Electron-impact ionization of atomic oxygen

Abstract

Electron-impact ionization cross sections for atomic oxygen are calculated in the Born approximation. The initial bound state of atomic oxygen is represented by a configuration interaction wavefunction. Configurations used in the expansion were determined by calculating certain bound-bound oscillator strengths and comparing with recent experimental data. The final continuum state of atomic oxygen is represented by a close-coupling wavefunction. As a final test of the wavefunctions photoionization cross sections are calculated in the dipole length and velocity approximations and compared with other experimental and theoretical works. In the case of electron-impact ionization, triple, double, and single differential and total cross sections are calculated as well as generalized oscillator strengths. An interesting feature in the triple differential cross sections is the appearance of a dip in the binary peak. A comparison of total cross sections is made with available experimental and theoretical works. The comparisons are favorable. Finally, sources of error are indicated along with suggestions for improvement. ABSTRACT