Simulation of the eigenmode spectrum below the Toroidicity-induced Alfvén Eigenmode gap generated by the coupling of Alfvén and slow-magnetosonic waves in tokamaks
Abstract
The discrete Alfven Eigenmode spectrum below the TAE frequency is studied for hybrid and sawtooth scenarios in tokamaks whereby the full coupling between the Alfven and slow magnetosonic waves are taken into account. In this frequency regime the ususally applied slow-sound approximation is not valid and modes in this frequency regime were recently called Alfven-Slow Eigenmodes (ASE). For the hybrid scenarios (central q ≈ 2 up to ρ ≈ 0.6) a rich spectrum of eigenmodes was found that depend on the plasma pressure and magnetic shear. It was found that the number of modes below the TAE gap is the highest for weakly reversed q~profiles while the number of modes increases with pressure. For zero central shear q-profiles the number of modes is lower than in the reversed shear case while for the normal shear hybrid q-profiles the number of eigenmode first increased with increasing pressure followed by a decrease in the number of eigenmodes. For plasma scenarios with central q < 1 (sawtoothing plasmas) modes were found outside the q=1 surface that are consistent with observations in contrast to the conventional BAE which located at the q=1 surface. The frequency behaviour of the modes below the TAE gap wasmore »
- Authors:
-
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Publication Date:
- Research Org.:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1617638
- Alternate Identifier(s):
- OSTI ID: 1633818
- Grant/Contract Number:
- AC02-09CH11466
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Plasma Physics and Controlled Fusion
- Additional Journal Information:
- Journal Volume: 62; Journal Issue: 7; Journal ID: ISSN 0741-3335
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Citation Formats
Kramer, Gerrit J., Cheng, Frank C. Z., Podesta, Mario, and Nazikian, Raffi. Simulation of the eigenmode spectrum below the Toroidicity-induced Alfvén Eigenmode gap generated by the coupling of Alfvén and slow-magnetosonic waves in tokamaks. United States: N. p., 2020.
Web. doi:10.1088/1361-6587/ab9153.
Kramer, Gerrit J., Cheng, Frank C. Z., Podesta, Mario, & Nazikian, Raffi. Simulation of the eigenmode spectrum below the Toroidicity-induced Alfvén Eigenmode gap generated by the coupling of Alfvén and slow-magnetosonic waves in tokamaks. United States. https://doi.org/10.1088/1361-6587/ab9153
Kramer, Gerrit J., Cheng, Frank C. Z., Podesta, Mario, and Nazikian, Raffi. Tue .
"Simulation of the eigenmode spectrum below the Toroidicity-induced Alfvén Eigenmode gap generated by the coupling of Alfvén and slow-magnetosonic waves in tokamaks". United States. https://doi.org/10.1088/1361-6587/ab9153. https://www.osti.gov/servlets/purl/1617638.
@article{osti_1617638,
title = {Simulation of the eigenmode spectrum below the Toroidicity-induced Alfvén Eigenmode gap generated by the coupling of Alfvén and slow-magnetosonic waves in tokamaks},
author = {Kramer, Gerrit J. and Cheng, Frank C. Z. and Podesta, Mario and Nazikian, Raffi},
abstractNote = {The discrete Alfven Eigenmode spectrum below the TAE frequency is studied for hybrid and sawtooth scenarios in tokamaks whereby the full coupling between the Alfven and slow magnetosonic waves are taken into account. In this frequency regime the ususally applied slow-sound approximation is not valid and modes in this frequency regime were recently called Alfven-Slow Eigenmodes (ASE). For the hybrid scenarios (central q ≈ 2 up to ρ ≈ 0.6) a rich spectrum of eigenmodes was found that depend on the plasma pressure and magnetic shear. It was found that the number of modes below the TAE gap is the highest for weakly reversed q~profiles while the number of modes increases with pressure. For zero central shear q-profiles the number of modes is lower than in the reversed shear case while for the normal shear hybrid q-profiles the number of eigenmode first increased with increasing pressure followed by a decrease in the number of eigenmodes. For plasma scenarios with central q < 1 (sawtoothing plasmas) modes were found outside the q=1 surface that are consistent with observations in contrast to the conventional BAE which located at the q=1 surface. The frequency behaviour of the modes below the TAE gap was studied for a reversed shear q-profile in which q_min was varied and it was found that ASEs increase and/or decrease in frequency as function of q_min thereby emerging from and/or disappearing into the continuum.},
doi = {10.1088/1361-6587/ab9153},
journal = {Plasma Physics and Controlled Fusion},
number = 7,
volume = 62,
place = {United States},
year = {Tue Jun 16 00:00:00 EDT 2020},
month = {Tue Jun 16 00:00:00 EDT 2020}
}
Web of Science
Figures / Tables:
Works referenced in this record:
Improving fast-ion confinement in high-performance discharges by suppressing Alfvén eigenmodes
journal, March 2017
- Kramer, G. J.; Podestà, M.; Holcomb, C.
- Nuclear Fusion, Vol. 57, Issue 5
Kinetic Alfvén eigenmodes at ASDEX Upgrade
journal, November 2009
- Lauber, Ph; Brüdgam, M.; Curran, D.
- Plasma Physics and Controlled Fusion, Vol. 51, Issue 12
Reversed shear Alfvén eigenmodes in the frequency range of the triangularity induced gap on JET
journal, June 2008
- Kramer, G. J.; Fu, G. Y.; Nazikian, R.
- Plasma Physics and Controlled Fusion, Vol. 50, Issue 8
Observation of beta-induced Alfvén eigenmodes in the DIII-D tokamak
journal, August 1993
- Heidbrink, W. W.; Strait, E. J.; Chu, M. S.
- Physical Review Letters, Vol. 71, Issue 6
Analysis of alpha particle‐driven toroidal Alfvén eigenmodes in Tokamak Fusion Test Reactor deuterium–tritium experiments
journal, November 1996
- Fu, G. Y.; Cheng, C. Z.; Budny, R.
- Physics of Plasmas, Vol. 3, Issue 11
Global Alfvén modes: Theory and experiment*
journal, July 1993
- Turnbull, A. D.; Strait, E. J.; Heidbrink, W. W.
- Physics of Fluids B: Plasma Physics, Vol. 5, Issue 7
Toroidal alfvén eigenmodes driven with ICRF accelerated protons in JT-60U negative shear discharges
journal, August 1998
- Kusama, Y.; Kimura, H.; Ozeki, T.
- Nuclear Fusion, Vol. 38, Issue 8
Investigation of fast particle driven modes on Alcator C-Mod
journal, March 2000
- Snipes, J. A.; Fasoli, A.; Bonoli, P.
- Plasma Physics and Controlled Fusion, Vol. 42, Issue 4
Systematic study of toroidicity-induced Alfvén eigenmodes at low- q discharges in JT-60U
journal, September 1998
- Saigusa, M.; Kimura, H.; Kusama, Y.
- Plasma Physics and Controlled Fusion, Vol. 40, Issue 9
Finite pressure effects on reversed shear Alfvén eigenmodes
journal, September 2004
- Kramer, G. J.; Gorelenkov, N. N.; Nazikian, R.
- Plasma Physics and Controlled Fusion, Vol. 46, Issue 11
Observation of high-frequency waves during strong tearing mode activity in FTU plasmas without fast ions
journal, October 2005
- Buratti, P.; Smeulders, P.; Zonca, F.
- Nuclear Fusion, Vol. 45, Issue 11
A numerical study of the high‐ n shear Alfvén spectrum gap and the high‐ n gap mode
journal, November 1992
- Chu, M. S.; Greene, J. M.; Lao, L. L.
- Physics of Fluids B: Plasma Physics, Vol. 4, Issue 11
A review of Alfvén eigenmode observations in toroidal plasmas
journal, January 1999
- Wong, King-Lap
- Plasma Physics and Controlled Fusion, Vol. 41, Issue 1
Predictions and observations of low-shear beta-induced shear Alfvén–acoustic eigenmodes in toroidal plasmas
journal, October 2007
- Gorelenkov, N. N.; Berk, H. L.; Fredrickson, E.
- Physics Letters A, Vol. 370, Issue 1
Monitoring Alfvén Cascades with Interferometry on the JET Tokamak
journal, October 2004
- Sharapov, S. E.; Alper, B.; Fessey, J.
- Physical Review Letters, Vol. 93, Issue 16
Coupling of global toroidal Alfvén eigenmodes and reversed shear Alfvén eigenmodes in DIII-D
journal, May 2007
- Van Zeeland, M. A.; Austin, M. E.; Gorelenkov, N. N.
- Physics of Plasmas, Vol. 14, Issue 5
Noncircular Triangularity and Ellipticity-Induced Alfvén Eigenmodes Observed in JT-60U
journal, March 1998
- Kramer, G. J.; Saigusa, M.; Ozeki, T.
- Physical Review Letters, Vol. 80, Issue 12
New Interpretation of Alpha-Particle-Driven Instabilities in Deuterium-Tritium Experiments on the Tokamak Fusion Test Reactor
journal, September 2003
- Nazikian, R.; Kramer, G. J.; Cheng, C. Z.
- Physical Review Letters, Vol. 91, Issue 12
Magnetic safety factor profile before and after sawtooth crashes investigated with toroidicity and ellipticity induced Alfvén eigenmodes
journal, September 2001
- Kramer, G. J.; Cheng, C. Z.; Kusama, Y.
- Nuclear Fusion, Vol. 41, Issue 9
Excitation of beta Alfvén eigenmodes in Tore-Supra
journal, August 2009
- Nguyen, C.; Garbet, X.; Sabot, R.
- Plasma Physics and Controlled Fusion, Vol. 51, Issue 9
Low-n shear Alfvén spectra in axisymmetric toroidal plasmas
journal, January 1986
- Cheng, C. Z.; Chance, M. S.
- Physics of Fluids, Vol. 29, Issue 11
β suppression of Alfvén cascade modes in the National Spherical Torus Experiment
journal, October 2007
- Fredrickson, E. D.; Crocker, N. A.; Gorelenkov, N. N.
- Physics of Plasmas, Vol. 14, Issue 10
Interpretation of core localized Alfvén eigenmodes in DIII-D and Joint European Torus reversed magnetic shear plasmas
journal, May 2006
- Kramer, G. J.; Nazikian, R.; Alper, B.
- Physics of Plasmas, Vol. 13, Issue 5
NOVA: A nonvariational code for solving the MHD stability of axisymmetric toroidal plasmas
journal, July 1987
- Cheng, C. Z.; Chance, M. S.
- Journal of Computational Physics, Vol. 71, Issue 1
Radial Structure of Alfvén Eigenmodes in the DIII-D Tokamak through Electron-Cyclotron-Emission Measurements
journal, September 2006
- Van Zeeland, M. A.; Kramer, G. J.; Austin, M. E.
- Physical Review Letters, Vol. 97, Issue 13
Beta-induced Alfvén-acoustic eigenmodes in National Spherical Torus Experiment and DIII-D driven by beam ions
journal, May 2009
- Gorelenkov, N. N.; Van Zeeland, M. A.; Berk, H. L.
- Physics of Plasmas, Vol. 16, Issue 5
Theory of Alfvén-slow frequency gaps and discovery of Alfvén-slow eigenmodes in tokamaks
journal, August 2019
- Cheng, C. Z.; Kramer, G. J.; Podesta, M.
- Physics of Plasmas, Vol. 26, Issue 8
Alfvén eigenmode observations on DIII-D via two-colour CO 2 interferometry
journal, August 2005
- Zeeland, M. A. Van; Kramer, G. J.; Nazikian, R.
- Plasma Physics and Controlled Fusion, Vol. 47, Issue 9
High-n ideal and resistive shear Alfvén waves in tokamaks
journal, April 1985
- Cheng, C. Z.; Chen, Liu; Chance, M. S.
- Annals of Physics, Vol. 161, Issue 1
Observation of Odd Toroidal Alfvén Eigenmodes
journal, January 2004
- Kramer, G. J.; Sharapov, S. E.; Nazikian, R.
- Physical Review Letters, Vol. 92, Issue 1
What is the “beta-induced Alfvén eigenmode?”
journal, April 1999
- Heidbrink, W. W.; Ruskov, E.; Carolipio, E. M.
- Physics of Plasmas, Vol. 6, Issue 4
Kinetic extensions of magnetohydrodynamics for axisymmetric toroidal plasmas
journal, February 1992
- Cheng, C. Z.
- Physics Reports, Vol. 211, Issue 1
Reversed shear Alfvén eigenmodes associated with the ellipticity and triangularity Alfvén gaps
journal, July 2006
- Kramer, G. J.; Fu, G-Y
- Plasma Physics and Controlled Fusion, Vol. 48, Issue 9
Fast-ion transport in qmin>2, high-
β steady-state scenarios on DIII-Da)
journal, May 2015
- Holcomb, C. T.; Heidbrink, W. W.; Ferron, J. R.
- Physics of Plasmas, Vol. 22, Issue 5
Electron cyclotron heating can drastically alter reversed shear Alfvén eigenmode activity in DIII-D through finite pressure effects
journal, July 2016
- Van Zeeland, M. A.; Heidbrink, W. W.; Sharapov, S. E.
- Nuclear Fusion, Vol. 56, Issue 11
Confinement degradation by Alfvén-eigenmode induced fast-ion transport in steady-state scenario discharges
journal, August 2014
- Heidbrink, W. W.; Ferron, J. R.; Holcomb, C. T.
- Plasma Physics and Controlled Fusion, Vol. 56, Issue 9
Frequency Chirping of Core-Localized Toroidicity-Induced Alfvén Eigenmodes and their Coupling to Global Alfvén Eigenmodes
journal, October 1999
- Kramer, G. J.; Cheng, C. Z.; Fu, G. Y.
- Physical Review Letters, Vol. 83, Issue 15
Figures / Tables found in this record: