MODEL CALCULATION OF ENERGETIC NEUTRAL ATOMS PRECIPITATION AT LOW ALTITUDES

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 rem ote 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 flu xes are significantly high. AMPTE/CCE energetic ion measurements and t he geocoronal neutral H altitude profile axe used to simulate the char ge exchange process leading to ENA production. We discuss the relative contribution of ring current and radiation belts, as well as the rela tive contribution of H+ and O+ to the ENA generation.