用于脉冲n/γ混合场中n、γ甄别的新型探测器的研究

Study of New Type Detector for Neutron and Gamma Discrimination in Pulsed n/γ Mixture Field

以塑料闪烁体和聚合物基复合材料为探测介质,开展用于脉冲n/γ混合场中n、γ甄别的新型探测器的研究。采用闪烁体探测器+契仑科夫探测器联合探测的方法,通过对n、γ产生的荧光和契仑科夫辐射的相关性测量,以实现n、γ的甄别,并给出脉冲中子的通量。利用蒙特卡罗方法计算了塑料闪烁体最佳厚度、n和γ在塑料闪烁体产生的次级电子能谱。同时利用模拟结果确定契仑科夫探测器探测介质的折射率,使得只有光子生成的次级电子可以在其中产生信号。

Using the plastic scintillator and polymer matrix composites material as the detecting medium,a new type detector was designed to discriminate neutron and gamma in pulsed n/γ mixture field.By measuring the relationship between the fluorescence and Cherenkov lights,a detection system consisting of a plastic scintillator detector and a Cherenkov detector was used to realize the neutron and gamma discrimination.Then,the pulsed neutron flux can be obtained through the difference between the counts in scintillator and Cherenkov radiator.Monte-Carlo method was used to optimize thickness of plastic scintillator,and give the spectra of charged particles produced by the detector interacting with the neutron and gamma ray.At last,the refractive index of the polymer matrix composites was calculated to ensure that only the secondary particles of gamma ray can generate Cherenkov light.