基于信号功率谱梯度分析的n-γ甄别方法研究

Research on n-γ Discrimination Method Based on Spectrum Gradient Analysis of Signals

发现了液体闪烁体探测器在分别与中子和γ射线作用时输出脉冲的功率谱梯度存在较大差异这一特征,由此提出一种基于脉冲信号的频域特征参数来甄别中子和γ射线的方法———功率谱梯度分析(SGA)法。本文论述了SGA法的基本原理及其可行性,并通过伴随粒子中子飞行实验验证了SGA法n-γ甄别结果的正确性。研究了SGA法在采样率从5G/s逐步递减到250M/s下甄别性能的变化。结果表明,与基于时域特征的n-γ甄别方法相比,SGA法对噪声较不敏感,抗干扰能力强,甄别性能更为稳定且计算量小。

Having discovered that there are distinct differences between the spectrum gradient of the output neutron and T-ray signal from liquid scintillator detectors, this paper presented a n-γ discrimination method called spectrum gradient analysis （SGA） based on frequency-domain features of the pulse signals. The basic principle and feasi- bility of SGA method were discussed and the validity of n-γ discrimination results of SGA was verified by the associated particle neutron flight experiment. The discrimina- tion performance of SGA was evaluated under different conditions of sampling rates ran- ging from 5 G/s to 250 M/s. The results show that SGA method exhibits insensitivity to noise, strong anti-interference ability, stable discrimination performance and lower amount of calculation in contrast with time-domain n-T discrimination methods.