Research And The Establishment Of The Alanine / Esr Dose System

This paper studies several dosimetric characteristics of alanine/ESR dosimetry system on 60Co Y -ray and electron beam irradiation. It also makes certain of the best parameters for ESR measurement of alanine film dosimeter, which is produced in big batch by extruding, 30 X 7.5 X 0.2mm3 in dimension, and it's batch homogeneity is better than 0.7%. It's useful dose range is about 20-3 X 105Gy and linear range is 102~104Gy. The linear factor is better than 0.9999 for Y rays and 0.9995 for electron beams. It's ESR response is increased in 0.26%/癈 in the range of 15~50癈 for irradiation temperature, no evident change found for different dose ranges. For IkGy and lOkGy dosimeters, the fading rate is about 1% for one year after being stored in low temperature and low relative humidity (RH<60%). In the range of 299-355K, ESR response is reduced due to low sensitivity with increase of measuring temperature. The results of orientation response in the resonant cavity show that it is best to measure alanine film dosimeter in horizontal orientation paralleling to the magnetic field, which can obtain the highest amplitude and the smallest uncertainty. Besides, no distinct difference of the response between 60Co y -ray irradiation and electron beam irradiation is found, nor energy and dose rate reliability. In the linear dose range, the extensive uncertainty of alanine/ESR dosimetry system is 4% for 60Co Y -ray irradiation and 6% for electron beam irradiation (in 95% confidence level). The agreement is also within the uncertainty when being compared with the alanine and CTA film dosimeters made by JAERI. In addition, this dosimetry system is used to measure field and depth-dose distribution curves for 12MeV electron beams, which shows it's suitability and practicability for electron beam irradiation.This project is one of research plans in Radiometrology Center in NDSTC (National Defense of Science and Technology Committee). It will also make a contribution to unification and dissemination of the quantity values of the absorbed dose for electron beams in CNNC (China National Nuclear Corporation).