Harrison R M, Walker C, Aukett R J
Regional Medical Physics Department, Newcastle General Hospital, UK.
Phys Med Biol. 1990 Sep;35(9):1247-54. doi: 10.1088/0031-9155/35/9/005.
Significant discrepancies of up to 10% exist between backscatter factors (BSF) recommended in a recent IAEA dosimetry Code of Practice (1987) compared with those published in Br. J. Radiol. Supplement 17 (1983), for the x-ray quality range 0.1-2.0 mm Al HVL. In an attempt to resolve this discrepancy, BSFs have been measured using thermoluminescence dosimetry (TLD) with small lithium borate chips, in order to minimise displacement effects associated with the use of larger volume ionisation chambers. Although subject to uncertainties inherent in the TLD calibration and readout process, the results indicate that the BJR (1983) data overestimate BSFs in this quality range. Broad agreement with the IAEA data is indicated, for the limited number of x-ray qualities and field sizes used.
与英国《放射学杂志》增刊17（1983年）公布的后散射因子（BSF）相比，国际原子能机构最近的剂量测定操作规范（1987年）所推荐的后散射因子在0.1 - 2.0毫米铝半值层的X射线质范围内存在高达10%的显著差异。为了解决这一差异，已使用带有小硼酸锂芯片的热释光剂量测定法（TLD）测量后散射因子，以便将与使用较大体积电离室相关的位移效应降至最低。尽管结果受到TLD校准和读数过程中固有的不确定性影响，但结果表明，在该质量范围内，英国《放射学杂志》（1983年）的数据高估了后散射因子。对于所使用的有限数量的X射线质和射野大小，结果表明与国际原子能机构的数据大致相符。
