title: Total, partial, and electron-capture cross sections for ionization of water vapor by 20-150 keV protons.
abstract: We present experimental results for proton ionization of water molecules based on a novel event by event analysis of the different ions produced (and lost). We are able to obtain mass analyzed product ion signals (e.g., H2O+, OH+, O+, O++, H+) in coincidence with the projectile analyzed after the collision, i.e., either being H+, neutral H after single electron capture during the ionization event, or H- after double electron capture. After proper calibration we are thus able to determine a complete set of cross sections for the ionization of a molecular target by protons including the total and the partial cross sections and in addition also the direct ionization and the electron capture cross sections.
authors.affiliation: Institut de Physique Nucléaire de Lyon, IN2P3-CNRS et Université Claude Bernard Lyon 1, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne Cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Gobet
authors.forename: B
authors.initials: B
authors.lastname: Farizon
authors.forename: M
authors.initials: M
authors.lastname: Farizon
authors.forename: M J
authors.initials: MJ
authors.lastname: Gaillard
authors.forename: M
authors.initials: M
authors.lastname: Carré
authors.forename: M
authors.initials: M
authors.lastname: Lezius
authors.forename: P
authors.initials: P
authors.lastname: Scheier
authors.forename: T D
authors.initials: TD
authors.lastname: Märk