Photodesorption of ionized water clusters from water physisorbed on rare gas solids

The photon-stimulated desorption of (H2O)nH+ from water physisorbed on a rare gas solid (Ne, Ar, Kr, and Xe) has been investigated. From the measurements of the desorption yield as a function of the incident photon energy, the (H2O)nH+ desorption is effectively and indirectly induced by the multiple-excitation and -ionization of rare gas substrates. The direct excitation of the water molecule does not induce noticeable desorption of (H2O)nH+.