Extended-MHD modeling of DIII-D tokamak quiescent H-mode (QH-mode) discharges with nonlinear NIMROD simulations saturates into a turbulent state but does not saturate when the steady-state flow inferred from measurements is not included. This is consistent with the experimental observations of the quiescent regime on DIII-D. The simulation with flow develops into a saturated turbulent state where the n Φ = 1 and 2 toroidal modes become dominant through an inverse cascade. Each mode in the range of n Φ = 1–5 is dominant at a different time. Consistent with experimental observations during QH-mode, the simulated state leads to large particlemore »
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The extended-MHD NIMROD code (Sovinec and King 2010 J. Comput. Phys. 229 5803) models broadband-MHD activity from a reconstruction of a quiescent H-mode shot on the DIII-D tokamak (Luxon 2002 Nucl. Fusion 42 614). Computations with the reconstructed toroidal and poloidal ion flows exhibit low-n Φ perturbations (n Φ ≃1–5) that grow and saturate into a turbulent-like MHD state. The workflow used to project the reconstructed state onto the NIMROD basis functions re-solves the Grad–Shafranov equation and extrapolates profiles to include scrape-off-layer currents. In conclusion, evaluation of the transport from the turbulent-like MHD state leads to a relaxation of themore »Cited by 4
The linear, collisional, constant-ψ drift-tearing mode is analyzed for different regimes of the plasma-β, ion-skin-depth parameter space with an unreduced, extended-magnetohydrodynamic model. Here, new dispersion relations are found at moderate plasma β and previous drift-tearing results are classified as applicable at small plasma β.Cited by 5
Fusion Energy Sciences Exascale Requirements Review. An Office of Science review sponsored jointly by Advanced Scientific Computing Research and Fusion Energy Sciences, January 27-29, 2016, Gaithersburg, MarylandThe additional computing power offered by the planned exascale facilities could be transformational across the spectrum of plasma and fusion research — provided that the new architectures can be efficiently applied to our problem space. The collaboration that will be required to succeed should be viewed as an opportunity to identify and exploit cross-disciplinary synergies. To assess the opportunities and requirements as part of the development of an overall strategy for computing in the exascale era, the Exascale Requirements Review meeting of the Fusion Energy Sciences (FES) community was convened January 27–29, 2016, with participation from a broad range ofmore »
Creator / Author"King, Jacob"
Creator / Author