Feasibility Study of the Plasma Mirror Concept for High Power Lasers

Abstract : This report results from a contract tasking Vienna University of Technology as follows: 1) Theoretical Assessment: The reflectivity of a plasma at least at the radiation of a carbon dioxide laser depends strongly on the number of free electrons per unit volume. The latter electron density is known from the literature for the case of a metal vapor plasma in deep penetration laser welding or drilling for the case of plasma shielding. So by comparing theoretical work on plasma shielding in the case of deep penetration welding and the outcomings of the arc models, arc currents can be estimated where electron densities become comparable to those which cause plasma shielding in laser welding and where the desired mirror action can be expected.