CAJ | 학술논문

快中子多重性分析技术是当前核材料衡算领域的热门研究方向。针对中子伽马脉冲形状甄别的效果在探测距离很近时明显变差的实验现象展开了研究。使用GEANT4工具箱模拟了液体闪烁体探测器测量裂变中子伽马的粒子输运过程，并基于计算机模拟数据分析了使用BC－501 A液体闪烁体探测器测量裂变中子时，裂变物质与探测器的距离（几何效率）对中子－伽马甄别效果的影响。分析的结果与实验现象相符，表明在基于液体闪烁体探测器的核材料属性测量中，若单个探头的探测效率较高，裂变中子伽马脉冲叠加会严重影响甄别结果和测量计数。
쾌중자다중성분석기술시당전핵재료형산영역적열문연구방향。침대중자가마맥충형상견별적효과재탐측거리흔근시명현변차적실험현상전개료연구。사용GEANT4공구상모의료액체섬삭체탐측기측량렬변중자가마적입자수운과정，병기우계산궤모의수거분석료사용BC－501 A액체섬삭체탐측기측량렬변중자시，렬변물질여탐측기적거리（궤하효솔）대중자－가마견별효과적영향。분석적결과여실험현상상부，표명재기우액체섬삭체탐측기적핵재료속성측량중，약단개탐두적탐측효솔교고，렬변중자가마맥충첩가회엄중영향견별결과화측량계수。
Fast Neutron Multiplicity Counting has drawn much attention from nuclear material accounting .The reason of bad pulse shape discrimination (PSD) result in near detection is studied .With GEANT4 toolkit, a simulation of the particle transport process of detecting fission neutron and gamma with liquid scintillator was re -alized .Based on the simulation data , the impact of the distance between nuclear material and the detector ( ge-ometry efficiency ) on the PSD in measuring fission neutron by BC -501 A liquid scintillator is discussed in de-tail.The analysis result is generally consistent with the experiment .The analysis show that if the detection effi-ciency of single detector is high , the pile up neutron and gamma may seriously affect the discrimination result and measurement counts.