X rays from Van Allen belt electrons

Abstract

The x-ray spectrum due to atmospheric absorption of Van Allen radiation belt electrons is calculated, based on the assumption that small-angle atmospheric scattering is the dominant loss mechanism for these electrons. It is concluded that, although the x-ray flux is highly variable, at peak intensity it should be detectable above the cosmic radiation background at balloon altitudes. A detailed series of balloon measurements of the x-ray flux at several locations around the earth, including the Capetown region, could provide quantitative data on the rate at which electrons are lost from the radiation belt and, therefore, information on the Van Allen electron source strength. Such measurements would provide an experimental test to differertiate between the neutron decay origin and the local acceleration origin for the Van Allen belt electrons. Funthermore, it should be possible from such observations to make a definitive statement as to whether the primary loss of outer zone electrons occurs through atmospheric scattering or through rapid dumping during geomagnetic storms. Specific balloon experiments are suggested. (auth)