182 citations · 411 across the 17 of their papers we have counts for
17 papers
Difference in Neoclassical Edge Flows Between Strongly Negative and Positive Triangularities in the XGC Gyrokinetic Simulation
S. Ku, C. S. Chang, R. Hager +2
The neoclassical baseline study of a strongly negative triangularity (NT) plasma and the corresponding positive triangularity plasma is performed using the edge-specialized, total-…
Gyrokinetic prediction of core tungsten peaking in a WEST plasma with nitrogen impurities
J. Dominski, P. Maget, O. Manas +7
Tungsten peaking is predicted in the core of a WEST plasma with total-f gyrokinetic simulations, including both collisional and turbulent transport. This prediction is validated wi…
Intrinsic toroidal rotation driven by turbulent and neoclassical processes in tokamak plasmas from global gyrokinetic simulations
Hongxuan Zhu, T. Stoltzfus-Dueck, R. Hager +2
Gyrokinetic tokamak plasmas can exhibit intrinsic toroidal rotation driven by the residual stress. While most studies have attributed the residual stress to the parallel-momentum f…
Unraveling Diffusion in Fusion Plasma: A Case Study of In Situ Processing and Particle Sorting
Junmin Gu, Paul Lin, Kesheng Wu +6
This work starts an in situ processing capability to study a certain diffusion process in magnetic confinement fusion. This diffusion process involves plasma particles that are lik…
Neoclassical transport of tungsten ion bundles in total-f neoclassical gyrokinetic simulations of a whole-volume JET-like plasma
J. Dominski, C. S. Chang, R. Hager +3
The application of a bundling technique to model the diverse charge states of tungsten impurity species in total-f gyrokinetic simulations is demonstrated. The gyrokinetic bundling…
Effects of collisional ion orbit loss on tokamak radial electric field and toroidal rotation in an L-mode plasma
Hongxuan Zhu, T. Stoltzfus-Dueck, R. Hager +2
Ion orbit loss has been used to model the formation of a strong negative radial electric field in the tokamak edge, as well as edge momentum transport and toroidal rotation.…
Transport Barrier and Spinning Blob Dynamics in the Tokamak Edge
Junyi Cheng, James Myra, Seung-Hoe Ku +3
In this work, we investigate the dynamics of plasma blobs in the edge of magnetic confinement devices using a full-f gyrokinetic particle-in-cell code with X-point geometry. In sim…
Effects of collisional ion orbit loss on neoclassical tokamak radial electric fields
Hongxuan Zhu, T. Stoltzfus-Dueck, R. Hager +2
Ion orbit loss is considered important for generating the radially inward electric field in a tokamak edge plasma. In particular, this effect is emphasized in diverted tokama…
Verification of a Fully Implicit Particle-in-Cell Method for the Formalism of Electromagnetic Gyrokinetics in the XGC Code
Benjamin J. Sturdevant, S. Ku, L. Chacón +8
A fully implicit particle-in-cell method for handling the -formalism of electromagnetic gyrokinetics has been implemented in XGC. By choosing the -formali…
Constructing a new predictive scaling formula for ITER's divertor heat-load width informed by a simulation-anchored machine learning
C. S. Chang, S. Ku, R. Hager +6
Understanding and predicting divertor heat-load width is a critically important problem for an easier and more robust operation of ITER with high fusion gain. Previous predic…
Comparison of edge turbulence characteristics between DIII-D and C-Mod simulations with XGC1
I. Keramidas Charidakos, J. R. Myra, S. Ku +4
The physical processes taking place at the edge region are crucial for the operation of tokamaks as they govern the interaction of hot plasma with the vessel walls. Numerical model…
A tight-coupling scheme sharing minimum information across a spatial interface between gyrokinetic turbulence codes
Julien Dominski, Seung-Hoe Ku, Choong-Seock Chang +5
A new scheme that tightly couples kinetic turbulence codes across a spatial interface is introduced. This scheme evolves from considerations of competing strategies and down-select…
Analysis of equilibrium and turbulent fluxes across the separatrix in a gyrokinetic simulation
I. Keramidas Charidakos, J. R. Myra, S. Parker +4
The SOL width is a parameter of paramount importance in modern tokamaks as it controls the power density deposited at the divertor plates, critical for plasma-facing material survi…
Gyroaveraging operations using adaptive matrix operators
Julien Dominski, Seung-Hoe Ku, Choong-Seock Chang
A new adaptive scheme to be used in Particle-In-Cell codes for carrying out gyroaveraging operations with matrices is presented. This new scheme uses an intermediate velocity grid…
Electrostatic gyrokinetic simulation of global tokamak boundary plasma and the generation of nonlinear intermittent turbulence
S. Ku, R. M. Churchill, C. S. Chang +5
Boundary plasma physics plays an important role in tokamak confinement, but is difficult to simulate in a gyrokinetic code due to the scale-inseparable nonlocal multi-physics in ma…
Gyrokinetic projection of the divertor heat-flux width from present tokamaks to ITER
C. S. Chang, S. Ku, A. Loarte +11
The XGC1 edge gyrokinetic code is used for a high fidelity prediction for the width of the heat-flux to divertor plates in attached plasma condition. The simulation results are val…
A fast low-to-high mode bifurcation dynamics in a tokamak edge plasma gyrokinetic simulation
C. S. Chang, S. Ku, G. R. Tynan +6
Transport barrier formation and its relation to sheared flows in fluids and plasmas are of fundamental interest in various natural and laboratory observations and of critical impor…