Energy distributions of recoil ions produced in 100 MeV collisions of Si⁸⁺ with CO₂ and CS₂ molecules

Abstract

Energy discriminated mass spectra have been measured for recoil ions produced in 100 MeV collisions of Si⁸⁺ with linear triatomics CS₂ and CO₂ using a cross-beams apparatus incorporating a quadrupole mass spectrometer and a retarding potential energy analyser. Fragment atomic and diatomic ions are observed in the mass spectra whose precursors are very highly charged molecular ions which undergo rapid dissociation. Kinetic energy measurements of atomic recoil ions indicate that the peripheral S ions (in the case of CS₂ target) and O ions (in the case of CO₂ target) possess larger energies than the ions of the central C atom; the relatively large energies imparted to C ions are explained in terms of a sequential dissociation model involving formation of an intermediate molecular ion with inner shell vacancies.