ALANINE-POLYSTYRENE DOSIMETERS PREPARED BY INJECTION-MOLDING

The alanine-polystyrene dosimeters analysed by electron spin resonance (ESR) spectrometry were manufactured for large-scale use as a routine dosimeter in industrial radiation processing facilities by using an i njection moulding method. Injection moulding enables us to achieve mas s production of uniform dosimeters at a reduced cost. Their primary ch aracteristics for dosimetry were studied in terms of their gamma-ray d ose-response at radiation processing dose levels, precision, and effec t of temperature during irradiation at an absorbed dose of 1 kGy. The precision of dose-response in the range 0.1-100 key is within +/- 2% a t a 68% confidence level with and without correction for sample-to-sam ple mass scattering. The irradiation temperature coefficient for dosim eters irradiated to 1 kGy is estimated to be 0.25%/degrees C, by norma lizing to those irradiated at 25 degrees C in the temperature range fr om 5 to 45 degrees C. The fading of the radiation-induced ESR signal a t doses of 0.1-100 kGy at 25 degrees C and r.h. 40% is < 1% for at lea st 2 months after irradiation. (C) 1997 Elsevier Science Ltd.