低能电子入射电离He原子二重微分截面的理论研究  

A theoretical study on double differential cross sections for electron impact ionization of helium at low energies

作　　者：张穗萌[1] 吴兴举[1] 孙瑞[1] 杨欢[2] 高矿[2] 周军[1] 

机构地区：[1]安徽皖西学院数理系原子与分子物理研究所,六安237012 [2]安徽师范大学物理与电子信息学院,芜湖241000

出　　处：《物理学报》2007年第11期6378-6385,共8页Acta Physica Sinica

基　　金：安徽省自然科学基金(批准号:03406203);安徽省教育厅重大科研项目基金(批准号:ZD2007002-1);安徽省教育厅自然科学基金(批准号:2006KJ267B);省高校拔尖人才专项基金(批准号:[2003]022)资助的课题.~~

摘　　要：研究了低能电子入射单电离He原子的二重微分截面(DDCS),通过对散射电子三重微分截面在全空间的角度积分得到敲出电子的DDCS.分别用DS3C模型和BBK模型计算了入射能为26.3,28.3,30.3,32.5,34.3,36.5和40.7eV时,低能电子入射电离He原子的DDCS;研究表明:DS3C的计算结果,除在低入射能(比如26.3eV)和小敲出角之外,均能与绝对测量的实验结果较好地符合.此外,对直接和交换效应也进行了研究,给出了交换效应对截面的贡献.　In the present work we have studied the double differential cross sections for single ionization of a helium atom by electron impact at low energies.The double differential cross sections of the secondary ejected electron have been obtained by integrating the triple differential cross sections over the entire angular range of the primary scattered electron.The double differential cross sections for electron impact ionization of helium at incident energies of 26.3,28.3,30.3,32.5,34.3,36.5 and 40.7eV have been calculated in the BBK and DS3C model.The present DS3C results are compared with the absolute measurements,and reasonably good agreement has generally been found except for low incident energies（e.g.,26.3eV）and low ejected angles.In addition,the direct and exchange amplitudes are also considered.It has also been shown how the exchange effects contribute to the cross sections.

关 键 词：二重微分截面 低能入射电子 交换效应 

分 类 号：O562[理学—原子与分子物理]