α-Al_2O_3:C晶体的热释光和光释光特性

以高纯α-Al2O3和石墨为原料,采用温梯法生长了α-Al2O3:C晶体,使用RisΦTL/OSL-DA-15型热释光和光释光仪研究了其热释光和光释光特性.α-Al2O3:C晶体在462K附近有单一热释光峰,发射波长位于410nm.随着辐照剂量的增加,热释光强度逐渐增强,462K的热释光特征峰位置保持不变.α-Al2O3:C晶体的光释光衰减曲线由快衰减和慢衰减两个部分组成,随着辐照剂量的增加,快衰减部分衰减速率变化不大,而慢衰减部分衰减速率加快.在5×10-6—10Gy剂量范围内,α-Al2O3:C晶体的热释光剂量响应呈现良好的线性关系,30Gy时达到饱和;光释光剂量响应在5×10-6—60Gy剂量范围内呈现良好的线性关系,100Gy时达到饱和.与热释光相比,光释光剂量响应具有更高的灵敏度和更宽的线性剂量响应范围.

In this work, alpha-Al2O3 :C crystal was grown by temperature gradient technique using alpha-Al2O3 and graphite powder as raw materials, and the thermoluminescence (TL) and optically stimulated luminescence (OSL) of the crystal were investigated by Ris circle divide TL/OSL-DA-15. The as-grown alpha-Al2O3 :C crystal shows a single TL peak at 462 K and blue emission peak at 410 nm. The TL intensity increases as irradiation dose increases, but no shift is found in the position of the glow peak. The OSL decay curve of alpha-Al2O3 : C crystal consists of two components, namely the fast component and the slow component. With the increasing of the dose, the decay rate of the fast component almost remains unaltered while that of the slow component increases. The TL response of the crystal shows excellent linear characteristic in the dose range. of 5 x 10(-6)-10 Gy, and saturation is observed at 30 Gy. The OSL response shows excellent linear characteristic in the dose range of 5 x 10(-6) 60 Gy, and reaches saturation at 100 Gy. Compared with TL response, OSL response shows higher sensitivity and wider linear dose response.

National Natural Science Foundation of China [60607015]; National High Technology Development Program of China [2006AA03A104]