随着环境保护工作日益被人们重视,对放射性分析水平的下限提出了更高的要求。为此,反符合屏蔽γ谱仪应运而生。这里研制的以塑料闪烁体为反符合屏蔽探测器的NaI(Tl)γ谱仪,其设计有较大灵活性,可以用Ge(Li)探测器代替NaI(Tl)主探测器,以构成性能更完美的低本底符合—反符合屏蔽γ谱仪。本工作较细致地观测了塑料环晶体的谱响应特性,并利用它的某些特点作了符合测量的尝试,获得了较好的结果。对环晶体及主晶体的一些污染等缺陷做了分析。 With the increasing attention paid to environmental protection work, higher requirements have been set for the lower limit of the level of radioactive analysis. To this end, anti-coincidence shielding γ spectrometer came into being. The NaI (Tl) gamma spectrometer developed here, which uses a plastic scintillator as an anti-shielding detector, is designed to be flexible enough to use a Ge (Li) detector instead of a NaI (Tl) main detector to make up the performance More perfect low background coincidence - anti-fit shielded gamma spectrometer. In this work, the spectral response characteristics of plastic ring crystals were observed in detail, and some characteristics of the plastic ring crystals were tested in line with the measurement. Good results were obtained. The ring crystal and some of the main crystal pollution defects were analyzed.