Abstract The electron paramagnetic resonance (EPR) response of alanine pellet dosimeters irradiated in a 40 kV x-ray beam with effective energy 9 keV was investigated, which is a factor of three lower than for currently available literature data. The response was compared to the EPR response of alanine pellets irradiated in a reference cobalt-60 field to obtain the relative efficiency of the dosimeter – the ratio of detector response per dose-to-detector in the x-ray beam relative to the reference field. Due to the low filtration of the beam, and subsequent low half-value layer, a correction for the dose gradient within the pellet was necessary to implement for the EPR response of x-ray irradiated pellets. Calculation of the dose gradient in a pellet, together with dose-to-alanine to dose-to-water ratio, was carried out using the EGSnrc Monte Carlo code. The relative efficiency of the alanine pellet dosimeter in this x-ray field compared to a reference cobalt-60 field was found to be G Q , Q 0 = 0.91 ± 0.04 .

中文翻译：

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相对于钴 60，40 k V X 射线束中的丙氨酸颗粒剂量计效率

摘要 研究了丙氨酸丸剂剂量计在 40 kV X 射线束中以 9 keV 有效能量照射的电子顺磁共振 (EPR) 响应，这比目前可用的文献数据低三倍。将该响应与在参考钴 60 场中辐照的丙氨酸颗粒的 EPR 响应进行比较，以获得剂量计的相对效率——X 射线束中每个剂量对探测器的探测器响应与参考场的比值. 由于光束的低过滤性和随后的低半值层，需要对颗粒内的剂量梯度进行校正，以实现 X 射线照射颗粒的 EPR 响应。计算丸剂中的剂量梯度，以及剂量与丙氨酸与剂量与水的比例，使用 EGSnrc Monte Carlo 代码进行。与参考钴 60 场相比，丙氨酸颗粒剂量计在该 X 射线场中的相对效率为 GQ，Q 0 = 0.91 ± 0.04。