Application of simulations and theory of sub-cyclotron frequency modes to DIII-D

Belova, Elena; Crocker, Neal A.; Lestz, Jeff; Fredrickson, Eric

doi:10.1088/1741-4326/ac84f0

Application of simulations and theory of sub-cyclotron frequency modes to DIII-D

Journal Article · Mon Sep 05 00:00:00 EDT 2022 · Nuclear Fusion

DOI:https://doi.org/10.1088/1741-4326/ac84f0· OSTI ID:1880113

^[1]; ^[2]; ^[3]; Fredrickson, Eric ^[1]

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Univ. of California, Los Angeles, CA (United States)
Univ. of California, Irvine, CA (United States)

Theoretical and numerical study of Alfvén eigenmodes (AEs) in the sub-cyclotron frequency range explains the observed frequency scaling with beam parameters in experiments across different devices. Global Alfvén (GAEs) and compressional Alfvén eigenmodes (CAEs) are frequently excited during neutral beam injection (NBI) in the National Spherical Torus Experiment (NSTX/NSTX-U), as well as other beam-heated devices such as MAST and DIII-D. These modes are driven unstable through the Doppler shifted cyclotron resonance with the NBI ions and can be excited in ITER due to super-Alfvénic velocities and anisotropy of the fast ion distribution. Numerical models and theory for sub-cyclotron frequency modes, previously developed and used to study the excitation of GAEs/CAEs in the NSTX(-U), have been successfully applied to explain the DIII-D observations. Simulations for DIII-D demonstrate that the modes with ω/ω_ci ≈ 0.6, previously mis-identified as compressional Alfvén eigenmodes, have shear polarization and should be identified as the GAEs. Simulation results match the observed frequencies and estimated toroidal mode numbers in DIII-D experiments. Good agreement is found between scaling of the experimentally observed GAE frequencies with NBI parameters for NSTX, NSTX-U and DIII-D and scaling predicted by the theory and simulations. Here, the DIII-D simulation results also demonstrate that GAEs can be excited for larger aspect-ratio devices and smaller (sub- Alfvénic) beam injection velocities, therefore they can be unstable in ITER.

View Accepted Manuscript (DOE)

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

Sponsoring Organization:: USDOE

Grant/Contract Number:: AC02-09CH11466

OSTI ID:: 1880113

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 10 Vol. 62; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (27)

Energetic ion distribution resulting from neutral beam injection in tokamaks Gaffey, John D. Journal of Plasma Physics, Vol. 16, Issue 2 https://doi.org/10.1017/s0022377800020134	journal	October 1976
Numerical study of tilt stability of prolate field-reversed configurations Belova, E. V.; Jardin, S. C.; Ji, H. Physics of Plasmas, Vol. 7, Issue 12 https://doi.org/10.1063/1.1318929	journal	December 2000
Self-consistent equilibrium model of low aspect-ratio toroidal plasma with energetic beam ions Belova, E. V.; Gorelenkov, N. N.; Cheng, C. Z. Physics of Plasmas, Vol. 10, Issue 8 https://doi.org/10.1063/1.1592155	journal	August 2003
High-frequency shear Alfvén instability driven by circulating energetic ions in NSTX Kolesnichenko, Ya. I.; White, R. B.; Yakovenko, Yu. V. Physics of Plasmas, Vol. 13, Issue 12 https://doi.org/10.1063/1.2402129	journal	December 2006
Bi-directional Alfvén cyclotron instabilities in the mega-amp spherical tokamak Sharapov, S. E.; Lilley, M. K.; Akers, R. Physics of Plasmas, Vol. 21, Issue 8 https://doi.org/10.1063/1.4891322	journal	August 2014
Nonlinear simulations of beam-driven compressional Alfvén eigenmodes in NSTX Belova, E. V.; Gorelenkov, N. N.; Crocker, N. A. Physics of Plasmas, Vol. 24, Issue 4 https://doi.org/10.1063/1.4979278	journal	April 2017
Numerical simulations of global Alfvén eigenmodes excitation and stabilization in NSTX-U Belova, E. V.; Fredrickson, E. D.; Lestz, J. B. Physics of Plasmas, Vol. 26, Issue 9 https://doi.org/10.1063/1.5116357	journal	September 2019
Analytic stability boundaries for compressional and global Alfvén eigenmodes driven by fast ions. I. Interaction via ordinary and anomalous cyclotron resonances Lestz, J. B.; Gorelenkov, N. N.; Belova, E. V. Physics of Plasmas, Vol. 27, Issue 2 https://doi.org/10.1063/1.5127551	journal	February 2020
Analytic stability boundaries for compressional and global Alfvén eigenmodes driven by fast ions. II. Interaction via Landau resonance Lestz, J. B.; Gorelenkov, N. N.; Belova, E. V. Physics of Plasmas, Vol. 27, Issue 2 https://doi.org/10.1063/1.5127552	journal	February 2020
A fully nonlinear characteristic method for gyrokinetic simulation Parker, S. E.; Lee, W. W. Physics of Fluids B: Plasma Physics, Vol. 5, Issue 1 https://doi.org/10.1063/1.860870	journal	January 1993
Discrete Alfvén eigenmode spectrum in magnetohydrodynamics Mahajan, S. M. Physics of Fluids, Vol. 26, Issue 8 https://doi.org/10.1063/1.864404	journal	January 1983
Spectrum of compressional Alfvén waves Mahajan, S. M. Physics of Fluids, Vol. 26, Issue 9 https://doi.org/10.1063/1.864445	journal	January 1983
Theory and observations of high frequency Alfv n eigenmodes in low aspect ratio plasmas Gorelenkov, N. N.; Fredrickson, E.; Belova, E. Nuclear Fusion, Vol. 43, Issue 4 https://doi.org/10.1088/0029-5515/43/4/302	journal	March 2003
Observation of compressional Alfvén eigenmodes (CAE) in a conventional tokamak Heidbrink, W. W.; Fredrickson, E. D.; Gorelenkov, N. N. Nuclear Fusion, Vol. 46, Issue 2 https://doi.org/10.1088/0029-5515/46/2/016	journal	January 2006
Internal amplitude, structure and identification of compressional and global Alfvén eigenmodes in NSTX Crocker, N. A.; Fredrickson, E. D.; Gorelenkov, N. N. Nuclear Fusion, Vol. 53, Issue 4 https://doi.org/10.1088/0029-5515/53/4/043017	journal	March 2013
Excitation of global eigenmodes of the Alfven wave in Tokamaks Appert, K.; Gruber, R.; Troyuon, F. Plasma Physics, Vol. 24, Issue 9 https://doi.org/10.1088/0032-1028/24/9/010	journal	September 1982
Compressional Alfvén Eigenmodes on MAST Appel, L. C.; Fülöp, T.; Hole, M. J. Plasma Physics and Controlled Fusion, Vol. 50, Issue 11 https://doi.org/10.1088/0741-3335/50/11/115011	journal	October 2008
Recent progress in understanding electron thermal transport in NSTX Ren, Y.; Belova, E.; Gorelenkov, N. Nuclear Fusion, Vol. 57, Issue 7 https://doi.org/10.1088/1741-4326/aa4fba	journal	March 2017
Density perturbation mode structure of high frequency compressional and global Alfvén eigenmodes in the National Spherical Torus Experiment using a novel reflectometer analysis technique Crocker, N. A.; Kubota, S.; Peebles, W. A. Nuclear Fusion, Vol. 58, Issue 1 https://doi.org/10.1088/1741-4326/aa953e	journal	December 2017
High frequency Alfvén eigenmodes detected with ion-cyclotron-emission diagnostics during NBI and ICRF heated plasmas on the ASDEX Upgrade tokamak Ochoukov, R.; Bilato, R.; Bobkov, V. Nuclear Fusion, Vol. 60, Issue 12 https://doi.org/10.1088/1741-4326/abb79f	journal	November 2020
Hybrid simulations of sub-cyclotron compressional and global Alfvén eigenmode stability in spherical tokamaks Lestz, J. B.; Belova, E. V.; Gorelenkov, N. N. Nuclear Fusion, Vol. 61, Issue 8 https://doi.org/10.1088/1741-4326/abf028	journal	July 2021
Identification of slow-wave ion cyclotron emission on JT-60U Sumida, S.; Shinohara, K.; Ichimura, M. Nuclear Fusion, Vol. 61, Issue 11 https://doi.org/10.1088/1741-4326/ac2777	journal	October 2021
Correlation between Electron Transport and Shear Alfvén Activity in the National Spherical Torus Experiment Stutman, D.; Delgado-Aparicio, L.; Gorelenkov, N. Physical Review Letters, Vol. 102, Issue 11 https://doi.org/10.1103/physrevlett.102.115002	journal	March 2009
Coupling of Neutral-Beam-Driven Compressional Alfvén Eigenmodes to Kinetic Alfvén Waves in NSTX Tokamak and Energy Channeling Belova, E. V.; Gorelenkov, N. N.; Fredrickson, E. D. Physical Review Letters, Vol. 115, Issue 1 https://doi.org/10.1103/physrevlett.115.015001	journal	June 2015
Suppression of Alfvén Modes on the National Spherical Torus Experiment Upgrade with Outboard Beam Injection Fredrickson, E. D.; Belova, E. V.; Battaglia, D. J. Physical Review Letters, Vol. 118, Issue 26 https://doi.org/10.1103/physrevlett.118.265001	journal	June 2017
Stabilization of Alfvén Eigenmodes in DIII-D via Controlled Energetic Ion Density Ramp and Validation of Theory and Simulations Tang, S. X.; Carter, T. A.; Crocker, N. A. Physical Review Letters, Vol. 126, Issue 15 https://doi.org/10.1103/physrevlett.126.155001	journal	April 2021
Observation of Compressional Alfvén Modes During Neutral-Beam Heating on the National Spherical Torus Experiment Fredrickson, E. D.; Gorelenkov, N.; Cheng, C. Z. Physical Review Letters, Vol. 87, Issue 14 https://doi.org/10.1103/physrevlett.87.145001	journal	September 2001

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