Further investigations of a radiation detector based on ionization-induced modulation of optical polarization.
Further investigations of a radiation detector based on ionization-induced modulation of optical polarization.
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DOI：
10.1088/1361-6560/abe027
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发表时间：
2021-02-20
影响因子：
3.5
通讯作者：
Levin C
中科院分区：
文献类型：
--
作者：
Wang Y;Tao L;Abbaszadeh S;Levin C
电离辐射诱导的光学特性调制是超快、低时间抖动探测光子到达时间的一种很有前途的方法。如果成功，这种方法可以用于飞行时间正电子发射断层扫描，获得接近10ps的符合时间分辨率。在这项工作中，进一步发展了基于光学特性调制的方法，重点是基于两个交叉偏振器的检测装置。以前的工作表明，这种光学装置可以用于辐射检测，但其检测灵敏度有待提高。为了理解和提高基于光偏振调制的方法的检测灵敏度，本工作研究了偏振器之间的夹角和检测晶体内的电场分布。在这项工作中，我们研究了碲化镉作为探测晶体。从理论和实验上探讨了两种交叉偏振器的“魔角”(即最佳工作角度)。实验结果表明，通过确定合适的魔角，可以使检测灵敏度提高10%左右。然后，我们利用CdTe晶体研究了探测灵敏度与电场分布以及探测器晶体两端的偏置电压的关系。实验结果表明，探测器晶体上的电极越小，或电场分布越集中，检测灵敏度越高。对于CdTe，2.5 mm×2.5 mm方形电极的探测器晶体样品的检测灵敏度是5 mm×5 mm方形电极探测器晶体样品的两倍。增加饱和前的偏置电压可以进一步提高调制强度，从而提高灵敏度。我们的研究表明，通过确定合适的偏振器工作角度和探测器的偏置电场分布，我们可以提高所提出的光学装置的灵敏度。
Optical property modulation induced by ionizing radiation is a promising approach for ultra-fast, lower time jitter detection of photon arrival time. If successful, this method can be utilized in time-of-flight positron emission tomography to achieve a coincidence time resolution approaching 10 ps. In this work, the optical property modulation based method is further developed with focus on a detection setup based on two crossed polarizers. Previous work demonstrated that such an optical setup could be utilized in radiation detection, though its detection sensitivity needed improvement. This work investigates the angle between polarizers and electric field distribution within the detection crystal to understand and improve the detection sensitivity of an optical polarization modulation based method. For this work, cadmium telluride (CdTe) was studied as the detector crystal. The ‘magic’ angle (i.e. optimal working angle) of the two crossed polarizers based optical setup with CdTe were explored theoretically and experimentally. The experimental results show that the detection sensitivity could be improved by around 10% by determining the appropriate ‘magic’ angle. We then studied the dependence of detection sensitivity on electric field distribution as well as on the bias voltage across the detector crystal using CdTe crystals. The experimental results show that a smaller electrode on the detector crystal, or a more concentrated electric field distribution could improve detection sensitivity. For CdTe, a detector crystal sample with 2.5 mm × 2.5 mm square electrode has twice the detection sensitivity of a detector crystal with 5 mm × 5 mm square electrode. Increasing the bias voltage before saturation for CdTe could further enhance the modulation strength and thus, the sensitivity. Our investigations demonstrated that by determining the proper working angle of polarizers and bias electrical distribution to the detector, we could improve the sensitivity of the proposed optical setup.
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影响因子：
3.5
作者：
Gundacker, Stefan;Auffray, Etiennette;Lecoq, Paul
通讯作者：
Lecoq, Paul
影响因子：
3.5
作者：
Cates, Joshua W.;Levin, Craig S.
通讯作者：
Levin, Craig S.
影响因子：
3.5
作者：
Cates, Joshua W.;Levin, Craig S.
通讯作者：
Levin, Craig S.
飞行时间宠物对全身肿瘤研究的影响：人类观察者病变检测和定位研究。
DOI：
10.2967/jnumed.110.086678
发表时间：
2011-05
期刊：
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
影响因子：
--
作者：
Surti S;Scheuermann J;El Fakhri G;Daube-Witherspoon ME;Lim R;Abi-Hatem N;Moussallem E;Benard F;Mankoff D;Karp JS
通讯作者：
Karp JS
DOI：
10.1016/j.nima.2013.11.025
发表时间：
2014-02-11
影响因子：
1.4
作者：
Gundacker, S.;Knapitsch, A.;Lecoq, P.
通讯作者：
Lecoq, P.