State Selective Measurements Of Hcl Produced By Strong Ultrashort Laser-Clusters Interaction

We have performed studies of keV X-ray production from (Ar)(n), (Kr)(n) and (Xe)(n) rare gas clusters (with n between 10(4) and 10(6) atoms/cluster) submitted to intense (10(18) W/cm(2)) infrared (790 nm) laser pulses. We have determined the photon energies and the absolute photon emission yields as a function of several physical parameters governing the interaction: size and atomic number of the clusters, peak intensity of the laser. Up to 10(6) 3 keV photons per pulse at a moderate (10(15)/cm(3)) atomic density have been observed. High resolution spectroscopy studies in the case of (Ar)(n) clusters have also been performed, giving unambiguous evidence of highly charged (up to heliumlike) ions with K vacancies production. The results obtained indicate that X-rays are emitted before cluster explosion on a subpicosecond time scale, and shed some light on the mechanisms involved in the first stage of the production of the nanoplasma induced from each cluster.