2013 Radiation Belts Workshop: Comprehending, Specifying and Forecasting their Dynamics

Under-cutoff protons at low Earth orbits measured by the PAMELA experiment

1 Jul 2013, 10:00

30m

Island of Santorini, Greece (http://en.wikipedia.org/wiki/Santorini)

Oral AP-9, AE-9 International Collaboration AP-9/AE-9 Business Meeting

Speaker

Dr Alessandro Bruno (INFN, Bari, Italy)

Description

We present a precise measurement of the under-cutoff proton fluxes with kinetic energy > 63 MeV performed by the PAMELA mission at low Earth orbits (350-610 km). The analyzed proton sample was classified into four categories: stably-trapped protons from the inner radiation belt; quasi-trapped protons near the magnetic equator; short-lived un-trapped protons, spreading over all latitudes; and pseudo-trapped protons with chaotic motion at middle-high latitudes, including the penumbra region. The properties of the different magnetospheric populations were investigated in detail, including locations, energy spectra and pitch angle distributions. PAMELA results significantly improve the description of the low altitude radiation environment and can be used to validate various existing models, providing information on the trapping and interaction processes in the magnetosphere.