| Affiliation: | (1) Fachbereich Physik, Universität Rostock, 18051 Rostock, Germany;(2) Department of Physics and National Institute for Nuclear Theory, University of Washington, 98195 Seattle, Washington, USA |
| Abstract: | The time-dependent response of simple metal clusters to femtosecond laser pulses is investigated using the semiclassical theory based on the Vlasov equation. Starting from a Thomas-Fermi ground state the dynamics are calculated by use of the pseudoparticle method. Systems studied here are sodium clusters containing up to 147 atoms. Both, the energy transfer to the cluster, which is largely affected by the plasmon enhanced absorption, and the following release of energy to the ions are examined in detail. During the laser excitation the feedback of the absorption to the development of the plasmon energy is controlled by competing mechanisms: ionization and cluster expansion. Characteristics of the Coulomb explosion are studied as function of photon energy and cluster size, particularly with regard to the dynamical influence of collective excitations of the electrons. We also predict features in the angular distribution of the ions that could be measured to test the calculated dynamics.Received: 9 December 2003, Published online: 16 March 2004PACS: 52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.) - 36.40.Vz Optical properties of clusters - 36.40.Gk Plasma and collective effects in clusters |
