Kinetic energy release distributions of multiply charged NOq+ (q = 2–7) molecular ions produced in collisions with 1.6 MeV Ar8+ ion beam

Abstract

We report the fragmentation dynamics of multiply charged molecular ions of NO under the impact of highly charged Ar8+ ions in the intermediate velocity (vp ≈ 1 a.u.) range. Coincidence measurements of ionic fragments from NOq+ (2 ≤q≤ 7) were performed utilizing the three-dimensional momentum imaging technique of a recoil-ion momentum spectrometer equipped with a time- and position-sensitive detector and a multi-hit data acquisition system. With a 1.6 MeV Ar8+ beam, we observed a total of 13 fragmentation channels. Coulomb breakup of the unstable parent molecular ion shows a clear preference for the symmetric charge breakup over the asymmetric one. We have measured the Kinetic Energy Release Distributions (KERDs) for various fragmentation channels. We have also generated the potential energy curves for NOq+ molecular ions using the internally contracted multi-reference configuration interaction approach with complete active space self-consistent field wave functions. The obtained KERDs are compared and discussed in the background of the ab initio potential energy curves as well as the simple Coulomb explosion model.