L'autoionisation électronique dans le Monoxide de Carbone: les effets du mouvement vibrationnel.

New continuous measurements of the vibrationally resolved photoionization cross sections of CO+ X2Sigma+ and A2Pi between 63 and 83 nm are reported. We assign the Rydberg series converging to CO+ A2Pi. The effects of the vibrational motion are interpreted on the basis of the Condon approximation. This approximation is shown to allow a qualitative understanding of the decay of the Rydberg series converging to the A2Pi and B2Sigma+ states of CO+

Theoretical Study of Electronic Autoionization in CO: Vibrationally resolved results between 17 and 18.3 eV.

peer reviewedWe have theoretically studied the electronic autoionization between 17 and 18.3 eV of Rydberg series converging to the B 2Sigma+ state of CO+ (RB series). We have obtained partial and vibrationally resolved differential and total photoionization cross sections by combining ab initio electronic quantities with a variant of the two-step multichannel quantum defect theory (MQDT). The formalism of the Feshbach projection operators is used to separate the electronic quantities needed in the first and second steps of the MQDT. We have introduced the vibrational motion within the Condon approximation. Our results lead to new unambiguous assignments of the RB series. The vibrationally resolved cross sections, the associated branching ratios, and the background and resonant features are discussed in detail and compared with the available experimental data. There is an overall agreement between theory and experiement except for the angular distribution of photoelectrons