Photoionization and electron-impact ionization of Ar5+

Authors

Jing Cheng Wang, University of Nevada - Reno
M. Lu, University of Nevada - RenoFollow
D. A. Esteves, University of Nevada - Reno
M. Habibi, University of Nevada - Reno
G. Alna’washi, University of Nevada - Reno
R. A. Phaneuf, University of Nevada - RenoFollow
A. L. D. Kilcoyne, Lawrence Berkeley National LaboratoryFollow

Date of this Version

2007

Citation

Physical Review A 75, 062712 (2007); DOI: 10.1103/PhysRevA.75.062712

Abstract

Absolute cross sections for photoionization and electron-impact ionization of Ar⁵⁺ have been measured using two different interacting-beams setups. The spectra consist of measurements of the yield of products due to single ionization as a function of electron or photon energy. In addition, absolute photoionization and electron-impact ionization cross sections were measured to normalize the measured Ar⁶⁺ product-ion yield spectra. In the energy range from 90 to 111 eV, both electron-impact ionization and photoionization of Ar⁵⁺ are dominated by indirect 3s subshell excitation-autoionization. In the energy range from 270 to 285 eV, resonances due to 2p-3d excitation-autoionization are prominent in the photoionization spectrum. In the range from 225 to 335 eV, an enhancement due to 2p-nl (n > 2) excitations is evident in the electron-impact ionization cross section. The electron and photon impact data show some features due to excitation of the same intermediate autoionizing states.