能量响应修正法现场校准固定式γ剂量仪

On-Site Calibration of Stationary Gamma Dosimeter Using Energy Response Correction Method

为解决大范围布放式探测器校准的难题,以便携式X射线为校准源,采用能量响应修正法对固定式γ剂量仪现场校准方法进行研究。在实验室对待校准同类型剂量仪进行了高能区和低能区的能量响应测试,结合蒙特卡罗模拟获取了剂量仪器能量响应曲线;在待标仪器现场,采用替代法对剂量仪器进行校准,通过已得到的能量响应曲线对校准系数进行修正,以获得最终的校准系数。比对实验结果表明,现场校准系数与实验室校准系数误差在5%以内,该方法提高了固定式γ剂量仪测量准确性,对于辐射安全管理和辐射环境评价具有重要意义。

In order to solve the difficult problem of calibration for large range radiation detectors,an onsite calibration method for stationary gamma dosimeter was studied using X ray source. The energy response of both high energy and low energy regions for dosimeter which was the same type as the on-site instrument were tested in the laboratory,and the energy response curve of the dosimeter was obtained using Monte Carlo simulation. Then the substitution method was used for dosimeter calibration in the field,and the calibration coefficients were modified with the energy response curve. The results of comparison experiment have shown that the error between on-site calibration coefficient and laboratory calibration coefficient was less than 5%. This method can improve the measurement accuracy of stationary dosimeter,and it has great reference value for the radiation safety management and radiation environment evaluation.