分压电流对7.62 cm光电倍增管性能的影响

Effect of divider current on 7.62 cm photomultiplier tube performance

7.62 cm(3英寸)光电倍增管(Photomultiplier Tube,PMT)是江门中微子实验(Jiangmen Underground Neutrino Observatory,JUNO)巨型探测器的重要组成部分,以此构成的一套独立探测系统,承担着独立物理测量、与50.8 cm(20英寸)PMT探测系统相互检验等重要任务。为提高探测系统的可靠性,使每个7.62 cm PMT供电高压的单通道电流不超过10?A,研究了不同高压电流对7.62 cm PMT探测性能的影响。采用三种高压电流的分压器,对海南展创生产的型号为XP72B20(样管编号为70069)的7.62 cm PMT的性能进行实验测试,包括增益、能量分辨率、峰谷比和阳极输出信号的非线性。结果表明:不同分压电流对7.62 cm PMT性能的影响较小。这个结果为该7.62 cm PMT在JUNO探测器中使用小分压电流的方案提供了重要的实验依据。

[Background] The 7.62 cm（3-inch） photomultiplier tube（PMT） is an important component of the Jiangmen Underground Neutrino Observatory（JUNO） giant detector, which will work as an independent detection system for the physics measurements, and will calibrate as well as crosscheck the 50.8 cm（20-inch） PMT detection system. It is required that the single-channel current supply of each 7.62 cm PMT high voltage does not exceed 10 ？A. [Purpose] This study aims to reduce the performance requirements of the high-voltage power supply system and improve the reliability of the system. [Methods] The effects of different high-voltage currents on the detection performance of the 7.62 cm PMT are studied by experiments. Three kinds of high voltage current dividers were used to test the performance of an HZC XP72 B20 7.62 cm PMT sample（serial number 70069）, including gain, energy resolution, peak to valley ratio and non-linearity of the anode output signal. [Results] The change of the divider current has negligible impact on these probing performances. [Conclusions] This result provides an important experimental reference for the use of small divider current in the JUNO detector for the7.62 cm PMT.