Performance characteristics of high resolution Compton telescopes

Abstract

To build upon the goals of the upcoming INTEGRAL mission the next generation soft γ-ray (0.2-20 MeV) observatory will require improved sensitivity to continuum and nuclear line emission while maintaining high spectroscopy to resolve Doppler shifts and broadenings. We present the simulated performance of two germanium Compton telescope (GCT) designs in high Earth orbit conditions. The goal of this work is both to determine realistic sensitivities for the GCTs as well as determine the geometry which best takes advantage of the spectral imaging and stopping power of germanium detectors. We find that a novel Compact design optimizes the sensitivity to both nuclear line and continuum sources with an effective factor of 2.0 improvement over a Classical design. The Compact GCT would provide an order of magnitude improvement in sensitivity over INTEGRAL.