Zoetelief J, Jansen J T
TNO Centre for Radiological Protection and Dosimetry, HV Rijswijk, The Netherlands.
Phys Med Biol. 1997 Aug;42(8):1491-504. doi: 10.1088/0031-9155/42/8/002.
Several dosimetry intercomparisons for whole body irradiation of mice have been organized by the European Late Effects Project Group (EULEP). These studies were performed employing a mouse phantom loaded with LiF thermoluminescent dosemeters (TLDs). In-phantom, the energy response of the LiF TLDs differs from free-in-air, due to spectral differences caused by attenuation and scatter of x-rays. From previous studies, energy response correction factors in-phantom relative to free-in-air were available for full scatter conditions. In the more recent intercomparisons, however, full scatter conditions were not always employed by the participants. Therefore, Monte Carlo calculations of radiation transport were performed to verify the LiF TLD energy response correction factors in-phantom relative to free-in-air for full scatter conditions and to obtain energy response correction factors for geometries where full scatter conditions are not met. For incident x-rays with HVLs in the 1 to 3.5 mm Cu range, the energy response correction factor in-phantom deviates by 2 to 4 per cent from that measured free-in-air. This is in reasonable agreement with previously published results. The energy response correction factors obtained from the present study refer to a calibration in terms of muscle tissue dose in-phantom using 60Co gamma rays. For geometries where full scatter conditions are not fulfilled, the energy response correction factors are different by up to about 3 per cent at maximum from that at full scatter conditions. The dependence of the energy response correction factor as a function of the position in-phantom is small, i.e. about 1 per cent at maximum between central and top or bottom positions.
欧洲迟发效应项目组（EULEP）组织了多项针对小鼠全身照射的剂量学比对研究。这些研究是使用装有氟化锂热释光剂量计（TLD）的小鼠体模进行的。在体模中，由于X射线的衰减和散射导致光谱差异，氟化锂TLD的能量响应与空气中的不同。根据先前的研究，在全散射条件下可获得体模中相对于空气中的能量响应校正因子。然而，在最近的比对研究中，参与者并非总是采用全散射条件。因此，进行了辐射传输的蒙特卡罗计算，以验证在全散射条件下体模中相对于空气中的氟化锂TLD能量响应校正因子，并获得在不满足全散射条件的几何形状下的能量响应校正因子。对于半值层在1至3.5毫米铜范围内的入射X射线，体模中的能量响应校正因子与在空气中测量的值相差2%至4%。这与先前发表的结果合理一致。本研究获得的能量响应校正因子是指使用60Coγ射线对体模中的肌肉组织剂量进行校准的结果。对于不满足全散射条件的几何形状，能量响应校正因子与全散射条件下的相比，最大相差约3%。能量响应校正因子作为体模中位置的函数的依赖性很小，即中心位置与顶部或底部位置之间最大约为1%。
