2015/04/23 by Adriani, O., Barbarino, G. C., Bazilevskaya, G. A. +56
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Space Physics (physics.space-ph)
paper · doi:10.48550/arxiv.1504.06253
We present a precise measurement of downward-going albedo proton fluxes for kinetic energy above ∼ 70 MeV performed by the PAMELA experiment at an altitude between 350 and 610 km. On the basis of a trajectory tracing simulation, the analyzed protons were classified into quasi-trapped, concentrating in the magnetic equatorial region, and un-trapped spreading over all latitudes, including both short-lived (precipitating) and long-lived (pseudo-trapped) components. In addition, features of the penumbra region around the geomagnetic cutoff were investigated in detail. PAMELA results significantly improve the characterization of the high energy albedo proton populations at low Earth orbits.