Experimental study on the interaction of multiply-charged ions with rare gas solid surfaces

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Experimental study has been done on the interaction of multiply-charged ions and low-energy electrons with rare gas solid surfaces. Following results have been obtained.・Time-of-Flight spectra have been measured for the desorbed metastable atoms from the surface of solid Ne by low energy electron impact. By annealing the sample surface at the temperature of 7.0K, the kinetic energy of desorbed atoms was increased, and the sharpness of the angular distribution was also increased toward the normal direction of the sample surface. These results have been explained by considering the crystallization of the sample surface by annealing.・Cluster ions desorbed from the surface of solid Ne by multiply charged ion impact have been measured. Surprisingly large clusters the size of which reached to 100 was observed.・Absolute desorption yields have been measured from the surface of solid Ne by Ar^<q+>(q=1〜6) and Ne^<q+>(<q=1〜5) impact. We have succeeded in separating the contribution of 'Potential Sputtering' and 'Kinetic Sputtering' by measuring the dependence of the desorption yield on the incident ion energy. The present results show that 'Kinetic Sputtering' yield was 2.5 atoms per 1 eV incident energy, and 'Potential sputtering' was 3.8 atoms per 1 eV internal energy. We have also shown that the threshold energy for the 'Potential Sputtering' for solid Ne was about 20 eV, which corresponds to the exciton creation energy and band gap energy of solid Ne.