Model calculation of energetic neutral atoms precipitation at low altitudes

Abstract

It has become apparent during recent years that global magnetospheric imaging through the detection of energetic neutral atoms (ENA) will be a crucial tool for the advancement of magnetospheric research via remote sensing technique. This report presents model calculations of ENA precipitation as detectable from a satellite orbiting at low altitudes (<1500 km). The ENA generation via charge exchange between energetic ions and geocoronal neutrals is simulated in the inner magnetosphere, between 1.5 R E and 10 R E , where both neutral densities and ion fluxes are significantly high. AMPTE/CCE energetic ion measurements and the geocoronal neutral H altitude profile are used to simulate the charge exchange process leading to ENA production. We discuss the relative contribution of ring current and radiation belts, as well as the relative contribution of H + and O + to the ENA generation.