The measurement method of gamma ray air absorbed dose rate based on LaBr 3 (Ce) detector

Abstract

Objective Based on the lanthanum bromide scintillator detector, the calculation method of G( E) function was developed to measure the air absorbed dose rate. Methods Firstly, the gamma energy spectrumof the lanthanum bromide detector were simulated and the response functions with different energies were determined with Monte Carlo simulation method. Then, the G( E) function was calculated by the least square method. Finally, the air absorbed dose rate measured by the lanthanum bromide detector using G( E) function conversion method was compared with the theoretical calculation value based on the point source experiments. Results The experimental verification results showed that the relative deviation between thecalculated value with G( E) function and the theoretical calculation value wasmostly controlled within ± 6%, which verified the accuracy of G( E) function. Conclusion The results showed that the method of G( E) function could be applied to calculate the gamma radiation dose rate based on the in-situ the gamma spectrum with LaBr 3 detector. 摘要： 目的 针对溴化镧闪烁体探测器, 开展了 G( E) 函数的计算方法研宄, 最终实现了空气吸收剂量率的测量。 方法 首先, 基于蒙特卡罗模拟计算方法, 模拟计算出溴化镧探测器的 γ 能谱, 给出不同能量的响应函数;然后, 利用 最小二乘法计算得到了 G( E) 函数;最后, 利用标准点源实验, 将溴化镧探测器利用 G( E) 函数转换测量得到的空气吸 收剂量率与理论计算值进行了比较。 结果 实验验证结果表明, 基于 G( E) 函数得到的空气吸收剂量率与理论计算值 的相对偏差控制在 ± 6% 以内, 验证了 G( E) 函数的准确性。 结论 基于 γ 谱-剂量转换方法, 就地 γ 谱仪可应用于辐射 剂量的测量。