ELECTRON-STIMULATED DESORPTION FROM THE SURFACE OF SOLID NE - KINETIC-ENERGY AND ANGULAR-DISTRIBUTIONS OF DESORBED METASTABLES

Electron stimulated desorption of metastable species from the surface of solid Ne was investigated. Ne metastables through various desorption channels were identified in the kinetic energy distributions which were obtained by time-of-flight measurement. The energy distribution is identical to that obtained by photo-stimulated desorption experiments. Two dominant species observed in the time-of-flight spectrum showed different characteristics in the angular distribution of desorption. The lower kinetic energy one, which has a kinetic energy of approximately 0.18 eV and was attributed to a ''cavity-ejection'' mechanism, had a sharp angular distribution along the surface normal with FWHM of approximately 30-degrees. The other one, which has approximately 1.4 eV and was attributed to a ''excimer-dissociation'' mechanism, did not show a preferential direction of desorption.