摘要
本文使用5—27 keV能量范围的电子轰击纯厚Al(Z=13),Ti(Z=22),Zr(Z=40),W(Z=74)和Au(Z=79)靶,利用硅漂移探测器(SDD)收集产生的X射线,给出了K,L壳层特征X射线产额的测量结果,并将所得实验数据与基于扭曲波玻恩近似理论模型(DWBA)的蒙特卡罗模拟值进行了比较,两者在小于或约为10%的范围内符合.根据测得的特征X射线产额进一步得到了相应的内壳层电离截面或特征X射线产生截面.通过对比电子入射角度为45°和90°的两种情况下解析模型与蒙特卡罗模拟的特征X射线产额,发现在入射角度为90°时两者符合较好.同时,本文还给出了次级电子、轫致辐射光子对特征X射线产额的贡献,该贡献与入射电子能量关系较弱,表现出与原子序数较密切的相关性.
In this paper,pure thick Al(Z=13),Ti(Z=22),Zr(Z=40),W(Z=74)and Au(Z=79)targets are bombarded by electrons in an energy range of 5–27 keV,and the experimental thick-target characteristic X-ray yields of K-shell and L-shell,the X-ray production cross sections and the ionization cross sections of inner shells are presented.The present experimental setup and data processing are improved,specifically,a deflection magnet is installed in front of the X-ray detector to prevent the backscattered electron from entering into the X-ray detector,and the bremsstrahlung background spectra calculated from PENELOPE Monte Carlo simulations are used to deduce the net peak areas.The X-ray detector used in this experiment is the XR-100SDD manufactured by Amptek Inc.with a 25 mm2 C2 ultra-thin window which can detect the low-energy xrays down to boron Ka line(0.183 keV).Standard sources(55Fe,57Co,137Cs and 241Am)with an activity accuracy range of 1%–3%(k=2),supplied by the Physikalisch-Technische Bundesanstalt,Germany(PTB),are used to perform the detector’s efficiency calibration,and in a low-energy range(<3.3 keV)the efficiency calibration is accomplished by measuring characteristic X-ray spectra produced by 20 keV electron impacting various thickness solid targets(i.e.by the characteristic peak method).The uncertainty of the detector’s efficiency calibration obtained in this paper is^1.6%.The experimental thick-target characteristic X-ray yield data with an uncertainty of 1.7%–6.2%are compared with the PENELOPE Monte Carlo simulations,in which the inner-shell ionization cross sections are based on the distorted-wave Born approximation(DWBA)calculations,and they are in good agreement with a difference of less than or^10%.According to the measured thick-target characteristic x-ray yields,the K-shell ionization cross sections for Al,Ti and Zr and the L-shell Xray production cross sections for Zr,W and Au are also obtained with an uncertainty of 5%–8%(except for Al due to large K-shell fluorescence yield uncertainty),the dif
作者
李颖涵
安竹
朱敬军
李玲
Li Ying-Han;An Zhu;Zhu Jing-Jun;Li Ling(Key Laboratory of Radiation Physics and Technology of Ministry of Education,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第13期58-70,共13页
Acta Physica Sinica
基金
中国工程物理研究院核物理与化学研究所(批准号:19H0746)资助的课题.
关键词
特征X
射线产额
内壳层电离截面
特征X
射线产生截面
蒙特卡罗模拟
characteristic X-ray yields
atomic inner-shell ionization
characteristic X-ray production cross section
Monte Carlo simulation
