环形正负电子对撞机带电粒子鉴别的飞行时间探测器  

Time of flight detector for charged particle identification based on circular electron-positron collider

作　　者：牟家连 吕军光[2,3] 孙希磊 兰小飞[1] 黄永盛 Mou Jia-Lian;LüJun-Guang;Sun Xi-Lei;Lan Xiao-Fei;Huang Yong-Sheng(School of Physics and Astronomy,China West Normal University,Nanchong 637001,China;Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Particle Detection and Electronics,Beijing 100049,China;School of Science,Shenzhen Campus of Sun Yat-sen University,Shenzhen 518107,China)

机构地区：[1]西华师范大学物理与天文学院,南充637001 [2]中国科学院高能物理研究所,北京100049 [3]核探测与核电子学国家重点实验室,北京100049 [4]中山大学·深圳理学院,深圳518107

出　　处：《物理学报》2023年第12期65-73,共9页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2022YFB3503600)资助的课题。

摘　　要：环形正负电子对撞机(circular electron-positron collider,CEPC)通过d E/dx的测量进行长寿命带电粒子的鉴别,要求对d E/dx的测量达到约3%的精度.但d E/dx的测量对带电粒子π/K,π/P和K/P各有一个分辨盲区,对应的横动量分别为1 GeV/c,1.6 GeV/c和2 GeV/c.一种解决方案是采用高精度飞行时间(time of flight,TOF)探测器填补分辨盲区,探测器系统的时间分辨要求小于50 ps.针对这一要求本文提出一种小颗粒飞行时间探测器,具体方案为采用小块塑料闪烁体(1 cm×1 cm×0.3 cm)侧面耦合硅光电倍增管读出.介绍了该探测器的构建以及利用^(90 )Sr电子准直源和高速波形采集电子学对该探测器的性能标定.结果显示,采用恒比定时法,该探测器的时间分辨约为48 ps,可以满足CEPC对飞行时间探测器的要求.The circular electron-positron collider(CEPC)requires a 3%precision in the measurement of dE/dx to identify long-lived charged particles.However,the measurement of dE/dx has a blind area for each of charged particles ofπ/K,π/P,and K/P,having transverse momenta of 1 GeV/c,1.6 GeV/c,and 2 GeV/c respectively.One potential solution is to use a high-precision time-of-flight(TOF)detector with a time resolution of less than 50 ps to fill in the blind area.To address this,we propose a small particle TOF detector that uses small plastic scintillators(1cm×1cm×0.3cm)silicon photomultipliers for readout.In this work,we introduce the construction of the detector and calibrate its performance by using ^(90)Sr electron collimators and high-speed waveform acquisition electronics.Using a constant fraction timing method,we find that the time resolution of the detector is about 48 ps,satisfying the CEPC’s requirements for TOF detection.

关 键 词：粒子鉴别 飞行时间探测器 硅光电倍增管 飞行时间分辨 

分 类 号：O572.214[理学—粒子物理与原子核物理]