闪烁体中子探测器读出ASIC-MaPMT_v10性能测试的设计与实现  

Design and implementation of testing system of the readout ASIC-Ma PMT_v10 for scintillator neutron detector

作　　者：濮亚男 曾云[1] 赵豫斌[2,3] 李怀申[3] 吴文欢[3] 陈少佳[2,3] 

机构地区：[1]湖南大学物理与微电子科学学院,长沙410082 [2]东莞中子科学中心,东莞523808 [3]中国科学院高能物理研究所,北京100049

出　　处：《核技术》2015年第2期27-32,共6页Nuclear Techniques

基　　金：中国散裂中子源(CSNS)工程项目经费资助

摘　　要：中国散裂中子源(China Spallation Neutron Source,CSNS)工程通用粉末衍射谱仪(General Purpose Powder Diffractometer,GPPD)使用二维位置灵敏型闪烁体中子探测器(Position-sensitive Scintillation Neutron Detector,SSND)来获取中子击中位置和时间信息。MaPMT_v10是由中国科学院高能物理研究所电子学组专门为闪烁体探测器前端电子学读出研发的一款专用集成电路(Application-specific Integrated Circuit,ASIC)。为了使该芯片更快地应用于CSNS工程项目中,设计了针对该芯片的测试电路板。该电路板既能在电子学实验室对MaPMT_v10进行各项性能测试,又能直接连接光电倍增管,与探测器组进行联合调试。本文介绍了MaPMT_v10的测试电路板,并给出了该芯片积分非线性(Integral nonlinearity,INL)、噪声等测试的方法和结论。利用本文搭建的测试平台,得到了MaPMT_v10可靠的性能测试结果,该芯片正常稳定和运行可靠。Background： An application specific integrated circuit （ASIC） chip applied to the Multi-anode Photo Multiplier Tubes （MaPMT） readout electronics system for the scintillator neutron detector was developed by the Institute of High Energy Physics （IHEP）. It is a key equipment for the General Purpose Powder Diffractometer （GPPD） of China SpallationNeutron Source （CSNS）. The chip includes 16 electronic channels, and each channel contains charge pre-amplifier, shaper, discriminator and mono-stable block. Purpose： This study aims to describe the chip design philosophy, verify its functionalities, and obtain its performance parameters. Methods： A circuit board designed for testing the ASIC MaPMT_v10 is implemented as a platform in which the input signals generated in two ways go through the ASIC and are measured at the output nodes of pre-amplifier, shaper and discriminator respectively. We also use one FPGA chip to function as a controller of the circuit and a USB module to communicate with PC for user interface and visualization of measuring results. The shaping waveforms of the simulation signals from the MaPMT are also tested through the test circuit board. Results： The integral nonlinearity （INL） of the MaPMT vl0 is between 0.72%-1.1%. And the value of signal-to-noise ratio （SNR） is 29. The shaped waveforms show that the MaPMT_v10 could distinguish neutron signals from gamma signals easily by setting appropriate threshold. Conclusion： Test results indicate that the chip realizes the function of identifying the particles by the amount of charge. In order to meet the actual needs of the project, the chip will be further optimized and improved on the integration.

关 键 词：闪烁体中子探测器 核电子学 专用集成电路 积分非线性 

分 类 号：TN41[电子电信—微电子学与固体电子学] TN492