γ能谱分区采集可调同步脉冲控制电路设计  

γ-ray Energy Spectrum Partition Acquisition Adjustable Pulse Control and Synchronization Circuit Design

作　　者：张书瑜 乔双[1] ZHANG Shu-yu;QIAO Shuang(School of Physics,Northeast Normal University,Changchun 130024,China)

机构地区：[1]东北师范大学物理学院,吉林长春130024

出　　处：《核电子学与探测技术》2020年第4期554-563,共10页Nuclear Electronics & Detection Technology

基　　金：国家重大科学仪器设备专项(2013YQ040861);国家自然科学基金(11275046)资助。

摘　　要：利用脉冲中子与被测物各反应在时间上的差异,同时考虑信号在传输过程中的延时,利用FPGA研制出一种针对γ能谱分区采集的控制与同步电路。该电路输出的脉冲信号可分别控制中子管产生中子和多道分析仪捕获反馈信号,通过改变脉冲延时大小,达到分区采集总γ谱和本底谱的要求,并采用双门减本底法计算得到净非弹散射γ谱。实验结果表明,采用50 MHz时,输出脉冲信号的频率调节范围在0.1 Hz^100 kHz之间,延迟时间最小调节步长为20 ns,满足对γ能谱进行分区采集的要求。Based on the difference in time between the response of the pulse neutron and the meas-ured object,and considering the delay of the signal in the process of transmission,a control and synchronization circuit for the acquisition ofγ-ray energy spectrum was developed by FPGA.The output pulse signal of the circuit can control the generation of neutron in the neutron tube and the acquisition of the feedback signal by the multi-channel analyzer.By changing the delay size of the pulse,the totalγray energy spectrum and the background spectrum can be collected in different regions.The experimental results show that when 50 MHz is adopted,the frequency regulation range of the output pulse signal is between 0.1 hz 100 kHz,and the minimum regulation step length of the delay time is 20 ns,which meets the requirements of the partitioned-acquisition forγ-ray energy spectrum.

关 键 词：Γ能谱 脉冲中子 同步脉冲 分区采集 

分 类 号：TL816.3[核科学技术—核技术及应用]