电流模式飞行时间中子能谱测量方法研究

Study of Neutron Energy Spectra Measurement Using Current Mode Time-of-Flight Method

中国散裂中子源在中子学性能调试期间需要发展快速的中子能谱测量系统,希望在一个或几个质子脉冲周期内获得中子能谱。本研究发展了一套高探测效率的电流模式飞行时间能谱测量系统,测量系统由锂玻璃探测器、NI-PXIe-5122数据采集卡、Lab VIEW数据采集控制软件、高压电源等组成。在绵阳研究堆极化中子反射谱仪中子束线上开展了电流模式飞行时间中子能谱测量系统测试,分别测量了中子能谱和中子通量。同时,利用脉冲计数模式飞行时间方法和金箔活化法分别测量了该中子束线的中子能谱和中子通量,将测得的数据与电流模式飞行时间中子能谱测量系统测量结果进行对比,验证了电流模式飞行时间方法测量中子能谱和中子通量的可靠性。

During neutronic performance debugging in China Spallation Neutron Source,it is of great importance in engineering research to measure neutron energy spectrum rapidly. The technique of current mode time of flightusing lithium glass detector working in current mode will be used during neutronic performance in China Spallation Neutron Source and the neutron energy spectrum can be measured with a single shot pulse in principle. This paper aims at dealing with the general description and theoretical analysis of the technique of current mode time of flight,system device composition and data processing method,relative experimental test of the system in polarized neutron flight time spectrometer at China Mianyang Research Reactor. In addition,pulse mode time of flight technique and gold foil activation were used to measured neutron energy spectrum and neutron flux respectively. The experiment result verified the feasibility of current mode time of flight technique.