Thermoluminescence and Color Center Correlations in Dosimetry LiF
Thermoluminescence and Color Center Correlations in Dosimetry LiF
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LiF 剂量测定中的热释光和色心相关性
DOI：
10.1063/1.1659346
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发表时间：
1970
影响因子：
3.2
通讯作者：
N. Johnson
中科院分区：
文献类型：
--
作者：
M. Mayhugh;R. W. Christy;N. Johnson
剂量测定 LiF 经 γ 辐照至 10 000 R，并在室温以上研究所得热释光以及 190 至 400 nm 之间的光学吸收。各种光学和热处理后发光曲线和吸收光谱的变化表明，热释光过程始于电子从中心热释放，导致 310-380 nm 区域的光吸收。此外，在 200°C 附近产生重要的剂量测定辉光峰的中心似乎具有两种激发态，因此这些中心在 310 nm 处和 250 nm 处的 F 带下方都有光学吸收带。特别是 200°C 附近的两个辉光峰与两个 310 nm 吸收带相关，这两个吸收带通过不同的光学漂白率来区分。对于通常用于剂量测定的辉光峰，辉光峰和 310 nm 波段的热活化能相等支持这种相关性。要根据这些相关性解释所有数据，需要假设发光位点的可用性受到限制。讨论了光子产生机制和陷阱结构的含义。还发现 LiF 的 F 带不对称，就好像存在大的 K 带一样。
Dosimetry LiF was γ irradiated up to 10 000 R, and the resulting thermoluminescence was studied above room temperature in conjunction with the optical absorption between 190 and 400 nm. Changes in the glow curves and absorption spectra after various optical and thermal treatments show that the thermoluminescence process begins with thermal release of electrons from centers causing optical absorption in the 310–380‐nm region. Moreover, the centers causing the important dosimetry glow peaks near 200°C appear to have two excited states, so that these centers have optical absorption bands at both 310 nm and under the F band at 250 nm. In particular two glow peaks near 200°C are correlated with two 310‐nm absorption bands which are distinguished by different optical bleaching rates. For the glow peak usually used for dosimetry, the correlation is supported by an equality of thermal activation energies for the glow peak and 310‐nm band. To interpret all the data in terms of these correlations requires assuming a restriction in the availability of luminescence sites. Implications for the photon production mechanisms and the trap structures are discussed. An asymmetry in the F band of LiF, as if a large K band were present, is also found.