Radiation of cosmic rays measured on the international space station

Abstract

Radiation impact on astronauts and radiation risk are dominated by high LET (Linear Energy Transfer) particles. The preferred passive personal dosimeters used for astronauts are CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. The Matroshka research facility is designed for investigating the depth distribution of the radiation dose in different organs of astronaut during a mission with or without an EVA (Extra Vehicular Activity). Matroshka experiments conducted successfully in Zvezda service module of ISS (International Space Station) from 2004 to 2006. Radiation LET spectra and quantities were measured for the different organs and skin locations of Matroshka phantom inside and outside ISS using CR-39 PNTDs. The experimental results can be used to determine the radiation quantities for astronauts in LEO (Low Earth Orbit). This paper introduces LET spectrum method using CR-39 detectors and the Matroshka experiments and presents radiation results measured with CR-39 PNTDs for the Matroshka experiments.