Systematic Fuel Cavity Asymmetries in Directly Driven Inertial Confinement Fusion Implosions.

We present narrow-band self-emission x-ray images from a titanium tracer layer placed at the fuel-shell interface in 60-laser-beam implosion experiments at the OMEGA facility. The images are acquired during deceleration with inferred convergences of ∼9-14. Novel here is that a systematically observed asymmetry of the emission is linked, using full sphere 3D implosion modeling, to performance-limiting low mode asymmetry of the drive.

Laboratory measurements of resistivity in warm dense plasmas relevant to the microphysics of brown dwarfs.

Since the observation of the first brown dwarf in 1995, numerous studies have led to a better understanding of the structures of these objects. Here we present a method for studying material resistivity in warm dense plasmas in the laboratory, which we relate to the microphysics of brown dwarfs through viscosity and electron collisions. Here we use X-ray polarimetry to determine the resistivity of a sulphur-doped plastic target heated to Brown Dwarf conditions by an ultra-intense laser.

Study of the internal structure and small-scale instabilities in the dense Z pinch.

High-resolution laser diagnostics at the wavelength of 266 nm were applied for the investigation of Z pinches at the 1-MA generator. The internal structure of the stagnated Z pinches was observed in unprecedented detail. A dense pinch with strong instabilities was seen inside the column of the trailing plasma.

Measurement of the ionization state and electron temperature of plasma during the ablation stage of a wire-array Z pinch using absorption spectroscopy.

Wire-array plasmas were investigated in the nonradiative ablation stage via x-ray absorption spectroscopy. A laser-produced Sm plasma was used to backlight Al wire arrays. The Sm spectrum was simultaneously observed by two spectrometers: one recorded the unattenuated spectrum and the other the transmission spectrum with 1.

Effect of reentrant cone geometry on energy transport in intense laser-plasma interactions.

The energy transport in cone-guided low- Z targets has been studied for laser intensities on target of 2.5x10(20) W cm(-2). Extreme ultraviolet (XUV) imaging and transverse optical shadowgraphy of the rear surfaces of slab and cone-slab targets show that the cone geometry strongly influences the observed transport patterns.