The generation of high energy ions by photo-induced dissociation of atomicclusters

The interaction of an intense laser pulse of sub-picosecond duration with a n atomic cluster larger than a few hundred atoms can be extremely energetic . The high local density within the cluster together with a dynamic dielect ric resonance in the expanding cluster microplasma greatly enhance coupling of the laser to both ion and electron kinetic energies. In contrast to the few tens of eV temperatures typically produced in laser irradiation of mon atomic gases, cluster targets can produce electron energy distributions in the few keV range, mean ion temperatures of 10-50 keV and peak ion kinetic energies up to 1 MeV. In addition, charge states up to 40(+) can be produce d with quite modest laser intensities (approximate to 10(16) Wcm(-2)). Clus ter targets are also surprisingly efficient (>90%) at absorbing intense las er light, and thus provide a new route to producing very high energy densit y, highly ionized laboratory plasmas of interest to a broad range of discip lines. Here we review recent experimental results and outline some areas of current research in this new field.