Quantum defect theory VIII. Resonances in the collision strengths for O+ 2p3 2D3/2-2D5/2

Abstract

Transitions between the levels ²D_3/2, ²D_5/2 of O⁺ 2p³, produced by electron impact, are of importance in determining the relative intensities of the lines ²D_J-⁴S observed in gaseous nebulae. Saraph, Seaton and Shemming have made calculations for energies above the threshold for excitation of 2p^{3 2}P. Below this threshold the ²D_3/2-²D_5/2 cross section contains series of resonances converging on ²P. The reactance matrices of Saraph et al. are extrapolated to energies below the ²P threshold, and the cross sections are calculated using resonance theory for the case of degenerate closed channels, as developed by Gailitis in 1963 and discussed in the paper `Quantum defect theory VII'.