Laser plasma plume parameters for cascade fission of metal micro- and nanodroplets

Abstract

The cascade fission under the action of Coulomb forces of metal droplets charged up to the Rayleigh limit in a vacuum has been well studied and it is widely used in vacuum technology. Experimental works using the laser electrodispersion method showed that such a division can be carried out in the plasma of a laser plasma plume during the process of nanosecond ablation of metals. The previously published analytical model made it possible to work out requirements for plasma parameters, at which droplets can be divided to nanometer scales, but the limits of applicability of this model were not known. In this paper we present a more accurate numerical model for charging metal droplets in a laser plasma plume, which was used to obtain laser plasma parameters for implementation of cascade metal droplet fission. A comparison with the results obtained using the analytical model is presented.