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198 results on '"Flippo, K."'

153. First observation of quasi-monoenergetic electron bunches driven out of ultra-thin diamond-like carbon (DLC) foils.

Author

Kiefer, D., Henig, A., Jung, D., Gautier, D. C., Flippo, K. A., Gaillard, S. A., Letzring, S., Johnson, R. P., Shah, R. C., Shimada, T., Fernández, J. C., Liechtenstein, V. Kh., Schreiber, J., Hegelich, B. M., and Habs, D.

Subjects
LASER beams, PARTICLES (Nuclear physics), X-rays, ELECTRONS, NUCLEAR physics
Abstract

Electrons have been accelerated from ultra-thin diamond-like carbon (DLC) foils by an ultrahigh-intensity laser pulse. A distinct quasi-monoenergetic electron spectrum peaked at 30 MeV is observed at a target thickness as thin as 5 nm which is in contrast to the observations of wide spectral distributions for thicker targets. At the same time, a substantial drop in laser-accelerated ion energies is found. The experimental findings give first indication that relativistic electron sheets can be generated from ultra-thin foils which in future may be used to generate brilliant X-ray beams by the coherent reflection of a second laser. [ABSTRACT FROM AUTHOR]

Published
2010
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154. Spectroscopic diagnostics for multi-TW laser-produced plasmas

Author

Cobble, J. A., Fernández, J. C., Hegelich, B. M., Flippo, K. A., Gautier, D. C., Cobble, J. A., Fernández, J. C., Hegelich, B. M., Flippo, K. A., and Gautier, D. C.

Abstract

Data from a pinhole camera and a transmission grating spectrograph are used in multi-TW laser irradiance of thin metal films to assess the maximum laser spot size and to show tenths of a percent conversion of laser light to K-, L-, and M-band x rays. The distribution of target debris, an operational issue for the survivability of an unshielded parabola in a large laser system, is revealed by x-ray fluorescence measurements of witness samples. At the 25-J, 30-TW level, we find little evidence of damage to the f/3 parabola with an angle of incidence on target greater than 22°.

Published
2006
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155. Theoretical Understanding of Enhanced Proton Energies from Laser-Cone Interactions

Author

Kluge, T., Gaillard, S. A., Bussmann, M., Flippo, K. A., Burris-Mog, T., Gall, B., Geissel, M., Stephan Kraft, Lockard, T., Metzkes, J., Offermann, D. T., Rassuchine, J., Schollmeier, M., Schramm, U., Sentoku, Y., Zeil, K., and Cowan, T. E.

Subjects
flat top cone, maximum energy, Physics::Accelerator Physics, ion, acceleration, laser, proton
Abstract

For the past ten years, the highest proton energies accelerated with high-intensity lasers was 58 MeV, observed in 2000 at the LLNL NOVA Petawatt laser, using flat foil targets. Recently, 67.5 MeV protons were observed in experiments at the Los Alamos National Laboratory (LANL) Trident laser, using one-fifth of the PW laser pulse energy, incident into novel conical targets. We present a focused study of new theoretical understanding of this measured enhancement from collisional Particle-in-Cell simulations, which shows that the hot electron temperature, number and maximum energy, responsible for the Target Normal Sheath Acceleration (TNSA) at the cone-top, are significantly increased when the laser grazes the cone wall. This is mainly due to the extraction of electrons from the cone wall by the laser electric field, and their boost in the forward direction by the v×B term of the Lorentz force. This result is in contrast to previous predictions of optical collection and wall-guiding of electrons in angled cones. This new wall-grazing mechanism offers the prospect to linearly increase the hot electron temperature, and thereby the TNSA proton energy, by extending the length over which the laser interacts in a grazing fashion in suitably optimized targets. This may allow achieving much higher proton energies for interesting future applications, with smaller, lower energy laser systems that allow for a high repetition rate.

166. Hydro-scaling of direct-drive cylindrical implosions at the OMEGA and the National Ignition Facility.

Author

Palaniyappan, S., Sauppe, J. P., Tobias, B. J., Kawaguchi, C. F., Flippo, K. A., Zylstra, A. B., Landen, O. L., Shvarts, D., Malka, E., Batha, S. H., Bradley, P. A., Loomis, E. N., Vazirani, N. N., Kot, L., Schmidt, D. W., Day, T. H., Gonzales, R., and Kline, J. L.

Subjects
*INERTIAL confinement fusion, *RAYLEIGH-Taylor instability, *GROWTH factors
Abstract

Deceleration-phase Rayleigh–Taylor instability (RTI) growth during inertial confinement fusion capsule implosions significantly affects the performance as it mixes cold ablator material into the fuel. Precise measurements of such instability growth are essential for both validating the existing simulation codes and improving our predictive capability. RTI measurements on the inner surface of a spherical shell are limited and are often inferred indirectly at limited convergence. In contrast, cylindrical implosions allow for direct diagnostic access to the converging interface by imaging down the cylinder axis while retaining the effects of convergence. We have performed direct-drive cylindrical implosion experiments at both the OMEGA and the NIF laser facilities using scaled targets. RTI growth is demonstrated to be scale-invariant between the cylindrical targets at OMEGA and similar targets at the NIF, which are scaled up by a factor of three in the radial dimension. Single-mode (m = 20) instability growth factors of ∼14 are measured at a convergence ratio (CR) ∼ 2.5 with nearly identical mode growth at both scales. The measurements are in agreement with xRAGE radiation-hydrodynamics simulations. In addition, we have developed the Bayesian-inference-engine method to account for the variations in the target alignment, magnification, and the parallax effect in the measurement, allowing a more precise comparison between the experimental data and the simulations. [ABSTRACT FROM AUTHOR]

Published
2020
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167. The modeling of delayed-onset Rayleigh-Taylor and transition to mixing in laser-driven HED experiments.

Author

Di Stefano, C. A., Doss, F. W., Rasmus, A. M., Flippo, K. A., and Haines, B. M.

Subjects
*HYDRODYNAMICS, *LASERS, *LOYALTY, *DELAYED fluorescence
Abstract

In this work, we discuss simulations, along with a benchmarking experiment, performed using the xRAGE code which demonstrate the ability of a laser model to predict laser-driven, high-energy-density shock hydrodynamics with good fidelity. This directly contributes to our ability to model hydrodynamic-instability dynamics produced by a laser drive typical of those available at OMEGA, OMEGA-EP, NIF, and similar facilities. In particular, we show how the laser model is essential for predicting deceleration-phase Rayleigh-Taylor arising from laser turn-off. We do this using the experimental case of a seeded single-mode perturbation. Then, we turn to a seeded multimode perturbation to show how the above result permits us to access the modeling of hydrodynamic mixing, a topic of interest for future work. [ABSTRACT FROM AUTHOR]

Published
2019
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168. Shock-driven discrete vortex evolution on a high-Atwood number oblique interface.

Author

Rasmus, A. M., Di Stefano, C. A., Flippo, K. A., Doss, F. W., Kline, J. L., Hager, J. D., Merritt, E. C., Desjardins, T. R., Wan, W. C., Cardenas, T., Schmidt, D. W., Donovan, P. M., Fierro, F., Martinez, J. I., Zingale, J. S., and Kuranz, C. C.

Subjects
*SHOCK waves, *QUANTUM perturbations, *RICHTMYER-Meshkov instability, *WAVELENGTHS, *COMPUTER simulation, *HELMHOLTZ free energy
Abstract

We derive a model describing vorticity deposition on a high-Atwood number interface with a sinusoidal perturbation by an oblique shock propagating from a heavy into a light material. Limiting cases of the model result in vorticity distributions that lead to Richtmyer-Meshkov and Kelvin-Helmholtz instability growth. For certain combinations of perturbation amplitude, wavelength, and tilt of the shock, a regime is found in which discrete, co-aligned, vortices are deposited on the interface. The subsequent interface evolution is described by a discrete vortex model, which is found to agree well with both RAGE simulations and experiments at early times. [ABSTRACT FROM AUTHOR]

Published
2018
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169. Beryllium capsule implosions at a case-to-capsule ratio of 3.7 on the National Ignition Facility.

Author

Zylstra, A. B., Yi, S. A., MacLaren, S., Kline, J., Kyrala, G., Ralph, J. E., Bae, J., Batha, S., Callahan, D., Flippo, K., Huang, H., Hurricane, O., Khan, S. F., Kabadi, N., Kong, C., Kot, L. B., Lahmann, B., Loomis, E. N., Masse, L. P., and Millot, M.

Subjects
*BERYLLIUM, *INERTIAL confinement fusion, *ABLATION (Aerothermodynamics), *PLASMA physics
Abstract

Beryllium is a candidate ablator material for indirect-drive inertial confinement fusion experiments, motivated by its high mass ablation rate, which is advantageous for implosion coupling efficiency and stabilization of the ablation-front instability growth. We present new data on the shock propagation, in-flight shape, and hot spot self-emission shape from gas-filled capsules that demonstrate the feasibility of predictable, symmetric, controllable beryllium implosions at a case-to-capsule ratio of 3.7. The implosions are round (Legendre mode 2 amplitude ≲ 5 %) at an inner beam power and the energy fraction of 26%–28% of the total, indicating that larger beryllium capsules could be driven symmetrically using the National Ignition Facility. [ABSTRACT FROM AUTHOR]

Published
2018
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170. Ablative stabilization of Rayleigh-Taylor instabilities resulting from a laser-driven radiative shock.

Author

Huntington, C. M., Shimony, A., Trantham, M., Kuranz, C. C., Shvarts, D., Di Stefano, C. A., Doss, F. W., Drake, R. P., Flippo, K. A., Kalantar, D. H., Klein, S. R., Kline, J. L., MacLaren, S. A., Malamud, G., Miles, A. R., Prisbrey, S. T., Raman, K. S., Remington, B. A., Robey, H. F., and Wan, W. C.

Subjects
*RAYLEIGH-Taylor instability, *LASER ablation, *SHOCK waves, *INERTIAL confinement fusion, *STELLAR winds, *SUPERNOVAE
Abstract

The Rayleigh-Taylor (RT) instability is a common occurrence in nature, notably in astrophysical systems like supernovae, where it serves to mix the dense layers of the interior of an exploding star with the low-density stellar wind surrounding it, and in inertial confinement fusion experiments, where it mixes cooler materials with the central hot spot in an imploding capsule and stifles the desired nuclear reactions. In both of these examples, the radiative flux generated by strong shocks in the system may play a role in partially stabilizing RT instabilities. Here, we present experiments performed on the National Ignition Facility, designed to isolate and study the role of radiation and heat conduction from a shock front in the stabilization of hydrodynamic instabilities. By varying the laser power delivered to a shock-tube target with an embedded, unstable interface, the radiative fluxes generated at the shock front could be controlled. We observe decreased RT growth when the shock significantly heats the medium around it, in contrast to a system where the shock did not produce significant heating. Both systems are modeled with a modified set of buoyancy-drag equations accounting for ablative stabilization, and the experimental results are consistent with ablative stabilization when the shock is radiative. This result has important implications for our understanding of astrophysical radiative shocks and supernova radiative hydrodynamics [Kuranz et al., Nature Communications 9(1), 1564 (2018)]. [ABSTRACT FROM AUTHOR]

Published
2018
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171. A platform for studying the Rayleigh--Taylor and Richtmyer-Meshkov instabilities in a planar geometry at high energy density at the National Ignition Facility.

Author

Nagel, S. R., Raman, K. S., Huntington, C. M., MacLaren, S. A., Wang, P., Barrios, M. A., Baumann, T., Bender, J. D., Benedetti, L. R., Doane, D. M., Felker, S., Fitzsimmons, P., Flippo, K. A., Holder, J. P., Kaczala, D. N., Perry, T. S., Seugling, R. M., Savage, L., and Zhou, Y.

Subjects
*RAYLEIGH number, *STOKES velocity, *FREE convection, *ENERGY storage, *ENERGY transfer
Abstract

A new experimental platform has been developed at the National Ignition Facility (NIF) for studying the Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities in a planar geometry at high-energy-densities. The platform uses 60 beams of the NIF laser to drive an initially solid shock tube containing a pre-machined interface between dense and light materials. The strong shock turns the initially solid target into a plasma and the material boundary into a fluid interface with the imprinted initial condition. The interface evolves by action of the RT and RM instabilities and the growth is imaged with backlit x-ray radiography. We present our first data involving sinusoidal interface perturbations driven from the heavy side to the light side. Late-time radiographic images show the initial conditions reaching the deeply nonlinear regime and an evolution of fine structure consistent with a transition to turbulence. We show preliminary comparisons with post-shot numerical simulations and discuss the implications for future campaigns. [ABSTRACT FROM AUTHOR]

Published
2017
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172. Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility.

Author

Opachich, Y. P., Heeter, R. F., Barrios, M. A., Garcia, E. M., Craxton, R. S., King, J. A., Liedahl, D. A., McKenty, P. W., Schneider, M. B., May, M. J., Zhang, R., Ross, P. W., Kline, J. L., Moore, A. S., Weaver, J. L., Flippo, K. A., and Perry, T. S.

Subjects
*OPACITY (Optics), *MICROWAVE reflectometry, *PLASMA lasers, *LIGHT sources, *X-ray spectroscopy, *STYRENE
Abstract

Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0mm diameter polyalpha-methyl styrene capsules with ~20 μm thickness have been performed. X-ray yields of up to ~1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ~100 μm FWHM, with ~350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments. [ABSTRACT FROM AUTHOR]

Published
2017
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173. Multimode instability evolution driven by strong, high-energy-density shocks in a rarefaction-reflected geometry.

Author

Di Stefano, C. A., Rasmus, A. M., Doss, F. W., Flippo, K. A., Hager, J. D., Kline, J. L., and Bradley, P. A.

Subjects
*QUANTUM perturbations, *SPECTRUM analysis, *BAYESIAN analysis, *INTERFACE circuits, *RAYLEIGH model
Abstract

We present an experiment using lasers to produce a shock pressure of >10 Mbar, which we then use to drive Richtmyer-Meshkov and Rayleigh-Taylor growth at a 2D multimode perturbed interface. Key features of this platform are that we can precisely reproduce the perturbation from iteration to iteration of the experiment, facilitating analysis, and that the lasers allow us to produce very strong shocks, creating a plasma state in the system. We also implement a Bayesian technique to analyze the multimode spectra. This technique enables us to draw quantitative conclusions about the spectrum, even in the presence of significant noise. For instance, we measure the signal contained in the seeded modes over time, as well as the transition of the initial growth rate of these modes into the overall saturation behavior of the spectrum. [ABSTRACT FROM AUTHOR]

Published
2017
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175. High-contrast laser acceleration of relativistic electrons in solid cone-wire targets.

Author

Higginson, D. P., Link, A., Sawada, H., Wilks, S. C., Bartal, T., Chawla, S., Chen, C. D., Flippo, K. A., Jarrott, L. C., Key, M. H., McLean, H. S., Patel, P. K., Pérez, F., Wei, M. S., and Beg, F. N.

Subjects
*RELATIVISTIC electrons, *PLASMA gases, *COPPER wire, *ELECTRON accelerators, *CHEMICAL precursors, *COUPLING reactions (Chemistry)
Abstract

The consequences of small scale-length precursor plasmas on high-intensity laser-driven relativistic electrons are studied via experiments and simulations. Longer scale-length plasmas are shown to dramatically increase the efficiency of electron acceleration, yet, if too long, they reduce the coupling of these electrons into the solid target. Evidence for the existence of an optimal plasma scale-length is presented and estimated to be from 1 to 5 μm. Experiments on the Trident laser (I = 5 × 1019 W/cm²) diagnosed via Kα emission from Cu wires attached to Au cones are quantitively reproduced using 2D particle-in-cell simulations that capture the full temporal and spatial scale of the nonlinear laser interaction and electron transport. The simulations indicate that 32 % ± 8%(6.5% ± 2%) of the laser energy is coupled into electrons of all energies (1-3 MeV) reaching the inner cone tip and that, with an optimized scale-length, this could increase to 35% (9%). [ABSTRACT FROM AUTHOR]

Published
2015
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176. Modifying mixing and instability growth through the adjustment of initial conditions in a high-energy-density counter-propagating shear experiment on OMEGA.

Author

Merritt, E. C., Doss, F. W., Loomis, E. N., Flippo, K. A., and Kline, J. L.

Subjects
*ENERGY density, *SHEAR waves, *SURFACE roughness, *TURBULENT flow, *THICKNESS measurement
Abstract

Counter-propagating shear experiments conducted at the OMEGA Laser Facility have been evaluating the effect of target initial conditions, specifically the characteristics of a tracer foil located at the shear boundary, on Kelvin-Helmholtz instability evolution and experiment transition toward nonlinearity and turbulence in the high-energy-density (HED) regime. Experiments are focused on both identifying and uncoupling the dependence of the model initial turbulent length scale in variable-density turbulence models of k- type on competing physical instability seed lengths as well as developing a path toward fully developed turbulent HED experiments. We present results from a series of experiments controllably and independently varying two initial types of scale lengths in the experiment: the thickness and surface roughness (surface perturbation scale spectrum) of a tracer layer at the shear interface. We show that decreasing the layer thickness and increasing the surface roughness both have the ability to increase the relative mixing in the system, and thus theoretically decrease the time required to begin transitioning to turbulence in the system. We also show that we can connect a change in observed mix width growth due to increased foil surface roughness to an analytically predicted change in model initial turbulent scale lengths. [ABSTRACT FROM AUTHOR]

Published
2015
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177. Quantifying equation-of-state and opacity errors using integrated supersonic diffusive radiation flow experiments on the National Ignition Facility.

Author

Guymer, T. M., Moore, A. S., Morton, J., Kline, J. L., Allan, S., Bazin, N., Benstead, J., Bentley, C., Comley, A. J., Cowan, J., Flippo, K., Garbett, W., Hamilton, C., Lanier, N. E., Mussack, K., Obrey, K., Reed, L., Schmidt, D. W., Stevenson, R. M., and Taccetti, J. M.

Subjects
*EQUATIONS of state, *OPACITY (Optics), *ULTRASONIC waves, *DIFFUSION, *COMPUTER simulation
Abstract

A well diagnosed campaign of supersonic, diffusive radiation flow experiments has been fielded on the National Ignition Facility. These experiments have used the accurate measurements of delivered laser energy and foam density to enable an investigation into SESAME's tabulated equation-of-state values and CASSANDRA's predicted opacity values for the low-density C8H7Cl foam used throughout the campaign. We report that the results from initial simulations under-predicted the arrival time of the radiation wave through the foam by Ââ22%. A simulation study was conducted that artificially scaled the equation-of-state and opacity with the intended aim of quantifying the systematic offsets in both CASSANDRA and SESAME. Two separate hypotheses which describe these errors have been tested using the entire ensemble of data, with one being supported by these data. [ABSTRACT FROM AUTHOR]

Published
2015
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178. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics.

Author

Schollmeier, M., Sefkow, A. B., Geissel, M., Arefiev, A. V., Flippo, K. A., Gaillard, S. A., Johnson, R. P., Kimmel, M. W., Offermann, D. T., Rambo, P. K., Schwarz, J., and Shimada, T.

Subjects
*RELATIVISTIC plasmas, *ENERGY conversion, *PICOSECOND pulses, *PARTICLE acceleration, *HARMONIC generation, *ELECTROMAGNETIC fields, *ELECTRON plasma
Abstract

High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and selfconsistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge of the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45MeV and 75MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results show that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes. [ABSTRACT FROM AUTHOR]

Published
2015
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180. Laser acceleration of quasi-monoenergetic MeV ion beams.

Author

Hegelich, B. M., Albright, B. J., Cobble, J., Flippo, K., Letzring, S., Paffett, M., Ruhl, H., Schreiber, J., Schulze, R. K., and Fernández, J. C.

Subjects
*LASER-plasma interactions, *PARTICLES, *ION bombardment, *ION accelerators, *IONS, *LASER beams
Abstract

Acceleration of particles by intense laser–plasma interactions represents a rapidly evolving field of interest, as highlighted by the recent demonstration of laser-driven relativistic beams of monoenergetic electrons. Ultrahigh-intensity lasers can produce accelerating fields of 10 TV m-1 (1 TV = 1012 V), surpassing those in conventional accelerators by six orders of magnitude. Laser-driven ions with energies of several MeV per nucleon have also been produced. Such ion beams exhibit unprecedented characteristics—short pulse lengths, high currents and low transverse emittance—but their exponential energy spectra have almost 100% energy spread. This large energy spread, which is a consequence of the experimental conditions used to date, remains the biggest impediment to the wider use of this technology. Here we report the production of quasi-monoenergetic laser-driven C5+ ions with a vastly reduced energy spread of 17%. The ions have a mean energy of 3 MeV per nucleon (full-width at half-maximum ∼0.5 MeV per nucleon) and a longitudinal emittance of less than 2 × 10-6 eV s for pulse durations shorter than 1 ps. Such laser-driven, high-current, quasi-monoenergetic ion sources may enable significant advances in the development of compact MeV ion accelerators, new diagnostics, medical physics, inertial confinement fusion and fast ignition. [ABSTRACT FROM AUTHOR]

Published
2006
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181. A split imaging spectrometer for temporally and spatially resolved titanium absorption spectroscopy.

Author

Hager, J. D., Lanier, N. E., Kline, J. L., Flippo, K. A., Bruns, H. C., Schneider, M., Saculla, M., and McCarville, T.

Subjects
*CRYSTALS, *ABSORPTION, *SILICA, *SPECTRUM analysis, *ELECTRIC waves
Abstract

We present a temporally and a spatially resolved spectrometer for titanium x-ray absorption spectroscopy along 2 axial symmetric lines-of-sight. Each line-of-sight of the instrument uses an elliptical crystal to acquire both the 2p and 3p Ti absorption lines on a single, time gated channel of the instrument. The 2 axial symmetric lines-of-sight allow the 2p and 3p absorption features to be measured through the same point in space using both channels of the instrument. The spatially dependent material temperature can be inferred by observing the 2p and the 3p Ti absorption features. The data are recorded on a two strip framing camera with each strip collecting data from a single line-of-sight. The design is compatible for use at both the OMEGA laser and the National Ignition Facility. The spectrometer is intended to measure the material temperature behind a Marshak wave in a radiatively driven SiO2 foam with a Ti foam tracer. In this configuration, a broad band CsI back-lighter will be used for a source and the Ti absorption spectrum measured. [ABSTRACT FROM AUTHOR]

Published
2014
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182. Demonstration of Scale-Invariant Rayleigh-Taylor Instability Growth in Laser-Driven Cylindrical Implosion Experiments.

Author

Sauppe, J. P., Palaniyappan, S., Tobias, B. J., Kline, J. L., Flippo, K. A., Landen, O. L., Shvarts, D., Batha, S. H., Bradley, P. A., Loomis, E. N., Vazirani, N. N., Kawaguchi, C. F., Kot, L., Schmidt, D. W., Day, T. H., Zylstra, A. B., and Malka, E.

Subjects
*RAYLEIGH-Taylor instability, *GROWTH factors, *FORECASTING
Abstract

Rayleigh-Taylor instability growth is shown to be hydrodynamically scale invariant in convergent cylindrical implosions for targets that varied in radial dimension and implosion timescale by a factor of 3. The targets were driven directly by laser irradiation providing a short impulse, and instability growth at an embedded aluminum interface occurs as it converges radially inward by a factor of 2.25 and decelerates on a central foam core. Late-time growth factors of 14 are observed for a single-mode m=20 azimuthal perturbation at both scales, despite the differences in laser drive conditions between the experimental facilities, consistent with predictions from radiation-hydrodynamics simulations. This platform enables detailed investigations into the limits of hydrodynamic scaling in high-energy-density systems. [ABSTRACT FROM AUTHOR]

Published
2020
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183. Extracting a mixing parameter from 2D radiographic imaging of variable-density turbulent flow.

Author

Kurien, S., Doss, F.W., Livescu, D., and Flippo, K.

Subjects
*TURBULENCE, *BEER-Lambert law
Abstract

We extract a suitably averaged fluctuating density from the two-dimensional radiographic image of a flow. The X-ray attenuation is given by the Beer–Lambert law which exponentially damps the incident beam intensity by a factor proportional to the density, opacity and thickness of the target. By making reasonable assumptions for the mean density, opacity and effective thickness of the target flow, we estimate the density fluctuation contribution to the attenuation. The extracted density fluctuations averaged across the thickness of the flow in the direction of the beam may be used to form the density–specific-volume correlation b. In a statistical description of variable-density turbulence, b quantifies the degree of mixedness. The ability to extract a measure of mixedness from experimental data would be a powerful tool that could be used in the validation of mix models. The scheme proposed is tested for DNS data computed for variable density buoyancy-driven mixing. We quantify the deficits in the extracted value of b due to target thickness, Atwood number and modeled signal noise. This analysis justifies using the proposed scheme to infer the mix parameter from thin targets at moderate to low Atwood numbers. To illustrate how the scheme might be used in a practical problem, we demonstrate its application to a radiographic image of counter-shear flow obtained from experiments at the National Ignition Facility. • Method to extract mixing parameter from radiographic data. • Use of DNS to verify the scheme. • Application of scheme to radiographic data from NIF. [ABSTRACT FROM AUTHOR]

Published
2020
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184. Evolution of surface structure in laser-preheated perturbed materials.

Author

Di Stefano, C. A., Merritt, E. C., Doss, F. W., Flippo, K. A., Rasmus, A. M., and Schmidt, D. W.

Subjects
*LASERS, *SURFACE structure, *HYDRODYNAMICS
Abstract

We report an experimental and computational study investigating the effects of laser preheat on the hydrodynamic behavior of a material layer. In particular, we find that perturbation of the surface of the layer results in a complex interaction, in which the bulk of the layer develops density, pressure, and temperature structure and in which the surface experiences instability-like behavior, including mode coupling. A uniform one-temperature preheat model is used to reproduce the experimentally observed behavior, and we find that this model can be used to capture the evolution of the layer, while also providing evidence of complexities in the preheat behavior. This result has important consequences for inertially confined fusion plasmas, which can be difficult to diagnose in detail, as well as for laser hydrodynamics experiments, which generally depend on assumptions about initial conditions in order to interpret their results. [ABSTRACT FROM AUTHOR]

Published
2017
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185. Quantitative radiography for determining density fluctuations in HED experiments.

Author

Merritt EC, Doss FW, Levesque JM, Rasmus AM, Desjardins T, Di Stefano CA, Flippo KA, and Schmidt DW

Abstract

We have developed a method to extract density fluctuation measurements from x-ray radiographs of high-energy density (HED) instability growth and turbulence experiments. We use this information to calculate density fluctuation statistics for constraining the performance of turbulent mix models in HED systems. The density calculation combines image filtering, removal of systemic effects such as backlighter variation, calculation of transmission across multiple materials, and use of tracer materials to generate an approximate single-material density field. From the density map, we calculate both average density and a variance-like moment b (density-specific-volume covariance), which we compare to our models. We infer both quantities from a single image, which is significantly more information than the historic single scalar mix width measurements. We also develop a method of analyzing simulation outputs that incorporate both the density fluctuation metric from a turbulence model and the bulk material maps from the hydrodynamic code. This analysis helps address the question of how to initialize the simulations for best comparison to data from systems with large separations of scale in the mixing perturbation initial condition. We find that our data analysis method yields 1D average density and b curves with similar morphology and amplitudes as those from preliminary simulation comparisons., (© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC) license (https://creativecommons.org/licenses/by-nc/4.0/).)

Published
2024
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186. Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment.

Author

Abu-Shawareb H, Acree R, Adams P, Adams J, Addis B, Aden R, Adrian P, Afeyan BB, Aggleton M, Aghaian L, Aguirre A, Aikens D, Akre J, Albert F, Albrecht M, Albright BJ, Albritton J, Alcala J, Alday C, Alessi DA, Alexander N, Alfonso J, Alfonso N, Alger E, Ali SJ, Ali ZA, Allen A, Alley WE, Amala P, Amendt PA, Amick P, Ammula S, Amorin C, Ampleford DJ, Anderson RW, Anklam T, Antipa N, Appelbe B, Aracne-Ruddle C, Araya E, Archuleta TN, Arend M, Arnold P, Arnold T, Arsenlis A, Asay J, Atherton LJ, Atkinson D, Atkinson R, Auerbach JM, Austin B, Auyang L, Awwal AAS, Aybar N, Ayers J, Ayers S, Ayers T, Azevedo S, Bachmann B, Back CA, Bae J, Bailey DS, Bailey J, Baisden T, Baker KL, Baldis H, Barber D, Barberis M, Barker D, Barnes A, Barnes CW, Barrios MA, Barty C, Bass I, Batha SH, Baxamusa SH, Bazan G, Beagle JK, Beale R, Beck BR, Beck JB, Bedzyk M, Beeler RG, Beeler RG, Behrendt W, Belk L, Bell P, Belyaev M, Benage JF, Bennett G, Benedetti LR, Benedict LX, Berger RL, Bernat T, Bernstein LA, Berry B, Bertolini L, Besenbruch G, Betcher J, Bettenhausen R, Betti R, Bezzerides B, Bhandarkar SD, Bickel R, Biener J, Biesiada T, Bigelow K, Bigelow-Granillo J, Bigman V, Bionta RM, Birge NW, Bitter M, Black AC, Bleile R, Bleuel DL, Bliss E, Bliss E, Blue B, Boehly T, Boehm K, Boley CD, Bonanno R, Bond EJ, Bond T, Bonino MJ, Borden M, Bourgade JL, Bousquet J, Bowers J, Bowers M, Boyd R, Boyle D, Bozek A, Bradley DK, Bradley KS, Bradley PA, Bradley L, Brannon L, Brantley PS, Braun D, Braun T, Brienza-Larsen K, Briggs R, Briggs TM, Britten J, Brooks ED, Browning D, Bruhn MW, Brunner TA, Bruns H, Brunton G, Bryant B, Buczek T, Bude J, Buitano L, Burkhart S, Burmark J, Burnham A, Burr R, Busby LE, Butlin B, Cabeltis R, Cable M, Cabot WH, Cagadas B, Caggiano J, Cahayag R, Caldwell SE, Calkins S, Callahan DA, Calleja-Aguirre J, Camara L, Camp D, Campbell EM, Campbell JH, Carey B, Carey R, Carlisle K, Carlson L, Carman L, Carmichael J, Carpenter A, Carr C, Carrera JA, Casavant D, Casey A, Casey DT, Castillo A, Castillo E, Castor JI, Castro C, Caughey W, Cavitt R, Celeste J, Celliers PM, Cerjan C, Chandler G, Chang B, Chang C, Chang J, Chang L, Chapman R, Chapman TD, Chase L, Chen H, Chen H, Chen K, Chen LY, Cheng B, Chittenden J, Choate C, Chou J, Chrien RE, Chrisp M, Christensen K, Christensen M, Christiansen NS, Christopherson AR, Chung M, Church JA, Clark A, Clark DS, Clark K, Clark R, Claus L, Cline B, Cline JA, Cobble JA, Cochrane K, Cohen B, Cohen S, Collette MR, Collins GW, Collins LA, Collins TJB, Conder A, Conrad B, Conyers M, Cook AW, Cook D, Cook R, Cooley JC, Cooper G, Cope T, Copeland SR, Coppari F, Cortez J, Cox J, Crandall DH, Crane J, Craxton RS, Cray M, Crilly A, Crippen JW, Cross D, Cuneo M, Cuotts G, Czajka CE, Czechowicz D, Daly T, Danforth P, Danly C, Darbee R, Darlington B, Datte P, Dauffy L, Davalos G, Davidovits S, Davis P, Davis J, Dawson S, Day RD, Day TH, Dayton M, Deck C, Decker C, Deeney C, DeFriend KA, Deis G, Delamater ND, Delettrez JA, Demaret R, Demos S, Dempsey SM, Desjardin R, Desjardins T, Desjarlais MP, Dewald EL, DeYoreo J, Diaz S, Dimonte G, Dittrich TR, Divol L, Dixit SN, Dixon J, Do A, Dodd ES, Dolan D, Donovan A, Donovan M, Döppner T, Dorrer C, Dorsano N, Douglas MR, Dow D, Downie J, Downing E, Dozieres M, Draggoo V, Drake D, Drake RP, Drake T, Dreifuerst G, Drury O, DuBois DF, DuBois PF, Dunham G, Durocher M, Dylla-Spears R, Dymoke-Bradshaw AKL, Dzenitis B, Ebbers C, Eckart M, Eddinger S, Eder D, Edgell D, Edwards MJ, Efthimion P, Eggert JH, Ehrlich B, Ehrmann P, Elhadj S, Ellerbee C, Elliott NS, Ellison CL, Elsner F, Emerich M, Engelhorn K, England T, English E, Epperson P, Epstein R, Erbert G, Erickson MA, Erskine DJ, Erlandson A, Espinosa RJ, Estes C, Estabrook KG, Evans S, Fabyan A, Fair J, Fallejo R, Farmer N, Farmer WA, Farrell M, Fatherley VE, Fedorov M, Feigenbaum E, Fehrenbach T, Feit M, Felker B, Ferguson W, Fernandez JC, Fernandez-Panella A, Fess S, Field JE, Filip CV, Fincke JR, Finn T, Finnegan SM, Finucane RG, Fischer M, Fisher A, Fisher J, Fishler B, Fittinghoff D, Fitzsimmons P, Flegel M, Flippo KA, Florio J, Folta J, Folta P, Foreman LR, Forrest C, Forsman A, Fooks J, Foord M, Fortner R, Fournier K, Fratanduono DE, Frazier N, Frazier T, Frederick C, Freeman MS, Frenje J, Frey D, Frieders G, Friedrich S, Froula DH, Fry J, Fuller T, Gaffney J, Gales S, Le Galloudec B, Le Galloudec KK, Gambhir A, Gao L, Garbett WJ, Garcia A, Gates C, Gaut E, Gauthier P, Gavin Z, Gaylord J, Geddes CGR, Geissel M, Génin F, Georgeson J, Geppert-Kleinrath H, Geppert-Kleinrath V, Gharibyan N, Gibson J, Gibson C, Giraldez E, Glebov V, Glendinning SG, Glenn S, Glenzer SH, Goade S, Gobby PL, Goldman SR, Golick B, Gomez M, Goncharov V, Goodin D, Grabowski P, Grafil E, Graham P, Grandy J, Grasz E, Graziani FR, Greenman G, Greenough JA, Greenwood A, Gregori G, Green T, Griego JR, Grim GP, Grondalski J, Gross S, Guckian J, Guler N, Gunney B, Guss G, Haan S, Hackbarth J, Hackel L, Hackel R, Haefner C, Hagmann C, Hahn KD, Hahn S, Haid BJ, Haines BM, Hall BM, Hall C, Hall GN, Hamamoto M, Hamel S, Hamilton CE, Hammel BA, Hammer JH, Hampton G, Hamza A, Handler A, Hansen S, Hanson D, Haque R, Harding D, Harding E, Hares JD, Harris DB, Harte JA, Hartouni EP, Hatarik R, Hatchett S, Hauer AA, Havre M, Hawley R, Hayes J, Hayes J, Hayes S, Hayes-Sterbenz A, Haynam CA, Haynes DA, Headley D, Heal A, Heebner JE, Heerey S, Heestand GM, Heeter R, Hein N, Heinbockel C, Hendricks C, Henesian M, Heninger J, Henrikson J, Henry EA, Herbold EB, Hermann MR, Hermes G, Hernandez JE, Hernandez VJ, Herrmann MC, Herrmann HW, Herrera OD, Hewett D, Hibbard R, Hicks DG, Higginson DP, Hill D, Hill K, Hilsabeck T, Hinkel DE, Ho DD, Ho VK, Hoffer JK, Hoffman NM, Hohenberger M, Hohensee M, Hoke W, Holdener D, Holdener F, Holder JP, Holko B, Holunga D, Holzrichter JF, Honig J, Hoover D, Hopkins D, Berzak Hopkins LF, Hoppe M, Hoppe ML, Horner J, Hornung R, Horsfield CJ, Horvath J, Hotaling D, House R, Howell L, Hsing WW, Hu SX, Huang H, Huckins J, Hui H, Humbird KD, Hund J, Hunt J, Hurricane OA, Hutton M, Huynh KH, Inandan L, Iglesias C, Igumenshchev IV, Ivanovich I, Izumi N, Jackson M, Jackson J, Jacobs SD, James G, Jancaitis K, Jarboe J, Jarrott LC, Jasion D, Jaquez J, Jeet J, Jenei AE, Jensen J, Jimenez J, Jimenez R, Jobe D, Johal Z, Johns HM, Johnson D, Johnson MA, Gatu Johnson M, Johnson RJ, Johnson S, Johnson SA, Johnson T, Jones K, Jones O, Jones M, Jorge R, Jorgenson HJ, Julian M, Jun BI, Jungquist R, Kaae J, Kabadi N, Kaczala D, Kalantar D, Kangas K, Karasiev VV, Karasik M, Karpenko V, Kasarky A, Kasper K, Kauffman R, Kaufman MI, Keane C, Keaty L, Kegelmeyer L, Keiter PA, Kellett PA, Kellogg J, Kelly JH, Kemic S, Kemp AJ, Kemp GE, Kerbel GD, Kershaw D, Kerr SM, Kessler TJ, Key MH, Khan SF, Khater H, Kiikka C, Kilkenny J, Kim Y, Kim YJ, Kimko J, Kimmel M, Kindel JM, King J, Kirkwood RK, Klaus L, Klem D, Kline JL, Klingmann J, Kluth G, Knapp P, Knauer J, Knipping J, Knudson M, Kobs D, Koch J, Kohut T, Kong C, Koning JM, Koning P, Konior S, Kornblum H, Kot LB, Kozioziemski B, Kozlowski M, Kozlowski PM, Krammen J, Krasheninnikova NS, Krauland CM, Kraus B, Krauser W, Kress JD, Kritcher AL, Krieger E, Kroll JJ, Kruer WL, Kruse MKG, Kucheyev S, Kumbera M, Kumpan S, Kunimune J, Kur E, Kustowski B, Kwan TJT, Kyrala GA, Laffite S, Lafon M, LaFortune K, Lagin L, Lahmann B, Lairson B, Landen OL, Land T, Lane M, Laney D, Langdon AB, Langenbrunner J, Langer SH, Langro A, Lanier NE, Lanier TE, Larson D, Lasinski BF, Lassle D, LaTray D, Lau G, Lau N, Laumann C, Laurence A, Laurence TA, Lawson J, Le HP, Leach RR, Leal L, Leatherland A, LeChien K, Lechleiter B, Lee A, Lee M, Lee T, Leeper RJ, Lefebvre E, Leidinger JP, LeMire B, Lemke RW, Lemos NC, Le Pape S, Lerche R, Lerner S, Letts S, Levedahl K, Lewis T, Li CK, Li H, Li J, Liao W, Liao ZM, Liedahl D, Liebman J, Lindford G, Lindman EL, Lindl JD, Loey H, London RA, Long F, Loomis EN, Lopez FE, Lopez H, Losbanos E, Loucks S, Lowe-Webb R, Lundgren E, Ludwigsen AP, Luo R, Lusk J, Lyons R, Ma T, Macallop Y, MacDonald MJ, MacGowan BJ, Mack JM, Mackinnon AJ, MacLaren SA, MacPhee AG, Magelssen GR, Magoon J, Malone RM, Malsbury T, Managan R, Mancini R, Manes K, Maney D, Manha D, Mannion OM, Manuel AM, Manuel MJ, Mapoles E, Mara G, Marcotte T, Marin E, Marinak MM, Mariscal DA, Mariscal EF, Marley EV, Marozas JA, Marquez R, Marshall CD, Marshall FJ, Marshall M, Marshall S, Marticorena J, Martinez JI, Martinez D, Maslennikov I, Mason D, Mason RJ, Masse L, Massey W, Masson-Laborde PE, Masters ND, Mathisen D, Mathison E, Matone J, Matthews MJ, Mattoon C, Mattsson TR, Matzen K, Mauche CW, Mauldin M, McAbee T, McBurney M, Mccarville T, McCrory RL, McEvoy AM, McGuffey C, Mcinnis M, McKenty P, McKinley MS, McLeod JB, McPherson A, Mcquillan B, Meamber M, Meaney KD, Meezan NB, Meissner R, Mehlhorn TA, Mehta NC, Menapace J, Merrill FE, Merritt BT, Merritt EC, Meyerhofer DD, Mezyk S, Mich RJ, Michel PA, Milam D, Miller C, Miller D, Miller DS, Miller E, Miller EK, Miller J, Miller M, Miller PE, Miller T, Miller W, Miller-Kamm V, Millot M, Milovich JL, Minner P, Miquel JL, Mitchell S, Molvig K, Montesanti RC, Montgomery DS, Monticelli M, Montoya A, Moody JD, Moore AS, Moore E, Moran M, Moreno JC, Moreno K, Morgan BE, Morrow T, Morton JW, Moses E, Moy K, Muir R, Murillo MS, Murray JE, Murray JR, Munro DH, Murphy TJ, Munteanu FM, Nafziger J, Nagayama T, Nagel SR, Nast R, Negres RA, Nelson A, Nelson D, Nelson J, Nelson S, Nemethy S, Neumayer P, Newman K, Newton M, Nguyen H, Di Nicola JG, Di Nicola P, Niemann C, Nikroo A, Nilson PM, Nobile A, Noorai V, Nora RC, Norton M, Nostrand M, Note V, Novell S, Nowak PF, Nunez A, Nyholm RA, O'Brien M, Oceguera A, Oertel JA, Oesterle AL, Okui J, Olejniczak B, Oliveira J, Olsen P, Olson B, Olson K, Olson RE, Opachich YP, Orsi N, Orth CD, Owen M, Padalino S, Padilla E, Paguio R, Paguio S, Paisner J, Pajoom S, Pak A, Palaniyappan S, Palma K, Pannell T, Papp F, Paras D, Parham T, Park HS, Pasternak A, Patankar S, Patel MV, Patel PK, Patterson R, Patterson S, Paul B, Paul M, Pauli E, Pearce OT, Pearcy J, Pedretti A, Pedrotti B, Peer A, Pelz LJ, Penetrante B, Penner J, Perez A, Perkins LJ, Pernice E, Perry TS, Person S, Petersen D, Petersen T, Peterson DL, Peterson EB, Peterson JE, Peterson JL, Peterson K, Peterson RR, Petrasso RD, Philippe F, Phillion D, Phipps TJ, Piceno E, Pickworth L, Ping Y, Pino J, Piston K, Plummer R, Pollack GD, Pollaine SM, Pollock BB, Ponce D, Ponce J, Pontelandolfo J, Porter JL, Post J, Poujade O, Powell C, Powell H, Power G, Pozulp M, Prantil M, Prasad M, Pratuch S, Price S, Primdahl K, Prisbrey S, Procassini R, Pruyne A, Pudliner B, Qiu SR, Quan K, Quinn M, Quintenz J, Radha PB, Rainer F, Ralph JE, Raman KS, Raman R, Rambo PW, Rana S, Randewich A, Rardin D, Ratledge M, Ravelo N, Ravizza F, Rayce M, Raymond A, Raymond B, Reed B, Reed C, Regan S, Reichelt B, Reis V, Reisdorf S, Rekow V, Remington BA, Rendon A, Requieron W, Rever M, Reynolds H, Reynolds J, Rhodes J, Rhodes M, Richardson MC, Rice B, Rice NG, Rieben R, Rigatti A, Riggs S, Rinderknecht HG, Ring K, Riordan B, Riquier R, Rivers C, Roberts D, Roberts V, Robertson G, Robey HF, Robles J, Rocha P, Rochau G, Rodriguez J, Rodriguez S, Rosen MD, Rosenberg M, Ross G, Ross JS, Ross P, Rouse J, Rovang D, Rubenchik AM, Rubery MS, Ruiz CL, Rushford M, Russ B, Rygg JR, Ryujin BS, Sacks RA, Sacks RF, Saito K, Salmon T, Salmonson JD, Sanchez J, Samuelson S, Sanchez M, Sangster C, Saroyan A, Sater J, Satsangi A, Sauers S, Saunders R, Sauppe JP, Sawicki R, Sayre D, Scanlan M, Schaffers K, Schappert GT, Schiaffino S, Schlossberg DJ, Schmidt DW, Schmit PF, Smidt JM, Schneider DHG, Schneider MB, Schneider R, Schoff M, Schollmeier M, Schroeder CR, Schrauth SE, Scott HA, Scott I, Scott JM, Scott RHH, Scullard CR, Sedillo T, Seguin FH, Seka W, Senecal J, Sepke SM, Seppala L, Sequoia K, Severyn J, Sevier JM, Sewell N, Seznec S, Shah RC, Shamlian J, Shaughnessy D, Shaw M, Shaw R, Shearer C, Shelton R, Shen N, Sherlock MW, Shestakov AI, Shi EL, Shin SJ, Shingleton N, Shmayda W, Shor M, Shoup M, Shuldberg C, Siegel L, Silva FJ, Simakov AN, Sims BT, Sinars D, Singh P, Sio H, Skulina K, Skupsky S, Slutz S, Sluyter M, Smalyuk VA, Smauley D, Smeltser RM, Smith C, Smith I, Smith J, Smith L, Smith R, Smith R, Schölmerich M, Sohn R, Sommer S, Sorce C, Sorem M, Soures JM, Spaeth ML, Spears BK, Speas S, Speck D, Speck R, Spears J, Spinka T, Springer PT, Stadermann M, Stahl B, Stahoviak J, Stanley J, Stanton LG, Steele R, Steele W, Steinman D, Stemke R, Stephens R, Sterbenz S, Sterne P, Stevens D, Stevers J, Still CH, Stoeckl C, Stoeffl W, Stolken JS, Stolz C, Storm E, Stone G, Stoupin S, Stout E, Stowers I, Strauser R, Streckart H, Streit J, Strozzi DJ, Stutz J, Summers L, Suratwala T, Sutcliffe G, Suter LJ, Sutton SB, Svidzinski V, Swadling G, Sweet W, Szoke A, Tabak M, Takagi M, Tambazidis A, Tang V, Taranowski M, Taylor LA, Telford S, Theobald W, Thi M, Thomas A, Thomas CA, Thomas I, Thomas R, Thompson IJ, Thongstisubskul A, Thorsness CB, Tietbohl G, Tipton RE, Tobin M, Tomlin N, Tommasini R, Toreja AJ, Torres J, Town RPJ, Townsend S, Trenholme J, Trivelpiece A, Trosseille C, Truax H, Trummer D, Trummer S, Truong T, Tubbs D, Tubman ER, Tunnell T, Turnbull D, Turner RE, Ulitsky M, Upadhye R, Vaher JL, VanArsdall P, VanBlarcom D, Vandenboomgaerde M, VanQuinlan R, Van Wonterghem BM, Varnum WS, Velikovich AL, Vella A, Verdon CP, Vermillion B, Vernon S, Vesey R, Vickers J, Vignes RM, Visosky M, Vocke J, Volegov PL, Vonhof S, Von Rotz R, Vu HX, Vu M, Wall D, Wall J, Wallace R, Wallin B, Walmer D, Walsh CA, Walters CF, Waltz C, Wan A, Wang A, Wang Y, Wark JS, Warner BE, Watson J, Watt RG, Watts P, Weaver J, Weaver RP, Weaver S, Weber CR, Weber P, Weber SV, Wegner P, Welday B, Welser-Sherrill L, Weiss K, Wharton KB, Wheeler GF, Whistler W, White RK, Whitley HD, Whitman P, Wickett ME, Widmann K, Widmayer C, Wiedwald J, Wilcox R, Wilcox S, Wild C, Wilde BH, Wilde CH, Wilhelmsen K, Wilke MD, Wilkens H, Wilkins P, Wilks SC, Williams EA, Williams GJ, Williams W, Williams WH, Wilson DC, Wilson B, Wilson E, Wilson R, Winters S, Wisoff PJ, Wittman M, Wolfe J, Wong A, Wong KW, Wong L, Wong N, Wood R, Woodhouse D, Woodruff J, Woods DT, Woods S, Woodworth BN, Wooten E, Wootton A, Work K, Workman JB, Wright J, Wu M, Wuest C, Wysocki FJ, Xu H, Yamaguchi M, Yang B, Yang ST, Yatabe J, Yeamans CB, Yee BC, Yi SA, Yin L, Young B, Young CS, Young CV, Young P, Youngblood K, Yu J, Zacharias R, Zagaris G, Zaitseva N, Zaka F, Ze F, Zeiger B, Zika M, Zimmerman GB, Zobrist T, Zuegel JD, and Zylstra AB

Abstract

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Published
2024
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187. Opioidergic signaling contributes to food-mediated suppression of AgRP neurons.

Author

Sayar-Atasoy N, Yavuz Y, Laule C, Dong C, Kim H, Rysted J, Flippo K, Davis D, Aklan I, Yilmaz B, Tian L, and Atasoy D

Subjects
Animals, Mice, Agouti-Related Protein metabolism, Eating, Hypothalamus metabolism, Signal Transduction, Analgesics, Opioid pharmacology, Neurons metabolism
Abstract

Opioids are generally known to promote hedonic food consumption. Although much of the existing evidence is primarily based on studies of the mesolimbic pathway, endogenous opioids and their receptors are widely expressed in hypothalamic appetite circuits as well; however, their role in homeostatic feeding remains unclear. Using a fluorescent opioid sensor, deltaLight, here we report that mediobasal hypothalamic opioid levels increase by feeding, which directly and indirectly inhibits agouti-related protein (AgRP)-expressing neurons through the μ-opioid receptor (MOR). AgRP-specific MOR expression increases by energy surfeit and contributes to opioid-induced suppression of appetite. Conversely, its antagonists diminish suppression of AgRP neuron activity by food and satiety hormones. Mice with AgRP neuron-specific ablation of MOR expression have increased fat preference without increased motivation. These results suggest that post-ingestion release of endogenous opioids contributes to AgRP neuron inhibition to shape food choice through MOR signaling., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Published
2024
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188. Homogeneous, Micron-Scale High-Energy-Density Matter Generated by Relativistic Laser-Solid Interactions.

Author

Beier NF, Allison H, Efthimion P, Flippo KA, Gao L, Hansen SB, Hill K, Hollinger R, Logantha M, Musthafa Y, Nedbailo R, Senthilkumaran V, Shepherd R, Shlyaptsev VN, Song H, Wang S, Dollar F, Rocca JJ, and Hussein AE

Abstract

Short-pulse, laser-solid interactions provide a unique platform for studying complex high-energy-density matter. We present the first demonstration of solid-density, micron-scale keV plasmas uniformly heated by a high-contrast, 400 nm wavelength laser at intensities up to 2×10^{21}  W/cm^{2}. High-resolution spectral analysis of x-ray emission reveals uniform heating up to 3.0 keV over 1  μm depths. Particle-in-cell simulations indicate the production of a uniformly heated keV plasma to depths of 2  μm. The significant bulk heating and presence of highly ionized ions deep within the target are attributed to the few MeV hot electrons that become trapped and undergo refluxing within the target sheath fields. These conditions enabled the differentiation of atomic physics models of ionization potential depression in high-energy-density environments.

Published
2022
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189. Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment.

Author

Abu-Shawareb H, Acree R, Adams P, Adams J, Addis B, Aden R, Adrian P, Afeyan BB, Aggleton M, Aghaian L, Aguirre A, Aikens D, Akre J, Albert F, Albrecht M, Albright BJ, Albritton J, Alcala J, Alday C, Alessi DA, Alexander N, Alfonso J, Alfonso N, Alger E, Ali SJ, Ali ZA, Alley WE, Amala P, Amendt PA, Amick P, Ammula S, Amorin C, Ampleford DJ, Anderson RW, Anklam T, Antipa N, Appelbe B, Aracne-Ruddle C, Araya E, Arend M, Arnold P, Arnold T, Asay J, Atherton LJ, Atkinson D, Atkinson R, Auerbach JM, Austin B, Auyang L, Awwal AS, Ayers J, Ayers S, Ayers T, Azevedo S, Bachmann B, Back CA, Bae J, Bailey DS, Bailey J, Baisden T, Baker KL, Baldis H, Barber D, Barberis M, Barker D, Barnes A, Barnes CW, Barrios MA, Barty C, Bass I, Batha SH, Baxamusa SH, Bazan G, Beagle JK, Beale R, Beck BR, Beck JB, Bedzyk M, Beeler RG, Beeler RG, Behrendt W, Belk L, Bell P, Belyaev M, Benage JF, Bennett G, Benedetti LR, Benedict LX, Berger R, Bernat T, Bernstein LA, Berry B, Bertolini L, Besenbruch G, Betcher J, Bettenhausen R, Betti R, Bezzerides B, Bhandarkar SD, Bickel R, Biener J, Biesiada T, Bigelow K, Bigelow-Granillo J, Bigman V, Bionta RM, Birge NW, Bitter M, Black AC, Bleile R, Bleuel DL, Bliss E, Bliss E, Blue B, Boehly T, Boehm K, Boley CD, Bonanno R, Bond EJ, Bond T, Bonino MJ, Borden M, Bourgade JL, Bousquet J, Bowers J, Bowers M, Boyd R, Bozek A, Bradley DK, Bradley KS, Bradley PA, Bradley L, Brannon L, Brantley PS, Braun D, Braun T, Brienza-Larsen K, Briggs TM, Britten J, Brooks ED, Browning D, Bruhn MW, Brunner TA, Bruns H, Brunton G, Bryant B, Buczek T, Bude J, Buitano L, Burkhart S, Burmark J, Burnham A, Burr R, Busby LE, Butlin B, Cabeltis R, Cable M, Cabot WH, Cagadas B, Caggiano J, Cahayag R, Caldwell SE, Calkins S, Callahan DA, Calleja-Aguirre J, Camara L, Camp D, Campbell EM, Campbell JH, Carey B, Carey R, Carlisle K, Carlson L, Carman L, Carmichael J, Carpenter A, Carr C, Carrera JA, Casavant D, Casey A, Casey DT, Castillo A, Castillo E, Castor JI, Castro C, Caughey W, Cavitt R, Celeste J, Celliers PM, Cerjan C, Chandler G, Chang B, Chang C, Chang J, Chang L, Chapman R, Chapman T, Chase L, Chen H, Chen H, Chen K, Chen LY, Cheng B, Chittenden J, Choate C, Chou J, Chrien RE, Chrisp M, Christensen K, Christensen M, Christopherson AR, Chung M, Church JA, Clark A, Clark DS, Clark K, Clark R, Claus L, Cline B, Cline JA, Cobble JA, Cochrane K, Cohen B, Cohen S, Collette MR, Collins G, Collins LA, Collins TJB, Conder A, Conrad B, Conyers M, Cook AW, Cook D, Cook R, Cooley JC, Cooper G, Cope T, Copeland SR, Coppari F, Cortez J, Cox J, Crandall DH, Crane J, Craxton RS, Cray M, Crilly A, Crippen JW, Cross D, Cuneo M, Cuotts G, Czajka CE, Czechowicz D, Daly T, Danforth P, Darbee R, Darlington B, Datte P, Dauffy L, Davalos G, Davidovits S, Davis P, Davis J, Dawson S, Day RD, Day TH, Dayton M, Deck C, Decker C, Deeney C, DeFriend KA, Deis G, Delamater ND, Delettrez JA, Demaret R, Demos S, Dempsey SM, Desjardin R, Desjardins T, Desjarlais MP, Dewald EL, DeYoreo J, Diaz S, Dimonte G, Dittrich TR, Divol L, Dixit SN, Dixon J, Dodd ES, Dolan D, Donovan A, Donovan M, Döppner T, Dorrer C, Dorsano N, Douglas MR, Dow D, Downie J, Downing E, Dozieres M, Draggoo V, Drake D, Drake RP, Drake T, Dreifuerst G, DuBois DF, DuBois PF, Dunham G, Dylla-Spears R, Dymoke-Bradshaw AKL, Dzenitis B, Ebbers C, Eckart M, Eddinger S, Eder D, Edgell D, Edwards MJ, Efthimion P, Eggert JH, Ehrlich B, Ehrmann P, Elhadj S, Ellerbee C, Elliott NS, Ellison CL, Elsner F, Emerich M, Engelhorn K, England T, English E, Epperson P, Epstein R, Erbert G, Erickson MA, Erskine DJ, Erlandson A, Espinosa RJ, Estes C, Estabrook KG, Evans S, Fabyan A, Fair J, Fallejo R, Farmer N, Farmer WA, Farrell M, Fatherley VE, Fedorov M, Feigenbaum E, Feit M, Ferguson W, Fernandez JC, Fernandez-Panella A, Fess S, Field JE, Filip CV, Fincke JR, Finn T, Finnegan SM, Finucane RG, Fischer M, Fisher A, Fisher J, Fishler B, Fittinghoff D, Fitzsimmons P, Flegel M, Flippo KA, Florio J, Folta J, Folta P, Foreman LR, Forrest C, Forsman A, Fooks J, Foord M, Fortner R, Fournier K, Fratanduono DE, Frazier N, Frazier T, Frederick C, Freeman MS, Frenje J, Frey D, Frieders G, Friedrich S, Froula DH, Fry J, Fuller T, Gaffney J, Gales S, Le Galloudec B, Le Galloudec KK, Gambhir A, Gao L, Garbett WJ, Garcia A, Gates C, Gaut E, Gauthier P, Gavin Z, Gaylord J, Geissel M, Génin F, Georgeson J, Geppert-Kleinrath H, Geppert-Kleinrath V, Gharibyan N, Gibson J, Gibson C, Giraldez E, Glebov V, Glendinning SG, Glenn S, Glenzer SH, Goade S, Gobby PL, Goldman SR, Golick B, Gomez M, Goncharov V, Goodin D, Grabowski P, Grafil E, Graham P, Grandy J, Grasz E, Graziani F, Greenman G, Greenough JA, Greenwood A, Gregori G, Green T, Griego JR, Grim GP, Grondalski J, Gross S, Guckian J, Guler N, Gunney B, Guss G, Haan S, Hackbarth J, Hackel L, Hackel R, Haefner C, Hagmann C, Hahn KD, Hahn S, Haid BJ, Haines BM, Hall BM, Hall C, Hall GN, Hamamoto M, Hamel S, Hamilton CE, Hammel BA, Hammer JH, Hampton G, Hamza A, Handler A, Hansen S, Hanson D, Haque R, Harding D, Harding E, Hares JD, Harris DB, Harte JA, Hartouni EP, Hatarik R, Hatchett S, Hauer AA, Havre M, Hawley R, Hayes J, Hayes J, Hayes S, Hayes-Sterbenz A, Haynam CA, Haynes DA, Headley D, Heal A, Heebner JE, Heerey S, Heestand GM, Heeter R, Hein N, Heinbockel C, Hendricks C, Henesian M, Heninger J, Henrikson J, Henry EA, Herbold EB, Hermann MR, Hermes G, Hernandez JE, Hernandez VJ, Herrmann MC, Herrmann HW, Herrera OD, Hewett D, Hibbard R, Hicks DG, Hill D, Hill K, Hilsabeck T, Hinkel DE, Ho DD, Ho VK, Hoffer JK, Hoffman NM, Hohenberger M, Hohensee M, Hoke W, Holdener D, Holdener F, Holder JP, Holko B, Holunga D, Holzrichter JF, Honig J, Hoover D, Hopkins D, Berzak Hopkins L, Hoppe M, Hoppe ML, Horner J, Hornung R, Horsfield CJ, Horvath J, Hotaling D, House R, Howell L, Hsing WW, Hu SX, Huang H, Huckins J, Hui H, Humbird KD, Hund J, Hunt J, Hurricane OA, Hutton M, Huynh KH, Inandan L, Iglesias C, Igumenshchev IV, Izumi N, Jackson M, Jackson J, Jacobs SD, James G, Jancaitis K, Jarboe J, Jarrott LC, Jasion D, Jaquez J, Jeet J, Jenei AE, Jensen J, Jimenez J, Jimenez R, Jobe D, Johal Z, Johns HM, Johnson D, Johnson MA, Gatu Johnson M, Johnson RJ, Johnson S, Johnson SA, Johnson T, Jones K, Jones O, Jones M, Jorge R, Jorgenson HJ, Julian M, Jun BI, Jungquist R, Kaae J, Kabadi N, Kaczala D, Kalantar D, Kangas K, Karasiev VV, Karasik M, Karpenko V, Kasarky A, Kasper K, Kauffman R, Kaufman MI, Keane C, Keaty L, Kegelmeyer L, Keiter PA, Kellett PA, Kellogg J, Kelly JH, Kemic S, Kemp AJ, Kemp GE, Kerbel GD, Kershaw D, Kerr SM, Kessler TJ, Key MH, Khan SF, Khater H, Kiikka C, Kilkenny J, Kim Y, Kim YJ, Kimko J, Kimmel M, Kindel JM, King J, Kirkwood RK, Klaus L, Klem D, Kline JL, Klingmann J, Kluth G, Knapp P, Knauer J, Knipping J, Knudson M, Kobs D, Koch J, Kohut T, Kong C, Koning JM, Koning P, Konior S, Kornblum H, Kot LB, Kozioziemski B, Kozlowski M, Kozlowski PM, Krammen J, Krasheninnikova NS, Kraus B, Krauser W, Kress JD, Kritcher AL, Krieger E, Kroll JJ, Kruer WL, Kruse MKG, Kucheyev S, Kumbera M, Kumpan S, Kunimune J, Kustowski B, Kwan TJT, Kyrala GA, Laffite S, Lafon M, LaFortune K, Lahmann B, Lairson B, Landen OL, Langenbrunner J, Lagin L, Land T, Lane M, Laney D, Langdon AB, Langer SH, Langro A, Lanier NE, Lanier TE, Larson D, Lasinski BF, Lassle D, LaTray D, Lau G, Lau N, Laumann C, Laurence A, Laurence TA, Lawson J, Le HP, Leach RR, Leal L, Leatherland A, LeChien K, Lechleiter B, Lee A, Lee M, Lee T, Leeper RJ, Lefebvre E, Leidinger JP, LeMire B, Lemke RW, Lemos NC, Le Pape S, Lerche R, Lerner S, Letts S, Levedahl K, Lewis T, Li CK, Li H, Li J, Liao W, Liao ZM, Liedahl D, Liebman J, Lindford G, Lindman EL, Lindl JD, Loey H, London RA, Long F, Loomis EN, Lopez FE, Lopez H, Losbanos E, Loucks S, Lowe-Webb R, Lundgren E, Ludwigsen AP, Luo R, Lusk J, Lyons R, Ma T, Macallop Y, MacDonald MJ, MacGowan BJ, Mack JM, Mackinnon AJ, MacLaren SA, MacPhee AG, Magelssen GR, Magoon J, Malone RM, Malsbury T, Managan R, Mancini R, Manes K, Maney D, Manha D, Mannion OM, Manuel AM, Mapoles E, Mara G, Marcotte T, Marin E, Marinak MM, Mariscal C, Mariscal DA, Mariscal EF, Marley EV, Marozas JA, Marquez R, Marshall CD, Marshall FJ, Marshall M, Marshall S, Marticorena J, Martinez D, Maslennikov I, Mason D, Mason RJ, Masse L, Massey W, Masson-Laborde PE, Masters ND, Mathisen D, Mathison E, Matone J, Matthews MJ, Mattoon C, Mattsson TR, Matzen K, Mauche CW, Mauldin M, McAbee T, McBurney M, Mccarville T, McCrory RL, McEvoy AM, McGuffey C, Mcinnis M, McKenty P, McKinley MS, McLeod JB, McPherson A, Mcquillan B, Meamber M, Meaney KD, Meezan NB, Meissner R, Mehlhorn TA, Mehta NC, Menapace J, Merrill FE, Merritt BT, Merritt EC, Meyerhofer DD, Mezyk S, Mich RJ, Michel PA, Milam D, Miller C, Miller D, Miller DS, Miller E, Miller EK, Miller J, Miller M, Miller PE, Miller T, Miller W, Miller-Kamm V, Millot M, Milovich JL, Minner P, Miquel JL, Mitchell S, Molvig K, Montesanti RC, Montgomery DS, Monticelli M, Montoya A, Moody JD, Moore AS, Moore E, Moran M, Moreno JC, Moreno K, Morgan BE, Morrow T, Morton JW, Moses E, Moy K, Muir R, Murillo MS, Murray JE, Murray JR, Munro DH, Murphy TJ, Munteanu FM, Nafziger J, Nagayama T, Nagel SR, Nast R, Negres RA, Nelson A, Nelson D, Nelson J, Nelson S, Nemethy S, Neumayer P, Newman K, Newton M, Nguyen H, Di Nicola JG, Di Nicola P, Niemann C, Nikroo A, Nilson PM, Nobile A, Noorai V, Nora R, Norton M, Nostrand M, Note V, Novell S, Nowak PF, Nunez A, Nyholm RA, O'Brien M, Oceguera A, Oertel JA, Okui J, Olejniczak B, Oliveira J, Olsen P, Olson B, Olson K, Olson RE, Opachich YP, Orsi N, Orth CD, Owen M, Padalino S, Padilla E, Paguio R, Paguio S, Paisner J, Pajoom S, Pak A, Palaniyappan S, Palma K, Pannell T, Papp F, Paras D, Parham T, Park HS, Pasternak A, Patankar S, Patel MV, Patel PK, Patterson R, Patterson S, Paul B, Paul M, Pauli E, Pearce OT, Pearcy J, Pedrotti B, Peer A, Pelz LJ, Penetrante B, Penner J, Perez A, Perkins LJ, Pernice E, Perry TS, Person S, Petersen D, Petersen T, Peterson DL, Peterson EB, Peterson JE, Peterson JL, Peterson K, Peterson RR, Petrasso RD, Philippe F, Phipps TJ, Piceno E, Ping Y, Pickworth L, Pino J, Plummer R, Pollack GD, Pollaine SM, Pollock BB, Ponce D, Ponce J, Pontelandolfo J, Porter JL, Post J, Poujade O, Powell C, Powell H, Power G, Pozulp M, Prantil M, Prasad M, Pratuch S, Price S, Primdahl K, Prisbrey S, Procassini R, Pruyne A, Pudliner B, Qiu SR, Quan K, Quinn M, Quintenz J, Radha PB, Rainer F, Ralph JE, Raman KS, Raman R, Rambo P, Rana S, Randewich A, Rardin D, Ratledge M, Ravelo N, Ravizza F, Rayce M, Raymond A, Raymond B, Reed B, Reed C, Regan S, Reichelt B, Reis V, Reisdorf S, Rekow V, Remington BA, Rendon A, Requieron W, Rever M, Reynolds H, Reynolds J, Rhodes J, Rhodes M, Richardson MC, Rice B, Rice NG, Rieben R, Rigatti A, Riggs S, Rinderknecht HG, Ring K, Riordan B, Riquier R, Rivers C, Roberts D, Roberts V, Robertson G, Robey HF, Robles J, Rocha P, Rochau G, Rodriguez J, Rodriguez S, Rosen M, Rosenberg M, Ross G, Ross JS, Ross P, Rouse J, Rovang D, Rubenchik AM, Rubery MS, Ruiz CL, Rushford M, Russ B, Rygg JR, Ryujin BS, Sacks RA, Sacks RF, Saito K, Salmon T, Salmonson JD, Sanchez J, Samuelson S, Sanchez M, Sangster C, Saroyan A, Sater J, Satsangi A, Sauers S, Saunders R, Sauppe JP, Sawicki R, Sayre D, Scanlan M, Schaffers K, Schappert GT, Schiaffino S, Schlossberg DJ, Schmidt DW, Schmitt MJ, Schneider DHG, Schneider MB, Schneider R, Schoff M, Schollmeier M, Schölmerich M, Schroeder CR, Schrauth SE, Scott HA, Scott I, Scott JM, Scott RHH, Scullard CR, Sedillo T, Seguin FH, Seka W, Senecal J, Sepke SM, Seppala L, Sequoia K, Severyn J, Sevier JM, Sewell N, Seznec S, Shah RC, Shamlian J, Shaughnessy D, Shaw M, Shaw R, Shearer C, Shelton R, Shen N, Sherlock MW, Shestakov AI, Shi EL, Shin SJ, Shingleton N, Shmayda W, Shor M, Shoup M, Shuldberg C, Siegel L, Silva FJ, Simakov AN, Sims BT, Sinars D, Singh P, Sio H, Skulina K, Skupsky S, Slutz S, Sluyter M, Smalyuk VA, Smauley D, Smeltser RM, Smith C, Smith I, Smith J, Smith L, Smith R, Sohn R, Sommer S, Sorce C, Sorem M, Soures JM, Spaeth ML, Spears BK, Speas S, Speck D, Speck R, Spears J, Spinka T, Springer PT, Stadermann M, Stahl B, Stahoviak J, Stanton LG, Steele R, Steele W, Steinman D, Stemke R, Stephens R, Sterbenz S, Sterne P, Stevens D, Stevers J, Still CB, Stoeckl C, Stoeffl W, Stolken JS, Stolz C, Storm E, Stone G, Stoupin S, Stout E, Stowers I, Strauser R, Streckart H, Streit J, Strozzi DJ, Suratwala T, Sutcliffe G, Suter LJ, Sutton SB, Svidzinski V, Swadling G, Sweet W, Szoke A, Tabak M, Takagi M, Tambazidis A, Tang V, Taranowski M, Taylor LA, Telford S, Theobald W, Thi M, Thomas A, Thomas CA, Thomas I, Thomas R, Thompson IJ, Thongstisubskul A, Thorsness CB, Tietbohl G, Tipton RE, Tobin M, Tomlin N, Tommasini R, Toreja AJ, Torres J, Town RPJ, Townsend S, Trenholme J, Trivelpiece A, Trosseille C, Truax H, Trummer D, Trummer S, Truong T, Tubbs D, Tubman ER, Tunnell T, Turnbull D, Turner RE, Ulitsky M, Upadhye R, Vaher JL, VanArsdall P, VanBlarcom D, Vandenboomgaerde M, VanQuinlan R, Van Wonterghem BM, Varnum WS, Velikovich AL, Vella A, Verdon CP, Vermillion B, Vernon S, Vesey R, Vickers J, Vignes RM, Visosky M, Vocke J, Volegov PL, Vonhof S, Von Rotz R, Vu HX, Vu M, Wall D, Wall J, Wallace R, Wallin B, Walmer D, Walsh CA, Walters CF, Waltz C, Wan A, Wang A, Wang Y, Wark JS, Warner BE, Watson J, Watt RG, Watts P, Weaver J, Weaver RP, Weaver S, Weber CR, Weber P, Weber SV, Wegner P, Welday B, Welser-Sherrill L, Weiss K, Widmann K, Wheeler GF, Whistler W, White RK, Whitley HD, Whitman P, Wickett ME, Widmayer C, Wiedwald J, Wilcox R, Wilcox S, Wild C, Wilde BH, Wilde CH, Wilhelmsen K, Wilke MD, Wilkens H, Wilkins P, Wilks SC, Williams EA, Williams GJ, Williams W, Williams WH, Wilson DC, Wilson B, Wilson E, Wilson R, Winters S, Wisoff J, Wittman M, Wolfe J, Wong A, Wong KW, Wong L, Wong N, Wood R, Woodhouse D, Woodruff J, Woods DT, Woods S, Woodworth BN, Wooten E, Wootton A, Work K, Workman JB, Wright J, Wu M, Wuest C, Wysocki FJ, Xu H, Yamaguchi M, Yang B, Yang ST, Yatabe J, Yeamans CB, Yee BC, Yi SA, Yin L, Young B, Young CS, Young CV, Young P, Youngblood K, Zacharias R, Zagaris G, Zaitseva N, Zaka F, Ze F, Zeiger B, Zika M, Zimmerman GB, Zobrist T, Zuegel JD, and Zylstra AB

Abstract

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Published
2022
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190. Acquired hemophilia A after vaccination against SARS-CoV-2 with the mRNA-1273 (Moderna) vaccine.

Author

Melmed A, Kovoor A, and Flippo K

Abstract

Acquired hemophilia A is a rare bleeding diathesis most typically seen in systemic rheumatic disease, solid and hematologic malignancies, and pregnancy. We present a case of this condition that occurred immediately after vaccination against SARS-CoV-2 with the mRNA-1273 (Moderna) vaccine., (Copyright © 2022 Baylor University Medical Center.)

Published
2022
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191. Improved imaging using Mn He-α x rays at OMEGA EP.

Author

Fiedler Kawaguchi C, Flippo KA, Rasmus AM, Tobias B, Byvank T, Di Stefano CA, Merritt EC, Doss FW, Kelso KV, Vazirani NN, Stoeckl C, Bedzyk M, Jungquist R, and Mileham C

Abstract

In this paper, we report on a crystal based x-ray imaging system fielded at the OMEGA EP laser facility. This new system has a pointing accuracy of +/100 μm, a temporal resolution down to 100 ps (depending on backlighter characteristics), variable magnification, and a spatial resolution of 21.9 µm at the object plane at a magnification of 15×. The system is designed to use a crystal along the crystal plane that satisfies the Bragg condition for the x ray of interest. The thin crystal is then bent into a spherical geometry and attached to a glass backing substrate to hold it in the diagnostic, and the x rays are imaged onto a charge coupled device. We report on data acquired with the new Los Alamos National Laboratory supplied spherical quartz crystal to image the Mn He-α 6.15 keV line emission.

Published
2021
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192. Preparations for a European R&D roadmap for an inertial fusion demo reactor.

Author

Norreys PA, Ceurvorst L, Sadler JD, Spiers BT, Aboushelbaya R, Mayr MW, Paddock R, Ratan N, Savin AF, Wang RHW, Glize K, Trines RMGM, Bingham R, Hill MP, Sircombe N, Ramsay M, Allan P, Hobbs L, James S, Skidmore J, Fyrth J, Luis J, Floyd E, Brown C, Haines BM, Olson RE, Yi SA, Zylstra AB, Flippo K, Bradley PA, Peterson RR, Kline JL, and Leeper RJ

Abstract

A European consortium of 15 laboratories across nine nations have worked together under the EUROFusion Enabling Research grants for the past decade with three principle objectives. These are: (a) investigating obstacles to ignition on megaJoule-class laser facilities; (b) investigating novel alternative approaches to ignition, including basic studies for fast ignition (both electron and ion-driven), auxiliary heating, shock ignition, etc.; and (c) developing technologies that will be required in the future for a fusion reactor. A brief overview of these activities, presented here, along with new calculations relates the concept of auxiliary heating of inertial fusion targets, and provides possible future directions of research and development for the updated European Roadmap that is due at the end of 2020. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

Published
2021
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193. Experimental measurement of two copropagating shocks interacting with an unstable interface.

Author

Di Stefano CA, Doss FW, Merritt EC, Haines BM, Desjardins TR, DeVolder BG, Flippo KA, Kot L, Robey HF, Schmidt DW, and Millot M

Abstract

In this work, we present results from experiments capable of producing and measuring the propagation of multiple successive, copropagating shocks across an unstable planar interface, where the shocks are independently driven and separately controllable, enabling the study of this important phenomenon. Copropagating shocks play a significant role in a wide range of systems involving stratified media subject to a shock, and exhibit different physical characteristics compared to counterpropagating shocks. Existing techniques, however, preclude copropagating shocks, so experiments to date have been limited to the study of counterpropagating shocks. We address this previous limitation and open a physical parameter space for study using a new hohlraum platform on the National Ignition Facility. Initial experimental results are presented together with comparisons from numerical simulations.

Published
2020
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194. Implementation of a 1-2 keV point-projection x-ray spectrometer on the National Ignition Facility.

Author

King JA, Opachich YP, Huffman EJ, Knight R, Heeter RF, Ahmed M, Liedahl DA, Schneider MB, Thompson NB, Johns HM, Dodd E, Flippo KA, Kline JL, Lopez FE, Archuleta TN, and Perry TS

Abstract

A point-projection soft X-ray Opacity Spectrometer (OpSpec) has been implemented to measure X-ray spectra from ∼1 to 2 keV on the National Ignition Facility (NIF). Measurement of such soft X-rays with open-aperture point-projection detectors is challenging because only very thin filters may be used to shield the detector from the hostile environment. OpSpec diffracts X-rays from 540 to 2100 eV off a potassium (or rubidium) acid phthalate (KAP or RbAP) crystal onto either image plates or, most recently, X-ray films. A "sacrificial front filter" strategy is used to prevent crystal damage, while 2 or 3 rear filters protect the data. Since May 2017, OpSpec has been recording X-ray transmission data for iron-magnesium plasmas on the NIF, at "Anchor 1" plasma conditions (temperature ∼150 eV, density ∼7 × 10 21 e - /cm 3 ). Upgrades improved OpSpec's performance on 6 NIF shots in August and December 2017, with reduced backgrounds and 100% data return using filter stacks as thin as 2.9 μ m (total). Photometric noise is beginning to meet requirements, and further work will reduce systematic errors.

Published
2018
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195. How high energy fluxes may affect Rayleigh-Taylor instability growth in young supernova remnants.

Author

Kuranz CC, Park HS, Huntington CM, Miles AR, Remington BA, Plewa T, Trantham MR, Robey HF, Shvarts D, Shimony A, Raman K, MacLaren S, Wan WC, Doss FW, Kline J, Flippo KA, Malamud G, Handy TA, Prisbrey S, Krauland CM, Klein SR, Harding EC, Wallace R, Grosskopf MJ, Marion DC, Kalantar D, Giraldez E, and Drake RP

Abstract

Energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh-Taylor instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter, based on simple models and hydrodynamic simulations. Here we report experimental results from the National Ignition Facility to explore how large energy fluxes, which are present in supernovae, affect this structure. We observed a reduction in Rayleigh-Taylor growth. In analyzing the comparison with supernova SN1993J, a Type II supernova, we found that the energy fluxes produced by heat conduction appear to be larger than the radiative energy fluxes, and large enough to have dramatic consequences. No reported astrophysical simulations have included radiation and heat conduction self-consistently in modeling supernova remnants and these dynamics should be noted in the understanding of young supernova remnants.

Published
2018
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196. Late-Time Mixing Sensitivity to Initial Broadband Surface Roughness in High-Energy-Density Shear Layers.

Author

Flippo KA, Doss FW, Kline JL, Merritt EC, Capelli D, Cardenas T, DeVolder B, Fierro F, Huntington CM, Kot L, Loomis EN, MacLaren SA, Murphy TJ, Nagel SR, Perry TS, Randolph RB, Rivera G, and Schmidt DW

Abstract

Using a large volume high-energy-density fluid shear experiment (8.5  cm^{3}) at the National Ignition Facility, we have demonstrated for the first time the ability to significantly alter the evolution of a supersonic sheared mixing layer by controlling the initial conditions of that layer. By altering the initial surface roughness of the tracer foil, we demonstrate the ability to transition the shear mixing layer from a highly ordered system of coherent structures to a randomly ordered system with a faster growing mix layer, indicative of strong mixing in the layer at a temperature of several tens of electron volts and at near solid density. Simulations using a turbulent-mix model show good agreement with the experimental results and poor agreement without turbulent mix.

Published
2016
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197. Observation and analysis of emergent coherent structures in a high-energy-density shock-driven planar mixing layer experiment.

Author

Doss FW, Flippo KA, and Merritt EC

Abstract

Coherent emergent structures have been observed in a high-energy-density supersonic mixing layer experiment. A millimeter-scale shock tube uses lasers to drive Mbar shocks into the tube volume. The shocks are driven into initially solid foam (60 mg/cm^{3}) hemicylinders separated by an Al or Ti metal tracer strip; the components are vaporized by the drive. Before the experiment disassembles, the shocks cross at the tube center, creating a very fast (ΔU> 200 km/s) shear-unstable zone. After several nanoseconds, an expanding mixing layer is measured, and after 10+ ns we observe the appearance of streamwise-periodic, spanwise-aligned rollers associated with the primary Kelvin-Helmholtz instability of mixing layers. We additionally image roller pairing and spanwise-periodic streamwise-aligned filaments associated with secondary instabilities. New closures are derived to connect length scales of these structures to estimates of fluctuating velocity data otherwise unobtainable in the high-energy-density environment. This analysis indicates shear-induced specific turbulent energies 10^{3}-10^{4} times higher than the nearest conventional experiments. Because of difficulties in continuously driving systems under these conditions and the harshness of the experimental environment limiting the usable diagnostics, clear evidence of these developing structures has never before been observed in this regime.

Published
2016
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198. Development of a Big Area BackLighter for high energy density experiments.

Author

Flippo KA, Kline JL, Doss FW, Loomis EN, Emerich M, Devolder B, Murphy TJ, Fournier KB, Kalantar DH, Regan SP, Barrios MA, Merritt EC, Perry TS, Tregillis IL, Welser-Sherrill L, and Fincke JR

Abstract

A very large area (7.5 mm(2)) laser-driven x-ray backlighter, termed the Big Area BackLighter (BABL) has been developed for the National Ignition Facility (NIF) to support high energy density experiments. The BABL provides an alternative to Pinhole-Apertured point-projection Backlighting (PABL) for a large field of view. This bypasses the challenges for PABL in the equatorial plane of the NIF target chamber where space is limited because of the unconverted laser light that threatens the diagnostic aperture, the backlighter foil, and the pinhole substrate. A transmission experiment using 132 kJ of NIF laser energy at a maximum intensity of 8.52 × 10(14) W/cm(2) illuminating the BABL demonstrated good conversion efficiency of >3.5% into K-shell emission producing ~4.6 kJ of high energy x rays, while yielding high contrast images with a highly uniform background that agree well with 2D simulated spectra and spatial profiles.

Published
2014
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