Radiation Dose During Relativistic Electron Precipitation Events at the International Space Station. Issue 7 (6th July 2020) - Ueno, H.
Abstract: We provide a quantitative estimate of the radiation dose during relativistic electron precipitation (REP) events at the International Space Station (ISS). To this goal, we take advantage of the data collected by the CALorimetric Electron Telescope, the Monitor of All‐sky X‐ray Image, and the Space Environment Data Acquisition equipment‐Attached Payload. The three ISS detectors offer complementary REP observations, including energy spectra and flux directional information, during a period of approximately 2.5 years, from November 2015 to March 2018. We have identified 762 REP events during this period from which we obtain the distribution of radiation dose, relevant to extravehicular activities outside the ISS. Plain Language Summary: Extravehicular activities outside the International Space Station have been exposed to a sporadic radiation dose due to so‐called relativistic electron precipitation events. We evaluate the dose rate of such events at the International Space Station for the first time to determine whether the dose rate poses a significant danger to the health of astronauts. Key Points: The radiation dose of relativistic electron precipitation (REP) events at the ISS is quantitatively evaluated We have detected 762 REP events during the 2.5‐year observation and the maximum dose per event was 3.0 mSv The radiation dose during a single REP event can exceed the one induced by galactic cosmic rays in 1 day