A5041275030- High-pressure geophysics and materials
- Laser-Plasma Interactions and Diagnostics
- X-ray Spectroscopy and Fluorescence Analysis
- Diamond and Carbon-based Materials Research
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Laser-Matter Interactions and Applications
- Advanced Chemical Physics Studies
- Electron and X-Ray Spectroscopy Techniques
- Crystal Structures and Properties
- Rare-earth and actinide compounds
- Advanced X-ray Imaging Techniques
- Magnetic Properties of Alloys
- Nuclear Physics and Applications
- Electronic and Structural Properties of Oxides
- Space Satellite Systems and Control
- X-ray Diffraction in Crystallography
- Gamma-ray bursts and supernovae
- Geological and Geochemical Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Spaceflight effects on biology
- Advanced Electron Microscopy Techniques and Applications
- Gas Dynamics and Kinetic Theory
- Crystallography and Radiation Phenomena
- Cold Fusion and Nuclear Reactions
Energetics (United States)
2020-2025
University of Rochester
2020-2025
Applied Energetics (United States)
2023
Lawrence Livermore National Laboratory
2022
We present measurements on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>Fe</a:mi><a:mn>2</a:mn></a:msub><a:msub><a:mi mathvariant="normal">O</a:mi><a:mn>3</a:mn></a:msub></a:mrow></a:math> amorphization and melt under laser-driven shock compression up to 209(10) GPa via time-resolved x-ray diffraction. At 122(3) GPa, a diffuse signal is observed indicating the presence of noncrystalline phase. Structure factors have been extracted 182(6) showing two well-defined...
Spectroscopic measurements of dense plasmas at billions atmospheres provide tests to our fundamental understanding how matter behaves extreme conditions. Developing reliable atomic physics models these conditions, benchmarked by experimental data, is crucial an improved radiation transport in both stars and inertial fusion targets. However, detailed spectroscopic conditions are rare, traditional collisional-radiative equilibrium models, based on isolated-atom calculations ad hoc continuum...
Gas-filled plastic spherical shells have been imploded using the 60-beam OMEGA laser. The same laser pulse was used as in a previous experiment, which demonstrated dynamic formation of shell by irradiating homogeneous foam sphere [Igumenshchev et al., Phys. Rev. Lett. 131, 015102 (2023)]. In present initially implodes, bounces, and expands; new then forms undergoes second implosion. Analysis x-ray self-emission-streaked images sequences 2D self-emission framing camera show evolution that is...
The physics basis for an electron-beam-based Compton scattering x-ray source is investigated single-shot experiments at the major high-energy-density facilities, such as Omega Laser Facility, National Ignition and <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>Z</a:mi></a:mrow></a:math> pulsed power facility. A of monoenergetic (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML"...
Abstract Resonant inelastic x-ray scattering (RIXS) is a widely used spectroscopic technique, providing access to the electronic structure and dynamics of atoms, molecules, solids. However, RIXS requires narrow bandwidth probe achieve high spectral resolution. The challenges in delivering an energetic monochromated beam from free electron laser (XFEL) thus limit its use few-shot experiments, including for study energy density systems. Here we demonstrate that by correlating measurements...
High-pressure equation of state and isentropic sound speed data for fluid silicon to pressures 2100 GPa (21 Mbar) are reported. Principal Hugoniot measurements were performed using impedance matching techniques with \ensuremath{\alpha}-quartz as the reference. Sound speeds determined by time correlating imposed shock-velocity perturbations in both sample (Si) reference material (\ensuremath{\alpha}-quartz). A change shock velocity versus particle (${u}_{s}--{u}_{p}$) slope on principal is...
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).] laser-driven inertial confinement fusion deuterium-tritium fuel is initially in form of a homogeneous liquid inside wetted-foam spherical shell. This ignited using conventional implosion, which preceded by initial compression followed its expansion and dynamic formation high-density shell...
Iron, nickel, and their alloys are critically important materials for industrial technological applications due to unique magnetic properties, strength, thermal expansion. In this study, lasers were used compress heat ${\mathrm{Fe}}_{36}\mathrm{Ni}$ alloy (36 wt% Ni) pure nickel up the melting temperature using a combination of shock ramp compression. The structure was measured nanosecond in situ x-ray diffraction, simultaneous velocimetry measure pressure 454 GPa. A mixed...
High-energy-density (HED) experiments in convergent geometry are able to test physical models at pressures beyond hundreds of millions atmospheres. The measurements from these generally highly integrated and require unique analysis techniques procure quantitative information. This work describes a methodology constrain the physics HED by adapting methods common many other fields physics. As an example, mechanical model imploding shell is constrained data thin-shelled direct-drive...
At the Laboratory for Laser Energetics' Omega Facility, thin plastic shells were directly driven with ∼20 kJ resulting in a time-integrated x-ray yield of ∼1012 ph/eV/sr at 7 keV. Using temporally, spatially, and spectrally discriminating diagnostics, three emission phases identified: corona produced by laser ablation shell, core stagnation, afterglow due to expanding hot material after stagnation. The newly measured account ∼25% total signal produce different time or larger radius than...
Two extended x-ray absorption fine structure flat crystal spectrometers (EFX's) were designed and built for high-resolution spectroscopy over a large energy range with flexible, on-shot dispersion calibration capabilities. The EFX uses silicon [111] in the reflection geometry as dispersive optic covering of 6.3-11.4 keV achieving spectral resolution 4.5 eV source size 50 μm at 7.2 keV. A shot-to-shot configurable filter pack Bayesian inference routine used to constrain relation within ±3 eV....
We report here an equation-of-state measurement of ${\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ obtained with laser-driven shock compression. The data are in excellent agreement previous dynamic and static compression measurements at low pressure, extend the known Hugoniot up to 700 GPa. observe a large volume drop $\ensuremath{\sim}10%$ 86 GPa, which could be associated, according observations, iron spin transition. Our also suggest change curve between 150 250 Above GPa within our error bars, we do...
Energy flow and balance in convergent systems beyond petapascal energy densities controls the fate of late-stage stars potential for controlling thermonuclear inertial fusion ignition. Time-resolved x-ray self-emission imaging combined with a Bayesian inference analysis is used to describe information stored rebounding spherical shock at 0.22 PPa (2.2 Gbar or billions atmospheres pressure). This analysis, together simple mechanical model, describes trajectory shell time history pressure...
Time-gated Sc K-shell and Ge L-shell spectra are presented from a range of characterized thermodynamic states spanning ion densities 1019–1020cm−3 plasma temperatures around 2000 eV. For the higher studied 1000 to 3000 eV, x-ray emission consistent with steady-state calculations modern atomic kinetics model SCRAM. At lower achieved through expansion, however, require temperature reproduce observed spectrum. We attribute this ionization disequilibrium because time scales exceed hydrodynamic...
Resonant inelastic x-ray scattering (RIXS) is a widely used spectroscopic technique, providing access to the electronic structure and dynamics of atoms, molecules, solids. However, RIXS requires narrow bandwidth probe achieve high spectral resolution. The challenges in delivering an energetic monochromated beam from free electron laser (XFEL) thus limit its use few-shot experiments, including for study energy density systems. Here we demonstrate that by correlating measurements...
Experiments today can compress solids near isentropically to pressures approaching 100 × 106 atmospheres; however, determining the temperature of such matter remains a major challenge. Extended x-ray absorption fine-structure (EXAFS) spectroscopy is one few techniques sensitive bulk highly compressed solid matter, and validity this measurement relies on constraining local ion structure from EXAFS spectrum. At high-energy-density (HED) conditions, often becomes distorted, which must be...
We report here the first equation of state measurements Fe$_2$O$_3$ obtained with laser-driven shock compression. The data are in excellent agreement previous dynamic and static compression at low pressure, extend known Hugoniot up to 700 GPa. observe a large volume drop $\sim$10% 86 GPa, which could be associated, according observations, iron spin transition. Our also suggest change curve between 150 250 Above GPa within our error bars, we do not significant modifications maximum pressure...
We present measurements on Fe$_2$O$_3$ amorphization and melt under laser-driven shock compression up to 209(10) GPa via time-resolved in situ x-ray diffraction. At 122(3) GPa, a diffuse signal is observed indicating the presence of non-crystalline phase. Structure factors have been extracted 182(6) showing two well-defined peaks. A rapid change intensity ratio peaks identified between 145(10) 151(10) indicative phase change. Present DFT+$U$ calculations temperatures along Hugoniot are...