Soft X-Ray Emission Spectra from Laser-Irradiated High-Z Targets

摘要

X-ray data were acquired from mass-limited targets with the Pharos III lasersystem. 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 to the 14th power 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 4-20 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. Keywords: X ray spectroscopy; Laser heated plasmas; Continuum emission. (jhd)