真空康普顿探测器电流噪声抑制方法  

A Method of Current Noise Suppression in Vacuum Compton Detector

作　　者：胡启航 陈翔 卢毅 高帅 张侃 刘君红 冯蠡 管兴胤 HU Qihang;CHEN Xiang;LU Yi;GAO Shuai;ZHANG Kan;LIU Junhong;FENG Li;GUAN Xingyin(National Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Xi’an 710024,China;School of Nuclear Science and Technology,Lanzhou University,Lanzhou 73000,China)

机构地区：[1]强脉冲辐射环境模拟与效应全国重点实验室,西安710024 [2]兰州大学核科学与技术学院,兰州730000

出　　处：《现代应用物理》2024年第5期23-31,共9页Modern Applied Physics

基　　金：国家自然科学基金资助项目(12205238,12275220)。

摘　　要：真空康普顿探测器(vacuum Compton detector,VCD)具有超低γ射线灵敏度特性,探测系统中存在的电流噪声对其灵敏度的测量不确定度具有显著影响。针对VCD灵敏度测量系统中存在的较大电流噪声问题,主要研究了VCD电流噪声的来源和电流噪声的抑制技术。以强流脉冲辐射测量中典型VCD为例(发射极材料是厚度为2 mm的铁),实验研究了不同金属材料的发射极引入的电流噪声,并以铁为基底材料研究了不同组合金属发射极的电流噪声抑制效果,探索了发射极组合设计抑制电流噪声的可行性。实验结果表明,VCD灵敏度测量系统中的金属接触电势差对电流噪声具有重要贡献,采用合适的金属发射极(例如铝)能够有效抑制电流噪声,且抑制效果与金属材料功函数有关。当采用铁-铝组合发射极时,电流噪声抑制效果最好。该结果为抑制VCD电流噪声进而减小灵敏度测量不确定度提供了一条可行的技术途径。The vacuum Compton detector(VCD)has ultra-lowγ-ray sensitivity,and the current noise in the detection system has a significant influence on the measurement uncertainty of its sensitivity.To solve the problem of large current noise in VCD sensitivity measurement system,the source of current noise and the suppression technology of current noise are studied in this paper.In the high current pulse radiation measurement,taking a typical VCD whose emitter material is 2 mm thick Fe as an example,the current noise introduced by emitter of different metal materials is studied in the experiment.The current noise suppression effect of different composite metal emitters is studied based on Fe.The feasibility of composite emitter design to suppress current noise is explored.The experimental result shows that the metal contact potential difference in VCD sensitivity measurement system plays an important role in current noise.When the appropriate metal emitter such as Al is used,the current noise can be effectively suppressed,and the suppression effect is related to the work function of metal material.When the Fe-Al composite emitter is used,the current noise suppression effect is the best.The result provides a feasible method to suppress the current noise of VCD and reduce the measurement uncertainty of the sensitivity.

关 键 词：真空康普顿探测器 接触电势差 组合金属发射极 电流噪声 

分 类 号：TL816[核科学技术—核技术及应用] O571[理学—粒子物理与原子核物理]