不同测量方法对环境γ辐射空气吸收剂量率测量结果的影响分析

Impact of different measurement methods on results of environmentγradiation air absorbed dose rate

探讨采用不同测量方法对环境陆地γ辐射空气吸收剂量率测量结果的影响。本次方法探讨采用BR2000D型热释光剂量读出器和便携式FH40G型高灵敏度环境γ辐射剂量率仪开展连续累积和即时(瞬时)测量。结果表明:两种方法在多个相同地点测量其环境γ辐射空气吸收剂量率,在未扣除方法在各测量点位处的宇宙射线响应前,连续累积测量和即时(瞬时)测量结果范围分别为75~135nGy/h和63~130nGy/h,连续累积测量方法结果大于即时(瞬时)测量方法结果;当扣除测量方法在各测量点位处的宇宙射线响应后,连续累积测量和即时(瞬时)测量结果范围分别为28~83nGy/h和34~94nGy/h,连续累积测量方法结果小于即时(瞬时)方法测量结果。结论:本次方法比对结果在一定程度上证明了选用不同测量方法和仪器设备开展环境γ辐射空气吸收剂量率测量应扣除方法选用仪器探测器对宇宙射线响应的贡献,确保测量数据的剂量评价和可比性,在辐射环境测量方法优化方面有重要意义。

In this study,continuous accumulation and instant(instantaneous)measurement with BR2000D thermoluminescent dose reader and portable FH40G high-sensitivity ambient gamma radiation dose rate meter are compared.The two methods measure the ambient gamma radiation air absorbed dose rate at multiple identical locations.Before deducting the cosmic ray response of the method at each measurement point,the range of continuous cumulative measurement and instantaneous(instantaneous)measurement results are 75-135 nGy/h and 63-130nGy/h respectively,the continuous cumulative measurement method results are greater than the instantaneous(instantaneous)measurement method results.After deducting the cosmic ray response of the measurement method at each measurement point,the range of the continuous cumulative measurement and immediate(instantaneous)measurement results are 28-83 nGy/h and 34-94 nGy/h,respectively.Continuous cumulative measurement method results are smaller than immediate(instantaneous)method measurement results.The results of this method comparison prove to a certain extent that the selection of different measurement methods and instruments for the measurement of ambientγ-radiation air absorbed dose rate should deduct the contribution of the response to cosmic rays by the instrument detector,so as to ensure the dose evaluation and comparability of the measurement data.It is of great significance in the optimization of radiation environment measurement methods.