Collisional destruction of anionic carbon and silicon clusters by helium, neon, and argon atoms at intermediate velocities

Abstract

We measured the total destruction cross sections of small ${X}_{n}^{\ensuremath{-}}$ clusters $(X=\mathrm{Si}$ and C; $n=2,$ 3, and 4) in noble gas targets (Y = He, Ne, and Ar), with relative velocities $v$ in the 0.10--0.95 a.u interval for silicon, and in the 0.20--1.20 a.u. interval for carbon. The measured values increase monotonically with target and projectile sizes, as expected on a geometrical basis. In particular the dependence of the cross sections on n is linear for carbon clusters, agreeing with a quantitative model based on the linear structure of these clusters. Ratios of the measured cross sections for the several ${\mathrm{X}}_{n}^{\ensuremath{-}}$ clusters, ${\ensuremath{\sigma}}_{X,n}^{\mathrm{Ne}}(v)/{\ensuremath{\sigma}}_{X,n}^{\mathrm{He}}(v),$ ${\ensuremath{\sigma}}_{X,n}^{\mathrm{Ar}}(v)/{\ensuremath{\sigma}}_{X,n}^{\mathrm{He}}(v),$ and ${\ensuremath{\sigma}}_{X,n}^{\mathrm{Ar}}(v)/{\ensuremath{\sigma}}_{X,n}^{\mathrm{Ne}}(v),$ were verified to fall into universal curves, i.e., each cross section is the product of target- and projectile-dependent factors.