60 citations · 161 across the 11 of their papers we have counts for
11 papers
Multidisciplinary benchmarks of a conservative spectral solver for the nonlinear Boltzmann equation
George J. Wilkie, Torsten Keßler, Sergej Rjasanow
The Boltzmann equation describes the evolution of the phase-space probability distribution of classical particles under binary collisions. Approximations to it underlie the basis f…
Kinetic modeling of neutral transport for a continuum gyrokinetic code
T. N. Bernard, F. D. Halpern, M. Francisquez +6
We present the first-of-its-kind coupling of a continuum full-f gyrokinetic turbulence model with a 6D continuum model for kinetic neutrals, carried out using the Gkeyll code. Our…
Machine-learning based discovery of missing physical processes in radiation belt modeling
Enrico Camporeale, George J. Wilkie, Alexander Drozdov +1
Real-time prediction of the dynamics of energetic electrons in Earth's radiation belts incorporating incomplete observation data is important to protect valuable artificial satelli…
Alpha particle driven Alfvénic instabilities in ITER post-disruption plasmas
Andrej Lier, Gergely Papp, Philipp Lauber +3
Fusion-born alpha particles in ITER disruption simulations are investigated as a possible drive of Alfvénic instabilities. The ability of these waves to expel runaway electron (RE)…
Analytic slowing-down distributions as modified by turbulent transport
George J. Wilkie
The effect of electrostatic microturbulence on fast particles rapidly decreases at high energy, but can be significant at moderate energy. Previous studies found that, in addition…
Effect of partially ionized impurities and radiation on the effective critical electric field for runaway generation
Linnea Hesslow, Ola Embréus, George J Wilkie +2
We derive a formula for the effective critical electric field for runaway generation and decay that accounts for the presence of partially ionized impurities in combination with sy…
Global anomalous transport of ICRH- and NBI-heated fast ions
George J. Wilkie, Istvan Pusztai, Ian G. Abel +2
By taking advantage of the trace approximation, one can gain an enormous computational advantage when solving for the global turbulent transport of impurities. In particular, this…
Transport and deceleration of fusion products in microturbulence
George J. Wilkie, Ian G. Abel, Matt Landreman +1
The velocity-space distribution of alpha particles born in fusion devices is subject to modification at moderate energies due to turbulent transport. Therefore, one must calculate…
Turbulent transport of MeV range cyclotron heated minorities as compared to alpha particles
István Pusztai, George J. Wilkie, Yevgen O. Kazakov +1
We study the turbulent transport of an ion cyclotron resonance heated (ICRH), MeV range minority ion species in tokamak plasmas. Such highly energetic minorities, which can be prod…
Fundamental form of the electrostatic -PIC algorithm and discovery of a converged numerical instability
George J. Wilkie, William Dorland
The particle-in-cell algorithm has been a useful tool in studying the physics of plasmas, particularly turbulent magnetized plasmas in the context of gyrokinetics. The reducti…
Validating modelling assumptions of alpha particles in electrostatic turbulence
George Wilkie, Ian Abel, Edmund Highcock +1
To rigorously model fast ions in fusion plasmas, a non-Maxwellian equilibrium distribution must be used. In the work, the response of high-energy alpha particles to electrostatic t…