(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Physics of cosmic rays"

:^sz. 



I 



National Aeronautics ^m\ Space Admnist ration 
Goddard Sppce Fli-rht Center 







/mSA TT F-868U . 

V" ^ 



i5T-C!?- 1012^ 




oo^^ ,^^> 



^* .vOV^" 



\i^^ 



.0^^ 



{c^*^ 



rf.'* 



y^ 




N66 2934 



fTHRU) 




^ 













J-/ 



V^/ 



API?IL 1964 



liiAFT TBABSIAnOH 



mSk TT F~B68k 



ST-CR 10 124 



iBYSKS (»■ COSMIC RAYS ♦ 



"EriMda" Ho. 2 

I^. 82 - 87 

(Soscov, February 19^ 



£y G.B. ZtadanoY 



An All^-State Conference cm Cosoic Bays took place in Moscow on 
October ^10 I963, where 130 scientific reports were delivered lay yoting 
scientists. In their reports th^ had spoken about various problems and 
achievenents in the area of cosmic ray mastering. What are the last 
achievementsT What is new direction for future study? All these questions 
aroused intearest of most Soviet scientists. f\ UT 140 ^ 



XJEW IBKHaaCHTS AHD METHODS 

With further penetration into the depth of the attoosphere the cosmic 
ray fliax is rapidly decreasing and at the same time its coorposition be* 
comes more complex* ISierefore^ the penetration into open space depths is 
the main goal of cosmic ray studies. During last year this idea was 
materialised in the form of further development and building of new labor- 
atories on top of high moxmtains in Armenia^ Georgia^ Kazakhstan^ 
Uzbekkistan, in more frequent iise of the Air Force (flights at altitudes 
of 6 •* 12 km) and use of Cosmos-type scientific satellites. 

In order to analyze the nature of cosmic particle interaction with 
atomic nuclei it is iiaportant to make a close comparison with the conditions 



FIZIKA KOSMICHESKIIOI LUCEEY 




2. 



of contemporary eaqperiments tjy means of accelerators^ having more or less 
precise data on energies of colllcljng particles and at the same time a 
broad energy range by cooparison with the most powerful of all existing 
and even ciurrently built accelerators. 

!Biat is \d^ large-*scale coLorimetric installatlans are widely used 
todiy^for th^ allow to register all or part of cosmic particle energy on 
the basis of the casc^bde showers formed by cosmic particles inside thick 
filters divided by rows of ionization chambers * 



A new feature in the 
field is the introdxiction for 
the first tifi^ of Cex^nkov 
cooiputeirs and the use of coo- 
troOLled pliotograihic eauLsion 
instead of ioQizatlom chambers^ 

In case of using photo 
graphic emulsion the axrange- 
ment must be as follows: 
Above certain rows of icnized 
chambers lie mosaic rugs cod- 
sisting of a great mmiber of 
phpto emulsion blocks. Of 






I 






?tv;jtxj 




^ : .. '^^^ . I - - — — — :-l;U( 






*^ 






5- 

6- 






C 



! '" 



9- 



tJ\ 



I 




Fig.l.- One of the typical calori- 
metric inetallations for the study: of 
high-energy nuclear interactions, 
are the rows of hodoscopic 
counters^ 1 -- 12 are rows of ioniza- 
tion chambers* 



these, only that under which a heavy cosmic particle shower has passed is 
subject to development and analysis. 

The application of these various comcplementary methods helped to 
achieve more accurate and reliable results. ThB fiirst onessbiU are some- 
what unreliable, /b\xt decidedly promising results were obtained by reseasrchers 



3* 



bttvlng used spazk cbMft>erBj^ of idiich some types were worked out at NobcoWj 
Yerevan and TbiUal la3x>ratorie8. (jhe most interesting achievements have 
been obtained witb tbe aid of tracking spark cbanibers^ In which It Is 
pOBslhLe to fix the precise spatial picttore of the charged particle trail 
in the fom of a chain of brightly glowing pointsy 




Fig, 2#- Wakes (Trails) of fast | articles in 
the tracking spark chajnbers 



h. 



The informations about the magnitude of a particle impulse can be obtained 
by applying a magnetic field to the spark chamber. Xhe vorking material 
in sparking chamber vas undistorted^ contrary to what happened in the stand- 
ard '^Wilson Chamber**. !I3tierefo3re, the acctaracy of the sparking chambers is 
much higgler than that of the Wilson (Siamber. tEhere are very interesting 
perspectives for the apparatus developed in Yerevan and designed for a 
direct measurement of high"*energy charged particles* ISiis appartus is 
basecl on the registration of transitional eoiission inside stratified 
media vith m periodically modialated index of refaction. Xhe apparatus 
for complex study of broad atmospheric showers, which will also provide 
informations on each of thei&i has also been rapidly modernized. 

A new variant of such installation, occupying an area of about 
k lusctare (2,^71 acres) has been created at Moscow University. !l!he 
total working airea of all gas-discharge counters is of 100 m^ and their 



scintillation 6urea is of 10 m^. 



• 
SPACE FEXSrcS AND COSMIC RAYS 



During lemt yeaurs sresearch in the field of spflu:e pbysics 
developed mfldnly in two directions; Mastering various pxt>ce88es of 
natural acceleration of particles and using these pairtides as an 
instnment for cosmic space soundings. !Ebe various experimental studies 
of charged pasrbicles flows above the Earth's atmosphere in cocobination 
with other geophysical^ flustrqpfaysical researches^ have helped to move 
toward the solution of this fundamental problem. 



5. 



The next object of research in space nearest the Eaurbh and very, 
isiportant for many practical prolxLems consists of Earth ^s radiation belts, 
which tunve been discovered less than 3 years ago. l^ xintil now scientists 
have been using in the majority of cases only descriptive and not alvays 
reliable data about this most interesting phenomenon of the nature, and 
th^gr vere a long vay from the creation of the quantitative theory of 
radiation belts* 

Strict equations of particle flow inside the Earth *s niagnetic field 
could only be written recently talcing into account the non-stationary 
processes, conditioned by comparatively slow variations of this field 
under the Influence of solar corpuscular streams. Calculations have beaa 
made, which show how the slowly varying magnetic field determines simul- 
taneously the acceleration of charged particles and their bilatesral 
scattering. One of the scattering directions from space to Eeurth is 
connected with the capturing of solar corpusctdar flux particles 
(sdar wind) into the magnetosphere of the Earth (as a result of 
scattering, charged particles aire conqpletely trapped by the lines of 
force of the geomagnetic field). At the same time the intej^action of two 
factoids - diffusion of particles inside the magnetic field and their 
spreading on atoms of discharged gas of the otiter atmosphere leads 
toward characteristic spatial distribution of the intensity of elect- 
rons inside the outer radiation belt. 



6. 



I 
to* 



10 





/" 


'^,. 








/ 


V 


N 


V 


1 


' 


N 


[m 


} 





















S H/Rj 7 



Obe same tlieory permits tlie e^cplaxiatiozi 
of tbe cause for tbe aprpearaxsce in tMs 
belt of protons i?ith eiiergy of about 
10 miUioa eV. It is intereBttng to 
point out tbaA siich a celestial 
accelerator, vhich is slsilar to these 
created by men (BSTSAOSON) can probably 
use only 2!f> of energy carried to the 
Earth by the solar wind. 

Similar calculations have 
explained how a relatively lov 
altitiades the protons of higher energy 



Fig. 4#- Dependence of radiation 

intensity on the height H (in 

relative units) for fast elec-* 

trons of the outer radiation 

belt (in the Eaerth'e equatorial 

plane). The solid line gives the (about 100 Merv), injected by cosmic rays 

computations by Tverskaya (19^1) 

and the dashes — the days free* from the Earth's atmosphere, can stay 

vithin the inner radiation belt during several years, while a great heigjht 

(near the exterior border line of the outer blet) they escape into cosmic 

space after several days. 

In parallel with the breathing" of the outer Earth ^s radiation 
belt, two l^pes of cosmic ray intensity variations, well studied for the 
past years, are also being used as sensitive indicatozrs of the electro- 
magnetic processes in cosmic space « 

Bie first type of variation (the Forbush effect) consists in the 
decreasing intensily of emission because of scattering of charged peirticles 
along the non-homogeneous magnetic field in the area of encounter of the 

Sun's corpuscular streaias with the magnetosphere of the Earth* TSxe secoiad 

♦ Lcontinuation of caption!! ••• from magnetic storms (end of I962). 
The corresponding experimental data are given by crosses and small 
circles. The height is given in Earth's radius units (E). 



type (the cosmic ray intensity outbtirsts) are connected with the arrival 
on the Earth of fast-moving charged particles^ dispersed inside the active 
areas of the Sun's corona and then coming under the influence of slov 
diffusion through the magnetized plasma clouds. ^Qxe electromagnetic 
sittHKtion Inside the izrterplanetazy space is varying in accoardance vith 
the eleven year cycle of periodic variations of Sun^s activii^. During 
the years of maYimiwi activity displacement of cosmic rays of galactic 
nature lay the regular one hut vith more powerful corpuscular streams, vhose 
influence can he observed even at such distances as the orbit of Maurs • 

During the years of the Quiet Sun the magnetized plasma clouds are 
dispersing and this leads on the one hand to an increasing (approximately 
twofold) of general giOactic emission beu:kgroTand, and to a more effective 
egr^s of the conpleoeirfcaxy emission, ejected from the Sun during 
chromospherie flares ^ on the other. 

At substantionally larger scales of the whole Galaxy one can 
study the processes of cosmic ray diffusion through a non*-homogeneous 
magnetized plasma with the aid of analysis of primary cosmic emission 
of higher energies (lO^^eV), which induces inside the Earth's atmosphere 
gigantic showers, consisting of many millions even billions of particles. 
However, this analysis is, made more coaqplex because of the possibility 
for cosmic rays to egress into the intergalaetic space, of which we know 
very little. It is nevertheless nearly taken for granted that the 
escperimentally observed sharp break (toward the side of steeper energy 
drop) of the energy spectrum of broad atmospteric showers with energies of 
ICr - ICT eV is precisely related to the variation of the magnitude of 
the diffusive path of respective particles in tl:^ interstellar space* 



8. 



HuciEAB imsics RBSEaaCH 

Durixig past several years theoretical aand eaqperlmerital ptaysicists 
iMure been dlscxwaiikg the hypothesis of the ^f ire balXs** • Sbese are highly 
aetivatedi and hi^bly xmstihle clusters of "pure** laeson field aiovl&g for 
some tlsMF ifibdependently from the hi£^ energy (lOr^ ev) - nucleoai having 
HQdiKreone a nuclear collision. 

Although the nev esqperii&eatal data obtfldned in various laboratorieB 
are not coordinated as yet^ they nevertheless coorpelled us to consider 
that the ig;rpearance of the aysterious ^'f ire balls** is at least not the 
only nay ot generating high-energy particles. 

Que point of vlev on the stibject is that^ alongside the fire balls** 
the formation and tiie subsetaent decay of the higlOy agitated nueleooa ^^ 
isobars of the different aass^ have a decisive role in the generation of 
particles vith hig^ energy. This process must be less effective in 
reOLatlon to the nuober of newly formed particles ( ^ - mesons) but it 
is very effective for transf ering larger amounts of energy to the sepaarate 
ft «> mesons. According to a second^ more radical hypothesis^ the fire 
baUs are fiction, but in reality formation and decay of meson-nucleons 
resonant systems or **re6onoas**, discovered during the last tvo years vlth 
the aid of acceleratosrs, have been observed. Because of their increased 
mass, the resonons can differ from the directly formed ^ « mesons by 
greater energies aaod smaller angles of escape. Discovery ot nev, earlier 
tmknovn, processes of particle generation may still be used for the 
explanation of tvo more recently-revealed anomalies, the **behavlor** of 
cosmic particles with higjh energy. At first it helps to eacjlajn the 



9. 



nature of y ^ ^^^*^^'^^"° formations, vhose niimber/very difficult to correlate 
with the existing theory of birth directly through neutral ^ - mesons. 
Seco3adly, it has been discovered that in the flow of the nucleoactive component 
of cosmic rays, es:pecially at low altitudes, the part of unstable particles 
(mainly charged mescms } /iTonsiderably leurger than eiqpected earlier and con* 
stittites tens of percent at energies above 10 « 10 eV for a relatively 
high atmosphere density. Efforts of theoretical physicists have been directed 
toward the development of the quantitative theory of the peripheral nuclear 
collision, at which only a small part of the total mass and energy of the 
icqpjnging partners has been taking part in the formation of new particles. 
A characteristic feature of such relations is the exchange of the iarpingix^ 
particles with 02^ virtual meson* 
However, certain arguments have 
appeared in favor of the idea that 
besides characteristic for high 
energy peripheral interactions, 
the central type collision may take 
place, leading to simultaneous 
exchange with several virtual 
mesons and therefore with high 

efficiency for the utilization of kinetic energy of two impinging particles 
Finally, eacperimentators have recently started the stxidy of the psorticular*- 
ities of particle interaction with comoplex nuclei in comoparison with siiople 
nucleon-nucleon collision processes. Experimenting with cosmic rays 
physicists have heretofore \isually observed the processes which take place 




rirr. 5. - Scheme of peripheral inter- 
action of hir;h-energy nucleons (Ni,ITp 
vrith participation of virtual mesons 
and 01 the fire ball. Pashes indicate 
the ne^'ly createc particles. 



10. 



in cofSEilex, although at times in light nuclei^ vithoiit partlctalar regard 
to their coiapoaltioii, and otily recently the validity and the i^liahility of 
meaBtoreiDents have reached a level at vhich the resiiLts of collisioiia of 
se^parmte nucleona with the complex nuclei could be cooipared quantitatively. 
Because of this^ the conditions of the eigperioient become dearer. 

pRnainr souBCES 

What aire the prlnaxy sources of cosnic rays? An accurate analysla 
of radioettissions of local 8o\2rces (shells of the already exploded super-* 
novae) has permitted to master the energetic spectrun of particles se«tt«- 
ered by anlarglng shells, and to evaluate the whole energy transmitted to 
chaz^ged partidea (electrons) vhich become comparable with the total energy 
of the shell's magnetic field. It vms also ascesrtained that tte intensity 
of the total Galaxy radioemission (vhich is not coxmected with the rwmainc 
of supemovae) is mpproximately 100 times greater than the cosmic emission, 
wandering in the Galaxy «s a result of formation of secondary electrons. 
!I!be3refore, there arises the problem of searching for dlx-ect sources of 
electrons and of high-energy | - quanta (up to 10^^ • 10 eV). Hhe 
recently discovered explosion of the nucleous of one of tl^ distant 
Galaacies paves the way toward a new solution of the problem of cosmic ray 
sources in oxur Galai^. 

It is a fact that the power of such an explosion is minions of 
times greater than its effect on the average sixpemova* One such eiqplosion 
can supply our 3slaxy with cosmic rays for the next ^ « 100 million years. 
Calculations show that such hypothesis can even explain^ with the help 
of additional assuoQ>tion8, the cosmic rays energetic spectrum Inside 



21. 



our GmJjta^^ ^verer^ it can do so again vith the process of their diffusion 
through a non<»imifondy flMignetized interstellar pLasffls. Very interesting 
possibilities for verifying these various theories of the origin of coaaic 
rsoTB arise fron the anal^is of the isotopic coaposition of the aeteorite 
aatter* Qiis can in principle provide data on the intenai^ of coaaic 
r^ys at the reoote periphery of our solar system and far back in its 
history, as veil as that of the @ala3Qr as a vhole* 



* « 



EHD * ♦ 

Draft by N. A. PlrogOT 

Eeviaiftd by AIDEBB L* BEtlCHiffF, 
Consultants & Designers, Ine«, 
Arlington, Virginia, Ik j^prll X9Sh. 



G0DDABD8IC 


610 


NBBEDIXH 


6U 


Mc ixmuj> (3) 




FICBIBL 




USSWIS 




BH 


612 


BSniER (3) 


613 


KDHniAl (3) 


6Lk 


LUDEUff (3) 
BOOBEBAU (3) 


615 


6to 


BESS (3) 


651 


SHSHCER 




BEvrroH 


252 


LXHUBY (?) 


256 


FBEASB 



D3BTRISUII0II 



MASA HQg 



(XEBEBS 



ss 


BEHEU., CUBK 


AMES _ Sonett 


SP 


STAHBBU. 




S6 


BAUBIS 
SCHARDT 


JH. (5) 




¥EU£MS, JXJBJS 


IBS (5) 




HnSBERy BiQBOIHIIZ 






BONAH 






StOTR 




SL 


GAIXaSR 




SM 


Gm. 




RIR 


HBni. 




A1!8S 


SCBIBD 




ADA