Soni Anuj, Mishra D R, Polymeris G S, Bhatt B C, Kulkarni M S
Radiological Physics and Advisory Division, Bhabha Atomic Research Center, Trombay, 400 085, Mumbai, India,
Radiat Environ Biophys. 2014 Nov;53(4):763-74. doi: 10.1007/s00411-014-0554-5. Epub 2014 Jun 15.
Dental enamel was studied for its thermoluminescence (TL) and optically stimulated luminescence (OSL) defects. The TL studies showed a wide glow curve with multiple peaks. The thermally assisted OSL (TA-OSL) studies showed that the integrated TA-OSL and thus OSL signal increases with readout temperature between 100 and 250 °C, due to the temperature dependence of OSL. The thermally assisted energy E A associated with this increase is found to be 0.21 ± 0.015 eV. On the other hand, the signal intensity decreases with temperature between 260 and 450 °C. This decrease could be due to depletion of OSL active traps or possible thermal quenching. The increase of the OSL signal at increased temperature can be used to enhance the sensitivity of dental enamel for ex vivo measurements in retrospective dosimetry. The emission and excitation spectra of its luminescence centers were studied by photoluminescence and were found to be at 412 and 324 nm, respectively. It was found to possess multiple OSL active traps having closely lying photoionization cross sections characterized by continuous wave OSL and nonlinear OSL methods. The investigated dental enamel samples showed a linear OSL dose response up to 500 Gy. The dose threshold was found to be 100 mGy using a highly sensitive compact OSL reader with blue LED (470 nm) stimulation.
对牙釉质的热释光（TL）和光激发发光（OSL）缺陷进行了研究。热释光研究显示出一条具有多个峰值的宽发光曲线。热辅助光激发发光（TA - OSL）研究表明，由于光激发发光对温度的依赖性，在100至250°C之间的读出温度下，积分热辅助光激发发光以及因此的光激发发光信号会增加。发现与这种增加相关的热辅助能量EA为0.21±0.015电子伏特。另一方面，在260至450°C之间，信号强度随温度降低。这种降低可能是由于光激发发光活性陷阱的耗尽或可能的热猝灭。在升高温度时光激发发光信号的增加可用于提高牙釉质在回顾性剂量测定中离体测量的灵敏度。通过光致发光研究了其发光中心的发射光谱和激发光谱，发现分别为412纳米和324纳米。发现它具有多个光激发发光活性陷阱，这些陷阱具有通过连续波光激发发光和非线性光激发发光方法表征的紧密相邻的光电离截面。所研究的牙釉质样品在高达500戈瑞的剂量范围内显示出线性光激发发光剂量响应。使用具有蓝色发光二极管（470纳米）刺激的高灵敏度紧凑型光激发发光读数器，发现剂量阈值为100毫戈瑞。
