Trapped proton fluxes at low Earth orbits measured by the PAMELA experiment

TL;DR

This paper presents precise measurements of trapped proton fluxes at low Earth orbits by PAMELA, enhancing understanding of Earth's radiation environment and aiding validation of radiation models.

Contribution

First detailed characterization of trapped proton fluxes at low Earth orbits using PAMELA data, including energy spectra and pitch angle distributions.

Findings

Significant improvement in Earth's radiation environment description

Constraints on trapping and interaction processes

Validation data for trapped particle radiation models

Abstract

We report an accurate measurement of the geomagnetically trapped proton fluxes for kinetic energy above > 70 MeV performed by the PAMELA mission at low Earth orbits (350-610 km). Data were analyzed in the frame of the adiabatic theory of charged particle motion in the geomagnetic field. Flux properties were investigated in detail, providing a full characterization of the particle radiation in the South Atlantic Anomaly region, including locations, energy spectra and pitch angle distributions. PAMELA results significantly improve the description of the Earth's radiation environment at low altitudes placing important constraints on the trapping and interaction processes, and can be used to validate current trapped particle radiation models.