摘要
本文报道了以ＨＰＧｅ为主探测器的低本底反康普顿γ谱仪。该谱仪以环形和圆柱形ＮａＩ（Ｔｌ）组成阱型反符合屏蔽探测器，以钢、铅及不锈钢等材料组成复合结构屏蔽室。对４０Ｃｏ１３３２．５ｋｅＶγ射线，ＨＰＧｅ主探测器能量分辨率为１．８６ｋｅＶ，相对效率为３８％。在阱型反符合屏蔽条件下，谱仪对１３７Ｃｓ点状薄膜源测得康普顿抑制系数为４．４；峰康比为８７０∶１；５０～２０００ｋｅＶ能区内每ｍｉｎ积分本底为７．５；测量时间１０００ｍｉｎ，置信度为９５％，谱仪对１３７Ｃｓ点薄膜源的最小可探测活度为３．８ｍＢｑ。
This paper described a low background anti compton gamma ray spectrometer with a HPGe main detector which has the relative efficiency of 38% and energy resolution of 1.86keV for 1332.5keV gamma ray of 60 Co. An annulus and a cylindrical NaI(Tl) formed the well type anticoincidence shielded detector. The sheld chamber consists of steel, lead and stainlessteel. Under the condition of well type anticoincidence shield and using point source of 137 Cs, the integral compton suppression factor was 4.4; peak to compton ratio was 870:1; when the measuring time was 1000 minutes and the confidence level was 95%, the minimal measurable activity was 3.8×10 -3 Bq. The background count rate per minute was 7.5 in the energy range of 50keV to 2000keV. (
出处
《核电子学与探测技术》
CAS
CSCD
北大核心
1997年第4期256-261,共6页
Nuclear Electronics & Detection Technology
