AREMBES (Athena Radiation Environment Models and x-ray Background Effects Simulator) is an ESA project that foresees the development of a software simulator based on Geant4, capable of addressing all the background issues that the ATHENA mission will experience during its lifetime, together with the development of improved environment models for the L2 halo orbit radiation and the validation of relevant physical processes against available experimental results. The project, wthat has contribution from 10 scientific institutes/SME in 7 different countries, is divided in 3 phases:
1) Analyses of data relative to radiation effects and experience from previous X-ray missions, improvement of L2 radiation environment models, and improvement of the Geant4 physics models,
2) Development of a framework for a user-friendly radiation background simulator, construction of a representative ATHENA geometry model, and validation of the simulator performance
3) maintenance and upgrades.
We are at present in Phase 3.
We will review the results obtained so far in phase 1 and phase 2.