^(238)Pu低能光子源衰变γ能谱识别  

Identification of Gamma Spectrum Decayed by ^(238)Pu as a Low Energy Photon Source

作　　者：许旭 刘佳强 陆景彬[1] 刘玉敏[1] 马克岩 杨东[1] 刘运祚[1] 

机构地区：[1]吉林大学物理学院,吉林长春130012

出　　处：《同位素》2017年第4期249-258,共10页Journal of Isotopes

基　　金：国家重大科学仪器设备开发专项(2012YQ240121);国家自然科学基金(11405072)

摘　　要：利用同轴P型高纯锗探测器,对X荧光分析的^(238)Pu低能光子源进行γ能谱分析,并对^(233)Pa、^(224)Ra、^(212)Pb、^(212)Bi及^(208)Tl的特征γ射线进行分析,确定上述核素的来源。其中,^(233)Pa是生产^(238)Pu的原料237 Np的衰变产物,^(224)Ra、^(212)Pb、^(212)Bi及^(208)Tl均为生产^(238)Pu的副产物^(236)Pu的衰变子核。能量为350、440、844、1 014、1 130、1 266、1 368、1 454keV的γ射线是α粒子轰击源封装材料引起原子核库伦激发或γ射线照射周边环境引起核激发产生。进行效率刻度后,使用γ能谱法计算各放射性核素的活度,并根据放射性平衡计算各放射性核素的质量。通过对^(238)Pu源γ能谱的分析,建立计算放射性同位素活度与质量的方法。The gamma spectrum of ^238Pu low energy photon source which was used for X-ray fluorescence analysis was analyzed by using P-type coaxial HPGe detector.There were characteristic rays of ^233Pa,^224Ra,^212Pb,^212Bi and ^208Tl in the spectrum except the characteristic gamma rays of 238 Pu.^233Pa was the decay product of 237 Np,which was the raw material used to produce ^238Pu.^224Ra,^212Pb,^212Bi and ^208Tl were the daughter nuclei of ^236Pu,which was by-product in the process of ^238Pu＇s production.Gamma rays of 350,440,844,1 014,1 130,1 266,1 368,1 454 keV were caused by coulomb excitation that alpha particles bombarded encapsulation materials of the source,or nuclear excitation that gamma rays irradiated surroundings.After the basis of efficiency calibration,the radioactive activity of each radioactive nuclide was calculated by gamma ray spectrometry.The quality of each radioactive nuclide was calculated derived from the principle of radioactive equilibrium.Through the analysis of ^238Pu＇s gamma ray spec-trum,the method to calculate the radioisotope activity and the purity of radioactive sources was offered.

关 键 词：^238Pu低能光子源 特征射线 Γ能谱法 效率刻度 

分 类 号：O571.32[理学—粒子物理与原子核物理]