Low Energy Trapped Protons and Electrons

Abstract

The directional intensities of 100 keV to 10 MeV protons and the directional energy flux of 10keV to 100 keV electrons have been measured on Explorers satellites XII, XIV, and XV. Preliminary results on the spatial distribution and spectra of the low energy protons and the temporal characteristics of the protons and electrons are presented. The total number of trapped protons having energy greater than 97 keV in the region from L = 2.5 to 7 is 4.4 × 10²⁸ protons. The maximum proton intensity, 4.0 × 10⁷ protons/cm² sec ster, occurs at L = 3.5. Below L = 5 the proton intensity is constant to within ± 25 % during magnetically quiet times for the period of observation. Low energy electrons in this region and above undergo abrupt increases of as much as a factor of ten at the beginning of small M-region magnetic storms.