Proof-of-Principle Experiment on the Dynamic Shell Formation for Inertial Confinement Fusion.

In the dynamic-shell (DS) concept [V. N. Goncharov et al., Novel Hot-Spot Ignition Designs for Inertial Confinement Fusion with Liquid-Deuterium-Tritium Spheres, Phys. Rev. Lett. 125, 065001 (2020).PRLTAO0031-900710.1103/PhysRevLett.125.065001] for laser-driven inertial confinement fusion the deuterium-tritium fuel is initially in the form of a homogeneous liquid inside a wetted-foam spherical shell. This fuel is ignited using a conventional implosion, which is preceded by a initial compression of the fuel followed by its expansion and dynamic formation of a high-density fuel shell with a low-density interior. This Letter reports on a scaled-down, proof-of-principle experiment on the OMEGA laser demonstrating, for the first time, the feasibility of DS formation. A shell is formed by convergent shocks launched by laser pulses at the edge of a plasma sphere, with the plasma itself formed as a result of laser-driven compression and relaxation of a surrogate plastic-foam ball target. Three x-ray diagnostics, namely, 1D spatially resolved self-emission streaked imaging, 2D self-emission framed imaging, and backlighting radiography, have shown good agreement with the predicted evolution of the DS and its stability to low Legendre mode perturbations introduced by laser irradiation and target asymmetries.

High-resolution x-ray spectrometer for x-ray absorption fine structure spectroscopy.

Two extended x-ray absorption fine structure flat crystal x-ray spectrometers (EFX's) were designed and built for high-resolution x-ray spectroscopy over a large energy range with flexible, on-shot energy dispersion calibration capabilities. The EFX uses a flat silicon [111] crystal in the reflection geometry as the energy dispersive optic covering the energy range of 6.3-11.4 keV and achieving a spectral resolution of 4.5 eV with a source size of 50 µm at 7.2 keV. A shot-to-shot configurable calibration filter pack and Bayesian inference routine were used to constrain the energy dispersion relation to within ±3 eV. The EFX was primarily designed for x-ray absorption fine structure (XAFS) spectroscopy and provides significant improvement to the Laboratory for Laser Energetics' OMEGA-60 XAFS experimental platform. The EFX is capable of performing extended XAFS measurements of multiple absorption edges simultaneously on metal alloys and x-ray absorption near-edge spectroscopy to measure the electron structure of compressed 3d transition metals.

Constraining physical models at gigabar pressures.

High-energy-density (HED) experiments in convergent geometry are able to test physical models at pressures beyond hundreds of millions of atmospheres. The measurements from these experiments are generally highly integrated and require unique analysis techniques to procure quantitative information. This work describes a methodology to constrain the physics in convergent HED experiments by adapting the methods common to many other fields of physics. As an example, a mechanical model of an imploding shell is constrained by data from a thin-shelled direct-drive exploding-pusher experiment on the OMEGA laser system using Bayesian inference, resulting in the reconstruction of the shell dynamics and energy transfer during the implosion. The model is tested by analyzing synthetic data from a one-dimensional hydrodynamics code and is sampled using a Markov chain Monte Carlo to generate the posterior distributions of the model parameters. The goal of this work is to demonstrate a general methodology that can be used to draw conclusions from a wide variety of HED experiments.

Energy Flow in Thin Shell Implosions and Explosions.

Energy flow and balance in convergent systems beyond petapascal energy densities controls the fate of late-stage stars and the potential for controlling thermonuclear inertial fusion ignition. Time-resolved x-ray self-emission imaging combined with a Bayesian inference analysis is used to describe the energy flow and the potential information stored in the rebounding spherical shock at 0.22 PPa (2.2 Gbar or billions of atmospheres pressure). This analysis, together with a simple mechanical model, describes the trajectory of the shell and the time history of the pressure at the fuel-shell interface, ablation pressure, and energy partitioning including kinetic energy of the shell and internal energy of the fuel. The techniques used here provide a fully self-consistent uncertainty analysis of integrated implosion data, a thermodynamic-path independent measurement of pressure in the petapascal range, and can be used to deduce the energy flow in a wide variety of implosion systems to petapascal energy densities.

Randomized placebo-controlled trial of metronidazole 1% cream with sunscreen SPF 15 in treatment of rosacea.

BACKGROUND: Rosacea is a photoaggravated dermatosis responsive to treatment with topical and oral antibiotics. A formulation combining metronidazole 1% cream with sunscreen SPF 15 was developed for the treatment of rosacea. OBJECTIVE: The objective of this study was to determine the safety and efficacy of a formulation combining metronidazole 1% cream with sunscreen SPF 15 in the treatment of moderate to severe rosacea. METHODS: One hundred and twenty patients with moderate to severe rosacea were enrolled for a randomized, placebo-controlled (vehicle containing sunscreen with SPF 15), double-blind study. Study cream was applied twice daily to the entire face over a 12-week period. RESULTS: Treatment with metronidazole 1% cream with sunscreen SPF 15 resulted in significant improvement (p <0.05) in inflammatory lesion count, erythema and telangiectasiae scores, and investigator and patient global assessment scores compared with baseline and placebo. Adverse reactions related to study medication were typically mild, occurred at the site of application, and were reversible. There was no difference between the safety profiles of metronidazole 1% cream with sunscreen SPF 15 and placebo. CONCLUSIONS: The combined topical formulation of metronidazole 1% cream with sunscreen SPF 15 was an effective, well-tolerated topical agent for the treatment of moderate to severe rosacea.

Quantitative determination of isosorbide dinitrate and two metabolites in plasma.

A GLC method for the determination of plasma isosorbide dinitrate and two metabolites, isosorbide 2-mononitrate and isosorbide 5-mononitrate, is described. The three substances are extracted from alkalinized plasma with ether. Quantitation is effected by electron-capture detection after GLC separation with a 30% SE-30 column. The unusually heavy liquid phase loading is necessary to eliminate irreversible adsorption on the solid support. The electron-capture detector provides excellent sensitivity and specificity because of the electronegative nature of the nitric ester. The method was used to study the blood levels of isosorbide dinitrate and two metabolites in four beagle dogs after single oral doses of 40 mg of isosorbide dinitrate and in two human volunteers after a sublingual dose of 10 mg of isosorbide dinitrate.

Sexual Attraction and Mating Patterns in Cylindrocorpus longistoma and C. curzii (Nematoda: Cylindrocorporidae).

Females of Cylindrocorpus longistoma and C. curzii excrete attractants which probably function to bring the sexes together before mating. Intraspecific and interspecific heterosexual and homosexual pairing experiments showed the attractants to be species specific as well as sex specific. Observations on mating behavior support the hypothesis that sexual attraction and copulation require independent stimuli.