PMID- 37945083 OWN - NLM STAT- MEDLINE DCOM- 20231113 LR - 20231113 IS - 2214-5532 (Electronic) IS - 2214-5524 (Linking) VI - 39 DP - 2023 Nov TI - Observation of the radiation environment and solar energetic particle events in Mars orbit in May 2018- June 2022. PG - 106-118 LID - S2214-5524(23)00024-X [pii] LID - 10.1016/j.lssr.2023.03.006 [doi] AB - 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 microGy h(-1), particle flux is 3.3 +/- 0.17 cm(-2)s(-1), dose equivalent rate is 72.3 +/- 14.4 microSv 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. CI - Copyright (c) 2023 The Committee on Space Research (COSPAR). Published by Elsevier B.V. All rights reserved. FAU - Semkova, Jordanka AU - Semkova J AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. Electronic address: jsemkova@stil.bas.bg. FAU - Koleva, Rositza AU - Koleva R AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. FAU - Benghin, Victor AU - Benghin V AD - State Research Center, Institute of Biomedical Problems, Moscow, Russia. FAU - Krastev, Krasimir AU - Krastev K AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. FAU - Matviichuk, Yuri AU - Matviichuk Y AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. FAU - Tomov, Borislav AU - Tomov B AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. FAU - Maltchev, Stephan AU - Maltchev S AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. FAU - Dachev, Tsvetan AU - Dachev T AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. FAU - Bankov, Nikolay AU - Bankov N AD - Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria. FAU - Mitrofanov, Igor AU - Mitrofanov I AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Malakhov, Alexey AU - Malakhov A AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Golovin, Dmitry AU - Golovin D AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Litvak, Maxim AU - Litvak M AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Sanin, Anton AU - Sanin A AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Kozyrev, Alexander AU - Kozyrev A AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Mokrousov, Maxim AU - Mokrousov M AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Nikiforov, Sergey AU - Nikiforov S AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Lisov, Denis AU - Lisov D AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Anikin, Artem AU - Anikin A AD - Space Research Institute, Russian Academy of Sciences, Moscow, Russia. FAU - Shurshakov, Vyacheslav AU - Shurshakov V AD - State Research Center, Institute of Biomedical Problems, Moscow, Russia. FAU - Drobyshev, Sergey AU - Drobyshev S AD - State Research Center, Institute of Biomedical Problems, Moscow, Russia. FAU - Gopalswamy, Nat AU - Gopalswamy N AD - NASA Goddard Space Flight Center, Greenbelt Maryland, USA. LA - eng PT - Journal Article DEP - 20230331 PL - Netherlands TA - Life Sci Space Res (Amst) JT - Life sciences in space research JID - 101632373 SB - IM MH - Solar Activity MH - *Space Flight MH - Orbit MH - *Radiation Monitoring/methods MH - *Cosmic Radiation OTO - NOTNLM OT - Galactic cosmic rays OT - Mars orbit OT - Radiation measurement OT - Radiation quantities OT - Solar activity OT - Solar energetic particles COIS- Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. EDAT- 2023/11/10 00:44 MHDA- 2023/11/13 06:42 CRDT- 2023/11/09 20:56 PHST- 2023/01/16 00:00 [received] PHST- 2023/03/16 00:00 [revised] PHST- 2023/03/25 00:00 [accepted] PHST- 2023/11/13 06:42 [medline] PHST- 2023/11/10 00:44 [pubmed] PHST- 2023/11/09 20:56 [entrez] AID - S2214-5524(23)00024-X [pii] AID - 10.1016/j.lssr.2023.03.006 [doi] PST - ppublish SO - Life Sci Space Res (Amst). 2023 Nov;39:106-118. doi: 10.1016/j.lssr.2023.03.006. Epub 2023 Mar 31.