大面积GEM中子探测器高计数率读出电子学系统研制

Development of High Counting Rate Readout Electronics System for Large GEM Neutron Detector

研制并测试了GEM中子探测器的512通道高计数读出电子学系统,以满足中国散裂中子源高效率、高分辨、高通量二维位置灵敏中子探测器的需求.系统以Kintex-7 FPGA作为系统控制和数据分析的核心,使用8块AS20Board前端芯片对灵敏面积为200 mm×200 mm的探测器的两个维度的信号进行读出,读出通道为256×256.读出数据经FPGA分析后通过千兆以太网传输至计算机显示.计算机可通过千兆以太网发送配置指令对前端采样电路和FPGA算法进行配置.系统与探测器组装后在中子束流实验中测得系统最高瞬时计数率为(1.2±0.1)×10^6s^-1,系统运行稳定,受噪声干扰小.

A 512-channel high counting rate signal readout electronics system for GEM neutron detector was developed and tested to meet the demand of high-efficiency,high-resolution,and high-throughput two-dimensional position sensitive neutron detector in China Spallation Neutron Source.In this system,the Kintex-7 series FPGA was used as the center of system control and data analysis,and the eight AS20Board front end read-out chips were used to collect two-dimensional signals of detector with area of 200 mm× 200 mm to achieve 512 channels data readout.These readout data were analyzed by FPGA and then transmitted to the computer through Gigabit Ethernet for display.The computer sends configuration commands through Gigabit Ethernet to configure the front-end sampling circuit and FPGA algorithm.The results of neutron beam experi-ment show that the highest instantaneous counting rate of this system is(1.2±0.1)× 10^6s^-1.