Characteristics of Mg2SiO4:Tb (TLD-MSO-S) relevant for space radiation dosimetry

A PAssive Dosimeter for Life-science Experiments in Space (PADLES) has been developed for measuring total absorbed dose and dose equivalents in the radiation environments of the International Space Station (ISS) where the Linear Energy Transfer (LET) of radiation ranges from 0.2 (ionization minimum) to 10(3) keV mu m(-1) or more. PADLES consists of two types of passive and integrating radiation detectors: MSO-S (Mg2SiO4:Tb) ThermoLuminescence Dosimeters (TLDs) and antioxidant-doped CR-39 plastic nuclear track detectors. In this paper, we first describe a method to obtain a water-equivalent absorbed dose by combining data from these two types of detector. In order to increase the reliability of PADLES for ISS space radiation dosimetry, we investigated the following characteristics of MSO-S TLDs: calibration of our ThermoLuminescence (TL) readout system for high-energy protons and gamma rays from Co-60 and Cs-137 sources; dose responses for high-energy heavy ions (He, C, Si, Ar, Fe); response variation of different manufacture batches; directional response for the high-energy protons; the initial variations and long-term fading effects of the TL response for high-energy protons and heavy ions at temperatures from -80 degrees C to 60 degrees C; and LET response. (C) 2011 Elsevier Ltd. All rights reserved.