Angular Differential Cross Sections for the Excitation of 1¹S Helium to the 2¹S and 2¹P States by 25- to 100-keV-Proton Impact

Author

Thomas J. Kvale
Denver G. Seely
D. M. Blankenship
E. Redd
Timothy Gay
Mineo Kimura
Eduard P. Rille
Jerry Peacher, Missouri University of Science and TechnologyFollow
John T. Park, Missouri University of Science and TechnologyFollow

Abstract

Angular differential cross sections for the proton-impact excitation of ground-state helium (1¹S) to the 2¹S and 2¹P states have been measured for the first time in the energy range 25 to 100 keV with use of the energy-loss technique. The data indicate that, for very small scattering angles, at 25 keV the 2¹S differential cross section is greater than the 2¹P differential cross section. For impact energies greater than 50 keV, the 2¹P differential cross section clearly dominates over the 2¹S cross section in the very small scattering angle region. The present data have been numerically summed and integrated to compare with previous absolute experimental measurements on related processes. These are in very good agreement with the present results. An eight-state impact-parameter calculation incorporating the electron-capture channel was performed and resulted in the best agreement with the experimentally determined differential cross sections.

Recommended Citation

T. J. Kvale et al., "Angular Differential Cross Sections for the Excitation of 1¹S Helium to the 2¹S and 2¹P States by 25- to 100-keV-Proton Impact," Physical Review A, vol. 32, no. 3, pp. 1369 - 1378, American Physical Society (APS), Sep 1985.

The definitive version is available at https://doi.org/10.1103/PhysRevA.32.1369

Department(s)

Physics

International Standard Serial Number (ISSN)

1050-2947

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 1985 American Physical Society (APS), All rights reserved.

Publication Date

01 Sep 1985