Development of a Monte Carlo Simulator for the Astro-E2 hard X-ray detector (HXD-II)

The Hard X-ray Detector (HXD-II) is one of the scientific payloads on board the fifth Japanese cosmic X-ray satellite Astro-E2 , scheduled for launch in 2005. The HXD-II is designed to cover a wide energy range of 10-600 keV with a high sensitivity of about 10/sup -5/ cnt/s/cm/sup 2//keV. In order to derive the energy response of the sensor and to estimate the background, a Monte Carlo simulator based on the Geant4 toolkit is currently being developed. This paper describes the design concept of the HXD-II software package, including the analysis tools and the Monte Carlo simulator, and its verification through a comparison with actual data taken by pre-flight radio-isotope irradiation experiments, together with calculated outputs that can demonstrate the in-orbit performance of the HXD-II.