A5000028310- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Magnetic confinement fusion research
- Mass Spectrometry Techniques and Applications
- Laser Design and Applications
- Advanced Fiber Laser Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Diamond and Carbon-based Materials Research
- Spectroscopy and Quantum Chemical Studies
- Nuclear Physics and Applications
- Astro and Planetary Science
- Ion-surface interactions and analysis
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Cold Fusion and Nuclear Reactions
- Particle Accelerators and Free-Electron Lasers
- Geomagnetism and Paleomagnetism Studies
- Combustion and Detonation Processes
- Plasma Diagnostics and Applications
University of Rochester
2016-2025
Energetics (United States)
2016-2025
Applied Energetics (United States)
2011-2024
Kiel University
2024
University of South China
2023
University of Oxford
2023
Imperial College London
2020
Los Alamos National Laboratory
2004-2018
University of Nebraska–Lincoln
2002-2006
Liaoning Normal University
2003
We report the results of second charged-particle transport coefficient code comparison workshop, which was held in Livermore, California on 24–27 July 2023. This workshop gathered theoretical, computational, and experimental scientists to assess state computational techniques for understanding coefficients relevant high-energy-density plasma science. Data electronic ionic coefficients, namely, direct current electrical conductivity, electron thermal ion shear viscosity, conductivity were...
Understanding and designing inertial confinement fusion (ICF) implosions through radiation-hydrodynamics simulations relies on the accurate knowledge of equation state (EOS) deuterium tritium fuels. To minimize drive energy for ignition, imploding shell DT fuel must be kept as cold possible. Such low-adiabat ICF can access to coupled degenerate plasma conditions, in which analytical EOS models become inaccurate due many-body effects. Using path-integral Monte Carlo (PIMC) we have derived a...
Filamentation due to the growth of a Weibel-type instability was observed in interaction pair counterstreaming, ablatively driven plasma flows, supersonic, collisionless regime relevant astrophysical shocks. The flows were created by irradiating opposing plastic (CH) foils with 1.8 kJ, 2-ns laser pulses on OMEGA EP Laser System. Ultrafast laser-driven proton radiography used image Weibel-generated electromagnetic fields. experimental observations are good agreement analytical theory Weibel...
Single ionization of He by two oppositely circularly polarized, time-delayed attosecond pulses is shown to produce photoelectron momentum distributions in the polarization plane having helical vortex structures sensitive time delay between pulses, their relative phase, and handedness. Results are obtained both ab initio numerical solution two-electron time-dependent Schrödinger equation a lowest-order perturbation theory analysis. The energy, bandwidth, temporal duration ideal for observing...
Recent advances in attosecond science have relied upon the nearly instantaneous response of free electrons to an external field. However, it is still not clear whether bound are able rearrange on sublaser cycle time scales. Here, we probe optical Stark shifts induced by a few-cycle near infrared laser field helium states using isolated pulses transient absorption scheme and uncover subcycle laser-induced energy level shift laser-dressed 1s3p state.
Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics that are hydrodynamically equivalent designs on National Ignition Facility (NIF) [J. A. Paisner Laser Focus World 30, 75 (1994)]. It shown highest hot-spot (up 40 Gbar) achieved target with a fuel adiabat α ≃ 4, an implosion velocity 3.8 × 107 cm/s, and...
Accurate knowledge about the equation of state (EOS) deuterium is critical to inertial confinement fusion (ICF). Low-adiabat ICF implosions routinely access strongly coupled and degenerate plasma conditions. Using path integral Monte Carlo method, we have derived a first-principles EOS (FPEOS) table deuterium. It first ab initio which completely covers typical implosion trajectory in density temperature ranges ρ=0.002-1596 g/cm3 T=1.35 eV-5.5 keV. Discrepancies internal energy pressure been...
We measured the stopping of energetic protons in an isochorically heated solid-density Be plasma with electron temperature ∼32 eV, corresponding to moderately coupled [(e^{2}/a)/(k_{B}T_{e}+E_{F})∼0.3] and degenerate [k_{B}T_{e}/E_{F}∼2] "warm-dense matter" (WDM) conditions. present first high-accuracy measurements charged-particle energy loss through dense plasma, which shows increased relative cold matter, consistent a reduced mean ionization potential. The data agree models based on ad...
Observations of magnetic reconnection between colliding plumes magnetized laser-produced plasma are presented. Two counterpropagating flows created by irradiating oppositely placed plastic (CH) targets with 1.8-kJ, 2-ns laser beams on the Omega EP Laser System. The interaction region is prefilled a low-density background and an externally applied field, imposed perpendicular to flow, initialized X-type null point geometry B=0 at midplane B=8 T targets. counterflowing sweep up compress field...
Multistart spiral vortex patterns are predicted for the electron momentum distributions in polarization plane following ionization of helium atom by two time-delayed circularly polarized ultrashort laser pulses. For ultraviolet (UV) pulses having same frequency (such that photons required ionization), single-color two-photon interferometry with corotating or counter-rotating is found to lead respectively zero-start four-start ionized plane. In contrast, two-color one-photon plus UV one-start...
A record fuel hot-spot pressure ${P}_{\mathrm{hs}}=56\ifmmode\pm\else\textpm\fi{}7\text{ }\text{ }\mathrm{Gbar}$ was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium--tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to energy of National Ignition Facility, these achieved a Lawson parameter $\ensuremath{\sim}60%$ value required ignition [A. Bose et al., Phys. Rev. E 94,...
Accurate knowledge of the properties hydrogen at high compression is crucial for astrophysics (e.g., planetary and stellar interiors, brown dwarfs, atmosphere compact stars) laboratory experiments, including inertial confinement fusion. There exists experimental data equation state, conductivity, Thomson scattering spectra. However, analysis measurements extreme pressures temperatures typically involves additional model assumptions, which makes it difficult to assess accuracy rigorously. On...
We study the density modulation that appears in a Bose-Einstein condensate flowing with supersonic velocity against an obstacle. The experimental profiles observed at JILA are reproduced by numerical integration of Gross-Pitaevskii equation and then interpreted terms Cerenkov emission Bogoliubov excitations defect. phonon single-particle regions spectrum are, respectively, responsible for conical wave front fan-shaped series precursors.
The attosecond pump probe, in close analogy to the standard femtosecond probing technique, has been proposed and theoretically demonstrated with its application explore ultrafast electron motions inside atoms. We have performed realistic modeling for full dynamics of both pumping processes. Our simulations illustrated that an ultrashort oscillation period 2.0 fs can be mapped out a wave packet low-lying excited states helium atom. This opens prospect wealth similar probe experiments examine...
The performance of triple-picket deuterium-tritium cryogenic target designs on the OMEGA Laser System [T. R. Boehly, Opt. Commun. 133, 495 (1997)] is reported. These facilitate control shock heating in low-adiabat inertial confinement fusion targets. Areal densities up to 300 mg/cm2 (the highest ever measured implosions) are inferred experiments with an implosion velocity approximately 3x10(7) cm/s driven at peak laser intensities 8x10(14) W/cm2. Extension these ignition National Ignition...
The success of direct-drive-ignition target designs depends on two issues: the ability to maintain main fuel adiabat at a low level and control nonuniformity growth during implosion. A series experiments was performed OMEGA Laser System [T. R. Boehly, D. L. Brown, S. Craxton et al., Opt. Commun. 133, 495 (1997)] study physics low-adiabat, high-compression cryogenic assembly. Modeling these requires an accurate account for all sources shell heating, including shock heating suprathermal...
The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements cryogenic implosion experiments on Omega Laser Facility. hydrodynamic similarity developed in both one and two dimensions tested using multimode simulations with hydrocode DRACO [P. B. Radha 12, 032702 (2005)] hydro-equivalent implosions (implosions same velocity, adiabat, laser intensity). scale direct-drive OMEGA National Ignition...
Shocks act to convert incoming supersonic flows heat, and in collisionless plasmas the shock layer forms on kinetic plasma scales through collective electromagnetic effects. These shocks have been observed many space astrophysical systems [Smith 1975, Smith 1980, Burlaga 2008, Sulaiman 2015], are believed accelerate particles, including cosmic rays, extremely high energies [Kazanas 1986, Loeb 2000, Bamba 2003, Masters 2013, Ackermann 2013]. Of particular importance class of high-Mach number,...
Thermal conductivity (\ensuremath{\kappa}) of both the ablator materials and deuterium-tritium (DT) fuel plays an important role in understanding designing inertial confinement fusion (ICF) implosions. The extensively used Spitzer model for thermal conduction ideal plasmas breaks down high-density, low-temperature shells that are compressed by shocks spherical convergence imploding targets. A variety thermal-conductivity models have been proposed ICF hydrodynamic simulations such coupled...
Spherical shock-ignition experiments on OMEGA used a novel beam configuration that separates low-intensity compression beams and high-intensity spike beams. Significant improvements in the performance of plastic-shell, D2 implosions were observed with repointed The analysis coupling energy into imploding capsule indicates absorbed hot-electron contributes to coupling. backscattering laser was measured reach up 36% at single-beam intensities ∼8 × 1015 W/cm2. Hard x-ray measurements revealed...