Quantum-mechanical calculation of multiple electron removal and fragmentation cross sections in He+-H2O collisions

摘要

Electron removal and fragmentation cross sections are calculated for He+(1s)-H2Ocollisions at impact energiesnfrom 20 keV/amu to several MeV/amu by using the nonperturbative basis generator method for ion-moleculencollisions. Previous work for proton impact is extended to deal with the dressed projectile in the present case. Theneffects from the active projectile electron are taken into account by applying the same single-particle Hamiltoniannto all electrons and by using the inclusive-probability formalism in the final-state analysis. Fragment-ion yieldsnare evaluated from the single-, double-, and triple-electron removal cross sections, and the results are comparednwith the available experimental data. Very reasonable agreement is obtained for fragmentation caused by directnionization, while some discrepancies remain in the capture and loss data.