【摘要】 本文报告了一个用塑料闪烁体环探测器作反符合屏蔽的NaI（T₁）γ能谱仪的结构及主要性能。它采用Φ76×76mmNaI（Tl）晶体作为主探测器和符合探测器,以自制的Φ500×520mm塑料闪烁体作环探测器。在有无井型反符合屏蔽条件下,能量范围0.1—2MeV时,谱仪的积分本底比为2.8,对¹³⁷Csγ源的康普顿减弱因子（积分比）为2.5。当源位于晶体表面中心时,谱仪对¹³⁷Cs源的能量分辨率和全能峰效率分别为9.5％和8.4％。更多还原

【Abstract】 In this paper the structure and main parformance of a NaI(T1)gamma-ray scintillation spectrometer with an annular plastic scintillator used as the anticoincidence shield are reported. The main and coincidence detectors of the spectrometer are a Nal (T1) crystal φ76mm ×76mm, and a self-made plastic scintillator φ500 × 520mm is used as the annular detector. In the energy range from 0.1MeV to 2MeV, the integral background ratio between that without and with the well-type anticoincidence shie-ld is 2.8. For 137Cs gamma source, the Compton attenuation factor (integral ratio) is 2.5. When the source is placed to the center of the crystal surface, the energy resolution and the full-energv-peak efficiency of the spectrometer for 137Cs are 9.5% and 8.4% respectively.更多还原