Charge exchange and x-ray emission cross sections for multiply charged ions colliding withH2O

Abstract

Total and state selective $nl$-electron capture cross sections are presented for highly charged ions $Z=4--10$, 14, 18, and 26 colliding with water molecules. The energy range investigated was from $10\phantom{\rule{0.3em}{0ex}}\mathrm{eV}∕\mathrm{amu}$ $(v=0.02\phantom{\rule{0.3em}{0ex}}\mathrm{a.u.})\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}100\phantom{\rule{0.3em}{0ex}}\mathrm{keV}∕\mathrm{amu}$ $(v=2\phantom{\rule{0.3em}{0ex}}\mathrm{a.u.})$. An initialization for the $1B1$ and $3A1$ orbitals of the water molecule is introduced based on the one center expansion of Moccia and compared to our previous studies based on a hydrogenic approximation within the microcanonical ensemble. The $Z$ dependence of the calculated total cross sections is in reasonable agreement with the recent data of Mawhorter et al. [Phys. Rev. A 75, 032704 (2007)] and is improved over previous results. The energy dependence of the $n$- and $l$-level populations is investigated. The $K$-shell x-ray emission cross sections are determined by using the calculated state-selective electron capture results as input and then applying hydrogenic branching and cascading values for the photon emission. Our results compare favorably with experimental data from the KVI-Groningen, Jet Propulsion Laboratory and Lawrence Livermore National Laboratory groups.