Analysis of Activation Effects in Space-Borne &Proton-Beam Irradiated g-Ray Detectors

The selection of detector materials for space-borne discrete energy decay (electron capture, isomeric transition, y-ray system has plreviously been based on the response of the or a-decay) separated by a continuum principally due to p'- scintillator or semiconductor to incident source or background decay. y-rays, and the practicalities associated with the use of these materials in space. 'Today the availability of a greater variety of The availability of an increasing variety of detector detector materials allows potential optidsation for induced materials introduces the possibility of including background radioactive backgroipnd as well, which contributes an important characteristics of scintillators and semiconductors as part of source of backgrounld for instruments in the space environment. the trade-off process in the design of an instrument. This Studies have been conducted on induced activation effects in a paper reports on results collected from Space Shuttle and variety of y-ray detector materials Of interest for space proton beam irradiation experiments to quantify induced applications, including BaF2 and GSO. Results are Presented radioactive background levels in some novel detector experiments. Detailhd radiation transport computer simulations radiation transport calculations, used to predict the processes are used to compai'e and identify the effects observed in the of shielding, activation, radioactive decay and detector experimental spectra and, for the space experiments, to quantify the contributions lo detector activation from the different response. sources of radiation bxperienced in the Shuttle cabin. from Space and Protonmbeam (300 MeV and GeV) materials. These data are compared with output from