Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations
Abstract
Alfvén Eigenmodes (AE) and magneto-hydrodynamic (MHD) modes are destabilized in DIII-D reverse magnetic shear configurations and may limit the performance of the device. We use the reduced MHD equations in a full 3D system, coupled with equations of density and parallel velocity moments for the energetic particles as well as the geodesic acoustic wave dynamics, to study the properties of instabilities observed in DIII-D reverse magnetic shear discharges, with the purpose of discovering ways to avoid or minimize MHD and AE activity for different magnetic field configurations and neutral beam injector (NBI) operation regimes. The simulations show at the beginning of the discharge, before the reverse shear region is formed, a plasma AE unstable and marginally MHD stable. As soon as the reverse shear region appears, ideal MHD modes are destabilized with larger growth rate than the AE. Both MHD modes and AE coexist along the discharge, although the MHD modes are more unstable as the reverse shear region deepens. AE stability can be improved if the NBI injection is off axis, because on-axis injection leads to AE with larger growth rate and frequency. In addition, decreasing the beam energy or increasing the NBI injection lead to an AE withmore »
- Authors:
-
[1];
[1];
[1]
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Univ. Carlos III de Madrid (Spain)
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); General Atomics, San Diego, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- OSTI Identifier:
- 1648968
- Alternate Identifier(s):
- OSTI ID: 1567774
- Grant/Contract Number:
- AC05-00OR22725; FC02-04ER54698
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nuclear Fusion
- Additional Journal Information:
- Journal Volume: 59; Journal Issue: 4; Journal ID: ISSN 0029-5515
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Tokamak; DIII-D; pedestal; MHD; AE; energetic particles
Citation Formats
Varela, J., Spong, D. A., Murakami, M., Garcia, L., D’Azevedo, E., Van Zeeland, M. A., and Munaretto, S. Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations. United States: N. p., 2019.
Web. doi:10.1088/1741-4326/ab0052.
Varela, J., Spong, D. A., Murakami, M., Garcia, L., D’Azevedo, E., Van Zeeland, M. A., & Munaretto, S. Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations. United States. https://doi.org/10.1088/1741-4326/ab0052
Varela, J., Spong, D. A., Murakami, M., Garcia, L., D’Azevedo, E., Van Zeeland, M. A., and Munaretto, S. Wed .
"Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations". United States. https://doi.org/10.1088/1741-4326/ab0052. https://www.osti.gov/servlets/purl/1648968.
@article{osti_1648968,
title = {Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations},
author = {Varela, J. and Spong, D. A. and Murakami, M. and Garcia, L. and D’Azevedo, E. and Van Zeeland, M. A. and Munaretto, S.},
abstractNote = {Alfvén Eigenmodes (AE) and magneto-hydrodynamic (MHD) modes are destabilized in DIII-D reverse magnetic shear configurations and may limit the performance of the device. We use the reduced MHD equations in a full 3D system, coupled with equations of density and parallel velocity moments for the energetic particles as well as the geodesic acoustic wave dynamics, to study the properties of instabilities observed in DIII-D reverse magnetic shear discharges, with the purpose of discovering ways to avoid or minimize MHD and AE activity for different magnetic field configurations and neutral beam injector (NBI) operation regimes. The simulations show at the beginning of the discharge, before the reverse shear region is formed, a plasma AE unstable and marginally MHD stable. As soon as the reverse shear region appears, ideal MHD modes are destabilized with larger growth rate than the AE. Both MHD modes and AE coexist along the discharge, although the MHD modes are more unstable as the reverse shear region deepens. AE stability can be improved if the NBI injection is off axis, because on-axis injection leads to AE with larger growth rate and frequency. In addition, decreasing the beam energy or increasing the NBI injection lead to an AE with larger growth rate and frequency, so a NBI operation in the weakly resonant regime requires higher beam energies than in the experiment (Vth,ƒ/VA0 > 0.3). The MHD linear stability can be also improved if the reverse shear region and the q profile near the magnetic axis are in between the rational surfaces q = 2 and q = 1, specifically if there is a region in the core with negative shear, avoiding a flat q profile near the magnetic axis. The simulations also shows a smooth transition between MHD modes and low frequency AE, no critical βƒ, pointing out an overlap between MHD and AE activity for modes with frequency lower than 30 kHz. This is in the range of Beta Acosutic Alfvén Eigenmodes (BAAE) and Beta induced Alfvén Eigenmodes (BAE).},
doi = {10.1088/1741-4326/ab0052},
journal = {Nuclear Fusion},
number = 4,
volume = 59,
place = {United States},
year = {Wed Feb 27 00:00:00 EST 2019},
month = {Wed Feb 27 00:00:00 EST 2019}
}
Free Publicly Available Full Text
Publisher's Version of Record
Other availability
Search WorldCat to find libraries that may hold this journal
Cited by: 9 works
Citation information provided by
Web of Science
Web of Science
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.
Works referenced in this record:
Theoretical Model of Fishbone Oscillations in Magnetically Confined Plasmas
journal, November 1986
- Coppi, B.; Porcelli, F.
- Physical Review Letters, Vol. 57, Issue 18
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
Ellipticity induced Alfvén eigenmodes
journal, August 1991
- Betti, R.; Freidberg, J. P.
- Physics of Fluids B: Plasma Physics, Vol. 3, Issue 8
Stability of neutral beam driven TAE modes in DIII-D
journal, December 1993
- Strait, E. J.; Heidbrink, W. W.; Turnbull, A. D.
- Nuclear Fusion, Vol. 33, Issue 12
Active and fast particle driven Alfvén eigenmodes in Alcator C-Mod
journal, May 2005
- Snipes, J. A.; Basse, N.; Boswell, C.
- Physics of Plasmas, Vol. 12, Issue 5
Analysis of Alfven eigenmode destabilization in DIII-D high poloidal β discharges using a Landau closure model
journal, June 2018
- Varela, J.; Spong, D. A.; Garcia, L.
- Nuclear Fusion, Vol. 58, Issue 7
Improved Confinement with Reversed Magnetic Shear in TFTR
journal, December 1995
- Levinton, F. M.; Zarnstorff, M. C.; Batha, S. H.
- Physical Review Letters, Vol. 75, Issue 24
MHD instabilities and their effects on plasma confinement in Large Helical Device plasmas
journal, January 2004
- Toi, K.; Ohdachi, S.; Yamamoto, S.
- Nuclear Fusion, Vol. 44, Issue 2
Measurements, modelling and electron cyclotron heating modification of Alfvén eigenmode activity in DIII-D
journal, April 2009
- Van Zeeland, M. A.; Heidbrink, W. W.; Nazikian, R.
- Nuclear Fusion, Vol. 49, Issue 6
Internal transport barrier with improved confinement in the JT-60U tokamak
journal, July 1996
- Koide, Y.; Takizuka, T.; Takeji, S.
- Plasma Physics and Controlled Fusion, Vol. 38, Issue 7
Internal transport barrier formation in experiments with reverse magnetic shear in T-10 tokamak
journal, September 2005
- Kirneva, N. A.; Esipchuk, Yu V.; Borschegovskij, A. A.
- Plasma Physics and Controlled Fusion, Vol. 47, Issue 10
Optimization of DIII-D advanced tokamak discharges with respect to the β limit
journal, May 2005
- Ferron, J. R.; Casper, T. A.; Doyle, E. J.
- Physics of Plasmas, Vol. 12, Issue 5
Gyrokinetic simulation of global and local Alfvén eigenmodes driven by energetic particles in a DIII-D discharge
journal, January 2013
- Bass, E. M.; Waltz, R. E.
- Physics of Plasmas, Vol. 20, Issue 1
Experimental observations of enhanced radial transport of energetic particles with Alfvén eigenmode on the LHD
journal, September 2006
- Osakabe, M.; Yamamoto, S.; Toi, K.
- Nuclear Fusion, Vol. 46, Issue 10
Mode coupling in a toroidal sharp-boundary plasma. I. Weak-coupling limit
journal, December 1980
- D'Ippolito, D. A.
- Plasma Physics, Vol. 22, Issue 12
Effect of magnetic configuration on frequency of NBI-driven Alfvén modes in TJ-II
journal, October 2014
- Melnikov, A. V.; Ochando, M.; Ascasibar, E.
- Nuclear Fusion, Vol. 54, Issue 12
Theory of Alfvén eigenmodes in shear reversed plasmas
journal, September 2003
- Breizman, B. N.; Berk, H. L.; Pekker, M. S.
- Physics of Plasmas, Vol. 10, Issue 9
Internal Alfvén eigenmode observations on DIII-D
journal, September 2006
- Zeeland, M. A. Van; Austin, M. E.; Carlstrom, T. N.
- Nuclear Fusion, Vol. 46, Issue 10
Development in the DIII-D tokamak of advanced operating scenarios and associated control techniques for ITER
journal, September 2007
- Wade, M. R.
- Nuclear Fusion, Vol. 47, Issue 10
Integrated, advanced tokamak operation on DIII-D
journal, July 2003
- Wade, M. R.; Murakami, M.; Luce, T. C.
- Nuclear Fusion, Vol. 43, Issue 7
Demonstration of ITER operational scenarios on DIII-D
journal, June 2010
- Doyle, E. J.; DeBoo, J. C.; Ferron, J. R.
- Nuclear Fusion, Vol. 50, Issue 7
Direct Observation of the Structure of Global Alfvén Eigenmodes in a Tokamak Plasma
journal, October 1984
- Evans, T. E.; Valanju, P. M.; Benesch, J. F.
- Physical Review Letters, Vol. 53, Issue 18
Numerical calculations using the full MHD equations in toroidal geometry
journal, March 1986
- Charlton, L. A.; Holmes, J. A.; Hicks, H. R.
- Journal of Computational Physics, Vol. 63, Issue 1
Dynamic neutral beam current and voltage control to improve beam efficacy in tokamaks
journal, May 2018
- Austin, M. E.; Bardoczi, L.; Collins, C. S.
- Physics of Plasmas, Vol. 25, Issue 5
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
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
Excitation of Alfvén eigenmodes by low energy beam ions in the DIII-D and JET tokamaks
journal, May 2008
- Nazikian, R.; Gorelenkov, N. N.; Alper, B.
- Physics of Plasmas, Vol. 15, Issue 5
Steepest-descent moment method for three-dimensional magnetohydrodynamic equilibria
journal, January 1983
- Hirshman, S. P.
- Physics of Fluids, Vol. 26, Issue 12
Energetic Ion Experiments in DIII-D
journal, October 2005
- Heidbrink, W. W.
- Fusion Science and Technology, Vol. 48, Issue 2
Basic physics of Alfvén instabilities driven by energetic particles in toroidally confined plasmas
journal, May 2008
- Heidbrink, W. W.
- Physics of Plasmas, Vol. 15, Issue 5
Alfvén eigenmode and energetic particle research in JT-60U
journal, September 1998
- Kimura, H.; Kusama, Y.; Saigusa, M.
- Nuclear Fusion, Vol. 38, Issue 9
Loss of energetic beam ions during TAE instabilities
journal, May 1993
- Duong, H. H.; Heidbrink, W. W.; Strait, E. J.
- Nuclear Fusion, Vol. 33, Issue 5
Properties of toroidal Alfvén eigenmode in DIII-D plasma
journal, February 2015
- Wang, Zhixuan; Lin, Zhihong; Deng, Wenjun
- Physics of Plasmas, Vol. 22, Issue 2
Status of advanced tokamak scenario modelling with off-axis electron cyclotron current drive in DIII-D
journal, June 2000
- Murakami, M.; John, H. E. St; Casper, T. A.
- Nuclear Fusion, Vol. 40, Issue 6
The effect of the fast-ion profile on Alfvén eigenmode stability
journal, August 2013
- Heidbrink, W. W.; Van Zeeland, M. A.; Austin, M. E.
- Nuclear Fusion, Vol. 53, 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
Enhanced Confinement and Stability in DIII-D Discharges with Reversed Magnetic Shear
journal, December 1995
- Strait, E. J.; Lao, L. L.; Mauel, M. E.
- Physical Review Letters, Vol. 75, Issue 24
Optimizing stability, transport, and divertor operation through plasma shaping for steady-state scenario development in DIII-D
journal, May 2009
- Holcomb, C. T.; Ferron, J. R.; Luce, T. C.
- Physics of Plasmas, Vol. 16, Issue 5
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
Clustered frequency analysis of shear Alfvén modes in stellarators
journal, February 2010
- Spong, D. A.; D’Azevedo, E.; Todo, Y.
- Physics of Plasmas, Vol. 17, Issue 2
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
Linearized gyrofluid model of the alpha‐destabilized toroidal Alfvén eigenmode with continuum damping effects
journal, October 1992
- Spong, D. A.; Carreras, B. A.; Hedrick, C. L.
- Physics of Fluids B: Plasma Physics, Vol. 4, Issue 10
Alpha‐Alfvén local dispersion relation and solutions
journal, December 1992
- Hedrick, C. L.; Leboeuf, J. ‐N.; Spong, D. A.
- Physics of Fluids B: Plasma Physics, Vol. 4, Issue 12
New Alfvén Continuum Gaps and Global Modes Induced by Toroidal Flow
journal, March 2000
- van der Holst, B.; Beliën, A. J. C.; Goedbloed, J. P.
- Physical Review Letters, Vol. 84, Issue 13
MHD phenomena in reversed shear discharges on ASDEX Upgrade
journal, August 2000
- Günter, S.; Schade, S.; Maraschek, M.
- Nuclear Fusion, Vol. 40, Issue 8
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
Fluid moment models for Landau damping with application to the ion-temperature-gradient instability
journal, June 1990
- Hammett, Gregory W.; Perkins, Francis W.
- Physical Review Letters, Vol. 64, Issue 25
Alfvén eigenmode stability and fast ion loss in DIII-D and ITER reversed magnetic shear plasmas
journal, September 2012
- Van Zeeland, M. A.; Gorelenkov, N. N.; Heidbrink, W. W.
- Nuclear Fusion, Vol. 52, Issue 9
Measurements and modeling of Alfvén eigenmode induced fast ion transport and loss in DIII-D and ASDEX Upgrade
journal, May 2011
- Van Zeeland, M. A.; Heidbrink, W. W.; Fisher, R. K.
- Physics of Plasmas, Vol. 18, Issue 5
Physics and control of resistive wall modes
journal, May 2002
- Bondeson, A.; Liu, Y. Q.; Gregoratto, D.
- Physics of Plasmas, Vol. 9, Issue 5
Magnetic shear effects on plasma transport and turbulence at high electron to ion temperature ratio in DIII-D and JT-60U plasmas
journal, March 2017
- Yoshida, M.; McKee, G. R.; Murakami, M.
- Nuclear Fusion, Vol. 57, Issue 5
Low‐ n stability calculations for three‐dimensional stellarator configurations
journal, September 1990
- Garcia, L.; Carreras, B. A.; Dominguez, N.
- Physics of Fluids B: Plasma Physics, Vol. 2, Issue 9
Kinetic theory of low-frequency Alfvén modes in tokamaks
journal, November 1996
- Zonca, Fulvio; Chen, Liu; Santoro, Robert A.
- Plasma Physics and Controlled Fusion, Vol. 38, Issue 11
Alfvén eigenmode properties and dynamics in the TJ-II stellarator
journal, November 2012
- Melnikov, A. V.; Eliseev, L. G.; Ascasibar, E.
- Nuclear Fusion, Vol. 52, Issue 12
Stability of high-beta tokamaks to ballooning modes
journal, May 1980
- Strauss, H. R.; Park, W.; Monticello, D. A.
- Nuclear Fusion, Vol. 20, Issue 5
Gyrokinetic simulations of reverse shear Alfvén eigenmodes in DIII-D plasmas
journal, January 2013
- Chen, Y.; Munsat, T.; Parker, S. E.
- Physics of Plasmas, Vol. 20, Issue 1
Full torus Landau fluid calculations of ion temperature gradient-driven turbulence in cylindrical geometry
journal, December 2000
- Leboeuf, J. N.; Lynch, V. E.; Carreras, B. A.
- Physics of Plasmas, Vol. 7, Issue 12
An investigation of beam driven Alfvén instabilities in the DIII-D tokamak
journal, September 1991
- Heidbrink, W. W.; Strait, E. J.; Doyle, E.
- Nuclear Fusion, Vol. 31, Issue 9
Progress toward steady-state tokamak operation exploiting the high bootstrap current fraction regime
journal, June 2016
- Ren, Q. L.; Garofalo, A. M.; Gong, X. Z.
- Physics of Plasmas, Vol. 23, Issue 6
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
Unified theory of resonant excitation of kinetic ballooning modes by energetic ions and alpha particles in tokamaks
journal, December 1991
- Biglari, H.; Chen, L.
- Physical Review Letters, Vol. 67, Issue 26
Stability of Alfvén gap modes in burning plasmas
journal, June 1992
- Betti, R.; Freidberg, J. P.
- Physics of Fluids B: Plasma Physics, Vol. 4, Issue 6
A review of internal transport barrier physics for steady-state operation of tokamaks
journal, March 2004
- Connor, J. W.; Fukuda, T.; Garbet, X.
- Nuclear Fusion, Vol. 44, Issue 4
Characteristics of Alfvén eigenmodes, burst modes and chirping modes in the Alfvén frequency range driven by negative ion based neutral beam injection in JT-60U
journal, November 1999
- Kusama, Y.; Kramer, G. J.; Kimura, H.
- Nuclear Fusion, Vol. 39, Issue 11Y
Establishment of magnetic coordinates for a given magnetic field
journal, January 1982
- Boozer, Allen H.
- Physics of Fluids, Vol. 25, Issue 3
Role of stable eigenmodes in saturated local plasma turbulence
journal, February 2006
- Terry, P. W.; Baver, D. A.; Gupta, Sangeeta
- Physics of Plasmas, Vol. 13, Issue 2
Excitation of toroidal Alfvén eigenmodes in TFTR
journal, April 1991
- Wong, K. L.; Fonck, R. J.; Paul, S. F.
- Physical Review Letters, Vol. 66, Issue 14
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
Gyrokinetic particle simulations of reversed shear Alfvén eigenmode excited by antenna and fast ions
journal, November 2010
- Deng, Wenjun; Lin, Zhihong; Holod, Ihor
- Physics of Plasmas, Vol. 17, Issue 11
Energetic particle instabilities in fusion plasmas
journal, September 2013
- Sharapov, S. E.; Alper, B.; Berk, H. L.
- Nuclear Fusion, Vol. 53, Issue 10
Impact of ideal MHD stability limits on high-beta hybrid operation
journal, November 2016
- Piovesan, P.; Igochine, V.; Turco, F.
- Plasma Physics and Controlled Fusion, Vol. 59, Issue 1
Compatibility of internal transport barrier with steady-state operation in the high bootstrap fraction regime on DIII-D
journal, November 2015
- Garofalo, A. M.; Gong, X.; Grierson, B. A.
- Nuclear Fusion, Vol. 55, Issue 12
Recent progress of Alfvén eigenmode experiments using N-NB in JT-60U tokamak
journal, August 2002
- Shinohara, K.; Takechi, M.; Ishikawa, M.
- Nuclear Fusion, Vol. 42, Issue 8
Compressible linear and nonlinear resistive MHD calculations in toroidal geometry
journal, February 1990
- Charlton, L. A.; Holmes, J. A.; Lynch, V. E.
- Journal of Computational Physics, Vol. 86, Issue 2
Improved plasma performance in tokamaks with negative magnetic shear
journal, February 1994
- Kessel, C.; Manickam, J.; Rewoldt, G.
- Physical Review Letters, Vol. 72, Issue 8
Stability of alpha particle driven Alfvén eigenmodes in high performance JET DT plasmas
journal, March 1999
- Sharapov, S. E.; Borba, D.; Fasoli, A.
- Nuclear Fusion, Vol. 39, Issue 3
Experimental studies of energetic-ion-driven MHD instabilities in Large Helical Device plasmas
journal, April 2005
- Yamamoto, S.; Toi, K.; Ohdachi, S.
- Nuclear Fusion, Vol. 45, Issue 5
Simulation of Alfvén frequency cascade modes in reversed shear-discharges using a Landau-closure model
journal, April 2013
- Spong, D. A.
- Nuclear Fusion, Vol. 53, Issue 5
Transition to the second region of ideal MHD stability
journal, March 1989
- Sabbagh, S. A.; Hughes, M. H.; Phillips, M. W.
- Nuclear Fusion, Vol. 29, Issue 3
Stability of alpha particle driven Alfvén eigenmodes in high performance JET DT plasmas
journal, May 1999
- Sharapov, S. E.; Borba, D.; Fasoli, A.
- Nuclear Fusion, Vol. 39, Issue 5