Thermal transient analysis of pulsed heat deposition in sheet targets and observations of plasma spreading

Abstract

The decay of temperature transients in pulse-heated sheet targets can be analyzed to deduce the initial magnitude and spatial distribution of target heating. We present formulas describing such thermal transients, and give an example of analysis involving heating of aluminum by a pulsed CO2 laser with air plasma ignition. Plasma spreading of heat deposition over an area much larger than the laser beam cross section is shown.