THE NUCLEO-CASCADE PROCESS AND ITS ROLE IN THE DEVELOPMENT OF WIDE ATMOSPHERIC SHOWERS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000600260755-5
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 5
• Document Creation Date: December 22, 2016
• Document Release Date: August 3, 2011
• Sequence Number: 755
• Publication Date: November 15, 1949
• Content Type: REPORT

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CLASSIFICATION CCNPTDFNT:IIL~~~~~~~~~~~~~
CENTRAL INTELLIGENCE AGENCY kEPORT
INFORMATION FROM
S'OREIGP~ DOCUMENTS OR RADIO LiROADCAST5 CD NO,
COUNTRY T~SR
SUBJECT scientific - Ruclear physics
NOW
PUBLISHED Thrice m~thlp periodical
WHERE
DATE
PUBLISHED S1 A,~z 19ug
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THIN OOCONdNT CONTAINI INFO[YATIOM AIFNCri NY iN1 tlAT1UNA4 OOF[NI[
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NO. OF PAGES 5
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THIS IS UNEVALUATED INFORMATION
l IIaL 11 UVl.CIf-CAOVALAY ~W:YJS dLIL 11u A~~
IH TSE DBVSIAP~BT OF SiIDE AT1~4PE8RIC SBCW$RS
3. T. Zat3epir,, Pbye Inst imnni. P. N. Iabedev
Aced Sci l~SR
The results of the cork directed by A^ademiclsa D, q. S~bel'teya of the Physics
Iaetitnta ilmeni P. ]F. Lebedev, force sae to conclude that wido atmospheric ehoxers
carmot be identified xith elsctra~n-photon ahoxera from primary electrons. Analveis
of t'?id data ehoxe the importance of high-energy "nuclao-active" particles and unique
"nuclao-cascade" processes creating these particles do both the mechanism of atmoe-
pherlc shower forma+,ion and the process u>: its development. Szperimbntal data recent-
Jtiv obtained Pram the study of primary particles in cosmic: rays also forces one to
repudiate the nation t}`at a wills atmospheric shower arieee frem one pr?]marq partible.
It ie firmly established at prbeent that moat partic;lRe in primary ce.~lc radi-
ation are heavy aucleo-interacting particles (1, 2) -- mainly protons and some
heavies atomic nuclei (3) -- and now there ie no ranean tc aee~e +,hat there r.re
high-energy electrcme in primary radiation.
The results of the work, which ezpoeed definite anomalies in the phenamenam of
wide shovers, any be etti~med up ae foll~T++e:
1. The dependence oY altitude function upon ehcxer density dose not agree with
awe .a. the (hl
T1C;n~. .. ......,,.. ., .. *~
. ~~ 2. The showers are anomalously ride (5).
3. The high-energy electron-photon comporbent Se not focused in the narrow
region of tho shower "column," but hoe a distribution width actually ezceeding the ~:
theoretical (6). ,~`
Y
L. Tha .~hc,rrero cCntr.+sc a coae]d!NrsLle muober a: pesz9trating pnrtic?.ea. This
fact ie~aeither explained nor considered by the cxecade teary. The current density
of each ptiritclee in atmospheric sho.rere at average altitudes (approzimntely 4 kilo-
motera) it of the order of 1 - 2 percent (7) oP the current demity of electrons is
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eeatrnl (R approaimate3y l00 meters) regions oP the shower. The' spatial dls~ri-
bution of penetrating particles is wider 4E) t}aen that for,electrons.-'}Tak.ngYt~hs
era contained in vide shovers (8) (at an altitude of syprgaimately 4 kilometers,
their number may be roughly evaluated as 1~2 - 1/4 0? tihe number of "nonactive"
penetrating particles in the shower).
largeVaverag, energy per particle, is high end makes up (at am altitude of spproxi-
mmtely 4 kiloaetare) at least tens of percents of the total amergy of the shower
describe the :ormntion and development of a complex shower vhich includes the throe
components duet mentioned (electron-photon, penetrating, and nucleo-active), c:tart-
ing from. thn premise, that the prixaax?y particle generating the shower i.a a heavy
"auclaar" particle and not a high-speed electron. Until recently, there had begin
roc3eees which could form the foundation fcm erecting sucls,a their;/.
t
on
d
p
a
a
ao
liow, hovever, erxch data has bean provided by the discovery of the ao-called "special"
Works rolatirg to the study of specie 1 shovers ~3oth at Mt 1'smir and 1n the
stratosphere) reduce to the following concluelona:
i. Ai oh-enerav nucleo-active narticlee interact with nuclei having nn effectlce
cross section close to the geometric nuclear cross section, thus generating "special
eaploaive showers in the process.
2. Wham the special shover is created, both ~enetrat Lzg particles end high-
caergy electron-photon component are generated (10) (~oesibly through the agency
of decay of extremely short-lived mesons into photcme).
3. At 4- to 5-kilometers altitudes, a considerable number of the particles
(apparently the majority if them) which generate special showers are secondary oar-
tialee. Tbie is apparent ices the fact that there ie a neutral ~nsrnting component
(11) at these altitudes sad- moreover, this girt of the generating particles makes
up one of the components of wide shoxere (10 ).
4. Shokers generated by particles krovn to bs primary (obeervntione in the
stratosphere) have the same character eo the special showers generated by secondary
particles. Thus the geaerat'_cn of special showers is a very common process charac-
teristic of high-energy nucleo-active particles.
Having considered these facts, we deem it possible to melee certain l~ypotheeee
ae the.baeie for interpretir.a wide showers.
1. Wide atmospheric ahoKere are generated by heavy (micleo-active) particles
in primary cosmic radiation.
p, The initial pct ca~zeing such a shover is the stratoaphore le the emergence
oP the epsciel shower (in the cellieior. of n primary particle with an atomic
nucleus).
3. Three cemponerte are generated in this special shover: a soft (electroa-
photon), a penetrating (nu mesons, which probably emerge through the decay of pi
meson9 rather than in the initial act of gererntion), and a nucleo-active component.
Y~~-d~1~~E~~' aol
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4. The cascade process which leads to the emergence oP an avalanche of particles
forming a wide shower as an end result conai.eta, then, of the usual cascade malts^_
rrocesao The latte:? ceacmde process emerges because the nucleo-active particles
formed ia~ the special shower. containing rather high ea?rgy csn_agr~ln_geaerate special
a repetition of the primary nuclear pzocaes which generated the given wide shower.
tho preeenc? of a "ready" electroxi ou the M.rlphErv oP the atmosphere is thus due
net only to the Pact that the generatien process occurs at various atmospheric
l.evele according to the exponential abaorp'tion of primary "nuclear" particleA. Thv
eaparixmentally established fact of ..the eaiatenre of partlcla~ generating specihl
ahcwere Pe a ^ ~^p^rs?+? of wise ehowere (their number 4n the "average" shover ie poa-
eibly 10!{ - l0~) l~Fa? tG the c:-,clasi ~i that, Por sufficiently high energy is the
special ehcwer new nucleo-active high-eaer? particles ere created. Thus, we ors
forced to acxnowledga tuo ezietence of the nucleo-cascade process ,)oat mentioned.
'i"he absence of a maximum curve for ehowere generated by nucleo-tctive particles (12)
dove rot contradict the existence of the nucleo-cascade process, alnce the average
energy of primary particles necessary to create secondary pa~?ticles capable of pen-.
primary particles (approximately 3.10y eY),
Lain natural assumptions relative :o the origin of special high-onargy ehowPra.
1. TLe given hypotheala ie not contradicted by t?ie fact that moat particles
is a shower era el.ectrona. The "critical" energy ie much higher (3109 - 1010 eV)
fox? the nucleo-cascade process than for electrons ;approrlmato.y/ iw 9vj, shoe,
even in the shower's initial phase of development, when the main energy ie probably
~rluded in the "nuclear" component, the shower particles are predominantly electrons
since, in cascade multiplication of particles, the 1? number is inverea~y proportional
to "critical" energy. Iu the nucleo-cascade process, the energy apparently transfers
irreversibly from the nuclear component into the electron-photo and "nucleo-inac-
tive" mz-meson compoasnts. Nbreover, it should be assumed that many particles are
created Sn one act of generation of a bpeciel shower of very high energy. Both of
these factors a+ny load to rapid energy degradation of nuc.'_ear particles, since the
shower's energy may be mainly included in the electron-photon component and mu meecros
at great depths.
2. The anomalously wide distribution of particles in a ah^wer is due to the
]urge angles of separatiau of the initial directions for both penetratixg particles
sad particles of the electron-Thoton caaacnent Sa epac!.al eY.~~o:e (taeee angles are
eo small ae to be disregarded in an electron-photon ehswer). Tha spatial distri-
bution ie also wide because of the long paths cf penetrating-type particles. Since
the ehctron-photon component is creatod in the depths of the shower, its spatial
distribution is determined not only by the angular separation of the iniciel ~!irec-
tioas and scattering but also by the spatial distribution of its generating com-
pomant, The separation of the generating component moat be very great since the
path oP the particles in air cannot be less Lhan one kilometer. The mu mesons have
the gregtest width of separation.
3, The formation of special ehowere in wide showers and the nuclear fissions
connected with them are explained by the emergence of strongly ionizing pa:^ticlc;e
and neutrons (13 ).
It follows from the above discuseiGn that: ~1) the nuclear aspects of a shower
should be observed more clearly with Sncrease in altitude; (2) in wide ehowere,
espeeially in the initial phase oY their develryrmaat, it ie possible to observe a
structure coz~ected with the presence of special eho-vers emerging in air; and (3)
"young" ehowere (low energy) may be observed not only in the stratosphere, but also
~t1~F~D~ a~~AL
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~~Flfl~~~T~.
CO~FII3EidT7AL
50X1-HUM
at a7araga altitudes. Since energy not lase than 1013 - 1G1~+ e4 fe necessary to
Form a wide atsmospheric shaver densse enough to be observed, while lOlO~eY is nac-l
accompanying them. The specLsl shovers generated by those particles in air can-
+.aining alimited number of particles may be abaarved only chart distances from
the glace of emergence before the partiolas scatter over a large area. phis con-
dition holds in the case of "narrow" showers, It is passible to eliminate dlffi-
cultias e::countered in store comic ray phenomena connectr~d with nuclaa2? particles
("etarrs," avacial shovers, etc.) by conei.dering the esistance of the nuclao-cascade
pros???.
:In this article it has 'been iaapossibla to discuss the afore-mentioned hypoth-
esae asp. variations of the uuelso-..accede prMcce c: to ^a^.flider e?~ple?ing this
^_ty. a., ..? vi ~? L'~L`nye2'a fi'O~ `?rs Fta-~dnoint Bat
pracros? to a%plafa other pha.-.oa~:~.. ~ w
forth will haco fresh 9aterest, since further aetailed study of wide showers mill
rave 1 the charactoristics of nuclear interaction oP particles of vary high energies
(loll - 1018 e~). Itirect observations of such garticlae ie not poaeibla.
'Tke author thanes Academician D. V, Skobel~tsyn far directing the work on
the ettr3y of aide shovers and P. I. Pekeler and 1~, N. DobratAn for editing the
article, A. D, Sa:.harov and ~". 1. Fodgaretskiy perticipat6d in discussion of the
]~fpothas es .
i't
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3. 1'. Fraier, $. J,_Lo~graa, E, P. Ley, and F, Oppenbeir~er, F'hye. Rev., 74,
2. s. 1~, ?ernov, ZhE'P?r, 19, Ao 7, 621 (1549).
Charakhch'yaa, :aAl~, 61, 629, (1948),
1., G, T, Zataepln,.4, Y, M111er, I, L: Rozen+sl", and L,?Eh. Eydue, 7.hETF, lj,
1125 (1947).
T, .'.tstaepin aim^. i1111o-t, ii,~TN, 17, 939 f 1947) ,
6, D. K, Alak?eyev, G. T, 2ateepin, and I, G, Marozov, IaRft, 63, 375; (1948?.
7, G, T, Z!teepln, S. A, ~azclaay, and %. L, Rezental', DAl4, 61, 41 (1948),
$. 9', I, 9?keler, L, Y, Kuxnoeov, and A, L. Lyubiznov, ZhBTF, 17, 1026 (1947).
9, G. R. Zhdanov and A, L. Iyublatov, LA17, 55, I19, (1947).
30. ~'. G, Bigger, i1RFT, 60, i"o 9 (1948).
l.l, L, $, Eorablev, A, L, Iyubimov, and A, P, Miller, A9N, 61, 633 (1948).
I2, S, I, Alekeeyev and S, 1G, Varnov, T~AlY, 62, 119 (1948),
13, v. Tongiorgi, Phye. Rev., 73, 923 (1948).
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