Precipitation of energetic electrons into the atmosphere

Abstract

Measurements were made of electron fluxes and spectrums above 900 kev at altitudes between 200 and 700 km in early September and October 1962 aboard two near-polar Air Force satellites. The particle fluxes were observed with shielded solid-state detectors having a 2π solid angle. The results show that electrons are lost from the radiation belts into the atmosphere along narrow ranges of L near L = 1.2 and L = 2 as well as in the L = 3 to 8 region. The L = 2 and L = 3 to 8 fluxes and spectrums exhibit temporal variations. A typical precipitating flux at B = 0.35 gauss, L = 2.0, is 103/cm2 sec with E > 0.9 Mev. A typical integral energy spectrum for L = 2, B = 0.35 gauss, is E−3 between 0.9 and 1.7 Mev. Comparison of results with pre-Starfish measurements indicates that the fluxes of electrons observed near L = 1.2 and L = 2 are not connected with the high-altitude explosion of July 9, 1962.