Nuclear Radiation Management and Application Division, Defence Laboratory (DRDO), Ratanada, Jodhpur, Rajasthan 342011, India.
Advanced Materials and Device (A-MAD) Laboratory, Department of Physics, Indian Institute of Technology, Jodhpur, Rajasthan 342030, India.
Rev Sci Instrum. 2023 Feb 1;94(2):024101. doi: 10.1063/5.0126282.
We report the preparation of the ZnO-LiF composite with a polystyrene (PS) polymer as a host using the solution mixing process. LiF acts as a converter material that absorbs a thermal neutron and produces alpha particles, which excites ZnO micro-particles, resulting in UV-vis photons' emission. The free-standing ZnO-LiF/PS composite film is coupled to a photomultiplier tube (PMT). Am-Be (1Ci) is used as the neutron radiation source for measuring the response. We compared the response of the composite scintillator consisting of (i) natural LiF and (ii) 95% Li enriched LiF (LiF). The increased pulse heights are recorded for 95% Li enriched, i.e., LiF converter. It confirms the generation of alpha particles after the absorption of a neutron in LiF. Furthermore, ZnO and LiF are considered in different weight proportions, 2:1, 1:1, and 1:2, keeping the total loading 50% (w/w) of polystyrene. The ZnO:LiF (1:1)/PS composite showed higher scintillation pulse heights than the other two composites. Repetitive measurements are performed for the ZnO-LiF(1:1)/PS composite, showing ±5% variation in respective responses. We also investigated the impact of different counting times and source-to-detector responses for the ZnO-LiF(1:1)/PS composite. The response increases linearly with neutron dose, exhibiting a sensitivity of ∼203 counts/μSv. Neutron measurement counts at different source-to-detector distances have a similar trend as that of neutron dose measured by using a neutron dosimeter. Thus, this work demonstrated the potential of the ZnO-LiF/PS composite, coupled to PMT for detecting thermal neutron radiation.
我们报告了使用溶液混合工艺制备具有聚苯乙烯 (PS) 聚合物作为主体的 ZnO-LiF 复合材料。LiF 作为转换材料，吸收热中子并产生 α 粒子，激发 ZnO 微粒子，从而产生紫外可见光子的发射。将独立的 ZnO-LiF/PS 复合膜与光电倍增管 (PMT) 耦合。Am-Be(1Ci) 用作测量响应的中子辐射源。我们比较了由 (i) 天然 LiF 和 (ii) 95%富锂 LiF(LiF) 组成的复合材料闪烁体的响应。对于 95%富锂，即 LiF 转换器，记录到的脉冲幅度增加。这证实了 LiF 吸收中子后产生 α 粒子。此外，考虑了 ZnO 和 LiF 的不同重量比例，2:1、1:1 和 1:2，保持聚苯乙烯的总负载为 50%(w/w)。与另外两种复合材料相比，ZnO:LiF(1:1)/PS 复合材料显示出更高的闪烁脉冲幅度。对 ZnO-LiF(1:1)/PS 复合材料进行了重复测量，各自响应的变化在±5%以内。我们还研究了不同计数时间和源-探测器响应对 ZnO-LiF(1:1)/PS 复合材料的影响。响应随中子剂量线性增加，表现出约 203 个计数/μSv 的灵敏度。不同源-探测器距离的中子测量计数与使用中子剂量计测量的中子剂量具有相似的趋势。因此，这项工作证明了与 PMT 耦合的 ZnO-LiF/PS 复合材料检测热中子辐射的潜力。
