Improving the accuracy and precision of equivalent doses determined using the optically stimulated luminescence signal from single grains of quartz
Improving the accuracy and precision of equivalent doses determined using the optically stimulated luminescence signal from single grains of quartz
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DOI：
10.1016/j.radmeas.2012.01.006
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发表时间：
2012-09-01
影响因子：
2
通讯作者：
Duller, G. A. T.
中科院分区：
文献类型：
--
作者：
Duller, G. A. T.
石英的光激发发光（OSL）测量被广泛用于测量等效剂量（D-e）。在类似于100 Gy以上的辐射剂量下，阱的饱和导致OSL信号的增长率下降，这使得D-e的计算越来越困难。利用来自赞比亚Kalambo Falls的单粒石英进行了一系列剂量恢复实验，以探索单粒石英的饱和度。当对来自许多颗粒的OSL信号进行平均时，特征剂量（D-0）为47 Gy，这是石英的典型公布值。然而。单个颗粒的D-0变化范围类似于10到100戈瑞。高达平均D-0两倍的剂量可以准确地回收，但超过这个剂量，D-e就越来越被低估了。这种类型的实验的过度分散应该是零，但在所有数据集中都观察到；过色散值随D-e的增大而增大。对于单粒盐释光分析，提出了一个额外的接受标准，即快速比。该准则评估OSL信号的快速分量的相对贡献。将此作为附加的接受标准，可以提高精度，将过度分散降低到零，并提高高剂量时剂量恢复的准确性。(C) 2012 Elsevier Ltd.版权所有。
Optically stimulated luminescence (OSL) measurements of quartz are widely used to measure equivalent dose (D-e). At radiation doses above similar to 100 Gy, saturation of traps results in a decrease in the rate of growth of the OSL signal, and this makes calculation of D-e increasingly difficult. A series of dose recovery experiments was undertaken using single grains of quartz from Kalambo Falls, Zambia to explore saturation of single grains. When the OSL signal from many grains is averaged, the characteristic dose (D-0) is 47 Gy, typical of published values for quartz. However. D-0 for individual grains varies from similar to 10 to 100 Gy. Doses up to two times the average D-0 could be accurately recovered, but above this dose the D-e became increasingly underestimated. Overdispersion for this type of experiment should be zero, but was observed in all data sets; furthermore the value of overdispersion increased with D-e. An additional acceptance criterion, the Fast Ratio, is suggested for single grain OSL analysis. This criterion assesses the relative contribution of the fast component of the OSL signal. Including this as an additional acceptance criterion leads to an improved precision, with overdispersion reduced to zero, and improved accuracy in dose recovery at high doses. (C) 2012 Elsevier Ltd. All rights reserved.