Radiation physics simulator for space X-ray observatory Astro-E2

We constructed a Monte-Carlo simulator framework for the radiation environment of Astro-E2, the Japanese 5th X-ray astronomy satellite. We used Geant4 as the simulator engine, and embedded it into the analysis framework derived from what has been used for other Astro-E2 software development. The entire architecture is designed to make the learning cost of the framework programming as low as possible for not only end users but developers, and we implemented some software mechanisms to register Geant4 components such as physics processes and geometry builder into the framework without using the Geant4's run manager explicitly.