RADIATION EXPERIENCED BY ASTRONAUTS DETERMINED WITH CR-39 DOSIMETERS USING A HUMAN PHANTOM ON ISS

摘要

Humans will soon return to the moon and travel to the planets near Earth. Space radiation hazards are a key concern for human spaceflight. Radiation in deep space is much stronger than that in low Earth orbit (LEO). The radiation impact on humans depends strongly on the particles' linear energy transfer (LET) and is dominated by high LET radiation. CR-39 plastic nuclear track detectors (PNTDs) and thermoluminescent dosimeters (TLDs) are now widely used in radiation measurement and proved to be the best passive dosimeters. The Matroshka facility, using a human phantom torso provided us with the best opportunities to measure radiation for the astronaut's organs. CR-39 detectors were placed at different organ positions outside International Space Station (ISS) (Matroshka-1, 616 days) and inside ISS (Matroshka-2, 367 days). The LET spectra measured for an astronaut's organs will be useful for the further research on the radiation risk to astronauts. This paper introduces the role of high LET radiation in radiobiology, the LET spectrum method for radiation measurement using CR-39 detectors, and presents the LET spectra and radiation quantities determined with CR-39 PNTDs for the Matroshka experiment and compares the radiation levels outside and inside ISS for the same organ.