Measurement of soft x-ray production from slab targets heated by 130 femtosecond Ultrashort Pulse (USP) laser at LLNL.

We have measured the soft x-ray emission (500 to 2000 eV) from a variety of slab targets heated by the Ultrashort Pulse Laser (USP) at Lawrence Livermore National Laboratory. Emission spectra were measured using a transmission grating spectrograph coupled to a x-ray optic Kirkpatick-Baez microscope. Spectral measurements were complimented by broadband measurements using a backthinned CCD array coupled to an array of transmission filters. The targets were irradiated by a 200 - 300 mJ, 130 fs frequency-doubled (400 nm) Ti:Sapphire laser pulse focused to approximately 4-8× 10^17\:W cm^-2 using a f/15 off-axis parabola. The targets consisted of 1 μ m of Al, Si, Ti, Mn, Fe, Cu, Ge, and Ag coated onto a polished microscope slide. Preliminary comparisons with LASNEX hydrodynamic simulations provide some insight towards the laser energy absorption, thermal transport, and ionization physics characteristic of these near solid density plasmas.