Study Of Direct Multiple Ionization In Ion-atom Collisions

Direct single and multiple ionization of helium , argon induced by C^q+(q=1, 2,3, 4) in energy range from 0.2MeV to 5.8MeV have been studied. We have gotten the charge states distribution spectrum of the recoil ions corresponding to the scattered ions which of certain charge state using the coincidence technique of recoil ions and scattered ions, position sensitive detection techniques and multiple parameters acquiring system. And men the cross section ratios R₁₁ of direct multiple ionization to single ionization of helium and argon have been measured.To ion-helium collision system, the cross section ratios R₂₁ of direct double ionization to single ionization appeared a maximum with the variety of the energy for every nucleon energy or velocity of projectile. And the peaks of the maximum increased with the increasing of the charge of projectile. These phenomena can be explained qualitatively by atomic polarization effect. The experimental results are in agreement with that of other group.To ion-argon collision system, by the correction of the Auger transition, the changing trends of cross section ratios.R₂₁ , R₃₁ and R₄₁ are similar with the variety of velocity of projectile, and the maximums occurred, too. And the peaks of themaximum corresponding to R₁₁ increased with the increasing of the charge of projectile. These tendencies can also be explained with the atomic polarization effect.