X ray measurements at the South Atlantic Magnetic Anomaly

Balloon-borne experiments, using omnidirectional scintillation detectors which measure X-rays having energies between 30 and 150 keV were conducted during 1981 from Sao Jose dos Campos-Brazil. The measurements detected an intensification in the X-ray flux associated with a strong geomagnetic storm. The flux enhancement in this energy range, attributed to electron precipitation, was determined to be about 0.007 photons/sq cm s keV at 5 g/sq cm. The results are compared to similar ones obtained in the region of the South Atlantic Magnetic Anomaly and their implications are discussed briefly in the context of local energetic electron precipitation.