Spatial distribution of high-energy protons in the inner radiation belt on the data of low Earth orbit space experiments

TL;DR

This study analyzes high-energy proton distributions in the inner radiation belt using data from ARINA and VSPLESK instruments on low Earth orbit satellites, revealing spatial and energy-dependent patterns during solar cycle phases.

Contribution

It provides detailed measurements of high-energy protons in the inner radiation belt from two space experiments, highlighting their spatial and energy distributions over different solar cycle periods.

Findings

Proton flux varies with L-shell and energy.

Distribution patterns depend on solar cycle phase.

Data enhances understanding of radiation belt dynamics.

Abstract

Measurements of the ARINA instrument on board the Resurs-DK1 satellite (altitude $\sim$ 600 km and inclination $\sim$ 70$^{o}$, since 2006 till 2016) and the VSPLESK instrument on board the International Space Station (altitude $\sim$ 400 km and inclination $\sim$ 52$^{o}$, since 2008 till 2013) in low Earth orbits were presented in this report. Both instruments are identical in terms of physical layout. They can measure high-energy protons in the range 30-100 MeV with 10\% energy resolution and 7$^{o}$ angular accuracy. Data analysis was carried out for the total period of proton flux measurement by the instruments. L-B proton distributions in the inner radiation belt (L$<$2) were studied in dependence on proton energy. Geographical and pitch-angle distribution of proton intensity were studied for chosen L-shells. These distributions were analyzed during the decreasing part of the 23$^{rd}$ solar cycle and the main part of the 24$^{th}$ one.