Recent advances in cryogenic layering include the development of a self-contained and self-filling cro hohlraum, application of phase contrast x-ray measurements for ice layer characterization, an ice layer achieved with beta-layering which meets the NIF specification for surface roughness at 1.5 K below the triple point. In addition, recent results on target integration in a hohlraum show effective layer control using heaters on the hohlraum.

We experimentally demonstrate that application of laser smoothing schemes including smoothing by spectral dispersion (SSD) and polarization smoothing (PS) increases the intensity range for efficient coupling of frequency doubled (527 nm) laser light to a long scalelength plasma with n{sub e}/n{sub cr} = 0.14 and T{sub e} = 2 keV.

Handwritten in spiral notebook. A study of the carnivals and fiestas of the California Indians. Includes lengthy quotes from 1891 Century magazine article "A Carnival Ball in Monterey, 1829."

We are developing a petawatt laser for use as a high energy backlighter source in the 20{approx} 100 keV range. High energy x-ray backlighters will be essential for radiographing High-Energy- Density Experimental Science (HEDES) targets for NIF projects especially to probe implosions and high areal density planar samples. For these experiments we are employing two types of detectors: a columnar grown CsI scintillator coupled to a 2K x 2K CCD camera and a CdTe crystal with a special ASIC readout electronics in a 508 x 512 format array. We have characterized these sensors using radioactive sources. In addition, we utilized them to measure the Sm K{alpha} source size generated by the short pulse laser, JanUSP, at LLNL. This paper will present the results of our characterizations of these detectors.

We describe experiments which investigate convection effects on hydrogen ice layers in a transparent CH capsule suspended with a fill-tube. These experiments validate simulations which show that unmitigated convection from the hohlraum fill gas can produce significant distortions to the cryogenic hydrogen ice layer. Experimental results show good agreement with thermal simulations which include conduction and convection.

We use thermal conduction models to investigate the effects of tailored IR heating on the fuel layer symmetry within a target capsule supported inside of a National Ignition Facility (NIF) hohlraum. We calculate the layer thickness profile that would result from the IR heat distribution alone and in combination with additional temperature shimming of the cylindrical hohlraum wall. We use the same model to study the effect of convection within the high density tamping gas in the hohlraum. A seven-region model was developed to evaluate how effective additional thin film convection barriers may be in damping convection with the higher power dissipation introduced by IR heating.

The first experiments on the National Ignition Facility (NIF) have employed the first four beams to measure propagation and laser backscattering losses in large ignition-size plasmas. Gas-filled targets between 2 mm and 7 mm length have been heated from one side by overlapping the focal spots of the four beams from one quad operated at 351 nm (3{omega}) with a total intensity of 2 x 10{sup 15} W cm{sup -2}. The targets were filled with 1 atm of CO{sub 2} producing of up to 7 mm long homogeneously heated plasmas with densities of n{sub e} = 6 x 10{sup 20} cm{sup -3} and temperatures of T{sub e} = 2 keV. The high energy in a NIF quad of beams of 16kJ, illuminating the target from one direction, creates unique conditions for the study of laser plasma interactions at scale lengths not previously accessible. The propagation through the large-scale plasma was measured with a gated x-ray imager that was filtered for 3.5 keV x rays. These data indicate that the beams interact with the full length of this ignition-scale plasma during the last {approx}1 ns of the experiment. During that time, the full aperture measurements of the stimulated Brillouin scattering and stimulated Raman scattering show scattering into the four focusing lenses of 6% for the smallest length ({approx}2 mm). increasing to 12% for {approx}7 mm. These results demonstrate the NIF experimental capabilities and further provide a benchmark for three-dimensional modeling of the laser-plasma interactions at ignition-size scale lengths.