The dynamics of space radiations as observed by the Energetic Particle Telescope

Abstract:

The Energetic Particle Telescope (EPT) is a new compact and modular ionizing particle spectrometer that was launched on 7 May 2013 to a LEO polar orbit at an altitude of 820 km onboard the ESA satellite PROBA-V. Its high resolution observations show electron, proton and helium ion fluxes in the South Atlantic Anomaly (SAA) and electrons at high latitudes, with high flux increases during SEP (Solar Energetic Particles) events and geomagnetic storms. Several geomagnetic storms were analyzed and especially the big storm event on March 17, 2015 that injected unusual fluxes up to low radial distances in the radiation belts. Other major events appeared during the 4 years of the mission, again with injection of electrons in the inner belt. Spectra in the SAA and the outer belts were also obtained due to the good particle species discrimination of the instrument. Combined with model simulations and comparisons with other satellite measurements, these observations open many perspectives to better understand the source and loss mechanisms associated to the Van Allen belts, especially the dropouts that are observed before the injection of energetic electrons.