Effect of low irradiation temperature on the gamma-ray response of dyed and undyed PMMA dosimeters

Abstract

Temperature effects on dose responses of undyed and dyed polymethylmethacrylate (PMMA)_dosimeters were studied at doses of 2 and 25 kGy under irradiation temperatures from −196°C to +45°C. At 25 kGy, Radix RN15 has linear dependence with a coefficient of +0.15%/°C and +0.25%/°C for irradiation temperature below and above −15°C respectively, and Red 4034 and Amber 3042 have smaller dependence in this temperature range, although Red 4034 has relatively high responses at −196°C and −78°C. At a dose of 2 kGy, dose response of Amber 3042 increases nearly linearly with temperature above −78°C with a coefficient of about 0.5%/°C. The dose response of Gammachrome YR below −78°C is almost 30% higher than that at 20°C and decreases with increasing temperature above −78°C with temperature coefficient of −0.3%/°C.