Desorption of water cluster ions from the surface of solid rare gases

Abstract

Electron or photon irradiation on H 2 O adsorbed on the surface of rare gas solids induces the desorption of protonated water clusters, (H 2 O) n H + . The yield and the size n distribution of cluster ions depend on the coverage, the deposition temperature of water and the thickness of a rare gas film. These results indicate that the (H 2 O) n H + ions are originated from the isolated water cluster and most important factor determining the size n distribution of desorbed (H 2 O) n H + is the sizes of water islands on rare gas solid. The measurement of kinetic energy distributions indicated that the desorbing energy of clusters depend on the rare gas species of the substrates and the cluster size. It is suggested that the (H 2 O) n H + desorption is due to Coulomb repulsion between the ionic water cluster and the rare gas ion.

Desorption of neutrals, cations, and anions from core-excited amorphous solid water

“…Desorption of protonated clusters from water ice by core-excitation was reported before [48]. It has also been observed and studied in the case of electron [49,14] and ion [50,51] irradiation, as well as in field-assisted photon-stimulated desorption [52] or electron and UV photon stimulated desorption from water adsorbed on rare-gas solids [53,54,55].…”

Non-thermal ion desorption from an acetonitrile (CH3CN) astrophysical ice analogue studied by electron stimulated ion desorption

“…the ESID of pure water ice. [35][36][37][38][39] Moreover, the other members of the water cluster ion series (H 2 O) n + and (H 2 O) n H + with n Z 2 are absent, 40,41 probably because water molecules are well diluted on the frozen CH 3 CN surface. In this framework, Mejı ´as et al 42 showed that a single proton tends to stay bonded to H 2 O to form H 3 O + when solvated by more than one CH 3 CN molecule.…”

Desorption of cluster ions from solid Ne by low-energy ion impact

“…A mechanism based on inter-atomic charge transfer leading to Coulomb repulsion between neighboring ions has been proposed to account for ion desorption induced by electronic transitions (DIET) from the surface of rare gas solids [27]. Recent studies have reported low-energy electron-or photon-stimulated desorption by Coulomb repulsion of large cluster ions (n 8) from molecules adsorbed on condensed gas solids [28][29][30][31]. However, the results in figure 2(a) show that the monomer peak dominates and that only very small cluster ions are observed (n < 5).…”