One of the science goals of the Wide Field Imager (WFI) on ESA's Athena X-ray observatory is to map hot gas structures in the universe, such as clusters and groups of galaxies and the intergalactic medium. These deep observations of faint diffuse sources require low background and the best possible knowledge of that background. The WFI Background Working Group is approaching this problem from a variety of directions. Here we present analysis of Geant4 simulations of cosmic ray particles interacting with the structures aboard Athena, producing signal in the WFI. We search for phenomenological correlations between these particle tracks and detected events that would otherwise be categorized as X-rays, and explore ways to exploit these correlations to flag or reject such events in ground processing. In addition to reducing the Athena WFI instrumental background, these results are applicable to understanding the particle component in any silicon-based X-ray detector in space.
Cite
@article{arxiv.2012.01347,
title = {Reducing the Athena WFI charged particle background: Results from Geant4 simulations},
author = {Catherine E. Grant and Eric D. Miller and Marshall W. Bautz and Tanja Eraerds and Silvano Molendi and Jonathan Keelan and David Hall and Andrew D. Holland and Ralph P. Kraft and Esra Bulbul and Paul Nulsen and Steven Allen},
journal= {arXiv preprint arXiv:2012.01347},
year = {2020}
}
Comments
9 pages, 6 figures, to appear as Proc. SPIE 11444-53