Observation of the radiation environment and solar energetic particle events in Mars orbit in May 2018- June 2022

Jordanka Semkova; Rositza Koleva; Victor Benghin; Krasimir Krastev; Yuri Matviichuk; Borislav Tomov; Stephan Maltchev; Tsvetan Dachev; Nikolay Bankov; Igor Mitrofanov; Alexey Malakhov; Dmitry Golovin; Maxim Litvak; Anton Sanin; Alexander Kozyrev; Maxim Mokrousov; Sergey Nikiforov; Denis Lisov; Artem Anikin; Vyacheslav Shurshakov; Sergey Drobyshev; Nat Gopalswamy

doi:10.1016/j.lssr.2023.03.006

Observation of the radiation environment and solar energetic particle events in Mars orbit in May 2018- June 2022

Life Sci Space Res (Amst). 2023 Nov:39:106-118. doi: 10.1016/j.lssr.2023.03.006. Epub 2023 Mar 31.

Authors

Jordanka Semkova¹, Rositza Koleva², Victor Benghin³, Krasimir Krastev², Yuri Matviichuk², Borislav Tomov², Stephan Maltchev², Tsvetan Dachev², Nikolay Bankov², Igor Mitrofanov⁴, Alexey Malakhov⁴, Dmitry Golovin⁴, Maxim Litvak⁴, Anton Sanin⁴, Alexander Kozyrev⁴, Maxim Mokrousov⁴, Sergey Nikiforov⁴, Denis Lisov⁴, Artem Anikin⁴, Vyacheslav Shurshakov³, Sergey Drobyshev³, Nat Gopalswamy⁵

Affiliations

¹ Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. Electronic address: jsemkova@stil.bas.bg.
² Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria.
³ State Research Center, Institute of Biomedical Problems, Moscow, Russia.
⁴ Space Research Institute, Russian Academy of Sciences, Moscow, Russia.
⁵ NASA Goddard Space Flight Center, Greenbelt Maryland, USA.

PMID: 37945083
DOI: 10.1016/j.lssr.2023.03.006

Abstract

The dosimeter Liulin-MO for measuring the radiation environment onboard the ExoMars Trace Gas Orbiter (TGO) is a module of the Fine Resolution Epithermal Neutron Detector (FREND). Here we present results from measurements of the charged particle fluxes, dose rates and estimation of dose equivalent rates at ExoMars TGO Mars science orbit, provided by Liulin-MO from May 2018 to June 2022. The period of measurements covers the declining and minimum phases of the solar activity in 24th solar cycle and the rising phase of the 25th cycle. Compared are the radiation values of the galactic cosmic rays (GCR) obtained during the different phases of the solar activity. The highest values of the dose rate and flux from GCR are registered from March to August 2020. At the minimum of 24th and transition to 25th solar cycle the dose rate from GCR is 15.9 ± 1.6 µGy h^-1, particle flux is 3.3 ± 0.17 cm^-2s^-1, dose equivalent rate is 72.3 ± 14.4 µSv h^-1. Since September 2020 the dose rate and flux of GCR decrease. Particular attention is drawn to the observation of the solar energetic particle (SEP) events in July, September and October 2021, February and March 2022 as well as their effects on the radiation environment on TGO during the corresponding periods. The SEP event during15-19 February 2022 is the most powerful event observed in our data. The SEP dose during this event is 13.8 ± 1.4 mGy (in Si), the SEP dose equivalent is 21.9 ± 4.4 mSv. SEP events recorded in Mars orbit are related to coronal mass ejections (CME) observed by SOHO and STEREO A coronagraphs. Compared are the time profiles of the count rates measured by Liulin-MO, the neutron detectors of FREND and neutron detectors of the High Energy Neutron Detector (HEND) aboard Mars Odyssey during 15-19 February 2022 event. The data obtained is important for the knowledge of the radiation environment around Mars, regarding future manned and robotic flights to the planet. The data for SEP events in Mars orbit during July 2021-March 2022 contribute to the details on the solar activity at a time when Mars is on the opposite side of the Sun from Earth.

Keywords: Galactic cosmic rays; Mars orbit; Radiation measurement; Radiation quantities; Solar activity; Solar energetic particles.

MeSH terms

Cosmic Radiation*
Orbit
Radiation Monitoring* / methods
Solar Activity
Space Flight*