Simulations and Measurements of the Background Encountered by a High-Altitude Balloon-Borne Experiment for Hard X-ray Astronomy

摘要

We have modelled the hard X-ray background expected for a high-altitude balloon flight of the Energetic X-ray Telescope Experiment (EXITE2), an imaging phoswich detector/telescope for the 20--600 keV energy range. Photon and neutron-induced contributions to the background are considered. We describe the code and the results of a series of simulations with different shielding configurations. The simulated hard X-ray background for the actual flight configuration agrees reasonably well (within a factor of $sim$ 2) with the results measured on the first flight of EXITE2 from Palestine, Texas. The measured background flux at 100 keV is $sim$ 4 $imes$ 10$^{-4}$ counts cm$^{-2}$ s$^{-1}$ keV$^{-1}$.