APPLICATION OF DENSE-PLASMA BEAMS TO THE DEVELOPMENT OF A HIGH-EFFICIENCY LATERAL INJECTION-LASER AMPLIFIER

Recent developments in research on drivers for inertial confinement fu sion identified the need to develop laser amplifiers with efficiencies of 80% or more. This article discusses a novel free electron laser am plifier that is based on vacuum interaction of laser beams with electr ons, clusters of condensed matter, or neutral atoms. The scheme is bas ed on the inversion of the ponderomotive expulsion of plasma from a fo cussed laser beam. The problem of Liouville conservation of phase spac e is overcome by employing the laser pulse transient processes. The op tical energy for amplification is provided by the transfer of the tran slative kinetic energy of electrons, clusters, or neutral atoms that a re injected nearly laterally into the laser pulse. The gains predicted to be achievable with this process are of interest for clusters, alth ough the cluster densities presently available are too low to achieve the desired level of amplification. Neutral beams are shown to have th e greatest potential for achieving large amplifications.