Ogunleye O T, Attix F H, Paliwal B R
Phys Med Biol. 1980 Mar;25(2):203-13. doi: 10.1088/0031-9155/25/2/001.
Cobalt-60 gamma-ray absorbed dose measurements were carried out using LiF thermoluminescent (TL) dosemeters to obtain additional insight into cavity theory as applied to dosemeters of a size intermediate relative to the range of secondary electrons. Stacks of dosemeters (0.4 mm x 3 mm x 3 mm, hot-pressed LiF TLD-100) were surrounded by homogeneous LiF, polystyrene, aluminium, copper or lead. The absorbed dose in the stack (0.1 to 0.7 g cm-2 thick) was derived from TL readings of the individual dosemeters, and was compared with calculations based on the Burlin cavity theory. A relatively strong asymmetry in the experimental absorbed-dose distribution was found between the front, rear and middle dosemeters of the stack, especially when lead was the surrounding medium. Cavity theory shows good agreement with the experimental results obtained in polystyrene, while theory tends to overestimate the dose in the LiF dosemeters enclosed in Al, Cu, and Pb. The general trend predicted by the Burlin theory is somewhat steeper relative to cavity size than that observed experimentally. The theory was modified to make it more applicable to the dose at the centre of the stack. For lead this clearly agreed more closely with experimental results than did the conventional theory.
使用氟化锂热释光（TL）剂量计进行了钴 - 60γ射线吸收剂量测量，以便更深入地了解应用于尺寸介于二次电子射程之间的剂量计的空腔理论。剂量计叠层（0.4毫米×3毫米×3毫米，热压氟化锂TLD - 100）被均匀的氟化锂、聚苯乙烯、铝、铜或铅包围。叠层（厚度为0.1至0.7克/厘米²）中的吸收剂量由各个剂量计的热释光读数得出，并与基于伯林空腔理论的计算结果进行比较。发现叠层中前部、后部和中部剂量计之间的实验吸收剂量分布存在相对较强的不对称性，尤其是当周围介质为铅时。空腔理论与在聚苯乙烯中获得的实验结果显示出良好的一致性，而该理论往往高估了封装在铝、铜和铅中的氟化锂剂量计中的剂量。伯林理论预测的总体趋势相对于空腔尺寸比实验观察到的趋势更陡。对该理论进行了修正，使其更适用于叠层中心的剂量。对于铅，这与实验结果的一致性明显比传统理论更紧密。
