A5075763728- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Laser-Plasma Interactions and Diagnostics
- X-ray Diffraction in Crystallography
- Laser-induced spectroscopy and plasma
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Force Microscopy Techniques and Applications
- Geological and Geochemical Analysis
- Astro and Planetary Science
- High-Velocity Impact and Material Behavior
- Crystallography and Radiation Phenomena
- Advanced Chemical Physics Studies
- Nuclear physics research studies
- Muon and positron interactions and applications
- Ammonia Synthesis and Nitrogen Reduction
- Metal and Thin Film Mechanics
- Particle accelerators and beam dynamics
- Radiation Therapy and Dosimetry
- Microstructure and mechanical properties
- Advanced Materials Characterization Techniques
- Aluminum Alloy Microstructure Properties
- Spectroscopy and Laser Applications
- Ion-surface interactions and analysis
- Boron and Carbon Nanomaterials Research
University of Rochester
2016-2025
Energetics (United States)
2016-2025
Applied Energetics (United States)
2019-2024
Houghton University
2018
Nanosecond in situ x-ray diffraction and simultaneous velocimetry measurements were used to determine the crystal structure pressure, respectively, of ramp-compressed aluminum at stress states between 111 475 GPa. The solid-solid Al phase transformations, fcc--hcp hcp--bcc, are observed $216\ifmmode\pm\else\textpm\fi{}9$ $321\ifmmode\pm\else\textpm\fi{}12\text{ }\text{ }\mathrm{GPa}$, with bcc persisting high-pressure crystallographic texture hcp phases suggests close-packed or nearly...
We report details of an experimental platform implemented at the National Ignition Facility to obtain in situ powder diffraction data from solids dynamically compressed extreme pressures. Thin samples are sandwiched between tamper layers and ramp using a gradual increase drive-laser irradiance. Pressure history sample is determined high-precision velocimetry measurements. Up two independently timed pulses x rays produced or near time peak pressure by laser illumination thin metal foils. The...
We present the development of an experimental platform that can collect four frames x-ray diffraction data along a single line sight during laser-driven, dynamic-compression experiments at National Ignition Facility. The is comprised diagnostic imager built around ultrafast sensors with 2-ns integration time, custom target assembly serves also to shield imager, and 10-ns duration, quasi-monochromatic source produced by laser-generated plasma. demonstrate performance for Pb ramp compressed...
The properties of all materials at one atmosphere pressure are controlled by the configurations their valence electrons. At extreme pressures, neighboring atoms approach so close that core-electron orbitals overlap, and theory predicts emergence unusual quantum behavior. We ramp-compress monovalent elemental sodium, a prototypical metal ambient conditions, to nearly 500 GPa (5 million atmospheres). 7-fold increase density brings interatomic distance 1.74 Å well within initial 2.03 Na
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...
The evolution of non-uniform shocks produced by modulated laser irradiation or surface perturbations is relevant to studies inertial confinement fusion and material properties at high-energy-density conditions. We present results from an experiment conducted the OMEGA EP facility, where a 300 GPa shock was driven into fused silica sample with pre-fabricated single-mode modulations. Using time-resolved optical velocimetry, we captured continuous rippled motion, enabling comprehensive mapping...
The equation of state (EOS) carbon in its high-pressure solid and liquid phases is interest to planetary astrophysics inertial confinement fusion. Of particular are the shock release responses diamond as these provide rigorous constraints on important paths through EOS. This paper presents experimental Hugoniot data for both single-crystal (SCD) nanocrystalline (NCD), which comprised nanometer-scale grains $\ensuremath{\sim}5%$ less dense than SCD. We find that NCD has a stiffer SCD can be...
Experiments in high-energy-density physics often use optical pyrometry to determine temperatures of dynamically compressed materials. In combination with simultaneous shock-velocity and optical-reflectivity measurements using velocity interferometry, these experiments provide accurate equation-of-state data at extreme pressures (P > 1 Mbar) (T 0.5 eV). This paper reports on the absolute calibration streaked pyrometer (SOP) Omega Laser Facility. The wavelength-dependent system response was...
The properties of silica are important to geophysical and high-pressure equation-of-state research. Its most-prevalent crystalline form, α-quartz, has been extensively studied TPa pressures. This article presents Hugoniot measurements on amorphous silica, commonly referred as fused over a range from 200 1600 GPa using laser-driven shocks an α-quartz standard. These results extend the measured higher In 200- 600-GPa range, data in very good agreement with those obtained by Qi et al. [Phys....
MgO is a major constituent of the ${\text{MgO-FeO-SiO}}_{2}$ system that comprises Earth's mantle and super-Earth exoplanets. Knowledge its high-pressure behavior important for modeling more complex compounds. This paper presents measurements principal Hugoniot, sound velocity, temperature MgO, shocked to pressures 710 2300 GPa using laser-driven compression. The Hugoniot compare favorably previous results constraining shock response at extreme conditions. Gr\"uneisen parameter was...
Equation-of-state (pressure, density, temperature, internal energy) and reflectivity measurements on shock-compressed CO_{2} at above the insulating-to-conducting transition reveal new insight into chemistry of simple molecular systems in warm-dense-matter regime. samples were precompressed diamond-anvil cells to tune initial densities from 1.35 g/cm^{3} (liquid) 1.74 (solid) room temperature then shock compressed up 1 TPa 93 000 K. Variation density was leveraged infer thermodynamic...
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...
Constraining the melting behavior of magnesium oxide, a major constituent gaseous and rocky planets, is key to benchmarking their evolutionary models. Using double-shock technique, we extended MgO melt curve measurements 2 TPa; this twice pressure achieved by previous experiments on any material. A temperature plateau observed between 1218 1950 GPa in second-shock states, which attributed latent heat melting. At GPa, measured 17 600 K, 17% lower than recent theoretical predictions. The...
Abstract We present a framework based on non-equilibrium molecular dynamics (NEMD) to reproduce the phase transformation event of Aluminum under ramp compression loading. The simulated stress-density response, virtual x-ray diffraction patterns, and structure analysis are compared against previously observed experimental laser-driven in-situ data. NEMD simulations show solid–solid transitions consistent observations with close-packed face-centered cubic (fcc) (111), hexagonal (hcp) (002),...
The ionic structure of high-pressure, high-temperature fluids is a challenging theoretical problem with applications to planetary interiors and fusion capsules. Here we report multimessenger platform using velocimetry angularly spectrally resolved x-ray scattering measure the thermodynamic conditions ion factor materials at extreme pressures. We document pressure, density, temperature shocked silicon near <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mn>100</a:mn><a:mspace...
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...
We report on a series of experiments that use high-power lasers to ramp-compress aluminum (Al) up 475 GPa. Under this quasi-isentropic compression, Al remains in the solid state and two solid–solid phase transformations are observed. In situ x-ray diffraction is performed detect crystal structure. A velocimetry diagnostic measures particle velocities order infer pressure sample. show transition, consistent with transformation hexagonal close-packed (hcp) structure, occurs at 216 ± 9 At...
Ab initio evolutionary structure searches coupled with quasiharmonic calculations predict that the insulating Na hP4 phase transitions to a novel P63/m between 200 GPa at 150 K, and 350 1900 K. is topological semimetal Dirac nodal surface protected by non-symmorphic symmetry, S2z . It characterized localized non-nuclear charge within 1D honeycomb channels 0D cages rendering it an electride. These results highlight complexity of warm dense sodiums electronic free energy landscape emerges...
The sound velocity in a shocked material provides information about its off-Hugoniot behavior of at high pressures. This can be used to extend the knowledge gained Hugoniot experiments and model re-shock release behavior. Silica is one most important materials for equation state studies because prevalence earth's interior well-defined properties α-quartz. article presents measurements amorphous fused silica over range 200 1100 GPa using laser-driven shocks an α-quartz standard. These...
Results of recent experiments on the OMEGA Laser are presented, demonstrating ablator-driver shell collision relevant to outer two shells Revolver triple-shell inertial-confinement-fusion concept [K. Molvig et al., PRL~{\bf 116}, 255003 (2016)]. These nested two-shell measured pre- and post-collision outer-surface trajectory 7.19 g/cc chromium inner shell. Measurements in excellent agreement with simulations; velocity was $7.52\pm0.59$ cm/$\mu$s compared simulated value 7.27 cm/$\mu$s....
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...
Sodium is a simple metal at ambient conditions, while it transits to an electride phase pressures above \ensuremath{\sim}160 GPa along the room-temperature isotherm. We explore thermal effects on electronic properties of $\mathit{hP}4$ sodium $\ensuremath{\rho}=5.872\phantom{\rule{0.16em}{0ex}}\mathrm{g}/\mathrm{c}{\mathrm{m}}^{3}$ isochore. quantitatively classify this as insulator based criterion nearsightedness one-particle density matrix. Ab initio calculations suggest that band gap...
The principal Hugoniot, sound velocity, and Gr\"uneisen parameter of polystyrene were measured at conditions relevant to shocks in inertial confinement fusion implosions, from 100 1000 GPa. velocity is good agreement with quantum molecular dynamics calculations all tabular equation state models pressures below 200 Above GPa, the experimental results agree two examined tables, but do not most recent table developed for design (ICF) experiments. increases density...
We present measurements of diamond formation in doubly shocked Stycast 1266 epoxy (comprising C, H, Cl, N, and O) using situ x-ray diffraction. Epoxy samples were reshocked against a LiF window to pressures between 80 148 GPa experiments at the Omega Laser Facility. The pressure temperature conditions diagnosed velocimetry optical pyrometry, respectively. X-ray diffraction patterns compressed are consistent with cubic (Fd3¯m), indicating that can precipitate not only from twice-shocked CH...
Mechanical equation-of-state data of initially liquid and solid CO2 shock-compressed to terapascal conditions are reported. Diamond-sapphire anvil cells were used vary the initial density state samples that then further compressed with laser-driven shock waves, resulting in a set from which precise derivative quantities, including Grüneisen parameter sound speed, determined. Reshock states measured 800 GPa map same pressure-density as single using different thermodynamic paths. The...