For conservative evaluation of dose equivalent in space, a simple method using two glow peaks in TLD-700 has been proposed. This method is superior to the method using the two-peak ratio in terms of following the 1990 ICRP recommendation. Dependence of each peak on LET was confirmed using relativistic heavy-ion beams (He, C, Ne, Ar, and Kr) at NIRS-HIMAC. TL values as gamma-ray absorbed-dose equivalent of both peak areas were additionally combined to conservatively estimate a dose equivalent over a range of LET of 0.5-440 keV microm(-1). This method was tested in an 8.8-d Shuttle-Mir mission (STS-89) at 400 km x 51.65 degrees. The dose-equivalent rates obtained at two positions in the Spacehab module were about 0.9 mSv d(-1); this result is reasonable in a conservative sense.
Extraterrestrial Environment Gamma Rays