Speaker
Description
Notwithstanding notable improvements made in the last decades, the characterization of the near-Earth proton radiation environment is incomplete, with major uncertainties affecting the description of high-energy particles (>50 MeV) in the South Atlantic Anomaly (SAA) region. The Payload for Antimatter-Matter Exploration and Light Nuclei Astrophysics (PAMELA) satellite-borne experiment, operating between 2006 and 2014 at altitudes between 350 and 600 km, has recently provided first direct observations of geomagnetically trapped particles with energies up to a few GeV. Thanks to its high identification performance, it was able to carry out a precise and comprehensive measurement of particle fluxes in low-Earth orbit, including spectral, compositional, and angular information. PAMELA observations are fundamental not only for Space Weather purposes, but because they could help set important constraints on trapping and interaction processes in the Earth’s atmosphere and magnetosphere. Furthermore, they enable the testing and validation of current theoretical and empirical models of the inner radiation belt. In this contribution we report about an improved analysis of trapped protons detected in the SAA region between July 2006 and December 2009.
