γ全吸收型探测装置中子束流监视器的Geant4模拟

Geant4 Simulation of Neutron Beam Monitor in Gamma-Ray Total Absorption Facility

摘要: 利用Geant4模拟了γ全吸收型探测装置中用于中子束流监视的锂玻璃探测器的相对探测效率，给出了锂玻璃探测器在10 keV～1 MeV区间的中子探测效率，并对影响探测效率的相关因素进行了分析，讨论了弹性散射引起的时间滞后对TOF(time-of-flight)测量的影响和不同厚度锂玻璃探测器的n-γ分辨效果。在未来使用锂玻璃探测器作为keV中子源监视器时，这项工作将为更好地理解相关中子飞行时间谱和能谱提供依据。

Abstract: The relative detection efficiency of a lithium glass detector used as a neutron beam monitor in gamma-ray total absorption facility was simulated by Geant4. The neutron detection efficiency of the lithium glass detector was obtained between 10 keV and 1 MeV. Some factors affecting the efficiency were analyzed. The effect of the time delay caused by the elastic scattering upon TOF (time-of-flight) measurement, and the n-γ discrimination in different thickness lithium glass were discussed. The work will be helpful to understand better the neutron time of flight spectrum and energy spectrum from Li-glass detector which is used as a monitor of keV neutron source.