Studies of pellet evaporation by CO2 laser, using multiple-frame argon-ion laser shadow photography

Framing shadowgraphs have been used to investigate the interaction of a 1.5 GW CO2 laser with polythene pellets in vacuo. A Spectra-Physics argon-ion laser was used as source and a Hadland Imacon camera for recording, at framing rates of 105 to 107 Hz. Part of the pellet ionized, and the remainder fragmented. Theoretical analysis suggests that fragmentation can be avoided if the laser pulse and pellet geometry are mutually optimized; optimal parameters are estimated. (author)