Mechanism Of Ion-Atom Collision And Polarization Model

This work was done at the 2><1.7MV tandem accelerator in Lanzhou University. Various ionization cross sections were investigated for 0.2-6.3MeV C^q+(q=l-4) and 0.25-6.35MeV O^q+(q=1-4) colliding with He, Ne, Ar atoms respectively. The mechanism of capture and ionization in this energy region was discussed, and a new model—Polarization Model was presented. The Time-of-Flight measurement for recoil ions, position-sensitive detecting technique for scattering ions, and coincidence technique were employed to obtain correlation spectra.The pure ionization cross sections of Ne were investigated and compared with the n-body classical-trajectory-Monte-Carlo(nCTMC) calculations.The loss cross sections of O²⁺ were investigated and the effective charges of He and Ar atoms were obtained via comparison of experimental results and nCTMC calculations.The ionization cross sections of He were investigated and interpreted in the screening-and-antiscreening theory regime.The dependence on velocity and target atomic number of C^q+ and O^q+ was investigated and analyzed briefly in terms of effective charge and residual electron.Based on the Independent-Electron-Model, Polarization Model was established using semi-empirical method. It can calculate absolute cross sections for cooperated many channels and acquires good agreement with experimental results.