宽能谱高灵敏含硼塑料闪烁体探测器理论设计

Design of a high efficiency boron-loaded plastic scintillation detector for a wide spectrum of neutrons

为提高含硼塑料闪烁体探测器对0.02–0.25 MeV能区中子的探测效率,提出了在含硼塑料闪烁体外包围聚乙烯慢化体的结构设计,并用MCNP程序模拟计算含硼塑料闪烁体探测器的探测效率,给出了探测效率与前端和侧面聚乙烯慢化体厚度的关系。结果表明,通过侧面聚乙烯慢化体的添加,可以大大提高含硼塑料闪烁体探测器对0.02–0.25 MeV能区中子的探测效率。当侧面聚乙烯厚度为80 mm时,对该能区中子的探测效率提高~35倍,而前端慢化体的添加会降低其探测效率。最后证明在含硼塑料闪烁体侧面添加聚乙烯慢化体的设计可以实现对宽能谱中子的高灵敏探测。

For improving detection efficiency of 0.02–0.25 MeV neutrons by boron-loaded plastic scintillation detector（BLPSD）,surrounding the scintillator with polyethylene moderator is feasible way.In this paper,the detection efficiency of a BLPSD with front and side PE moderators of different thicknesses is simulated by MCNP code,and the thickness-dependant detection efficiencies are given.The results show the side PE moderator of 80 mm thick increases the BLPSD detection efficiency of 0.02–0.25 MeV neutrons by a factor of about,but the front PE moderator decreases the detection efficiency.Finally,the design structure of BLPSD surrounded by side PE moderator can realize high detection efficiency for a wide spectrum is proved.