直径30cm的等高圆柱形载钆液闪探测性能  

Performance measurement of large volume φ30 cm×30 cm gadolinium-loaded liquid scintillator detector

作　　者：朱传新[1] 牟云峰[1] 郑普[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,绵阳621900

出　　处：《核技术》2016年第2期39-45,共7页Nuclear Techniques

摘　　要：载钆液闪探测器是高能物理及核物理实验中重要的粒子探测工具。通过研制得到了一台大体积的直径为30 cm等高圆柱形载钆液闪探测器,载钆液闪溶液的载钆量为0.5%wt;利用252Cf中子源进行了中子与γ分辨性能实验测试,结果表明,直径30 cm等高圆柱形载钆液闪的中子与γ分辨性能较差;利用飞行时间技术通过符合测量的方法,分别测量了中子与伽马分辨谱中的中子与γ信号的时间分布,两者峰位之间的时间差为2 ns;利用252Cf裂变电离室的裂变碎片信号作为开门信号,通过符合测量的方法,获得了直径30 cm等高圆柱形载钆液闪的中子俘获时间分布实验数据,中子俘获平均时间为11μs。对于较大体积条件下,载钆液闪的中子与γ分辨性能较差的物理现象,通过实验给出了合理解释和分析。Background： The gadolinium-loaded liquid scintillator detector is an important tool for particle detecting in the area of high energy physics and nuclear physics experiments. Purpose： In this work, a large-size 030 cm×30cm gadolinium-loaded liquid scintillator detector has been developed for neutron measurement. Neutron gamma discrimination and distribution of neutron capture time of gadolinium-loaded liquid scintillator were main values of detecting performance. Methods： The n-gamma discrimination of the large-size gadolinium-loaded liquid scintillator detector has been studied using a 252Cf spontaneous fission neutron source by zero-crossing method. It was observed that the neutron-gamma discrimination property of large-size gadolinium-loaded liquid scintillator detector was poor. n-gamma discrimination spectra of 030 cm×30 cm gadolinium-loaded liquid scintillator detector within 1 gs after the fission event were captured with coincidence method based on the start signal of fission fragment from 252Cf fission chamber. Results： It was observed that the neutron-gamma discrimination property of large-size gadolinium-loaded liquid scintillator detector was also poor. The time distributions of neutron and gamma in the n-gamma discrimination spectra were measured by time-of-flight （TOF） technique and coincidence method. The peak time difference of neutron time distribution and gamma time distribution was 2 ns. The distribution of neutron capture time was measured for a 030 cmx30 cm gadolinium-loaded liquid scintillator detector with coincidence method based on the start signal of fission fragment from 252Cf fission chamber. The main signals of 7 by neutron capture of 030 cm×30 cm gadolinium-loaded liquid scintillator detector were in about 30us. The average time of neutron capture is 11us. Conclusion： The neutron capture time property of homemade gadolinium-loaded liquid scintillator meets the experimental requirements. For the most signal of neutron and gamma within the superposition, single peak wa

关 键 词：载钆液闪 中子与分辨 中子俘获时间分布 

分 类 号：O157.5[理学—数学]