Investigation of the electronic energy loss of hydrogen ions in H 2O: influence of the state of aggregation

Abstract

The gas-solid difference (phase effect) of the electronic stopping cross section (SCS) is investigated for hydrogen projectiles in H 2O at energies near the stopping maximum. We find experimentally, that at low ion velocities the SCS of the gas is considerably higher than that of the solid (up to 15%). This result is discussed in terms of differences between the valence states of H 2O vapor and of ice and in terms of the projectile inelastic processes.