Detector Simulation Studies for the proposed Gamma-Ray and AntiMatter Survey (GRAMS)

Abstract

GRAMS is a proposed balloon and satellite-borne gamma ray and antimatter detector aimed at exploring the MeV energy bandgap as well as indirectly detecting dark matter. This study addresses the MeV detection capabilities of GRAMS via truth-level GEANT4 simulations, as a function of detector geometry and response. In particular, we examine Compton scattering as the vehicle for point source detection. As a first study, we applied the simple backprojection algorithm of Compton cameras to accurately reconstruct point source location and energy and examined the all-sky angular resolution of GRAMS, using truth-level detector information. We also calculated the point source sensitivity against a power-law isotropic background spectrum as observed by COMPTEL