摘要
本文报道以φ100×100mm的低钾NaI(T1)晶体和GDB-76F型光电倍增管组合探头为探测器的室内外通用γ谱仪。在铅屏蔽室内,γ光子能量从0.05—2MeV范围本底计数率为1053计数/min。对^(137)Cs面源(φ5mm)的γ射线能量分辨率<10％,全能峰效率为16.3％,测量1000min,置信水平为95％,最小可探测下限为0.06Bq。环境就地测量20min可分析出10m半径范围内土壤中U系,Th系、^(40)K和^(137)Cs等核素的比放活度,并可给出距地面1m高处它们各自的γ吸收剂量率及总吸收剂量率值。
The NaI(Tl) r spectrometry system for both indoor and outdoor use, consisting of a low level φ100×100mm NaI (T1) detector with GDB-76F photomultiplier tube is reported. The background counts of r-ray photons, whose energy range is from 0.05 to 2 MeV, is 1053 cpm in the lead shield. The energy resolution for 137Cs area source is less than 10%,the detection efficiency of total-absorption peak is 16. 3%and minimal detectable limit is 0. 06Bq (measurement time is 1000 min . , the confidence levelis 95%). In-situ measurements for 20 min. can give the specific activity of some nuclides, such as U series, Th series, 40K and 137Cs et al ., in the soil within a radius of 10 metres. The values of the r absorbed doserate at 1 metre high above the ground for each nuclide and the sum of absorbed dose rate can also be given.
出处
《核电子学与探测技术》
CAS
CSCD
北大核心
1989年第5期267-276,共10页
Nuclear Electronics & Detection Technology
关键词
Γ谱仪
环境监测
Environmental measurement, Low level r spectrometry
