Cosmic-ray flux predictions and observations for and with Metis on board Solar Orbiter

0552553 - ASÚ 2022 RIV FR eng J - Journal Article
Grimani, C. - Andretta, V. - Chioetto, P. - Heinzel, Petr … Total 41 authors
Cosmic-ray flux predictions and observations for and with Metis on board Solar Orbiter.
Astronomy & Astrophysics. Roč. 656, December (2021), č. článku A15. ISSN 0004-6361. E-ISSN 1432-0746
Institutional support: RVO:67985815
Keywords : cosmic rays * solar-terrestrial relations * detectors
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 6.240, year: 2021
Method of publishing: Open access with time embargo
https://doi.org/10.1051/0004-6361/202140930

We aim to formulate a prediction of the GCR flux up to hundreds of GeV for the first part of the Solar Orbiter mission to study the performance of the Metis coronagraph. The GCR model predictions are compared to observations gathered on board Solar Orbiter by the High-Energy Telescope in the range between 10 MeV and 100 MeV in the summer of 2020 as well as with the previous measurements. Estimated cosmic-ray fluxes above 70 MeV n(-1) have been also parameterized and used for Monte Carlo simulations aimed at reproducing the cosmic-ray track observations in the Metis coronagraph VL images. The same parameterizations can also be used to study the performance of other detectors. By comparing observations of cosmic-ray tracks in the Metis VL images with FLUKA Monte Carlo simulations of cosmic-ray interactions in the VL detector, we find that cosmic rays fire only a fraction, on the order of 10(-4), of the whole image pixel sample. We also find that the overall efficiency for cosmic-ray identification in the Metis VL images is approximately equal to the contribution of Z greater than or similar to 2 GCR particles. A similar study will be carried out during the whole of the Solar Orbiter's mission duration for the purposes of instrument diagnostics and to verify whether the Metis data and Monte Carlo simulations would allow for a long-term monitoring of the GCR proton flux.
Permanent Link: http://hdl.handle.net/11104/0327661