X-ray emission from laser-irradiated gold targets with surface modulation

X-ray emission spectra in the 5-22 nm range were recorded from planar and s tructured (meshlike groove surface) gold targets at 45 degrees and 90 degre es to the laser axis. A laser beam of 10-ns duration with E-L less than or equal to 700 mJ and 1.06-mum wavelength was used for the experiment. Experi mental results indicate an enhanced X-ray yield from a structured target as compared to a planar target under identical experimental conditions. Incre ased X-ray emission is attributed to plasma confinement and the possibility of conversion of kinetic energy into localized thermal energy of the plasm a. Results are analyzed explicitly on the incident laser energy.