Simulations of vertical displacement oscillatory modes and global Alfvén Eigenmodes in JET geometry

Barberis, T.; Kim, C. C.; Porcelli, F.; Banerjee, D.; Hawkes, N.; O. Kazakov, Ye; Liu, Y. Q.; Oliver, H. J.C.; Sharapov, S. E.; Yolbarsop, A.

doi:10.1088/1741-4326/ad7ed2

Title: Simulations of vertical displacement oscillatory modes and global Alfvén Eigenmodes in JET geometry

Journal Article · 03 November 2024 · Nuclear Fusion

DOI: https://doi.org/10.1088/1741-4326/ad7ed2 · OSTI ID:2478137

^[1]; Kim, C. C. ^[2];

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^[4]; Hawkes, N. ^[5]; O. Kazakov, Ye ^[6];

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Polytechnic University of Turin, Torino (Italy); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Princeton University, NJ (United States)
SLS2 Consulting, San Diego, CA (United States)
Polytechnic University of Turin, Torino (Italy); University of Science and Technology of China, Hefei, Anhui (China)
Polytechnic University of Turin, Torino (Italy)
Culham Science Centre, Abingdon (United Kingdom)
Laboratory for Plasma Physics, Brussels (Belgium)
General Atomics, San Diego, CA (United States)
University of Science and Technology of China, Hefei (China)

Vertical Displacement Oscillatory Modes (VDOM), with frequency in the Alfvén range, are natural modes of oscillation of magnetically confined laboratory plasmas with elongated cross-section. These axisymmetric modes arise from the interaction between the plasma current, which is in equilibrium with currents flowing in external coils, and perturbed currents induced on a nearby conducting wall. The restoring force exerted by these perturbed currents on the vertical motion of the plasma column leads to its oscillatory behavior. An analytic model for VDOM was proposed based on an idealized 'straight tokamak' equilibrium with uniform equilibrium current density. This article introduces the first numerical simulations of VDOM in a realistic JET tokamak configuration, using the extended-MHD code NIMROD and drawing comparisons with Global Alfvén Eigenmodes (GAE). The results show qualitative agreement with analytic predictions regarding mode frequency and radial structure, supporting the identification of VDOM as a fundamental oscillation mode in tokamak plasmas. VDOM and GAE are modeled in a representative JET discharge, where axisymmetric perturbations with toroidal mode number n = 0 driven unstable by fast ions were observed. The two modes are examined separately using a forced oscillator within the NIMROD code, which enables a comparison of their characteristics and helps identify the experimentally observed mode possibly as a GAE.

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Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: Euratom Research and Training Programme; USDOE; University of Science and Technology of China

Contributing Organization:: NIMROD Team

OSTI ID:: 2478137

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 12 Vol. 64; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (31)

Vertical displacements close to ideal-MHD marginal stability in tokamak plasmas Porcelli, F.; Barberis, T.; Yolbarsop, A. Fundamental Plasma Physics, Vol. 5 https://doi.org/10.1016/j.fpp.2023.100017	journal	June 2023
Nonlinear magnetohydrodynamics simulation using high-order finite elements Sovinec, C. R.; Glasser, A. H.; Gianakon, T. A. Journal of Computational Physics, Vol. 195, Issue 1 https://doi.org/10.1016/j.jcp.2003.10.004	journal	March 2004
Vertical displacement oscillatory modes in tokamak plasmas Barberis, T.; Yolbarsop, A.; Porcelli, F. Journal of Plasma Physics, Vol. 88, Issue 5 https://doi.org/10.1017/S0022377822000988	journal	October 2022
Hydromagnetic stability of a current-carrying pinch with noncircular cross section Laval, G. Physics of Fluids, Vol. 17, Issue 4 https://doi.org/10.1063/1.1694796	journal	January 1974
A simple ideal magnetohydrodynamical model of vertical disruption events in tokamaks Fitzpatrick, R. Physics of Plasmas, Vol. 16, Issue 1 https://doi.org/10.1063/1.3068467	journal	January 2009
Understanding disruptions in tokamaks Zakharov, Leonid E.; Galkin, Sergei A.; Gerasimov, Sergei N. Physics of Plasmas, Vol. 19, Issue 5 https://doi.org/10.1063/1.4705694	journal	May 2012
Axisymmetric global Alfvén eigenmodes within the ellipticity-induced frequency gap in the Joint European Torus Oliver, H. J. C.; Sharapov, S. E.; Breizman, B. N. Physics of Plasmas, Vol. 24, Issue 12 https://doi.org/10.1063/1.5005939	journal	December 2017
Nonlinear, three-dimensional magnetohydrodynamics of noncircular tokamaks Strauss, H. R. Physics of Fluids, Vol. 19, Issue 1 https://doi.org/10.1063/1.861310	journal	January 1976
Linear NIMROD simulations of n = 0 modes for straight tokamak configuration and comparison with analytic results Banerjee, Debabrata; Kim, Charlson C.; Barberis, Tommaso Physics of Plasmas, Vol. 31, Issue 2 https://doi.org/10.1063/5.0184340	journal	February 2024
Vertical stability of elongated tokamaks Okabayashi, M.; Sheffield, G. Nuclear Fusion, Vol. 14, Issue 2 https://doi.org/10.1088/0029-5515/14/2/011	journal	April 1974
Stability boundaries of tokamaks with respect to rigid displacements Rebhan, E. Nuclear Fusion, Vol. 15, Issue 2 https://doi.org/10.1088/0029-5515/15/2/012	journal	April 1975
Stability of a high-β tokamak to uniform vertical displacements Haas, F. A. Nuclear Fusion, Vol. 15, Issue 3 https://doi.org/10.1088/0029-5515/15/3/006	journal	June 1975
Hydromagnetic stability of tokamaks Wesson, J. A. Nuclear Fusion, Vol. 18, Issue 1 https://doi.org/10.1088/0029-5515/18/1/010	journal	January 1978
Stability of axisymmetric modes in JET Perrone, M. R.; Wesson, J. A. Nuclear Fusion, Vol. 21, Issue 7 https://doi.org/10.1088/0029-5515/21/7/009	journal	July 1981
Reconstruction of current profile parameters and plasma shapes in tokamaks Lao, L. L.; St. John, H.; Stambaugh, R. D. Nuclear Fusion, Vol. 25, Issue 11 https://doi.org/10.1088/0029-5515/25/11/007	journal	November 1985
Simplified models of axisymmetric magnetohydrodynamic instabilities Hutchinson, I. H. Nuclear Fusion, Vol. 29, Issue 12 https://doi.org/10.1088/0029-5515/29/12/004	journal	December 1989
Control of the vertical instability in tokamaks Lazarus, E. A.; Lister, J. B.; Neilson, G. H. Nuclear Fusion, Vol. 30, Issue 1 https://doi.org/10.1088/0029-5515/30/1/010	journal	January 1990
Experimental study of the vertical stability of high decay index plasmas in the DIII-D tokamak Lister, J. B.; Lazarus, E. A.; Kellman, A. G. Nuclear Fusion, Vol. 30, Issue 11 https://doi.org/10.1088/0029-5515/30/11/011	journal	November 1990
Equilibrium analysis of iron core tokamaks using a full domain method O'Brien, D. P.; Lao, L. L.; Solano, E. R. Nuclear Fusion, Vol. 32, Issue 8 https://doi.org/10.1088/0029-5515/32/8/I05	journal	August 1992
Alfven frequency modes and global Alfven eigenmodes Villard, L.; Vaclavik, J. Nuclear Fusion, Vol. 37, Issue 3 https://doi.org/10.1088/0029-5515/37/3/I05	journal	March 1997
Prediction of the growth rates of VDEs in JET Albanese, R.; Mattei, M.; Villone, F. Nuclear Fusion, Vol. 44, Issue 9 https://doi.org/10.1088/0029-5515/44/9/009	journal	August 2004
Position dependence of the unstable vertical movement of JET plasmas triggered by ELMs Villone, Fabio; Riccardo, Valeria; Sartori, Filippo Nuclear Fusion, Vol. 45, Issue 11 https://doi.org/10.1088/0029-5515/45/11/014	journal	October 2005
Analytic theory of ideal-MHD vertical displacements in tokamak plasmas Yolbarsop, A.; Porcelli, F.; Liu, Wandong Plasma Physics and Controlled Fusion, Vol. 64, Issue 10 https://doi.org/10.1088/1361-6587/ac7ee6	journal	August 2022
Velocity-space distribution function of fast ions in a sawtoothing plasma Barberis, T.; Porcelli, F. Plasma Physics and Controlled Fusion, Vol. 66, Issue 7 https://doi.org/10.1088/1361-6587/ad481c	journal	May 2024
Active and passive stabilization ofn = 0 RWMs in future tokamak devices Portone, A. Nuclear Fusion, Vol. 57, Issue 12 https://doi.org/10.1088/1741-4326/aa8386	journal	October 2017
Vertical forces during vertical displacement events in an ITER plasma and the role of halo currents Clauser, C. F.; Jardin, S. C.; Ferraro, N. M. Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab440a	journal	October 2019
Beam modulation and bump-on-tail effects on Alfvén eigenmode stability in DIII-D Van Zeeland, M. A.; Bardoczi, L.; Gonzalez-Martin, J. Nuclear Fusion, Vol. 61, Issue 6 https://doi.org/10.1088/1741-4326/abf174	journal	May 2021
Evidence for Alfvén eigenmodes driven by alpha particles in D-³He fusion experiments on JET Kiptily, V. G.; Fitzgerald, M.; Kazakov, Ye. O. Nuclear Fusion, Vol. 61, Issue 11 https://doi.org/10.1088/1741-4326/ac26a2	journal	October 2021
Impact of magnetic X-points on the vertical stability of tokamak plasmas Yolbarsop, A.; Porcelli, F.; Fitzpatrick, R. Nuclear Fusion, Vol. 61, Issue 11 https://doi.org/10.1088/1741-4326/ac27c5	journal	October 2021
Fast-ion-driven vertical modes in magnetically confined toroidal plasmas Barberis, T.; Porcelli, F.; Yolbarsop, A. Nuclear Fusion, Vol. 62, Issue 6 https://doi.org/10.1088/1741-4326/ac5ad0	journal	April 2022
An algorithm for the machine calculation of complex Fourier series Cooley, James W.; Tukey, John W. Mathematics of Computation, Vol. 19, Issue 90 https://doi.org/10.1090/S0025-5718-1965-0178586-1	journal	May 1965

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