| This thesis concerns design studies for EXIST (Energetic X-ray Imaging Survey Telescope), a future hard X-ray, wide field-of-view, survey telescope. Scanning the full sky every 95 minutes, EXIST will search for black holes and gamma-ray bursts (GRBs). The work involves the background in EXIST's CZT detectors due to radiation environments of possible orbits. In the study, both prompt and delayed background rates are considered. Shielding options are evaluated for their ability to reduce the background rates in EXIST's high-energy detectors. In addition, I examine the feasibility of using active shielding to detect and measure the energy spectra of GRBs. I also incorporate different star formation histories produced from semi-analytical models to evaluate EXIST's potential for detecting GRBs originating as early as 200 million years after the big bang. |
