OPTIMIZATION OF SCINTILLATION DETECTOR TIMING SYSTEMS USING MONTE-CARLO ANALYSIS
OPTIMIZATION OF SCINTILLATION DETECTOR TIMING SYSTEMS USING MONTE-CARLO ANALYSIS
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DOI：
10.1109/23.281528
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发表时间：
1994-02-01
影响因子：
1.8
通讯作者：
BINKLEY, DM
中科院分区：
文献类型：
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作者：
BINKLEY, DM
蒙特卡罗分析用于模拟与闪烁探测器光电子发射和光电倍增管操作相关的统计噪声。此外，对光电倍增管、前端放大器和恒定分数鉴别器（CFD）的脉冲响应进行了建模，从而可以评估前端带宽、恒定分数延迟和分数对定时系统优化的影响。这种定时系统分析对于具有低光电子发射率的探测器是有用的，包括用于正电子发射断层扫描（PET）系统的锗酸铋（BGO）闪烁探测器。计算了BGO/光电倍增管闪烁探测器在康普顿散射下511-keV同步伽马射线的恒定延时函数。当采用三指数BGO闪烁模型时，蒙特卡罗计算结果与实测结果吻合较好。蒙特卡罗模拟扩展到包括CFD能量识别性能。在前端上升时间为10纳秒（10-90%）、CFD延迟为8纳秒、CFD分数为20%的情况下，蒙特卡罗能量识别性能与时序性能一起得到了实验验证（蒙特卡罗时序分辨率为3.22纳秒FWHM，实测分辨率为3.30纳秒FWHM）。
Monte Carlo analysis is used to model statistical noise associated with scintillation-detector photoelectron emissions and photomultiplier tube operation. Additionally, the impulse response of a photomultiplier tube, front-end amplifier, and constant-fraction discriminator (CFD) is modeled so the effects of front-end bandwidth and constant-fraction delay and fraction can be evaluated for timing-system optimizations. Such timing-system analysis is useful for detectors having low photoelectron-emission rates, including Bismuth Germanate (BGO) scintillation detectors used in Positron Emission Tomography (PET) systems. Monte Carlo timing resolution for a BGO/photomultiplier scintillation detector, CFD timing system is presented as a function of constant-fraction delay for 511-keV coincident gamma rays in the presence of Compton scatter. Monte Carlo results are in good agreement with measured results when a tri-exponential BGO scintillation model is used. Monte Carlo simulation is extended to include CFD energy-discrimination performance. Monte Carlo energy-discrimination performance is experimentally verified along with timing performance (Monte Carlo timing resolution of 3.22 ns FWHM versus measured resolution of 3.30 ns FWHM) for a front-end rise time of 10 ns (10-90%), CFD delay of 8 ns, and CFD fraction of 20%.