基于TDC-GP1测量前沿时间实现的n-γ脉冲甄别器  

The Neutron-Gamma Pulse Shape Discriminator Based on Rise Time Measurement with TDC-GP1

作　　者：曹宏睿[1,2] 吴军[1] 李世平[1,2] 徐修峰[1,2] 袁国梁[3] 杨青巍[3] 阴泽杰[1,2] 

机构地区：[1]中国科学技术大学近代物理系,合肥230026 [2]核探测与核电子学国家重点实验室,合肥230026 [3]核工业西南物理研究院,成都610041

出　　处：《核电子学与探测技术》2013年第2期158-161,共4页Nuclear Electronics & Detection Technology

基　　金：科技部国际热核聚变实验堆(ITER)计划专项(2008GB109000)资金支持

摘　　要：中子通量探测是国际热核聚变实验反应堆项目中一个关键性的测量课题,其难点在于如何有效地剔除聚变反应中伴生的α、γ等粒子及其他非中子信号,保留有用的中子信号,从而得到准确的中子通量。由于α、γ等粒子及其他非中子信号与中子信号在脉冲幅度和上升时间上均存在差别,根据这些特征设计的n-γ脉冲甄别器基于测量脉冲信号前沿上升时间,并辅以脉冲幅度甄别,实现了n-γ精确甄别。其中,上升时间测量是通过TDC-GP1配合双路恒比定时器实现的。经实验验证,此方法能够有效地识别中子信号并剔除α、γ信号等非中子信号的影响,n-γ脉冲甄别器探测中子信号计数率的动态范围可以达到0-106cps。Neutron Flux Monitor（NFM） is a key diagnostic system in International Thermonuclear Experimental Reactor（1TER）. The difficulty is how to eliminate or, and other non - neutron signal produced along with fusion reaction and retain useful neutron signal so as to obtain accurate neutron flux. Since a, γ/and other non - neutron are different from the neutron signal in amplitude and rise time, n - γ/pulse shape discriminator has been designed based on rise time measurement supplemented by the pulse amplitude discriminator, and achieved n - γ/accurate screening, Rise time measurement can be realized with TDC - GP1 and dual Constant Fraction Discriminator （CFD）. It is proved by the experiments that this method can identify the neutron signal effectively and exclude the impact of non - neutron signal, such as the a, T signals, and that the dynamic range for n - γ/pulse shape discriminator to detect neutron signal counting rate can reach 0 ～ 10^6eps.

关 键 词：n-γ脉冲甄别器 TDC-GP1 恒比定时器 中子通量监测器 国际热核聚变实验反应堆 

分 类 号：TL822.4[核科学技术—核技术及应用]