Cosmic ray intensity variation measured by Zond 3 and Venus 2 interplanetary probe

Chudakov, A. E.

Logachev, Yu. I.

Lyubimov, G. P.

Pereslegina, N. V.

Vakulov, P. V.

Vernov, S. N.

English

NASA Technical Reports Server

b 
4 
N;lt  iolilil !k ronau t  ics and Space8A&iiini s t r a t ion  
(;oJlJltril Space F l i g h t  Center 
Cont rac t  No.NAS-5-12487 
ST- CR-- PF - IS- 10550 
VARIATIONS OF COSMIC RAYS ACCORDING TO "E DATA OF 
INTERPIANtiTARY PROBES ZOND- 3 ANI1 VENUS- 2 
S. N. Vernov 
A. E. Chudakov 
p *  T",* 7 1 - 1  ... 7 _ _ _  
Yu. 1. Logachev 
G. P. Lyubimov 
N. V.  Pereslegina 
VdKUlUV 
(USSR) 
V I  
0, (ACCESSION NUMBER) 
5 
ITHRU) 
L o/ / 
_- 
27 DECBBER 1966 
https://ntrs.nasa.gov/search.jsp?R=19670009629 2020-03-16T18:54:20+00:00Z
. . 
Doklady A.N. SSSR, 
Geofizika 
Torn 1 7 1 ,  No.3, 
pp. 583-586, 
I Z ~ - V O  "NAUKA'', 1900 
by S. N .  Vernov 
A.  E .  Chudakov 
P.  V.  Vakulov 
Yu. I .  Logachev 
G .  P .  Lyubimov 
N .  V .  Pereslegina 
l h e  intensi ty  variations of cosmic rays are measured by the counters of 
Zond-3 m d  Venus-2; 
count fo r  t h e i r  temporal variations and t o  determine t h e i r  rad ia l  gradient. 
'Yo explain the rad ia l  gradient of protons with energy 1 15 bkv, detected by 
the probes' apparatus, and of which th,. teiii1)oral character is ruled ou t ,  various 
mechanisms a re  proposed, which concern iioth the galact ic  and solar  or igin of these 
protons. 
these probes moving in  different directions allow t o  ac- 
* 
k A 
Two interplanetary probes were simultaneously i n  f l i gh t  ai the end of 
1965 and a t  thr. beginning oC 1966. Tliese a re  VENIJS. 2 and ZOND-3. 
t e r  d r i f t e d  
e r  it. The t ra jectory projections on the e c l i p t i c  plane a re  shown i n  Fig.1. 
The simultaneous measurement of intensi ty  vi l  i.i:itioiis of cosmic rays on probes 
moving i n  d i f fe ren t  directions allows us t o  account i n  the best manner f o r  
t h e i r  temporal variations and t o  find t h e  dependence of t h i s  quantity 011 the 
distance from the Sun, tha t  i s ,  t o  determine t h e i r  rad ia l  gradient.  The est i -  
mates of the la t ter  were published earlier i n  references [ l - 3 3 .  
While the l a t -  
away from the Sun during i ts  motion, the former was drawing near- 
In Fig.2 we brought out the resul ts  of measurements of cosmic ray inten- 
s i t y  by the gas discharge counters STS-5 ins ta l led  aboard Venus-2 and Zond-3 
for t h e  period from 14 November 1965 t o  2 1  January 1966. 
ging of data was done for  4-hour interval ,  except for  the portion 19-26 Decem- 
ber 1965, fo r  which the average available covers the en t i r e  interval .  
available from Zond-3 f o r  tha t  time are only i n  the form of average values for  
large time intervals  (5  t o  7 days and more). 
4-hour values of the counting r a t e  oC the neutron monitor a t  Deep River. I t  may 
On Venus-2 the  avera- 
The data 
Plotted i n  Fig.4 a re  a lso the 
*VARIATSII KOSMICHESKIKH L~JCHEY PO DANNYM s rwsn ZOND-3 I VENERA-2 
2.  
be seen froiri Fig. .?  t h a t  the variations of intensi ty  in  d i f fe ren t  regions of 
interplanetary space 113vc iict only a d i f fe ren t  amplitude, but are  noncontem- 
porary, which is  par t icu lar ly  c lear ly  seen by the time of occurrence of cha- 
r a c t e r i s t i c  intensi ty  var ia t ions.  
This is why two f l i g h t  portions were 
chosen fo r  the detennirlation of  the rad ia l  
gradient of cosmic ray in tens i ty ,  a t  the 
beginning and a t  the end of the jo in t  f l i g h t  
of Venus-2 and Zond-3, characterized by a 
r e l a t ive  quiescent s t a t e  of intensi ty  of cos- 
mic rays. The portion t, Erom 15 t o  20 Ncv. 
was chosen a t  the beginning of the f l i g h t ,  
and t, from 4 t o  11 January 1966 a t  tlie end. 
The mean values of i n t ens i t i e s  f o r  these time 
in te rva ls  are  knovm with great  precision, up 
t o  0.02 percent. 
However, since tlie var ia t ions of inten- 
s i t i e s  i n  the regions of Venus-2 and Zond-3 
a re  d i f f e ren t ,  
values of i n t ens i t i e s  were determined by the 
counter readings of Venus-2 , and they were 
taken f o r  the measurement e r ror .  
tlie dispersions of the 4 - h O L I r  
hour 
71 
285 
2 
Ln 
-4 
2 81 
F i g .  1. Trajectory projections 
of Venus-2 and Zond-3 on the 
e c l i p t i c  plane.. The l i nes  from 
the Sun indicate the shape of 
the corpuscular stream f o r  r ad ia l  
velocity of 300 km/sec 
N 
Neutron monitor a t  Deep River 
Fig.2. Cosmic ray in tens i ty  registered on Venus-2 and Zond-3, and by ground 
neutron monitor a t  Deep River 
3. 
As a result of this, all the following values of mean counting rate of 
iond-3 and Venus-2 counters have been obtained for these time intervals, the 
probes being then at average distances R from the Sun as follows: 
where 
NZond-3 (ti, R1) = 26.38 *O.OlS; 
NZond-3 (t2, R2) = 26.31'0.03 ' 
F s - 2  (ti, R3) = 26.17 * 0.015; 
R1 = 182 lo6 km, 
R2 = 192 * lo6 km, 
R3 = 148 10; km, 
R4 = 134 * 10 km. 
(t2, R4) = 25.95 iO.03 ; enus - 2 
The value of the radial gradient, found from these data was 6 = (3.1 f 0.4) % 
on 1 a.u. 
The shift in time of the characteristic peculiarities of cosmic ray inten- 
sity behavior for  the various regions of the solar system may be conditioned by 
the displacement in space of magnetic inhomogeneities, either facilitating or 
hindering the hitting at the given point by particles of primary cosmic radiation. 
It is natural to assume that the displacement velocity of these inhomogeneities 
is near that of the solar wind, i. e., it constitutes some 300 km/sec. 
the time of the joint flight of Venus-2 and Zond-3 the difference of the distan- 
ces from the points of stations to the Sun varied from 30 to 65.  106 km. 
means that the characteristic variations o€ intensity must have been observed on 
Zond-3 
During 
This 
one t o  two days earlier than the torresponding variations on Venus-2.- 
In order to compare the counter readings on the probes Venus-2 and Zond-3 
we plotted in Fig.3 the mean values of intensities registered on the two probes 
at identical and coinciding time intervals (see Fig. 3aj, and ais0 at those 
shifted in time by 
from the Sun for the positions of Zond-3 and Venus-2 at the given moment of time, 
V being the solar wind velocity, equal to 300 km/sec. If we consider that such 
a shift leads to more correct accounting of temporal variations, and if we com- 
pute the gradient of cosmic rays on the basis of the values of intensities ob- 
tained after the shift and of length variation of averaging intervals, we shall 
find for the gradient a value 6 =  5% on 1 a.u. As may be seen from Fin. 3b. 
at = al/ V, where Alis the difference between the distances 
there is an ihegularity of the radial gradient, which may be linked with the 
variation of the character and of  the magnitude of the Forbush effects at various 
distances from the Sun. 
dient is determined by Forbush effects. 
This is why it is possible that the obtained radial gra- 
Two Forbush-drops of cosmic ray intensity took place during the flight of 
Venus-2 (see Fig.2). 
effect, a different character of its development is clearly perceptible. On Venus- 
-2 the Forbush effect sets in very rapidly, 
place in a time less than 4 hours for 31 December 1965 and near 8 hours for 18 Jan. 
1966. 
siderably slower drop, constituting some 2 - 3 days, i.e., 10 times slower than 
for Venus-2. 
Besides the above-noted absence of contemporaneity of this 
the sharp intensity decrease takes 
During both Forbush effects the neutron monitor on the ground shows a con- 
The gradual commencement of the Forbush-effect on the ground may be 
. 
- 
4. 
J 
e i t h e r  explained by the influence of the Earth 's  magnetosphere o r  by the f a c t  
t ha t  pa r t i c l e s  with greater impulses are  measured on the ground by coinparison 
with those on the probe Venus-2. 
pulse/sec ZONU- 33 
' I  
VENUS- 2 I I  I L - J  I 
I 
L!--.- 
I 
-_-- VENJS- 2 L - . r -  - -  - - - 7  
I I 
L . - J - - J  10 20 30 I D  ZD 311 ID 2p  ZOND-3 
Fig. 3. Values of the counting r a t e  for  the probes Venus-2 
and Zond-3 averaged for  several  days during the time of t h e i r  
j o i n t  f l i g h t ;  a) averaging by ident ical  contemporary time 
in te rva ls ;  b) averaging f o r  Venus-2 by time interval  sh i f ted  
r e l a t ive  t o  Zond-3 
I 
Fig.4. Dependence of proton in tens i ty  of 
1 + 5 MeV on the distance from the Sun. The 
dots correspond t o  average dai ly  in tens i ty  
f o r  quiet  days those. with observed proton 
f l a r e s  1 + 5 MeV being excluded 
5. 
Radial Gradient of Protons with Energy 1 2 5  Mev. Besides the sharp increase 
of the counting rate the n - p-detectors installed on the probes Zond-3, Venus-2 
and Venus-3, and sensitive to protons with energy 1 +5 MeV, revealed a very steady 
and rather constant in time background, exceeding by about a factor of 10 the pos- 
sible background of high-energy particles. 
The average daily readings of the proton detectors of Venus-2 and Zond-3 
are plotted in Fig.4. The time periods corresponding to sharp intensity increase 
(flares) are excluded. It may be seen from the graph that the intensity of pro- 
tons rises sharply with the distance from the Sun. 
130 .lo6 to 190 .106km, the intensity of this, apparently isotropic radiation of 
protons with energy 1 tS Mev increased fivefold. 
variation on Zond-3 and Ven~is-2 at different distances of the Sun rules out the 
temporal character of this phenomenon. As follows from Fig.4, the particularly 
rapid rise begins from distances of 160 .1061un. 
As the latter vari.ed from 
The segment of contemporary 
It is natural to assume that these protons have a solar origin. But then 
it is rather difficult to conceive the rise of their intensity as the distance 
from the Sun increases. It is nonetheless possible to propose certain mechanisms 
explaining qualitatively the rise in ixtensity with the distance from the source, 
provided we take into account that here reference is made to intensity ouside 
the channels, along which the ejection of particles from the Sun takes place. 
The sharp increase of intensity at a distance > 1.4 a.u. is evidence that 
the accumulation of protons, egressing along magnetic channels beyond the Earth's 
orbit, takes place at a comparatively small distance from the Sun, say, 1.5 5 2  a.u., 
i. e., we must assume that at these distances the field of magnetic tubes loses 
its orderliness, and the motion of protons acquires a chaotic and possible diffu- 
sive character. Part of particles of this proton belt leaves the solar system, 
and another part diffuses- toward the center. 
In order to explain the gradient we might take advantage of the Parker theory 
forecasting the gradient of galactic cosmic rays, but with the source not at infi- 
nity, but in the form of a ring, disposed in the 1965 period in the region of 
Mars' orbit. The value of the gradient of proton intensity ( 1 + 5  Mev) between the 
orbits of Venus and of the Earth constitutes 100 percent on 1 a.u., that is, 30 
times more than the possible gradient of galactic cosmic rays, This difference 
is apparently justifiable by the difference in particle energy, Incidently, it is 
possible that the application of the Parker diffusion theory for the explanation 
of gradient in the region of the terrestrial orbit, where the magnetic field has 
a quasiregular character, is unlawful. 
However, particle extrusion in the presence of a regular radial field is 
possible when these particles originate from without, at the expense of propa- 
gation from the Sun of magnetic disturbances and shock waves. 
ac'rlitted that the motion of protons in the region of the Earth's orbit takes place 
in a-very orderly fashion, with the preservation of the magnetic moment. 
difficult to expect in this case a gradient of galactic cosmic rays, 
protons of solar origin, the following mechanism is possible. 
But it may be 
It is 
But for 
6. 
Protons of 1: 5 MeV energy, which are often accelerated on the Sun (see 
[ 4 ] ) ,  along the lines of force, are carried at great distances from the Sun, 
where the magnetic field is strongly attenuated and loses its regular character. 
This is why the pitch-angle of particles may vary there in connection with the 
nonpreservation of the magnetic moment. 
the return motion of particles begins toward central regions of the solar system. 
If we assume that the pitch-angle varies basically by small angles, for the re- 
turning particles the maximum because of that must take place for a pitch-angle 
equal to 90’. 
distances from the Sun they must change their pitch-angle only by a small quan- 
tity. 
beyond the limits of the solar system, or return to its central parts with a 
pitch-angle close to 90’. 
dient of protons with energy 1: 5 MeV. 
When the pitch angle becomes > g o o ,  
Further, the particles may perform oscillations, for at great 
Contrary to that particles with a small pitch-angle will either depart 
The considered mechanism must lead to the presence of a large radial gra- 
Moscow State University 
in the name 
of M, V. Lomonosov 
CONTRACT NO. NAS-5-12487 
VOLT TECHNICAL CORPORATION 
i i 4 5  19 th  s t  Tu”v;T 
D.C. 20036. Tel: 223-6700 and 4930. 
bhnuscript received 
on 11 August 1966 
Translated by ANDRE L. BRICHANT 
on 27 December 1966 
REFERENCES 
1. J. A. SIMPSON, C. Y. FAN, P. MEYER. J. Phys.Soc. Japan, 17, Suppl A-2 
Part 2, 505, 1962. 
2 .  S. N. VERNOV ET AL. Kosmich. Issledov. 2, v.4, 633, 1964. 
3 .  
4. 
H. V. “ E R ,  H. R. ANDERSON.- J. Geophys, Res., 69, 1911, 1964. 
S. N. VERNOV, A. E. CHUDAKOV ET - AL. Dokl.AN SSSR, 171, No.. . (in print), 1966. 
. I  
ST-CR-PF-10 550 7 .  
D I S T R I B U T I O N  
NASA HQS OTHER CENTERS GODDARD SPACE F.C. 
100, 110,  400, 601 ss 
610 611 (12) ,  612 (10) SG 
613 ( 6 ) ,  614 (6) ,  615 (6) 
640 HESS 
0 ' KEEFE 
MEAD SL 
NORTHROP 
NAKADA 
OMIDVAR 
JONES 
READING RM RR 
630 G I  f o r  SS (3) RTR 
252 LIBRARY uss 
256 FREAS wx 
I.," VOLT 
NEWELL, NAUGLE 
MITCHELL SMITH 
S O T  
GLASER 
DUBIN 
BRUNK 
MOLLOY 
FELLOWS 
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HOROW I TZ 
KURZWEG 
W I L L  
NAGURNIY 
SWEET 
A F I E S  R C 
SONETT (3) 
LIBRARY 
LANGLEY R C 
116 KATZOFF 
160 ADAMSON 
185 WE&TJ%RWAX 
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183-401 NEUGEBAUER 
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plus a l l  permanent addressees 


Variations of cosmic rays according to the data of interplanetary probes Zond-3 and Venus-2

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