Soft x ray emission spectra from laser-irradiated high-Z targets

X ray data were acquired from mass-limited targets with the Pharos III laser system. Targets, mounted at the tip of thin glass stalks, were microscopic pieces of single or multiple high-Z element composition. The laser irradiance was 4 x 10(exp 14) W/sq cm with about 300J of focused 1.05 microns wavelength laser beam. A convex KAP crystal spectrograph was used for its capability to collect high resolution spectra in the 4 to 20 A soft x ray region. The recorded spectral film densities were microdensitometered and converted by computer-processing to absolute continuum and emission line intensities. The spectral features were identified with the aid of ab-initio atomic structure calculations. The continuum background was evaluated as a source of pseudo-continua for absorption studies of soft x rays.