Absorption of laser radiation by Al, Fe, and Au planar metallic targets

Abstract
Experiments to determine the absorptance of an 8‐nsec (FWHM) 1.064‐μm laser pulse incident on metallic targets were performed using a well‐characterized integrating sphere photometer. The absorptance was inferred by individually measuring the incident, back reflectd, and scattered laser radiation over the range ≃1013–1014 W/cm2 for three different elemental planr targets (Al, Fe, and Au). The absorptance varied approximately linearly from 0.9 at 1013 W/cm2 at 1014 W/cm2 and was independent of target material. The experimental accuracy was ±4%.