Spatial variation of the inner zone trapped proton spectrum

Abstract

The omnidirectional differential spectrum of trapped protons was measured in the energy range from 10 to 200 Mev in August 1964. At L ˜ 1.4 can be represented by a power law of the form E−n, where E is the proton energy. The exponent n is found to be a function of B and L. For example, at L = 1.6, B/B0 = 1.0, n = 3.75; and at B/B0 = 3.0, n = 2.3. At L = 2, B/B0 = 3.0, n = 4.2, and at B/B0 = 6.0, n = 3.4. The spectrum of protons above 55 Mev does not show the same B, L dependence. These data are evidence that at least two important sources of trapped protons exist in the same region of space.