ENERGY-DISTRIBUTIONS OF RECOIL IONS PRODUCED IN 100 MEV COLLISIONS OF SI-8+ WITH CO-2 AND CS-2 MOLECULES

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 crossed-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.