Establishment and Performance Testing of Measurement System for 4πγ Ionization Chamber Radioactivity Standard
LIU Jia-cheng1,WU Yong-le1,LIANG Jun-cheng2,YUAN Zhi-lun1,CHEN Jing2,YANG Yuan-di2
1. Nuclear and Radiation Safety Center of Ministry of Environment Protection, Beijing 100082, China;
2. National Institute of Metrology, Beijing 100013, China
Abstract：A measuring system based on Townsend induction balance method for 4πγ ionization chamber radioactivity standard is developed. The measuring system consists of high voltage source, voltage measurement, compensation circuit and control software. During Townsend balance process, the leakage currents and offset current are small in comparison with the current to be measured. The leakage and background current obtained with the measuring system is less than 3×10-14A. Measurements are performed to check the repeatability, stability, linearity and angle response of the system. The testing result shows that the measuring system meets the requirement of 4πγ ionization chamber radioactivity standard.
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2013, Vol. 34 
