硅光电倍增器件(SiPM)的自动增益校正

An Initial Study of Automatic Gain Stability of SiPM

硅光电倍增器件(SiPM)是近年来逐渐兴起的一种用于PET(Positron Emission Tomography)的光电探测器件。与传统的光电倍增管(PMT)相比,它有着尺寸小、工作电压低、对磁场不敏感等优点,但其缺点是增益对环境温度敏感。在PET探测器的研发中,为了改善温度变化引起的增益漂移,设计了一个SiPM的增益校正系统。该系统通过测量环境温度对SiPM的偏置电压实时调节,从而保证其增益的相对稳定。最后对该系统对温度变化引起的SiPM增益漂移的抑制能力做了定量评估。采用增益校正系统后,在相似的温度变化范围内,SiPM的最大增益漂移由校正前的79.67%减小到11.03%。该结果显示此系统对温度变化引起的SiPM增益漂移具有良好的抑制能力。该系统能够补偿因温度变化引起的SiPM增益漂移,从而提高基于SiPM阵列探测器模块的PET系统的稳定性。

Silicon Photomultiplier （SiPM） is a novel photon detector which has been increasingly used in Positron Emission Tomography （PET） instrumentation in recent years. It has many advantages comparing to conventional PMTs, such as its compact size, low bias voltage （typically 30 - 150 V）, high gain and insensitivity to magnetic field. One drawback of SiPM is that its gain is sensitive to ambient temperature. In PET detector development, to minimize the gain drift of SiPM caused by ambient temperature change, a gain - correction system is designed in this work. The main approach of the system is to measure the ambient temperature and to adjust the bias voltage accordingly online to stabilize the SiPM device. The ability of the system to inhibiting the gain drift caused by temperature change is assessed quantitatively. After using this system, the maximum gain drift of SiPM decreases from 79.67% to 11.03%. The results demonstrate that the system works well in inhibiting gain drift. With this system, SiPM gain is stabilized greatly, which will contribute to the stability of SiPM - based PET systems.