Mechanisms of Laser-Surface Interactions

This report describes investigations of the mechanisms by which high power laser radiation interacts with absorbing surfaces. Construction of a carbon dioxide laser used in this work is described, along with preliminary spectroscopic observations of the emission produced when this laser radiation interacts with a glass target. Measurements of ion emission produced by a ruby laser beam with flux densities of the order of 1000 megawatts per square centimeter incident on a tungsten target have been analyzed. From the results it is estimated that particle densities of the order of 10 to the 20th power per cubic centimeter are produced near the target surface. A computer program using these particle densities has been employed to calculate the expected amount of heating produced by absorption of the incident laser radiation in a sodium plasma of this density. The results indicate that rapid heating to temperatures of the order of tens of eV is possible within the time of the laser pulse duration. See also AD0672093.