LB6008型六路低本底α、β测量仪的性能评估  

Performance evaluation of LB6008 six channel low background alpha and/or beta measuring instrument

作　　者：冯洪杰[1] 王新明[2] 曾宪恒[1] 

机构地区：[1]北京市大兴区疾病预防控制中心,北京102600 [2]北京市疾病预防控制中心,北京100013

出　　处：《中国卫生检验杂志》2016年第21期3060-3063,共4页Chinese Journal of Health Laboratory Technology

摘　　要：目的掌握LB6008型六路低本底α、β测量仪性能指标,准确测量样品中总α、总β放射性体积活度。方法使用239Pu、90Sr-90Y工作源和241Am、40K粉末源对仪器进行效率刻度,对本底计数率、串道比及效率稳定性进行分析,依据GB/T 11682—2008和厂家指标进行评价。结果α本底计数率≤0.07计数/(cm2·h),β本底计数率≤5.1计数/(cm2·h),各路α探测器2π探测效率比均>80%,β探测器2π探测效率比均>50%;241Amα源探测效率为(5.62±0.33)%,40Kβ源探测效率为(26.22±2.11)%,5 d内探测效率变化≤4.58%;α射线对β道的串道比≤1.6%,β射线对α道的串道比≤0.12%;本底月稳定性实际测量值均在N_b±3δ可接受范围内,95%的测量值在N_b±2δ目标值范围内。结论该测量仪的基本性能指标均达到国家规定的Ⅱ级标准,适于样品总放射性水平的常规测量。Objective To master the performance parameters of LB6008 six channel low background alpha and / or beta measuring instrument,and to measure gross radioactivity of α or β in sample accurately. Methods Both239 Pu /90Sr-90 Y source and241 Am /40 K source were used to carry out the efficiency calibration. At the same time,background count rate,interfere ratio and efficiency stability of the measurement system were also assessed in terms of GB / T 11682—2008 and enterprise standard. Results The α background count rate was less than 0. 07 count /（ cm2·h） when the 2π efficiency ratio of239 Pu alpha source was more than 80%,and the β background count rate was less than 5. 1 count /（ cm2·h） under the condition of 2π efficiency ratio was more than 50%. The detection efficiency was（ 5. 62 ± 0. 33） % for241 Am alpha standard source and（ 26. 22 ± 2. 11） % for40 K beta standard source,respectively. The bias of efficiency stability of the system was less than 1. 6% within 5 days. The interfere ratio（ α） and interfere ratio（ β） are less than 1. 6% and 0. 12%,respectively. The measurement results of background stability in month were always in the acceptable range of N_b± 3δ,and ninety- five percent of the measurement results were in the target value range of N_b± 2δ. Conclusion The performance parameters of this equipment are reliable,and can be applied to detect the gross radioactivity of sample accurately.

关 键 词：总α放射性 总Β放射性 本底计数率 探测效率 

分 类 号：TH83[机械工程—仪器科学与技术]