Efficiency and angular resolution calculations for a prototype multiple Compton scatter camera

Abstract

Monte Carlo simulations were performed to optimize the layer thickness of a Compton camera which utilizes multiple Compton scatterings. The optimum layer thickness was found to be less than 0.5 mm for 150 keV, 2 mm for 511 keV gamma rays and approximately 5 mm for 1000 keV gamma rays. The efficiencies of two multiple Compton scatter cameras which consist of a 20 layer stack of either 1 mm or 4 mm thick Si strip detectors surrounded by a 2 cm thick CsI(Tl) side counter are presented for 150-1000 keV gamma rays. The expected angular resolution of the proposed design (1 mm thick, 20 layer Si) is presented for different assumed noise levels over the energy range 150-1000 keV.