Fragmentation dynamics of diatomic molecules under proton impact: Kinetic energy release spectra of CO^{q+} and NO^{q+} (q = 2, 3) molecular ions

TL;DR

This study investigates the fragmentation dynamics of triply charged NO and CO molecular ions under 200 keV proton impact, analyzing kinetic energy release spectra and potential energy curves to understand dissociation pathways.

Contribution

It provides new experimental KERDs for NO^{3+} and CO^{3+} ions and calculates their potential energy curves, offering insights into fragmentation mechanisms under proton impact.

Findings

Coulomb breakup favors N^{2+} + O^+ and C^{2+} + O^+ channels.

KERDs align with potential energy curves and Coulomb models.

Fragmentation pathways depend on molecular ion states.

Abstract

We report on the fragmentation dynamics of triply charged, diatomic, molecular ions of NO and CO. Dissociative fragmentation after multiple ionization of NO and CO is studied under the impact of 200 keV proton beam using recoil-ion momentum spectrometer. Kinetic Energy Release distributions (KERDs) for various fragmentation channels were obtained. We have also calculated the potential energy curves (PECs) for ground and several excited states of NO^{3+} and CO^{3+} molecular ion. The obtained KERDs are discussed in the background of the calculated PECs as well as the simple Coulomb excitation model. Coulomb breakup of the unstable precursor molecular ion shows a clear preference for the N^{2+} + O^+ (and C^{2+} + O^+) fragmentation channel.