Ejection of H2O,O2, H2 and H from water ice by 0.5–6 keV H+ and Ne+ ion bombardment |
| |
Authors: | A Bar-Nun G Herman ML Rappaport Yu Mekler |
| |
Institution: | Department of Geophysics and Planetary Sciences, Tel Aviv University, Tel Aviv 69978, Israel;Department of Physics and Astronomy,Tel Aviv University, Tel Aviv 69978, Israel;Department of Geophysics and Planetary Sciences, Tel Aviv University, Tel Aviv 69978, Israel |
| |
Abstract: | The ejection of H2O, O2, H2 and H from water ice at 30–140 K, bombarded by 0.5–6 keV H+ and Ne+ was studied experimentally. Neon ions in this energy range deposit their energy in the ice by nuclear collisions, whereas with protons of 0.5 to 6 keV the energy deposition mechanism shifts gradually from predominantly nuclear collisions to predominantly electronic processes. The existing theory of nuclear sputtering predicts very well the yield of ejected water molecules and the experimental results in the region of electronic processes agree well with the experimental results of Lanzerotti, Brown and Johnson. However, the major mass loss from water by ion bombardment is via the ejection of O2, H2 and H atoms, which exceed the ejection of water molecules. O2 and H2 production is markedly enhanced at temperatures exceeding ~100 K, whereas H2O and H production are temperature independent, suggesting that O2 and H2 are produced in the bulk of the ice whereas H2O and H atoms are ejected from the surface or near surface layers. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|