A5003676141- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Gas Dynamics and Kinetic Theory
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Computational Fluid Dynamics and Aerodynamics
- Laser-induced spectroscopy and plasma
- Fluid Dynamics and Turbulent Flows
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Superconducting Materials and Applications
- Model Reduction and Neural Networks
- Meteorological Phenomena and Simulations
- Advanced Numerical Methods in Computational Mathematics
- Planetary Science and Exploration
- Electromagnetic Simulation and Numerical Methods
- Dust and Plasma Wave Phenomena
- Spacecraft and Cryogenic Technologies
- Numerical methods for differential equations
- Earthquake Detection and Analysis
- Fluid Dynamics Simulations and Interactions
- Simulation Techniques and Applications
Princeton Plasma Physics Laboratory
2015-2024
Bandung Institute of Technology
2024
Princeton University
2015-2022
Virginia Tech
2017-2022
Fusion Academy
2020-2022
Plasma Technology (United States)
2020-2022
Fusion (United States)
2020-2022
University of Iowa
2022
General Atomics (United States)
2013-2022
Heliophysics
2015-2020
We consider multiphysics applications from algorithmic and architectural perspectives, where “algorithmic” includes both mathematical analysis computational complexity, “architectural” software hardware environments. Many diverse can be reduced, en route to their simulation, a common algebraic coupling paradigm. Mathematical of in this form is not always practical for realistic applications, but model problems representative discussed herein provide insight. A variety frameworks have been...
We introduce an extensible multi-fluid moment model in the context of collisionless magnetic reconnection. This evolves full Maxwell equations and simultaneously moments Vlasov-Maxwell equation for each species plasma. Effects like electron inertia pressure gradient are self-consistently embedded resulting equations, without need to explicitly solving a generalized Ohm's law. Two limits discussed, namely, five-moment limit that scalar pressures ten-moment anisotropic, non-gyrotropic tensor...
Fusion power plants are likely to require near complete detachment of the divertor plasma from target plates, in order have both acceptable heat flux at avoid prompt damage and also temperature surface, minimize long-term erosion. However hydrogenic impurity puffing experiments show that detached operation leads easily x-point MARFEs, impure plasmas, degradation confinement, lower helium pressure exhaust. The concept Lithium Vapor Box Divertor is use local evaporation strong differential...
Five-dimensional gyrokinetic continuum simulations of electrostatic plasma turbulence in a straight, open-field-line geometry have been performed using full- $f$ discontinuous-Galerkin approach implemented the Gkeyll code. While various simplifications used for now, such as long-wavelength approximations Poisson equation and Hamiltonian, these include basic elements fusion-device scrape-off layer: localised sources to model outflow from core, cross-field turbulent transport, parallel flow...
Abstract We studied the role of electron physics in 3‐D two‐fluid 10‐moment simulation Ganymede's magnetosphere. The model captures nonideal like Hall effect, inertia, and anisotropic, nongyrotropic pressure effects. A series analyses were carried out: (1) resulting magnetic field topology ion convection patterns investigated. fields shown to agree reasonably well with situ measurements by Galileo satellite. (2) collisionless reconnection carefully examined terms current sheet formation...
A discontinuous Galerkin method for the ideal 5 moment two-fluid plasma system is presented. The uses a second or third order spatial discretization and TVD Runge-Kutta time stepping scheme. benchmarked against an analytic solution of dispersive electron acoustic square pulse as well electromagnetic shock existing numerical solutions to GEM challenge magnetic reconnection problem. algorithm can be generalized arbitrary geometries three dimensions. An approach maintaining small gauge errors...
We present a novel discontinuous Galerkin algorithm for the solution of class Fokker–Planck collision operators. These operators arise in many fields physics, and our particular application is kinetic plasma simulations. In particular, we focus on an operator often known as ‘Lenard–Bernstein’ or ‘Dougherty’ operator. Several algorithmic innovations, based concept weak equality, are reported. equalities used to define that compute primitive moments, also determine reconstruction procedure...
We present algorithms and results from Gkeyll, a full-f continuum, electromagnetic gyrokinetic code, designed to study turbulence in the edge region of fusion devices. The is computationally very challenging, requiring robust that can handle large-amplitude fluctuations stable interactions with plasma sheaths. an energy-conserving high-order discontinuous Galerkin scheme solves equations Hamiltonian form. Efficiency improved by careful choice basis functions automatically generated...
To explain many natural magnetized plasma phenomena, it is crucial to understand how rates of collisionless magnetic reconnection scale in large magnetohydrodynamic (MHD) systems. Simulations isolated current sheets conclude such are independent system size and can be reproduced by the Hall-MHD model, but neglect sheet formation coupling MHD scales. Here, shown for problem flux-rope merging, which includes this coupling, that model fails reproduce kinetic results. The minimum sufficient must...
The kinetic study of plasma sheaths is critical, among other things, to understand the deposition heat on walls, effect sputtering, and contamination with detrimental impurities. sheath also provides a boundary condition can often have significant global impact bulk plasma. In this paper, studies classical are performed continuum code, Gkeyll, that directly solves Vlasov-Poisson/Maxwell equations. code uses novel version finite-element discontinuous Galerkin (DG) scheme conserves energy in...
Nonlinear effects associated with the physics of radiofrequency wave propagation through a plasma are investigated numerically in time domain, using both fluid and particle-in-cell (PIC) methods. We find favorable comparisons between parametric decay instability scenarios observed on Alcator C-MOD experiment [J. C. Rost, M. Porkolab, R. L. Boivin, Phys. Plasmas 9, 1262 (2002)] PIC models. The capability models to capture important nonlinear characteristic wave-plasma interaction (frequency...
As modeling of collisionless magnetic reconnection in most space plasmas with realistic parameters is beyond the capability today's simulations, due to separation between global and kinetic length scales, it important establish scaling relations model problems so as extrapolate scales. Recently, large scale particle-in-cell (PIC) simulations island coalescence have shown that time averaged rate decreases system size, while fluid systems at such scales Hall regime not been studied. Here we...
The Dougherty model Fokker-Planck operator is extended to describe nonlinear full-f collisions between multiple species in plasmas. Simple relations for cross-species interactions are developed which obey conservation laws, and reproduce familiar velocity temperature relaxation rates. This treatment of multispecies collisions, valid arbitrary mass ratios, satisfies the H-Theorem unlike analogous Bhatnagar-Gross-Krook operators.
Use of lithium as a surface coating in fusion devices improves plasma performance, but the change wall properties affects secondary electron emission material. Lithium oxidizes easily, which drives yield well above unity. We present here simulations demonstrating sheath structure from monotonic to nonmonotonic space-charge limited using an energy-dependent data-driven model self-consistently captures both and backscattering populations. Increased material has ramifications for degradation...
The integration of kinetic effects in fluid models is important for global simulations the Earth's magnetosphere. In particular, it has been shown that ion kinetics play a crucial role dynamics large reconnecting systems, and higher-order moment can account some these effects. Here, we use ten-moment model electrons ions, which includes off diagonal elements pressure tensor are magnetic reconnection. Kinetic recovered by using nonlocal heat flux closure, approximates linear Landau damping...
An electrostatic gyrokinetic-based model is applied to simulate parallel plasma transport in the scrape-off layer a divertor plate. The authors focus on test problem that has been studied previously, using parameters chosen heat pulse driven by an edge-localized mode JET. Previous work used direct particle-in-cell equations with full dynamics, or Vlasov fluid only dynamics. With use of gyrokinetic quasineutrality equation and logical sheath boundary conditions, spatial temporal resolution...
For the first time, we explore tightly coupled interior-magnetosphere system of Mercury by employing a three-dimensional ten-moment multifluid model. This novel fluid model incorporates non-ideal effects including Hall effect, inertia, and tensorial pressures that are critical for collisionless magnetic reconnection; therefore, it is particularly well suited investigating $collisionless$ reconnection in Mercury's magnetotail at planet's magnetopause. The able to reproduce observed field...
The integration of kinetic effects in fluid models is important for global simulations Earth's magnetosphere. use the two-fluid ten-moment model, which includes pressure tensor both species, has had some success simulating Ganymede and Mercury with a simple closure model. We discuss heat flux accounts limitations earlier work while remaining computationally tractable. Comparisons magnetic reconnection lower-hybrid drift instabilities show good agreement results improvements on previous models.
Using the field–particle correlation technique, we examine particle energization in a three-dimensional (one spatial dimension and two velocity dimensions; 1D-2V) continuum Vlasov–Maxwell simulation of perpendicular magnetized collisionless shock. The combination technique with high-fidelity representation distribution function provided by direct discretization Vlasov equation allows us to ascertain details exchange energy between electromagnetic fields particles phase space. We identify...
Abstract The finite volume wave propagation method and the element Runge-Kutta discontinuous Galerkin (RKDG) are studied for applications to balance laws describing plasma fluids. fluid equations explored dispersive not dissipative. physical dispersion introduced through source terms leads wide variety of waves. nature separates work in this paper from previous publications. linearized Euler with used as a model equation system compare RKDG methods. numerical methods then full two-fluid...