Abstract Details
| status: | file name: | submitted: | by: |
|---|---|---|---|
| approved | ku_abstract_sherwood.pdf | 2026-03-20 19:26:53 | Seung-Hoe Ku |
Abstracts
Author: Seung-Hoe Ku
Requested Type: Poster
Submitted: 2026-03-20 19:25:08
Co-authors: R. Hager, C.S. Chang, S.-J. Lee, A. Scheinberg
Contact Info:
Princeton Plasma Physics Laboratory
100 Stellarator Rd
Princeton, NJ 08540
USA
Abstract Text:
Total-f or full-f gyrokinetic simulations are essential for understanding the edge transport in diverted tokamak plasmas self-consistently. However, standard initialization techniques using a local Maxwellian distribution often generate large-amplitude initial transients, particularly Geodesic Acoustic Modes (GAMs). These transients are particularly severe in the plasma edge due to steep profile gradients, strong radial electric fields, and high safety factors. Such oscillations contaminate radial flux measurements and inflate the computational cost required to reach a saturated turbulent state. To address this, we present a novel initialization scheme for the XGC code that utilizes a numerical distribution function derived from a computationally efficient axisymmetric (neoclassical) simulation. By applying phase-space smoothing with canonical angular momentum conservation to the neoclassical equilibrium prior to full turbulence initialization, we demonstrate significant suppression of artificial GAMs and a reduction in particle noise. Application to the Cyclone Base Case and ASDEX Upgrade I-mode discharges confirms improved physical fidelity and a significant reduction in time-to-solution.
This research is supported by DOE FES through the SciDAC-5 Center, Computational Evaluation and Design of Actuators for Core-Edge Integration (CEDA), under award DE-AC02-09CH11466. Simulations utilized resources from the NERSC under award FES-ERCAP002368, as well as the Oak Ridge Leadership Computing Facility at ORNL, under award DE-AC05-00OR22725.
Characterization: 4.0
Comments: