Excitation of CO+ and NO+ Electronic States Via Single-electron Capture by B2+ Ions

Abstract

High-resolution translational energy loss spectrometry was performed to obtain the spectra for single-electron capture by 6 keV B2+ ions in collision with CO and NO molecules, to complement a previous investigation involving O2 and N2 targets. The spectrum for CO consists of eight well defined peaks, three of which correspond to capture into the ground state of CO+[X2Σ+] dominated by the 0–0 molecular transition. One intense peak and a subsidiary one are identified as capture into the first excited electronic state of CO+, responsible for subsequent emission of the comet-tail system CO+[A 2Πi→X 2Σ+]. The B 2Σ+ state of CO+, the upper electronic state of the Baldet-Johnson [B 2Σ+→A 2Σi] and the first negative [B 2Σ+→X 2Σ+] bands, is also accessed through two capture channels. The NO spectrum exhibits one intense narrow peak dominated by capture into the second triplet state of NO+ [b 3Π], together with subsidiary features which may involve capture into the ground X 1Σ+ and excited singlet (A 1Π,A′ 1Σ+, W 1Δ) and triplet (b 3Π, a 3Σ+, b′ 3Σ−) manifolds. The NO spectrum is complicated by energy overlap of relevant capture channels, which makes unambiguous identification difficult. © 1997 John Wiley & Sons, Ltd.