Predictions of Radiation Backgrounds for GRO/OSSE

In view of the important influence of background radiation induced by the charged particle environment on the sensitivity of space-borne gamma-ray instrumentation, an extensive series of simulations has been performed on representations of hte Oriented Scintillation Spectrometer Experiment and Gamma Ray Observatory Spacecraft. Previously reported results on shielding are summarized and new results are presented on the influence of detector and spacecraft orientation within anisotropic trapped proton distributions. For the cosmic ray calculation, confidence is obtained by comparison with background observations obtained during a balloon flight of a single detector unit over Alice Springs. Keywords: Great Britain; Space radiation; Gamma-ray detectors; Radioactivity; Radiation transport; Sodium iodide.