FIORETTI, VALENTINAVALENTINAFIORETTI2023-02-152023-02-152018http://hdl.handle.net/20.500.12386/33507The HITOMI/SXS instrument, despite its short life, provided more than 300 ks of Non X-ray Background (NXB) data and a unique opportunity for validating the Geant4 simulation of an X-ray micro- calorimeter background against in-flight real data. While HITOMI was flown in low Earth orbit (LEO), hence we expect a different composition for the background source population, the ability to reproduce the NXB spectra detected by the anti-coincidence and calorimeter instruments validated the Geant4 set-up for the X-IFU background simulation and that, in the specific, the X-IFU background evaluation is not missing any unexpected interaction affecting X-ray micro-calorimeters. We present here the Geant4 configuration (e.g. physics models, secondary production cut-offs), the models describing the space radiation environment, the simulated anti-coincidence and SXS X-ray spectra, and the comparison with observations.ELETTRONICOenResearch reportFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering