PET的多通道Si制光电倍增管_1270954杨英健分析.ppt

基于多通道Si制光电倍增管前端模拟电路的PET数据采集Base on A Front-end Analog Circuit for Multi-channel SiPM Readout of PET 杨英健 1270954 质量湮没现象 符合检测电路 利用两个γ射线光子向相反方向传播的这一特性，通过“符合检测”技术来实现投影数据的采集，并由此实现断层成像。 符合检测电路原理框图 成像装置 数据采集 A、B、C、D四个光电倍增管的输出决定光子的入射点，也决定接下来要进行的脉冲高度分析。 脉冲高度分析 脉冲过高可能是由于多个γ射线光子同时到达。 数据存储 湮没事件发生的位置、响应线的位置都具有不确定性。 有关在特定响应曲线 上发生的湮没事件可以在正弦图上记录下来。 只要把每次发生的湮没事件都以累加的方式在正弦图上记录下来，待数据相对完整后，就可以现实断层图像的重建。 衰减校正 Silicon photomultipliers (SiPM) is regarded as a promising device in many photon counting applications including high-energy physics, astroparticle physics, and medical imaging. Moreover, the multi-channel SiPMs have a relatively small dead space between each channel. we therefore present the detailed design scheme of this front- end readout module based on the charge division network that was employed for the easy extension of the module to a wider detection area. Electronics for signal multiplexing and data acquisition We designed theSiPM front-end readout module with which the four tileable 4X4 channel SiPMs can be combined(Fig.1). This means that the detector module needs at least 64 signal lines for a single signal readout scheme or 128 signal lines for a differential signal readout scheme if no signal multiplexing is involved. Fig. 1. Schematic of the front-end analog circuit for the SiPM readout module.(a)SiPM biasing circuit.(b )Resistive charge division network (RCN). (c)Differential amplifier circuit. 成像装置 Data Acquisition A、B、C、D四个光电倍增管的输出(four position encoding signals)决定光子的入射点，也决定接下来要进行的脉冲高度分析。 This front-end readout module based on RCN makes the PET block detector easily extendable. Fig. 2(a) shows the output pulses measured at positions A–D when only the SiPM cell nearest to A was fired.The SiPM cell positions were successfully separated using these four multiplexed position signals as illustrated in Fig. 2(b). Fig. 2. Electrical stimulation results of the SiPM block de