Abstract Details
Abstracts
Author: Seung-Hoe Ku
Requested Type: Poster
Submitted: 2024-04-12 11:32:46
Co-authors: C.S. Chang, R. Hager, L. W. Schmitz, Oak Nelson
Contact Info:
Princeton Plasma Physics Laboratory
100 Stellarator Rd
Princeton, NJ 08543
USA
Abstract Text:
Tokamak discharges with negative triangularity exhibit promising characteristics such as good energy confinement, no impurity accumulation, and the absence of detrimental edge localized modes [1]. In addition, it is reported that the H-mode transition is difficult with negative triangularity. To elucidate the impact of triangularity on neoclassical edge property, we conducted axisymmetric gyrokinetic simulations using the XGC code. We simulate two DIII-D-like geometries based on DIII-D negative triangularity discharge #193802: one has negative triangularity and the other has a manufactured positive triangularity with the separatrix and limiter/divertor shapes mirrored. Plasma profiles are kept the same between the two shapes. Our preliminary findings show that the radial electric field just inside the separatrix is similar. However, interestingly, the direction of parallel flow is found to be opposite between the positive and negative triangularity plasmas.
This research is supported by DOE FES via the DIII-D collaborative research grant to PICSciE, Princeton University, and the SciDAC-5 Center: Center for Edge of Tokamak OPtimization (CETOP). The simulation used resources from the National Energy Research Scientific Computing Center (NERSC).
[1] A. Marinoni et al 2021 Nucl. Fusion 61, 116010
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