Depth of γ-ray interaction within continuous crystals from the width of its scintillation light-distribution
Depth of γ-ray interaction within continuous crystals from the width of its scintillation light-distribution
复制标题
DOI：
10.1109/tns.2005.851424
复制
发表时间：
2005-06-01
影响因子：
1.8
通讯作者：
Martínez, J
中科院分区：
文献类型：
--
作者：
Lerche, CW;Benlloch, JM;Martínez, J
本文研究了一种新的测量大尺寸闪烁晶体γ射线探测器相互作用深度（DOI）的方法。这种方法利用了连续晶体中未受干扰的光分布宽度与伽马射线DOI之间的强相关性。为了量化分布宽度与DOI的相关性，我们首先研究了光分布的分析模型，并通过晶体内部光传输的蒙特卡罗（MC）模拟对其进行了测试。此外，我们提出了一种廉价的修改常用的电荷划分电路，允许模拟和瞬时计算的光分布的二阶矩，而不影响的质心的确定。这种重新设计的电阻网络基于位置敏感正比计数器（DPC）读数，并允许与位置敏感光电探测器一起额外测量光分布的标准偏差或。我们使用设计工具OrCAD测试了所提出的电路，发现信号足够大，可以进行数字化。最后，我们对一个真实的正电子发射断层扫描（PET）探测器模块设置进行了MC模拟，该模块模拟了尺寸为40 x 40 x 10 mm（3）的连续Lu2SiO5：Ce3+（LSO）晶体以及来自Hamamatsu的新型大面积位置敏感光电倍增管（PSPMT）H8500。康普顿散射对DOI测定的影响也通过MC模拟进行了估计。总之，我们得到了
We have studied a new and inexpensive method of measuring the depth of interaction (DOI) in gamma-ray detectors with large-sized scintillation crystals. This method takes advantage of the strong correlation between the width of the undisturbed light-distribution in continuous crystals and the gamma-ray's DOI. In order to quantify the dependence of the distribution's width with respect to the DOI, we first studied an analytical model of the light-distribution and tested it by means of Monte Carlo (MC) simulations of the light transport inside the crystal. Further we present an inexpensive modification of the commonly used charge division circuit that allows analog and instantaneous computation of the light-distribution's second moment without affecting the determination of the centroid. This redesigned resistor network is based on the position-sensitive proportional counter (DPC) readout and allows, together with position sensitive photo-detectors, the additional measurement of the light-distribution's standard-deviation or. We tested the proposed circuit using the design-tool OrCAD and found the signal sufficiently large for digitalization. Finally, we conducted MC simulations of a realistic Positron Emission Tomography (PET) detector module setup that mimic a continuous Lu2SiO5:Ce3+ (LSO) crystal of dimensions 40 x 40 x 10 mm(3) together with the new large area position-sensitive photo multiplier tube (PSPMT) H8500 from Hamamatsu. The influence of Compton scattering on the DOI determination was also estimated by MC simulations. Altogether, we obtained