As has been seen with previous space-based X-ray missions (XMM-Newton and Chandra), in addition to the actual X-rays propagated in the telescope mirror structures, the environmental charged particle background can pose a significant challenge to the operation and scientific outcome of such missions.
Of particular importance are low-energy protons and electrons transported via low-angle processes (e.g. “Firsov scattering”) along the mirror surfaces to the focal plane, leading to potential damage in the imaging instrumentation. While sweeping magnets can be employed to partially alleviate the problem, such mirror scattering processes are still today not fully understood. This source of background over the scientific observations is combined with the background induced by the incident primary radiation environment from galactic cosmic rays, solar particle events and L2 magnetotail charged particles, and a broad range of prompt and delayed secondary particles generated within the rest of the spacecraft. All these sources to be considered in the design of the telescope and its instruments.
This activity shall produce a software simulator to fully address the above radiation background issues encountered by Athena and adaptable to other future X-ray missions, together with the development of improved L2 halo orbit radiation environment models.