Influence factors of two dimensional position map on photomultiplier detector block designed by quadrant sharing technique  

作　　者：WEI Qingyang WANG Shi Ma Tianyu MA Fei DAI Tiantian XU Tianpeng WU Zhaoxia JIN Yongjie LIU Yaqiang 

机构地区：[1]Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Department of Engineering Physics, Tsinghua University, Beijing 100084, China

出　　处：《Nuclear Science and Techniques》2011年第4期224-229,共6页核技术（英文）

基　　金：Supported by in part by Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP200800031071);National Natural Science Foundation of China (No. 10975086);the National High Technology Research and Development Program (863 Program) of China (No. 2006AA020802)

摘　　要：The position decoding accuracy and the spatial resolution of positron emission tomography detectors are greatly influenced by the performance of the two-dimensional position map,including the gain uniformity of photomultiplier tube (PMT),the baseline offset of the PMT signals and the accuracy of analogue to digital converter (ADC).In this work,a PMT-quadrant sharing detector was designed.Two data acquisition platforms are employed to conduct the influence factors on the two-dimensional position map performances,one was that the waveforms of the PMT signals were scanned by the sequence acquisition mode based on the oscilloscope of LeCroy waveRunner 204MXi-A,and another was a self-developed high speed ADC data acquisition module.Results show that the event decoding positions were concentrated on the PMT with higher gain,the position map was distorted at the baseline offset of signal,and the cross-line artifacts were caused by the insufficient ADC sampling bit for a larger size position map.All the parameters need be adjusted properly to stabilize a real system,and the flexible oscilloscope platform can be used to design the detector block and the other platform with high ADC accuracy.Likely,the electrical circuit with a proper ADC accuracy adjusts the PMT gains and baseline offsets.The position decoding accuracy and the spatial resolution of positron emission tomography detectors are greatly influenced by the performance of the two-dimensional position map, including the gain uniformity of photomultiplier tube （PMT）, the baseline offset of the PMT signals and the accuracy of analogue to digital converter （ADC）. In this work, a PMT-quadrant sharing detector was designed. Two data acquisition platforms are employed to conduct the influence factors on the two-dimensional position map performances, one was that the waveforms of the PMT signals were scanned by the sequence acquisition mode based on the oscilloscope of LeCroy waveRunner 204MXi-A, and another was a self-developed high speed ADC data acquisition module. Results show that the event decoding positions were concentrated on the PMT with higher gain, the position map was distorted at the baseline offset of signal, and the cross-line artifacts were caused by the insufficient ADC sampling bit for a larger size position map. All the parameters need be adjusted properly to stabilize a real system, and the flexible oscilloscope platform can be used to design the detector block and the other platform with high ADC accuracy. Likely, the electrical circuit with a proper ADC accuracy adjusts the PMT gains and baseline offsets.

关 键 词：光电倍增管 三维位置 影响因素 共享技术 地图 设计 正电子发射断层扫描 象限 

分 类 号：TN152[电子电信—物理电子学] P228.4[天文地球—大地测量学与测量工程]