professor Jak (John Charles) Kelly FRSN 1S

Re-printed from Volume 145, Part 1, Nos. 443 & 444, pp 101-102.

Jak Kelly — Peerless Head of the School of Physics, UNSW 1985-1989
A timely intervention — Jak Kelly and Solar

The development of modern particle accelerators at the Stanford
Linear Accelerator Center |

Paper clips, rubber bands and satay sticks

Ion beams and channelling: the early days with Jak Kelly

Research cooperation with past president Jak Kelly

Highly charged ions and the search for the variation of fundamental
constants

(Jak Kelly Award Winner 2012)

Some aspects of the scientific development and astronomical research
of Penny Sackett

The flow around a fish-inspired heaving and pitching hydrofoil
Ontogenetic ecophysiology of secondary hemi-epiphytic vines
The 2013 Program of events of the RSNSW

The Royal Society of New South Wales Awards for 2013

The Royal Society of New South Wales
121 Darlington Road
Darlington NSW 2006 Australia

E-mail: info@royalsoc.org.au (general)

ia
83
91

103
110
116
136

142

153
155
158
169

Inside Back Cover

editor@royalsoc.org.au (editorial)

Published December 2013