IMAGING OF X-RAYS FOR MAGNETOSPHERIC INVESTIGATIONS

X-ray imagers can provide large-scale maps of bremsstrahlung x rays pr oduced by electron precipitation into the atmosphere. Complete day and night coverage is obtained and the electron energy spectra at each po sition in space can be derived from the measured x-ray energy spectra. Early x-ray imagers were limited in field of view and to one map for each pass over the emitting regions. The Magnetospheric Atmospheric X- ray Imaging Experiment, launched on a TIROS satellite, makes time-spac e mappings by scanning a 16-pixel pinhole camera. The data distinguish intensity Variations of a fixed auroral feature from motion of a stea dily radiating feature. However, the spatial deconvolution is complex and features stay in the field of view for only similar to 10 min. The se problems will be resolved by a high-altitude (similar to 9 R(e)) im aging spectrometer PIXIE on the ISTP/GGS Polar Satellite to be launche d in 1994. PIXIE's position-sensitive proportional counter will contin uously image the entire auroral zone for periods of hours.