MODEL DESCRIPTION DATA OF TRAPPED RADIATION AS USED TO ESTIMATE THE WEST-EAST ASYMMETRY EFFECT IN THE BRAZIL MAGNETIC ANOMALY

Exposure of spacecraft presented as two semi-spherical layers of diffe rent inside diameters to radiation-belt protons is simulated. The prot on angular distributions are calculated by converting the global trapp ed-proton flux defined by the model description (Russian State Standar d 25645.138-86), making allowance for the proton Aux west-east asymmet ry. The calculation results have shown that the occurrence of the west -east asymmetry effect at altitudes of < 500 km in the Brazil magnetic anomaly permits the equivalent dose received by a crew to be reduced additionally by a factor of 1.5-2.0 by means of an appropriate reorien tation of a spacecraft and the choice of an optimal distribution of th e shielding matter masses. Copyright (C) 1996 Elsevier Science Ltd.