质子入射In靶激发L系特征X射线的角分布研究  

Study on angular distribution of L characteristic X-ray emission from In target by proton impact

作　　者：柳钰[1,2] 王兴 徐忠锋[2] 周贤明[1,2] 程锐 张小安[1] 梁昌慧[1] LIU Yu;WANG Xing;XU Zhong-Feng;ZHOU Xian-Ming;CHENG Rui;ZHANG Xiao-An;Liang Chang-Hui(Ion Beam and Optical Physical Laboratory,Xianyang Normal University,Xianyang 712000,China;School of Physics,Xi’an Jiaotong University,710049 Xi’an,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]咸阳师范学院与中国科学院近代物理研究所联合共建离子束与光物理实验室,咸阳712000 [2]西安交通大学物理学院,西安710049 [3]中国科学院近代物理研究所,兰州730000

出　　处：《原子与分子物理学报》2025年第2期98-104,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11875219);陕西省科技厅自然科学基础研究计划(2023-JC-YB-032);陕西省教育厅科研计划(20JK0975);咸阳师范学院“青蓝人才”培养基金项目(XSYQL202007);咸阳师范学院重点培育项目(XSYK21037);咸阳市离子束与光物理重点实验室(L2022-CXNL-ZDSYS-001)。

摘　　要：本论文实验测量并分析了发射角以10°为间隔,125°-155°范围内,入射能量为250 keV的质子束激发In靶产生的特征L系X射线谱,根据实验测得能谱结果,综合考虑探测器的探测效率后,计算了不同探测角度下特征X射线的相对强度比L_(ι)/L_(γ1);由相对强度比L_(ι)/L_(γ1)与二阶勒让德函数P_(2)(cosθ)之间的函数关系,发现特征X射线Lι在被测能量下呈各向异性发射,推得Lι特征X射线的各向异性参数β为-0.179±0.011,进而得到In靶L_(3)亚壳层的定向度A_(20)为-0.422±0.025,实验结果与理论预测一致.根据PWBA(Plane wave born approximation)模型和ECPSSR(Energy-loss coulomb-repulsion perturbed-stationary-state relativistic)模型,计算了250 keV质子入射下,In靶L亚壳层电离截面σ及Coster-Kronig跃迁矫正因子κ,在根据各向异性参数计算L_(3)亚壳层定向度的过程中考虑了Coster-Kronig跃迁的作用.分析认为本实验碰撞速度下,通过电子转移方式产生空穴的截面比直接电离小的多,所以没有对L_(3)亚壳层定向度进行电子转移因素的修正.The L X-ray characteristic spectra of In induced by proton beams with energy of 250 keV and emission angles from 125°to 155°with an interval of 10°are measured.According to the measured experimentally energy spectrum results,after comprehensively considering the detection efficiency of the detector,the relative intensity ratios L_(l)/L_(γ1) of characteristic X-rays at different detection angles are calculated.The angular dependence of differential intensity ratio L_(l)/L_(γ1) is studied as a function of the second-order Legendre function P_(2)(cosθ).Our result demonstrates that the characteristic X-ray Lιis anisotropic emission at the measured energy,and the anisotropic parameter β of characteristic X ray Lιis derived to be-0.179±0.011,furthermore,the value of the alignment degree A_(20) for L_(3) sub-shell is determined to be-0.422±0.025.The experimental results are consistent with the theoretical predictions.According to PWBA(Plane wave born approximation)model and ECPSSR(Energy-loss coulomb-repulsion perturbed-stationary-state relativistic)model,In target L sub-shell ionization cross sectionsσand Coster-Kronig transition correction factorκare calculated under the 250 keV proton incidence.The effect of Coster-Kronig transition is considered in the calculation of L_(3) sub-shell’s anisotropic parameters.The analysis shows that the cross section of vacancies generated by electron transfer is much smaller than that of direct ionization at the collision velocity in this experiment,so the electron transfer factor is not modified for the orientation of L_(3) sub-shell.

关 键 词：碰撞电离 特征X射线 角分布 各向异性 

分 类 号：O54[理学—物理]