用Fisher线性判别方法甄别Cs_2LiYCl_6:Ce^(3+)晶体的n/γ波形

n/γ Pulse Shape Discrimination in Cs_2LiYCl_6:Ce^(3+) Crystal Using Fisher Linear Discriminant

Cs_2LiYCl_6:Ce^(3+)(CLYC)晶体是一种性能优异的无机闪烁晶体,具有良好的n/γ脉冲形状甄别能力。传统的电荷比较法常用来甄别CLYC晶体的n/γ,通过优化积分时间窗口的宽度来获得最优的甄别结果,计算量大。本文提出利用Fisher线性判别进行CLYC晶体的n/γ波形甄别,以获得高甄别品质因子为准则来构建投影向量。n/γ混合场由Am-Be源产生,用泰科DPO7104示波器记录探测器信号。结果表明,构建投影向量后,Fisher线性判别方法计算量小、可移植性强,且可得到优于电荷比较法的甄别结果。

Abstract： CszLiYC16 ：Ce3＋ （CLYC） crystal is a promising new inorganic scintillator. It can discriminate neutron and 7 rays with pulse shape discrimination （PSD） method. Charge comparison method, whose best discrimination result was achieved through opti- mizing the integral time window width with heavy calculation, was usually adopted to discriminate neutron and 7 rays in CLYC. In this work, Fisher linear discriminant, which aims to get high discrimination figure of merit through constructing projective vector, was used to discriminate neutron and 7 in CLYC crystal in Am-Be mixed radiation field. The signals from CLYC crystal were digitized using DPO7104 oscilloscope. The results show that after constructing projective vector, Fisher linear discriminant has small calculation and good robustness, and can get better discrimination results than charge comparison method.