Progress and Validation of Geant4 Based Radioactive Decay Simulation Using the Examples of Simbol-X and IXO

TL;DR

This paper evaluates Geant4 simulations for radioactive decay and cosmic ray backgrounds in next-generation X-ray space missions, demonstrating potential improvements with DEPFET detectors and validating simulation methods for space applications.

Contribution

It introduces validated Geant4-based radioactive decay simulation for space missions and compares cosmic ray backgrounds for Simbol-X and IXO detectors.

Findings

DEPFET detectors may reduce background flux in X-ray observatories

Geant4 radioactive decay simulation is validated for space applications

Background reduction strategies are feasible for future missions

Abstract

The anticipated high sensitivity and the science goals of the next generation X-ray space missions, like the International X-ray Observatory or Simbol-X, rely on a low instrumental background, which in turn requires optimized shielding concepts. We present Geant4 based simulation results on the IXO Wide Field Imager cosmic ray proton induced background in comparison with previous results obtained for the Simbol-X LED and HED focal plane detectors. Our results show that an improvement in mean differential background flux compared to actually operating X-ray observatories may be feasible with detectors based on DEPFET technology. In addition we present preliminary results concerning the validation of Geant4 based radioactive decay simulation in space applications as a part of the Nano5 project.