-his research was supSpace Administration --of the Magnetosphere,
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Ai3STFWTSeveral recent observations of low-energy proton and e l e c t r o n i n t e n s i t i e s within t h e energy range -100 eV to 50 keV i n t h e e a r t h ' s r a d i a t i o n zones with a s e n s i t i v e array of e l e c t r o s t a t i c analyzers borne on t h e e a r t h -s a t e l l i t e OGO 3 during mid-1966 a r e summarized.
Measurements of charged p a r t i c l e s of t h e e x t r a t e r r e s t r i a l r i n g current during a moderate geomagnetic storm, of t h e low-energy proton and e l e c t r o n d i s t r i b u t i o n s i n t h e v i c i n i t y of t h e midnight 'trappingboundary' near t h e magnetic equatorial. plane, and of upper limits for proton and i o n (100 eV < -< 50 keV) energy f l u x e s deep within t h e inner r a d i a t i o n zone a r e presented together with several introductory comments concerning t h e morphology of t h e omnidirectional i n t e n s i t i e s of energetic e l e c t r o n s (E > 40 keV, > 230 keV and > 1.6 MeV) a t t h e magnetic equator i n t h e outer r a d i a t i o n zone.
INTRODUCTIONA l a r g e c o l l e c t i o n of d e t a i l e d observations of energetic charged p a r t i c l e s within t h e v a s t region e n c i r c l i n g t h e e a r t h which i s dominated by t h e geomagnetic f i e l d has been acquired since t h e i n i t i a l discovery of intense fluxes of energetic protons and e l e c t r o n s i n t h e s e regions, t h e inner and outer r a d i a t i o n zones, with earths a t e l l i t e measurements i n 1958.observations of electrons E 2 10 keV and of protons E 2 100 key with instrumentation borne on earth-orbiting s a t e l l i t e s a t low and high a l t i t u d e s , -several hundred kilometers t o 30have been published over t h e p a s t several years [Van AJ-len, 1963; O'Brien, 1964a;Shabansky, 1965;Hess, 1965; Frank, 1965al. d
i r e c t e d toward d e t a i l e d s t u d i e s of e l e c t r o n and proton i n t e n s i t i e s i n t h e above energy ranges within t h e e a r t h ' s r a d i a t i o n zones, lower energy charged p a r t i c l e s with energies E < 10 keV dominate t h e s e regions i n terms of energy d e n s i t i e s and number d e n s i t i e s . For example, t h e r a t i o s of t h e number d e n s i t i e s and energy d e n s i t i e s of t h e oftenobserved e l e c t r o n (E > 1 MeV) i n t e n s i t i e s i n t h e h e m t of t h e outer r a d i a t i o n zone near t h e magnetic equatorial plane a t 4.5 t o t h ecorresponding number and energy d e n s i t i e s of e l e c t r o n s (E 5 10 keV) axe frequently -3 X 10 and 2 X 10-, respectively. Although t h e s e energetic
Current reviews concerning t h e (%, e a r t h r a d i u s ) ,Although t h e major f r a c t i o n of t h e l i t e r a t u r e has been Tu Tu -6 3 4 charged p a r t i c l e d i s t r i b u t i o n s have been and a r e p r e s e n t l y being thoroughly surveyed v i a i n s i t u measurements, t h e observations...
