ELECTRON IMPACT IONIZATION OF HELIUM FROM ITS GROUND AND METASTABLE STATES
Chen Zhang-jin (陈长进)ab, Xu Ke-zun (徐克尊)b
a Department of Physics, Anhui University, Hefei 230039, China; b Laboratory of Electron Collision Spectroscopy, University of Science and Technology of China, Hefei 230027, China
Abstract The triple differential cross sections for the ionization of helium from its ground state 11S and metastable states 21S and 23S in coplanar asymmetric geometry by 150, 250 and 400 eV electrons have been calculated in the BBK model. The present results are compared with the experimental data and/or the other theoretical ones. It has been found that the structures for the metastable states differ markedly from those for the ground state. The collision mechanisms for the new structures appearing in the cross sections for the ionization from metastable states have been analysed. And it has been shown how the intensity of recoil peak changes due to the size of the electron orbital. In addition, the optimal kinematical situations for the cross sections are explored for future experiment.
Received: 09 November 1998
Accepted manuscript online:
PACS:
34.80.Dp
(Atomic excitation and ionization)
Fund: Project supported by the National Natural Science Foundation of China (Grant No. 19634040) and by the Education Foundation of Anhui Province (Grant No. 97JL101), China.
Cite this article:
Chen Zhang-jin (陈长进), Xu Ke-zun (徐克尊) ELECTRON IMPACT IONIZATION OF HELIUM FROM ITS GROUND AND METASTABLE STATES 1999 Acta Physica Sinica (Overseas Edition) 8 331
X-ray emission from 424-MeV/u C ions impacting on selected target Xian-Ming Zhou(周贤明), Rui Cheng(程锐), Yu Lei(雷瑜), Yuan-Bo Sun(孙渊博), Yu-Yu Wang(王瑜玉), Xing Wang(王兴), Ge Xu(徐戈), Ce-Xiang Mei(梅策香), Xiao-An Zhang(张小安), Xi-Meng Chen(陈熙萌), Guo-Qing Xiao(肖国青), Yong-Tao Zhao(赵永涛). Chin. Phys. B, 2016, 25(2): 023402.
No Suggested Reading articles found!
Viewed
Full text
Abstract
Cited
Altmetric
blogs
tweeters
Facebook pages
Wikipedia page
Google+ users
Online attention
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.