物理学报2017，Vol.66Issue(7)：289-296,8.DOI:10.7498/aps.66.073401
电子垂直入射电离氦原子碰撞机理的理论研究
A theoretical study on collision mechanisms for low energy electron impact ionization of helium in the perpendicular geometry
摘要
Abstract
Under the condition of ten different incident energies ranging from 3 eV to 80 eV above the ionization potential of helium and the outgoing electrons having equal energies,by making use of 3C model and modified 3C model,the triple differential cross sections of electron-impact single ionization of the ground state of helium in the perpendicular geometry are calculated.The result is compared with corresponding experimental result to systematically investigate the influences of various screening effects on the triple differential cross sections for helium.The collision mechanisms of the triple differential cross sections are explored.The result shows that the effects of dynamic screening in the final state can directly affect the structures of the triple differential cross sections at lower incident energy,which will unavoidably affect the angular distribution and relative amplitude of side peaks at angles φ =90° and φ =270°.The screening effects of residual electron in the final state of He+ have a similar significant effect on the amplitude of triple differential cross section of helium and angular distributions and relative amplitudes of side peaks at angles φ =90° and φ =270°.When the incident energy is over 84.6 eV,the screening effect of residual electron in the final state of He+ has a slight effect on the amplitude of triple differential cross section,which can be overlooked.But the effects of dynamic screening in the final state on side peaks at angles φ =90° and φ =270° need considering.In addition,by taking advantage of DS3C-Z model,the results of collision mechanism of various peaks at angles φ =180°,φ =90° and φ =270° show that the middle peak at angle φ =180° is produced by a process called triple scattering mechanism and then the side peaks at angles φ =90° and φ =270° are produced by a process called double scattering mechanism.Such a collision mechanism has a direct influence on the generation and variation law of triple differential cross sections.关键词
DS3C模型/垂直入射/屏蔽效应/碰撞机理Key words
DS3C model/perpendicular geometry/screening effects/collision mechanisms引用本文复制引用
杨欢,张穗萌,邢玲玲,吴兴举,赵敏福..电子垂直入射电离氦原子碰撞机理的理论研究[J].物理学报,2017,66(7):289-296,8.基金项目
安徽省高等学校省级自然科学研究重点项目(批准号:KJ2016A749)、安徽省自然科学基金青年项目(批准号:1408085QA13)、安徽省教育厅自然科学研究重点项目(批准号:KJ2012A275)和安徽省教育厅自然科学研究重点项目(批准号:KJ2013A260)资助的课题.Project supported by the Key Projects of Anhui Provincial Department of Education,China (Grant No.KJ2016A749),the Anhui Provincial Natural Science Foundation,China (Grant No.1408085QA13),the Foundation for Key Research Program of Education Department of Anhui Province,China (Grant No.KJ2012A275),and the Foundation for Key Research Program of Education Department of Anhui Province,China (Grant No.KJ2013A260). （批准号:KJ2016A749）
