Citation and Similar Papers at Core.Ac.Ukw

4 https://ntrs.nasa.gov/search.jsp?R=19670007176 2020-03-16T18:43:02+00:00Z View metadata, citation and similar papers at core.ac.ukw .. -. brought to you by CORE I provided by NASA Technical Reports Server 1 . National Aeronautics and STace Administration Goddard Space Flight Center C ont r ac t No NAS -5 -f 7 60 THE OUTERMOST BELT OF CFLARGED PARTICLES _- .- - by K. I, Grin,yaue t: M, 2. I~alOkhlOV cussa 3 GPO PRICE $ CFSTI PRICE(S) $ 17 NOVEbI3ER 1965 Hard copy (HC) .J d-0 Microfiche (M F) ,J3’ ff 853 July 85 Issl. kosniicheskogo prostrznstva by K. N. Gringaua Trudy Vsesoyuzrloy koneferentsii & M. z. Khokhlov po kosaiches?%inlucham, 467 - 482 Noscon, June 1965. This report deals with the result of the study of a eone of charged pxticles with comparatively low ener-ies (from -100 ev to 10 - 4Okev), situated beyond the outer rzdiation belt (including the new data obtained on Ilectron-2 and Zond-2). 'The cutkors review, first of all, an2 in chronolo~icalorder, the space probes on which data on soft electrons 'and protons were obtained beyond the rsdistion belts. A brief review is given of soae examples of registration of soft electrons at high geominetic latitudes by Mars-1 and Elec- tron-2. It is shown that here, BS in other space probes, the zones of soft electron flwcys are gartly overlap7inr with the zones of trapped radiation. The spatial distributio;: of fluxcs of soft electrons is sixdied in liqht of data oStziined fro.1 various sFnce probes, such as Lunik-1, Explorer-12, Explorer-18, for the daytime rerion along the map-etosphere boundary &om the sumy side. The night re-ion of fluxes is exmined fron data provided by Lunik-2, 7xpiorer-12, Z~nd-2~~ni the results of various latest works with reKarr! to the relationshi- of that distribution with the structure of tire marnetic field are exCmined and cornpcved. The essentially new revelation of the magneto-neutral layer on the niRht side is discussed. The temporal vcriations accordin.; to data from Electron-2 are discussed. Finally the p.uthors I.n;ke brief remarks as to the ozigir? af snft electrons 2nd in conclusion they emphasize the imnortance of the outermost zone of charged particles from the geophysical standpoint. A further study is reconnended, pnrticulLvly of the pLvt of the outermost zone where the daytime and nip-httime parts op-arently join near the neutral points on the daytime side and in the mpgneto-neutrzl layer of the nisht part of the zone. * SAP'lYY VTESBNIY POYtS ZA2PAZHE"YKH CH/tSTITS 2. The results of the study of the zone of charged particles beyond the outer radiation belt and whose energies are comparatively low (from - 100 ev to 10-40 kev), are considered in the present work. The study includes more prticularly the new data contributed by observation aboard the satellite Electron-2 and the space rocket Zond-2. As is well known, the Earth's radiation belts were discovered in 1958 during experiments for the study of cosmic rays. In these exneriments the apparatus used was naturally appropriate for the registration of particles with comparatively low enerTies, beginning from tens of kev, and that is why the impression was conveyed at the outset that conditions, characteristic of interplanetary space9 must take place beyond the boundary of the zones of trapred radiation. Xxperiments with charged pnrticle traps on Soviet lunar rockets [l] have revealed that a zone of electron accumulation exists beyond the outer radiation belt near the geomsgnetic equator. In this zone, the concentra- tions and the fluxes exceed considerably those knovm to exist in the outer radiation belt. Accorc'iing to the data of Luna-2, the extension of this zone is of the order of 40000km. The apyearace of intense low-energy particle 8 fluxes ( -10 cm-'.sec'') beyond the outer radiation belt was interpreted as being the result of solar plasma flwtes'interaction with the peripheral regions of the Earth's magnetic ffeld C23. The mechanism indicated in C3] was considered as one of the possible theraalization processes of solar plasma. Scbsequentlg, ether various acceleration mechanisms of solar plasma electrons were also considered [4, 53; however, the basic idea of emergence of the outermost radiation belt, visualizedasaresult of certain boundmy effects of solar plasma fluxes' interaction with the Earth's magnetic field figlly kept its si,gnificance. Although more than five years have elapsed since the detection of this zone by Soviet lunar rockets, a significant part of the works devoted to it appeared only after 1962, so that the terminology, referring to it, is still unsettled. At the outset is was called the !'third radiation belt" C6, 71. TbLen, in 1961 it was proposed C81, in order to underline the distinc- tion of the physical properties of this zone from the radiation belts, to call this intermediate zone of ei:istence of low-energy charged particles, situated between the zone of trapped radiation and the unperturbed SO&= 3. wizld, the outermost belt of charged particles (see.also [9, 103, or, later on, the outermost sone of charged par- t i c 1 e s CUI. Other denomin-tions, and in particular the one proposed in I [12] for fluxes of soft charged particles beyond the boundary of trapped radiation c12], namely n auroral radiation", appear to us less fortunate. Table 1 shows in chronological order (according to launching data) the space probes on which were obtained data on soft electron and proton fluxes beyond the radiation belts, alongside with the method of their observations and the values of the angle x3c (see further the Fig, 71, correspond- inc to the moments of observations. The orbits of most of the space probes enumerated in the table, passe2 near the ecliptic plane. To the number of devices on which fluxes of electrons with energies Ee>lOO ev were observed beyond the boundary of trapTed radiation at high latitudes (and more remote from Earth), so far refer only to Mars-1 and Electron-2. 2. - OBSE2V;;TIONS- AT L0I.J UTITUDES Because of the lack of space we shall limit ourselves here to a brief review of soxe characteristic exxnples of registration of soft electron f luxe3. -".Ine rck;istr:Ltions nf the collector currents of the integral type of charmed particle traps, installed aboard the space rocket Luna-2, launched at the night side, are plotted in Fig.1 . Plotted in the same figure are the data of counter indications of hi3her-energy particles, installed on the reeke+ c207, As may be seen from the diagram, the zone of intensive fluxes of soft electrons are in the consicered case, entiraly beyond the zone of registration of enereetic pzrticles. During experiments aboard Luna-1, fired on the dayliyht side, these zones noticeably overlapped. It should be noted thst the trajectory of Luna-2 passed near the YcomFgnetic equator and crossed it near -8.5 RE. 4. TABLE 1 Space Probe Launching Method of measurements Date Ref erencc %* I LUNA- 1 1 Jan.1959 285 Integral Trap (Electrons with energy E, 7200 ev LUNA- 2 12 Sep.1959 135 Same EXPLOREZ-12 16 Sep.1961 285-36 Integral Detector CdS & 225 (Ec > 200 - 500 ev) MARS- 1 1 Nov.1962 CUI 200 Integral Trap (Ee>lOO ev) EXPLORER- 18 27 Nov.1963 C161 Sane I [17] 270-360Modulation trap (ionsEiNkev, electrons 65- 210 ev) EIECTRON- 2 30 Jan.1964 Ci81 IElectrostatic analyzer ~ (Ions E;- kev) - 290 & Integral trap (electrons 210 with E, > 100 ev) ~ C19 3 Electrostatic analyzer (ions and electrons with E Y 100 ev - 10kev) ZOND- 2 30 Nov.1964 c113 230 Integral Trap (electrons with E, 770ev) L Axis the angle between the directions Earth-Sun and Earth-AES ** ** the original denotation 'Y4 being maintained throughout. I Fig.1. - Collector currents of integral charged particle traps Cl] and counting rate of hard radiationC201 1- upper limit of collector currents in traps with damping grid '0 s - 10, - 5 and 0 v; 2 - lower limit of the same currents; 3- uplyer limit of currents in the trap with '4 = 15~;4 - counting rate in relative units. 5. The intensity course of electron fluxes registered at the daytime side with the aid of integral trap inetalled abowd Explorer-18 is shown in Fig. 2 C16J. As in the case of Luna-2 the electron fluxes were observed on both I sides of the boundary of trapped radiation (on the daylight side near the geo- mxgnetic equator the latter coincides with the boundary of the magnetosphere). Owing to the fact that the orbit apogee of Explorer-18 lay at great qistances from Earth, the outer boundary of the zone of thernnlized solar plasma vas also regis- Fig. 2. - E?.ectrm fluxes with this boundary is identified tered on it; E, 7 100 ev according to data witk the shock wave front. of the integral trap installed aboard Eicplorer- 18 [16] I Proton fluxes were registered in the entire transitional reFion beyond the magnetosphere boundary with the aid of a modulation trap [17] (they were also measured with the help of the I electrostatic analyzer with energies to -5 kev toyether with the omnidirectio-- nal fluxes of electrons in the 65- 210 ev range [17]). In the transitional re-ion, the intensity of fluxes of protons, originating from the side of the Sun exceeded by ?bout a factor of 2 the intensity of the fluxes from opposite direction. 2stl obtained on Explorer-12 at intersection by the probe of the maanetasphere boundary from the subsolar side on 13 3ovembe-r -nfiL~UL aL--- --im++Par*wv--- in the Fig.

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