A5044155444- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Dust and Plasma Wave Phenomena
- Magnetic confinement fusion research
- Laser-induced spectroscopy and plasma
- Theoretical and Computational Physics
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Cold Atom Physics and Bose-Einstein Condensates
- Statistical Mechanics and Entropy
- Gaussian Processes and Bayesian Inference
- Quantum, superfluid, helium dynamics
- Model Reduction and Neural Networks
- Enhanced Oil Recovery Techniques
- Reservoir Engineering and Simulation Methods
- Pulsed Power Technology Applications
- Quantum many-body systems
- Hydraulic Fracturing and Reservoir Analysis
- Vacuum and Plasma Arcs
- Solar and Space Plasma Dynamics
- High-Energy Particle Collisions Research
- Advanced Mathematical Theories and Applications
- Scientific Computing and Data Management
- Spectroscopy and Quantum Chemical Studies
Oak Ridge National Laboratory
2022-2024
RadiaSoft (United States)
2021-2023
Energetics (United States)
2022
University of Rochester
2022
Los Alamos National Laboratory
2019-2021
Computational Physics (United States)
2019
Michigan State University
2017
New Mexico Consortium
2015-2016
Centre National de la Recherche Scientifique
2008-2013
École Polytechnique
2011-2013
Beginning with the exact equations of Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, we obtain density, momentum, and stress tensor-moment equations. We close moment two closures, one that guarantees an equilibrium state given by density-functional theory another includes collisions in relaxation tensor. The introduction a density functional-theory closure ensures self-consistency equation-of-state properties plasma (ideal excess pressure, electric fields, correlations). resulting...
Dynamic density functional theory (DDFT) is emerging as a useful theoretical technique for modeling the dynamics of correlated systems. We extend DDFT to quantum systems application dense plasmas through hydrodynamics (QHD) approach. The DDFT-based QHD approach includes correlations in equation state self-consistently, satisfies sum rules and irreversibility arising from collisions. While can be used generally model non-equilibrium, heterogeneous plasmas, we employ DDFT-QHD framework...
The transition-Cherenkov terahertz radiation from a femtosecond laser filament in air is enhanced by three orders of magnitude the presence longitudinal static electric field, while pattern and polarization remain same. An amplified electron current inside responsible for this emission.
Plasma flows encountered in high-energy-density experiments display features that differ from those of equilibrium systems. Nonequilibrium approaches such as kinetic theory (KT) capture many, if not all, these phenomena. However, KT requires closure information, which can be computed microscale simulations and communicated to KT. We present a concurrent heterogeneous multiscale approach couples molecular dynamics (MD) with the limit near-equilibrium flows. To reduce cost gathering...
We address the problem of energy dispersion radiation pressure accelerated (RPA) ion beams emerging from a thin target. Two different acceleration regimes, namely phase-stable and multistage acceleration, are considered by means analytical modeling one-dimensional particle-in-cell simulations. Our investigations offer deeper understanding RPA allow us to derive some guidelines for generating monoenergetic beams.
The one-dimensional collisionless expansion into a vacuum of plasma with bi-Maxwellian electron distribution function and single ion species is studied both theoretically numerically. A shock wave occurs when the ratio temperatures between hot cold electrons larger than 5+√24 [B. Bezzerides, D. W. Forslund, E. L. Lindman, Phys. Fluids 21, 2179 (1978)]. theoretical model presented here gives coherent complete description rarefaction its effects on acceleration process. Analytical expressions...
We report measurements and simulations of the time-evolving rms velocity distribution in an ultracold neutral plasma. A strongly coupled Ca+ plasma is generated by photoionizing laser-cooled atoms close to threshold. fraction these ions then promoted second ionization state form a mixed Ca+-Ca2+ By varying time delay between first events, minimum ion heating achieved. show that Coulomb strong-coupling parameter Γ increases factor 1.4 maximum value 3.6. pure Ca2+ would have Γ=6.8, moving...
A kinetic theory of the expansion into a vacuum plasma thin foil with initially hot and cold Maxwellian electron population is examined one-dimensional code. Whereas electrons always lose energy to expanding ions, can either gain or depending on initial temperature density ratios time. When electrons' not too large, they experience an adiabatic compression by electric field associated rarefaction wave. The corresponding increase be as large factor few tens. Later on, expected, eventually...
Transport properties of high-energy-density plasmas are influenced by the ion collision rate. Traditionally, this rate involves Coulomb logarithm, $\ln\Lambda$. Typical values $\ln\Lambda$ $\approx 10~\mbox{to}~20$ in kinetic theories where transport dominated weak-scattering events caused long-range forces. The validity these breaks down for strongly-coupled plasmas, when is order one. We present measurements and simulations data small. Experiments carried out first dual-species ultracold...
ABSTRACT We develop a multicomponent hydrodynamic model based on moments of the Born–Bogolyubov–Green–Kirkwood–Yvon hierarchy equations for physical conditions relevant to astrophysical plasmas. These incorporate strong correlations through density functional theory closure, while transport enters relaxation approximation. This approach enables introduction Coulomb coupling correction terms into standard Burgers equations. The diffusive currents these strongly coupled plasmas is...
A comprehensive theory is developped to describe the expansion of a plasma into vacuum with two-temperature electron distribution function. The characteristics rarefaction shock which occurs in when hot- cold-electron temperature ratio larger than 9.9 are investigated semi-infinite plasma. Furthermore by using finite foil, possible heating cold electrons population evidenced, for sufficiently large density ratio.
Nonideal plasmas have nontrivial space and time correlations, which simultaneously impact both the excess thermodynamic quantities as well collision processes. However, hydrodynamics models for designing interpreting nonideal plasma experiments, such inertial-confinement fusion typically neglect electrodynamics, although some include electric fields indirectly through a generalized Fick's law. because most transport are not computed self-consistently with equation of state, there is double...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation S. D. Bergeson, M. Lyon, J. B. Peatross, N. Harrison, Crunkleton, Wilson, Rupper, A. Diaw, Murillo; A neutral strongly coupled laser-produced plasma by strong-field ionization in a gas jet. AIP Conf. Proc. 29 June 2015; 1668 (1): 040001. https://doi.org/10.1063/1.4923114 Download citation file: Ris (Zotero)...
Accurately predicting redeposition is vital for high-Z plasma-facing component (PFC) survivability in magnetic confinement fusion. In this study, we categorize into three mechanisms: geometric-driven (prompt), sheath-driven (local), and scrape-off-layer-driven (far) redeposition. To investigate these mechanisms, employ Monte Carlo transport codes to simulate azimuthally symmetric tungsten source erosion a tokamak. By iteratively analyzing critical parameters, evaluate scaling each mechanism....
Understanding the erosion of plasma facing components in fusion devices is vital, particularly for long-pulse operations. This study presents application synthetic optical diagnosis on all-W WEST tokamak. The analysis reveals reflections as significant contributors to measured emission, varying across main chamber limiters and divertor targets. Reflections at locations can be up 50% emission while 95% limiter locations. Oxygen investigated a proxy low-Z species underscores importance...
This paper introduces STRIPE (Simulated Transport of RF Impurity Production and Emission), an advanced modeling framework designed to analyze material erosion the global transport eroded impurities originating from radio-frequency (RF) antenna structures in magnetic confinement fusion devices. integrates multiple computational tools, each addressing different levels physics fidelity: SolEdge3x for scrape-off-layer plasma profiles, COMSOL 3D rectified voltage fields, RustBCA code yields...
Throughout computational science, there is a growing need to utilize the continual improvements in raw horsepower achieve greater physical fidelity through scale-bridging over brute-force increases number of mesh elements. For instance, quantitative predictions transport nanoporous media, critical hydrocarbon extraction from tight shale formations, are impossible without accounting for molecular-level interactions. Similarly, inertial confinement fusion simulations rely on numerical...
Magnetohydrodynamics (MHD) can be used to model capillary discharge waveguides in laser-wakefield accelerators. However, the predictive capability of MHD suffer due poor microscopic closure models. Here, we study impact electron heating and thermal conduction on waveguide performance as part an effort understand quantify uncertainties modeling designing next-generation plasma To do so, perform two-dimensional high-resolution simulations using argon-filled with three different transport...
Machine learning methods are increasingly used to build computationally inexpensive surrogates for complex physical models. The predictive capability of these suffers when data noisy, sparse, or time-dependent. As we interested in finding a surrogate that provides valid predictions any potential future model evaluations, introduce an online method empowered by optimizer-driven sampling. has two advantages over current approaches. First, it ensures all turning points on the response surface...
Throughout computational science, there is a growing need to utilize the continual improvements in raw horsepower achieve greater physical fidelity through scale-bridging over brute-force increases number of mesh elements. For instance, quantitative predictions transport nanoporous media, critical hydrocarbon extraction from tight shale formations, are impossible without accounting for molecular-level interactions. Similarly, inertial confinement fusion simulations rely on numerical...
Many scientific applications are inherently multiscale in nature.Such complex physical phenomena often require simultaneous execution and coordination of simulations spanning multiple time length scales.This is possible by combining expensive small-scale (such as molecular dynamics simulations) with larger scale continuum limit/hydro solvers) to allow for considerably systems using task data parallelism.However, the granularity tasks can be very large leads load imbalance.Traditionally, we...