Three-body fragmentation of multiply charged nitrous oxide induced by Ar8+ - and Xe15+ -ion impact

Abstract

We study multiple ionization and subsequent dissociation of nitrous oxide $({\mathrm{N}}_{2}\mathrm{O})$ in collisions with 1 a.u. ${\mathrm{Ar}}^{8+}$ and ${\mathrm{Xe}}^{15+}$ ions. The experiments are performed by using a recoil ion momentum spectrometer (RIMS) equipped with a position- and time-sensitive detector which allows the measurement of the momenta of fragment ions in coincidence. By measuring the momentum vectors of the recoiling fragment ions various important parameters, such as kinetic energy release and those related to molecular structure prior to fragmentation, have been derived. Furthermore, the projectile-charge-state dependence of the fragmentation dynamics of ${\mathrm{N}}_{2}\mathrm{O}$ is investigated and a very mild dependence has been noticed in a few channels. In addition, we also study the concerted and sequential mechanisms in the three-body decay of ${\mathrm{N}}_{2}{\mathrm{O}}^{q+}$ (where $q\phantom{\rule{4pt}{0ex}}\ensuremath{\le}7)$. It has been observed that ${\mathrm{N}}_{2}{\mathrm{O}}^{q+}$ breaks up mainly in a concerted manner except for the ${\mathrm{N}}_{2}{\mathrm{O}}^{3+}\ensuremath{\rightarrow}{\mathrm{N}}^{+}+{\mathrm{N}}^{+}+{\mathrm{O}}^{+}$ (1,1,1) and ${\mathrm{N}}_{2}{\mathrm{O}}^{4+}\ensuremath{\rightarrow}{\mathrm{N}}^{2+}+{\mathrm{N}}^{+}+{\mathrm{O}}^{+}$ (2,1,1) channels. For both these channels, the presence of an intermediate rotating ${\mathrm{NO}}^{2+}$ has been identified. Furthermore, by using Dalitz plot analysis, we have been able to separate various mutually mixed channels of highly charged ${\mathrm{N}}_{2}{\mathrm{O}}^{q+}$.