Lasky J B, Moran P R
Phys Med Biol. 1977 Sep;22(5):852-62. doi: 10.1088/0031-9155/22/5/004.
The response of single crystal and extruded ribbons of TLD-100 to 5-30 keV electrons was investigated. If annealing is done in a vacuum, the sensitivity of TLD-100 single crystals to these electrons and the resultant glow curve are essentially the same as when irradiation are carried out with 137Cs gamma rays. All discrepancies in sensitivity can then be accounted for by the higher LET of electrons. The commonly used 'standard annealing' at 400 degrees C for one hour produced a change in the glow curve shape and a loss in sensitivity in contrast to the vacuum anneal results. Diffusion of hydroxyl ions into the sample during air annealing is believed to be the primary cause for this change. These results explain the source of the 'dead layer' proposed to explain the variation with particle size of the luminescent efficiency of X-ray irradiated TLD-100 powder and the low TL efficiency from low energy electron irradiations. With the use of the vacuum annealing procedure, the same sensitivity and reproducibility can be achieved for the dosimetry of low energy electrons and other shallowly penetrating radiation as is currently achieved for the dosimetry of X-rays.
研究了TLD - 100单晶和挤压带对5 - 30 keV电子的响应。如果在真空中进行退火，TLD - 100单晶对这些电子的灵敏度以及由此产生的发光曲线与用137Csγ射线辐照时基本相同。然后，灵敏度上的所有差异都可以用电子的较高传能线密度来解释。与真空退火结果相比，常用的400℃ 1小时“标准退火”导致发光曲线形状发生变化且灵敏度降低。空气中退火期间羟基离子向样品中的扩散被认为是这种变化的主要原因。这些结果解释了为解释X射线辐照的TLD - 100粉末发光效率随颗粒尺寸变化以及低能电子辐照的低热释光效率而提出的“死层”的来源。通过使用真空退火程序，对于低能电子和其他浅穿透辐射的剂量测定，可以实现与目前X射线剂量测定相同的灵敏度和可重复性。
