Sardar M, Tufail M
Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad, Pakistan.
Appl Radiat Isot. 2012 May;70(5):897-900. doi: 10.1016/j.apradiso.2012.01.026. Epub 2012 Feb 24.
Thermoluminescence characteristics of colourless topaz collected from Pakistan were studied. The objective of this study was to design and develop a TL dosimeter for high-energy beams. Samples were irradiated with (60)Co, (137)Cs and linear accelerator (6 MV, 15 MV). Glow curves of the chips revealed four trapping levels at temperature ranges 71-82 °C (Peak 1), 173-185 °C (Peak 2), 197-210 °C (Peak 3) and 225-260 °C (Peak 4). Peak 4 is stable and rose linearly with increase of exposure levels. The TL response vs. exposure showed linear behaviour between 1 and 10(2) Gy. Initial fading is rapid in first 24 h and becomes 8% in next 19 days. The variation in response of the last 20th cycle with respect to the 1st cycle was found to be 4% with a maximum variation of 15% within all data points. The thermoluminescence response was observed to be higher at low energy. The chips remained mechanically intact during handling in all experiments. Topaz chips can effectively and efficiently be used as a TLD for high-energy beams.
对从巴基斯坦采集的无色黄玉的热释光特性进行了研究。本研究的目的是设计和开发一种用于高能束的热释光剂量计。用钴 -60、铯 -137 和直线加速器（6 兆伏、15 兆伏）对样品进行辐照。芯片的发光曲线在温度范围 71 - 82°C（峰 1）、173 - 185°C（峰 2）、197 - 210°C（峰 3）和 225 - 260°C（峰 4）处显示出四个俘获能级。峰 4 是稳定的，并且随着照射剂量的增加呈线性上升。热释光响应与照射剂量在 1 至 10² 戈瑞之间呈线性关系。初始衰退在最初 24 小时内迅速，在接下来的 19 天内变为 8%。发现第 20 个周期相对于第 1 个周期的响应变化为 4%，在所有数据点内最大变化为 15%。在低能量下观察到热释光响应更高。在所有实验中，芯片在处理过程中保持机械完整。黄玉芯片可有效且高效地用作高能束的热释光剂量计。
