Accession Number : ADA192154

Title :   Deep Dielectric Charging Effects Due to High Energy Electrons in Earth's Outer Magnetosphere,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA SPACE SCIENCES LAB

Personal Author(s) : Baker, D N ; Belian, R D ; Higbie, P R ; Klebesadel, R W ; Blake, J B

PDF Url : ADA192154

Report Date : 05 Feb 1988

Pagination or Media Count : 33

Abstract : Many spacecraft operational problems in Earth's outer magnetosphere appear to be due to intense, transient radiation phenomena. Three types of naturally occurring, and highly variable, hostile particle radiation environments are encountered at, or near, the geostationary orbit: (1) high-energy protons due to solar flares; (2) energetic ions and electrons produced by magnetospheric substorms; and (3) very high energy electrons of uncertain origin. In this report, particular emphasis is given to highly relativistic electrons, (3 approximately 10 MeV). Electron fluxes and energy spectra are shown which were measured by two high-energy electron sensor systems at 6.6 RE from 1979 through 1984. Large, persistent increases in this population were found to be relatively infrequent and sporadic in 1979-81 around solar maximum. During the approach to solar minimum (1981 - present), it is observed that the highly relativistic electrons occur with a regular 27-day periodicity and are well associated with the re-established solar wind stream structures. Through a superposed epoch analysis technique, we show that an energetic electron enhancement typically rises on a 2- to 3-day time scale and decays on a 3- to 4-day time scale at essentially all energies above approximately 3 MeV. The present analysis suggests that these electrons have a very deleterious influence on spacecraft systems due to deep dielectric charging and low-dose susceptibility effects.

Descriptors :   *MAGNETOSPHERE, *SPACE CHARGE, DOSAGE, EARTH(PLANET), ELECTRON FLUX, ELECTRONS, ENERGETIC PROPERTIES, EXTERNAL, HIGH ENERGY, INTENSITY, IONS, LOW LEVEL, MAGNETIC STORMS, OPTIMIZATION, PROTONS, RADIATION, SOLAR FLARES, SPACECRAFT, SPECTRA, TRANSIENTS, DIELECTRICS, SOLAR WIND

Subject Categories : Atmospheric Physics
      Astronautics

Distribution Statement : APPROVED FOR PUBLIC RELEASE