Single and multiple electron removal processes (capture and ionization) in proton-${\mathrm{H}}_2\mathrm{O}$ collisions have been investigated applying the continuum distorted wave with eikonal initial-state model within the framework of independent electron approach. Probabilities and cross sections for electron capture are derived from the same quantities evaluated for ionization using the continuity of transition quantities across the ionization threshold. Dissociation and fragmentation cross sections for the ${\mathrm{H}}_2{\mathrm{O}}^{q+}$ ($q=1$–3) ions have been evaluated by considering branching ratios that include the effect of multiple electron removal transitions. The results are compared with experimental and other theoretical data in the range of impact energies from 30 kev to 5 MeV. Generally, the evaluated cross sections and fragmentation yields show good agreement with experiments at impact energies above 100–150 keV.

• Received 18 December 2015
• Revised 27 January 2016

DOI:https://doi.org/10.1103/PhysRevA.93.032704