多电极高纯锗探测器信号读出模拟研究  

Simulation study of signal readout for multi-electrode high purity germanium detector

作　　者：杨璟喆 田阳[1,2] 杨铭鑫 曾志 薛涛[1,2] 曾鸣 代文翰[1,2] 李玉兰 YANG Jingzhe;TIAN Yang;YANG Mingxin;ZENG Zhi;XUE Tao;ZENG Ming;DAI Wenhan;LI Yulan(Department of Engineering Physics,Tsinghua University,Beijing 100084,China;Key Laboratory of Particle and Radiation Imaging,Ministry of Education,Beijing 100084,China;China Nuclear Energy Industry Corporation,Beijing 100032,China)

机构地区：[1]清华大学工程物理系,北京100084 [2]教育部粒子与辐射成像重点实验室,北京100084 [3]中国原子能工业有限公司,北京100032

出　　处：《核技术》2024年第11期57-65,共9页Nuclear Techniques

基　　金：国家自然科学基金(No.U1865205)资助。

摘　　要：多电极高纯锗探测器因兼具良好能量分辨率及位置灵敏的特点,在探测器内事例点信息提取方面具有一定的优势。对于多电极高纯锗探测器中的脉冲波形研究对γ谱分析性能优化、稀有事例探测和其他应用场景下的信号/本底甄别均具有关键参考意义。为了模拟多电极高纯锗探测器的脉冲波形,本文通过分析探测器内部电场和权电势的分布,以及载流子轨迹和读出电极处感应电荷,从而得到多电极高纯锗探测器不同读出电极处感应波形信息。通过分析模拟波形,发现沿电极分布方向上收集电极可以感应到显著不同的感应信号,同时相邻电极可以感应到较弱的镜像信号,说明多电极高纯锗探测器在沿电极分布方向上具有一定的位置分辨能力。通过模拟分析,验证了该方法可用于为γ径迹重建甄别的相关物理机制研究提供支持,同时还能对其应用效果进行模拟评估。[Background]Due to high energy resolution and position sensitivity features,the multi-electrode high purity germanium(M-HPGe)detector is widely applied in rare event physics for events extraction.[Purpose]This study aims to make use of pulse shape in M-HPGe detector as a useful reference to optimize the performance of gamma spectrometry,rare events detection and signal/background discrimination of M-HPGe detector in other scenarios.[Methods]The pulse shape of inductive charge at different readout electrodes in M-HPGe detector was simulated by joint calling process of Monte Carlo simulation process and single point position energy deposition pulse waveform simulation.Then,the pulse shape in M-HPGe detector was estimated through the distribution of the internal electric field,the weighting potential inside the detector,the carrier track and the inductive charge at the readout electrode.[Results]Simulation results of pulse shape in M-HPGe detector show that the collector electrodes along the electrodes distribution induces significantly different inductive signals,and weak mirror signals are induced by the adjacent electrodes.This indicates that the M-HPGe detector has position resolution feature along the electrodes distribution.[Conclusions]This method can be used to support the research on the physical mechanism of the gamma track reconstruction discrimination method,and it can also simulate and evaluate the application effect of the track reconstruction discrimination method.

关 键 词：多电极高纯锗探测器 脉冲波形模拟 径迹重建甄别 蒙特卡罗方法 

分 类 号：TL8[核科学技术—核技术及应用]