Pulsed UV laser induced desorption of ions from aluminum

A study of pulsed W laser induced desorption (LID) has been performed on an Al(111) sample. The positive ion desorption was investigated at low laser fluence, in a regime in which the ion yield exhibits a highly non-linear de pendence on the laser fluence. The peak of the kinetic energy distribution of the desorbed ions has been measured to be about 15 eV. This result is co nsistent with the conjecture that the ion departing the metal surface can a cquire a kinetic energy kick from a process associated with plasmon annihil ation. The Al+ ion kinetic energy peak is asymmetric and about 3 eV full-wi dth at half-maximum (FWHM). This experiment indicates that plasmon excitati on can play a significant role in laser stimulated desorption induced by el ectronic transitions (DIET). (C) 2000 Published by Elsevier Science B.V. Al l rights reserved.