Calibration Method of γ-ray Reference Radiation Field with Low Air Kerma Rate
LI De-hong1,HUANG Chen-wei2,WU Hui-li1,LI Xing-dong1,WU Meng-meng1,3
1. National Institute of Metrology, Beijing 100013, China
2. Henan Province Institute of Metrology, Zhengzhou, Henan 450008, China
3. Chengdu University of Technology, Chengdu, Sichuan 610051, China
Abstract In order to verify whether the use of large volume ionization chamber can measure the low rate of reference air kerma radiation dose rate,a calibrated high pressure ionization chamber and atmospheric pressure ionization chamber were used to measure in reference radiation field produced by different activity Cs-137 source, the difference between the two measurements is less than 0.8%, the difference between the calculated values obtained by quadratic approximation formula and measured values is less than 0.3%. In addition, through verifying the radiation field by the inverse square law,the scattering share of the radiation field was measured by the shadow mask method,and the results show that the radiation field can meet the requirements of ISO-4037.
LI De-hong,HUANG Chen-wei,WU Hui-li, et al. Calibration Method of γ-ray Reference Radiation Field with Low Air Kerma Rate[J]. Acta Metrologica Sinica, 2011, 32(z1): 18-21.
［1］ISO4037-1,part 1:X and gamma reference radiation for calibrating dosimeters and dose rate meters and for determining their response as a function of photon energy［S］.
［2］容超凡.电离辐射计量［M］.北京:原子能出版社,2002.
［3］Fernande S E. The radiation field characteristics of a 137Cs source used for calibration of radiation protection instruments［J］.Applied Radiation and Isotopes, 2004,61(6) :1425-1430.
［4］丁民德.环境辐射仪器γ照射量率刻度的阴影屏蔽法［J］.原子能科学技术.1989,23(3):8-14.
［5］Steele D R, Petrie C M, Herminghuysen K, et al. Evaluation of the shadow shield technique for the measurement of scattered radiation ［J］.Health Phys,2011,101(1):59-66.
［6］Attix F H. Introduction to Radiological Physics and Radiation Dosimetry［M］.Weinheim: Wiley-VCH,1986.
［7］Minniti R, Seltzer S M. Calibration of a 137Cs gamma-ray beam irradiator using large size chambers ［J］.Appl Radiat Isot,2007,65(4):401-406.
2011, Vol. 32 
