掺锂塑料闪烁体的制备与性能

Preparation and Characterization of Lithium-doped Plastic Scintillator

为了提高塑料闪烁探测器对低能中子的探测灵敏度,可在塑料闪烁体中引入热捕获截面积较大的6Li。通过酸碱中和反应合成了甲基丙烯酸锂,对其进行了结构表征,随后将其溶解到甲基丙烯酸中,并将甲基丙烯酸溶液转移至溶有第一闪烁物质和移波剂的苯乙烯溶液中,通过热聚合的方法制备出掺锂塑料闪烁体。所得闪烁体的最大掺锂质量分数为0. 89%,且随着掺锂量的增多,闪烁体的荧光性能逐渐降低;相对于蒽晶体,最大掺锂量的闪烁体的光产额为46. 27%;最大掺锂量塑料闪烁体的衰减时间为1. 64 ns。

6Li with a large thermal capture interface is introduced into the plastic scintillator to improve the detection sensitivity of the detector to the low-energy neutron.Lithium methacrylate was first synthesized by acid-base neutralization and its structure was characterized.Then lithium methacrylate was dissolved into methacrylic acid,and the generated solution was transferred to a styrene solution containing the primary additive and wavelength shifter.Finally,lithium-doped plastic scintillator was prepared by thermal polymerization.The maximum lithium content of the plastic scintillator was0.89%.With the increase of lithium content,the fluorescence intensity of plastic scintillator gradually decreased.The light yield of the scintillator with the maximum content of lithium was46.27%relative to the value of the anthracene crystal,and the decay time was1.64ns.