TRANSIENT TIME SPREAD FUNCTION OF SI-BASED PMT

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们提出的项目涉及快速光电探测器的响应特性的飞行时间正电子发射断层成像仪的发展。 近年来，人们一直在努力了解快速光电倍增管的上升时间和量子效率对它们与快速闪烁晶体耦合时所提供的时序分辨率的影响。 所做的大部分工作都集中在最基本的检测器-一个小晶体耦合到一个快速PMT提供的定时分辨率的表征和优化。 当这样的探测器被平铺以实现大面积覆盖时，如在PET扫描器或粒子探测器中所要求的，与独立探测器相比，所测量的定时分辨率显著降低。 我们的调查将试图了解这种退化的时间分辨率的来源，并设计一个数据采集和校准计划，以尽量减少it. The成功的调查将建立光电探测器增益，上升时间，量子效率和信号形状和大面积探测器的时间分辨率之间的相关性。 我们的努力的一个主要部分将涉及不同的光电探测器的单光子响应的特性和变化，在整个面对的光电探测器的响应。 这种变化被怀疑是在很大程度上负责在大面积探测器的定时分辨率的退化。 这项工作得到了NIH赠款5 R 01 CA 113941 -02和1 R21 EB 008142 -01的支持

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The project we propose involves the characterization of the response of fast photodetectors for the development of Time-Of-Flight Positron Emission Tomography imagers. A good deal of effort has been placed in recent years in understanding the effect of the rise time and quantum efficiency of fast PMTs on the timing resolution they afford when coupled to a fast scintillating crystal. Most of the work done has foccused on the characterization and optimization of the timing resolution afforded by the most basic detector - a single small crystal coupled to a fast PMT. When such detectors are tiled to achieve large area coverage, as is required in a PET scanner or particle detector, the measured timing resolution degrades considerably as compared to the stand alone detector. Our investigation will attempt to understand the source of this degradation in timing resolution, and devise a data acquisition and calibration scheme to minimize it. The successful investigation will establish the correlation between photodetector gain, rise time, quantum efficiency and signal shape and the large area detector timing resolution. A major part of our effort will involve the characterization of the single-photon response of different photodetectors and the variation in that response across the face of the photodetector. This variability is suspected of being greatly responsible for the degradation in timing resolution in a large-area detector. This work is supported by NIH grants 5R01CA113941-02 and 1R21EB008142-01