Abstract Details
Abstracts
Author: Jacob R King
Requested Type: Poster
Submitted: 2026-03-20 09:15:28
Co-authors: Cody Balos, Natalie Beams, Jesús Domínguez-Palacios, Fatima Ebrahimi, David Gardner, Eric Held, Alexei Pankin, Carol Woodward and the CETOP team
Contact Info:
Fiat Lux LLC
908 Harrison Dr
Lafayette, Colorado 80026
United States
Abstract Text:
Next generation fusion devices will require material walls that can withstand high heat fluxes. A prominent candidate material is tungsten, however it can be a significant radiator if ablated into the plasma. Present DIII-D experiments have pioneered regimes without edge-localized modes, such as wide-pedestal quiescent H-mode (WPQH-mode), but their compatibility with metallic walls remains unclear as DIII-D presently uses graphite tiles. While recent work [J.J. Dominguez-Palacios Duran et al 2026 Nucl. Fusion 66 036003] suggests that metallic impurity collisional effects do not impact the modes associated with DIII-D WPQH-mode plasmas, the corresponding radiative energy loss is critical to determining edge profiles. This work introduces an atomic radiative model and begins to assess the impact on WPQH-mode profiles when replacing carbon with tungsten. We report on progress to incorporate these effects within a GPU-accelerated version of the NIMROD code [Sovinec, JCP, 195, 355-386 (2004)]. We are presently using the plasma-aai code for integration of local atomic rate terms with the SUNDIALS code and the Kokkos backend for performance portability. We are accelerating NIMROD with the nimrod-aai framework and exploring GPU-amenable approximate preconditioners such as those available in the Ginkgo code. We describe the performance of these approximate preconditioners relative to a direct solve on a tearing mode test case and implications for linear and nonlinear modeling.
*Work supported by DOE SciDAC program, Center for Edge of Tokamak OPtimization (CETOP), under Award Number DE-AC02-09CH11466, and DOE grant DE-SC0024592.
Characterization: 2.0
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