Laser-induced shock effects in Plexiglas and 6061-T6 aluminum

Abstract

The mass removal per unit area from Plexiglas and 6061-T6 aluminum targets irradiated in air with a giant pulsed laser is presented as a function of incident fluence. This quantity appears to be a strong function of the focal length of the focusing lens. Air breakdown in the presence of a target occurs at fluences greater than 380 J/cm2 for Plexiglas targets and 159 J/cm2 for aluminum targets. Photographic evidence of the back-face spallation of a 0.1-cm-thick aluminum sample irradiated in vacuum is presented. The mirror-finished target was inclined at 45° to the incident beam and irradiated with a fluence of approximately 5000 J/cm2.