Multiple timescale calculations of sawteeth and other global macroscopic dynamics of tokamak plasmas

Jardin, S.C.; Ferraro, N.M.; Breslau, J.; Chen, J

doi:10.1088/1749-4699/5/1/014002

Cited by 82 publications

(84 citation statements)

References 4 publications

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“…Combining a global 3D MHD model for the plasma evolution with implicit time stepping and a model for a resistive wall, NIMROD [7], JOREK [8,9] and M3D-C 1 [10,11] are among a small set of codes possessing the necessary capabilities for 3D VDE simulations. Nevertheless, a benchmark between any of the three codes involving VDE calculations had not been performed.…”

Section: Introductionmentioning

confidence: 99%

Axisymmetric simulations of vertical displacement events in tokamaks: A benchmark of M3D-C1, NIMROD, and JOREK

et al. 2020

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A benchmark exercise for the modeling of vertical displacement events (VDEs) is presented and applied to the 3D nonlinear magneto-hydrodynamic codes M3D-C 1 , JOREK and NIMROD. The simulations are based on a vertically unstable NSTX equilibrium enclosed by an axisymmetric resistive wall with rectangular cross section. A linear dependence of the linear VDE growth rates on the resistivity of the wall is recovered for sufficiently large wall conductivity and small temperatures in the open field line region. The benchmark results show good agreement between the VDE growth rates obtained from linear NIMROD and M3D-C 1 simulations as well as from the linear phase of axisymmetric nonlinear JOREK, NIMROD and M3D-C 1 simulations. Axisymmetric nonlinear simulations of a full VDE performed with the three codes are compared and excellent agreement is found regarding plasma location and plasma currents as well as eddy and halo currents in the wall.

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Section: Introductionmentioning

confidence: 99%

Axisymmetric simulations of vertical displacement events in tokamaks: A benchmark of M3D-C1, NIMROD, and JOREK

et al. 2020

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“…However, as will be shown in Figures (3) and (4), this effect is normally secondary to the generation of the spatially varying dynamo voltage. The self-consistent calculations presented here illustrating the formation of the dynamo voltage were performed with the M3D-C1 [17] toroidal 3D MHD code, and could possibly explain non-sawtoothing discharges with q 0 1 such as hybrid modes in DIII-D [1], ASDEX-U [2], JT-60U [3] and JET [4,5] , and long-lived modes in NSTX [6] and MAST [7]. Stationary non-sawtoothing behavior has been observed in other 3D tokamak MHD simulations [18][19][20] but an explanation of how these configurations maintain themselves over resistive timescales has not appeared.…”

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confidence: 99%

“…In the illustrative simulations presented here, we solve the single fluid 3D (or 2D) resistive MHD equations with source terms as described in [17]. To illustrate the selforganized voltage clamping mechanism, we present results from 5 long time simulations.…”

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confidence: 99%

Self-Organized Stationary States of Tokamaks

2015

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“…For the timeindependent, neoclassical transport verification in this work, we will include the perpendicular and parallel current parts and ignore only the final term. Equation (2) has been implemented for electrons, ions and energetic particles in NIMROD. This implementation includes the full linearized, Coulomb collision operator, C(f), for like and unlike species (see Appendix).…”

Section: Formulationmentioning

confidence: 99%

“…2 However, kinetic effects also play a critical role in the performance of high-temperature, tokamak discharges and are necessary to predict the growth of neoclassical tearing modes (NTMs), 3 or provide self-consistent profiles in the pedestal 4 for determining the sensitivity of edge localized modes (ELMs) 5 to equilibrium bootstrap currents. Additionally, models of parallel heat transport inside magnetic islands must account for the kinetic effects of particle trapping in magnetic wells and free-streaming along perturbed magnetic field lines.…”

Section: Introductionmentioning

confidence: 99%

Verification of continuum drift kinetic equation solvers in NIMROD

Held

Kruger

et al. 2015

Physics of Plasmas

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Verification of continuum solutions to the electron and ion drift kinetic equations (DKEs) in NIMROD [C. R. Sovinec et al., J. Comp. Phys. 195, 355 (2004)] is demonstrated through comparison with several neoclassical transport codes, most notably NEO [E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 54, 015015 (2012)]. The DKE solutions use NIMROD's spatial representation, 2D finite-elements in the poloidal plane and a 1D Fourier expansion in toroidal angle. For 2D velocity space, a novel 1D expansion in finite elements is applied for the pitch angle dependence and a collocation grid is used for the normalized speed coordinate. The full, linearized Coulomb collision operator is kept and shown to be important for obtaining quantitative results. Bootstrap currents, parallel ion flows, and radial particle and heat fluxes show quantitative agreement between NIMROD and NEO for a variety of tokamak equilibria. In addition, velocity space distribution function contours for ions and electrons show nearly identical detailed structure and agree quantitatively. A H-centered, implicit time discretization and a block-preconditioned, iterative linear algebra solver provide efficient electron and ion DKE solutions that ultimately will be used to obtain closures for NIMROD's evolving fluid model. V C 2015 AIP Publishing LLC.

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Multiple timescale calculations of sawteeth and other global macroscopic dynamics of tokamak plasmas

Cited by 82 publications

References 4 publications

Axisymmetric simulations of vertical displacement events in tokamaks: A benchmark of M3D-C1, NIMROD, and JOREK

Axisymmetric simulations of vertical displacement events in tokamaks: A benchmark of M3D-C1, NIMROD, and JOREK

Self-Organized Stationary States of Tokamaks

Verification of continuum drift kinetic equation solvers in NIMROD

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