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| 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 |
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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.
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2011, Vol. 32 
