MEASUREMENT OF 0.35-MU-M LASER IMPRINT IN A THIN SI FOIL USING AN X-RAY LASER BACKLIGHTER

Imprinted modulations in optical depth of a thin Si foil due to 0.35 m u m laser irradiation at about 3 x 10(12) W/cm(2) have been measured a t shock breakout, These measurements were made by high resolution face -on radiography using a gain saturated yttrium x-ray laser backlighter operating at a wavelength of 15.5 nm with a multilayer optics imaging system. The imprinted modulation due to a static speckle pattern and a 0.29 and a 0.33 THz spectral dispersion smoothed speckle pattern wer e studied. Comparison of the imprinted modulation is made with simulat ions.