Synergy of two lower hybrid waves with different frequencies on EAST

Zhai, X. M.; Chen, J. L.; Xiang, N.; Bonoli, P. T.; Shiraiwa, S.

doi:10.1063/1.5095653

Synergy of two lower hybrid waves with different frequencies on EAST

Journal Article · Fri May 17 00:00:00 EDT 2019 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.5095653· OSTI ID:1611428

^[1]; ^[2]; Xiang, N. ^[2]; Bonoli, P. T. ^[3]; Shiraiwa, S. ^[3]

Chinese Academy of Sciences (CAS), Hefei (China); Univ. of Chinese Academy of Sciences, Beijing (China); DOE/OSTI
Chinese Academy of Sciences (CAS), Hefei (China)
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Lower hybrid current drive (LHCD) is one of the major approaches maintaining long pulse discharges on EAST. There are two lower hybrid (LH) systems on EAST launching waves at 4.6 GHz and 2.45 GHz into the plasma, respectively, and the input power of the 4.6 GHz wave is typically dominant. Here, the synergy of the two waves and the modification of the power deposition of the 4.6 GHz wave by coupling the 2.45 GHz wave are investigated theoretically. According to the phase space analysis, the wave propagation domains of the two LH waves always overlap substantially with each other for typical LHCD experimental parameters on EAST, indicating that the coupling between them might be strong. Ray-tracing/Fokker-Planck simulations for a LH current drive experiment on EAST show that the change of the power deposition profile due to the coupling could be understood by the rise and fall of the tails of the parallel electron distribution functions on different flux surfaces. If either the injected wave power at 2.45 GHz is comparable with that at 4.6 GHz or the incident N_∥ of the 2.45 GHz wave reaches a high value (e.g., $$5.7/\sqrt{T_{e,0}}$$), the power deposition profile of the 4.6 GHz wave can be modified greatly due to the coupling with the 2.45 GHz wave. With the parameters compatible with the ability of the LH wave system on EAST, injection of the 2.45 GHz wave can still modify the power deposition profile of the 4.6 GHz wave significantly by combining those two approaches. Finally, it is shown how a 4.6 GHz wave which cannot be Landau damped when injected alone is absorbed in low density plasmas with a magnetic shear reversal configuration in the presence of a 2.45 GHz wave.

View Accepted Manuscript (DOE)

Research Organization:: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Sponsoring Organization:: National ITER program of China; National Key R&D Program of China; National Natural Science Foundation of China (NNSFC); USDOE; USDOE Office of Science (SC)

Grant/Contract Number:: SC0010492

OSTI ID:: 1611428

Alternate ID(s):: OSTI ID: 1513324

Journal Information:: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 26; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

References (34)

A quasilinear Fokker-Planck code for the numerical solution of the lower-hybrid current-drive problem in the presence of electron cyclotron heating Shoucri, M.; Shkarofsky, I.; Fuchs, V. Computer Physics Communications, Vol. 55, Issue 3 https://doi.org/10.1016/0010-4655(89)90124-0	journal	October 1989
Combined kinetic and transport modeling of radiofrequency current drive Dumont, R.; Giruzzi, G.; Barbato, E. Physics of Plasmas, Vol. 7, Issue 12 https://doi.org/10.1063/1.1318355	journal	December 2000
Theory of synergy between electron cyclotron and lower hybrid waves Dumont, R. J.; Giruzzi, G. Physics of Plasmas, Vol. 11, Issue 7 https://doi.org/10.1063/1.1739234	journal	July 2004
Lower hybrid current drive experiments on Alcator C-Mod: Comparison with theory and simulation Bonoli, P. T.; Ko, J.; Parker, R. Physics of Plasmas, Vol. 15, Issue 5 https://doi.org/10.1063/1.2904569	journal	May 2008
Investigation of lower hybrid physics through power modulation experiments on Alcator C-Mod Schmidt, A.; Bonoli, P. T.; Meneghini, O. Physics of Plasmas, Vol. 18, Issue 5 https://doi.org/10.1063/1.3593112	journal	May 2011
Review of recent experimental and modeling progress in the lower hybrid range of frequencies at ITER relevant parameters Bonoli, Paul T. RADIOFREQUENCY POWER IN PLASMAS: Proceedings of the 20th Topical Conference, AIP Conference Proceedings https://doi.org/10.1063/1.4864497	conference	January 2014
Review of recent experimental and modeling progress in the lower hybrid range of frequencies at ITER relevant parameters Bonoli, Paul T. Physics of Plasmas, Vol. 21, Issue 6 https://doi.org/10.1063/1.4884360	journal	June 2014
Synergy effects during current drive by two lower-hybrid waves Yang, Youlei; Xiang, Nong; Hu, Ye Min Physics of Plasmas, Vol. 24, Issue 3 https://doi.org/10.1063/1.4977524	journal	March 2017
Numerical study of the synergy effects of electron cyclotron wave and two lower-hybrid waves in the current drive process Yang, Youlei; Xiang, Nong; Hu, Ye Min Physics of Plasmas, Vol. 24, Issue 8 https://doi.org/10.1063/1.4994547	journal	August 2017
The generalized accessibility and spectral gap of lower hybrid waves in tokamaks Takahashi, Hironori Physics of Plasmas, Vol. 1, Issue 7 https://doi.org/10.1063/1.870624	journal	July 1994
Cross-effect on electron cyclotron and lower hybrid current drive in tokamak plasmas Fidone, I.; Giruzzi, G.; Krivenski, V. Nuclear Fusion, Vol. 27, Issue 4 https://doi.org/10.1088/0029-5515/27/4/004	journal	April 1987
Lower hybrid current drive accessibility study with reconstructed magnetic equilibria in PBX-M Paoletti, F.; Ignat, D. W.; Kesner, J. Nuclear Fusion, Vol. 34, Issue 6 https://doi.org/10.1088/0029-5515/34/6/I01	journal	June 1994
Profile control with lower hybrid waves on ASDEX Soldner, F. X.; Leuterer, F.; Bartiromo, R. Nuclear Fusion, Vol. 34, Issue 7 https://doi.org/10.1088/0029-5515/34/7/I06	journal	July 1994
Chapter 6: Plasma auxiliary heating and current drive Drive, ITER Physics Expert Group on Energe; Editors, ITER Physics Basis Nuclear Fusion, Vol. 39, Issue 12 https://doi.org/10.1088/0029-5515/39/12/306	journal	December 1999
Current profile control and improvement of current drive efficiency by combined lower hybrid waves in TRIAM-1M Sakamoto, M.; Itoh, S.; Sato, K. N. Nuclear Fusion, Vol. 40, Issue 3Y https://doi.org/10.1088/0029-5515/40/3Y/303	journal	March 2000
Chapter 6: Steady state operation Gormezano, C.; Sips, A. C. C.; Luce, T. C. Nuclear Fusion, Vol. 47, Issue 6 https://doi.org/10.1088/0029-5515/47/6/S06	journal	June 2007
Progress towards steady-state regimes in Alcator C-Mod Shiraiwa, S.; Baek, G.; Bonoli, P. T. Nuclear Fusion, Vol. 53, Issue 11 https://doi.org/10.1088/0029-5515/53/11/113028	journal	October 2013
Recent progress on lower hybrid current drive and implications for ITER Hillairet, J.; Ekedahl, A.; Goniche, M. Nuclear Fusion, Vol. 53, Issue 7 https://doi.org/10.1088/0029-5515/53/7/073004	journal	May 2013
Nonlinear Dependence of the Synergetic Current by the Combined Effect of ECCD and LHCD on the Power Ratio on HL-2A Tokamak Lu, Wei; Chen, Shao-Yong; Tang, Chang-Jian Chinese Physics Letters, Vol. 30, Issue 6 https://doi.org/10.1088/0256-307X/30/6/065203	journal	June 2013
General properties of the lower hybrid ray trajectories in toroidal plasmas Esterkin, A. R.; Piliya, A. D. Plasma Physics and Controlled Fusion, Vol. 34, Issue 13 https://doi.org/10.1088/0741-3335/34/13/026	journal	December 1992
Sustainment and modification of reversed magnetic shear by LHCD on JT-60U Ide, S.; Fujita, T.; Naito, O. Plasma Physics and Controlled Fusion, Vol. 38, Issue 10 https://doi.org/10.1088/0741-3335/38/10/001	journal	October 1996
Stationary magnetic shear reversal experiments in Tore Supra Litaudon, X.; Arslanbekov, R.; Hoang, G. T. Plasma Physics and Controlled Fusion, Vol. 38, Issue 9 https://doi.org/10.1088/0741-3335/38/9/006	journal	September 1996
Modelling of the EAST lower-hybrid current drive experiment using GENRAY/CQL3D and TORLH/CQL3D Yang, C.; Bonoli, P. T.; Wright, J. C. Plasma Physics and Controlled Fusion, Vol. 56, Issue 12 https://doi.org/10.1088/0741-3335/56/12/125003	journal	October 2014
Advances in modeling of lower hybrid current drive Peysson, Y.; Decker, J.; Nilsson, E. Plasma Physics and Controlled Fusion, Vol. 58, Issue 4 https://doi.org/10.1088/0741-3335/58/4/044008	journal	February 2016
Theoretical analysis of key factors achieving reversed magnetic shear q -profiles sustained with lower hybrid waves on EAST Zhai, X. M.; Xiang, N.; Chen, J. L. Plasma Physics and Controlled Fusion, Vol. 61, Issue 4 https://doi.org/10.1088/1361-6587/aaffe5	journal	February 2019
Development of high poloidal beta, steady-state scenario with ITER-like tungsten divertor on EAST Garofalo, A. M.; Gong, X. Z.; Qian, J. Nuclear Fusion, Vol. 57, Issue 7 https://doi.org/10.1088/1741-4326/aa7186	journal	June 2017
Analysis of performance degradation in an electron heating dominant H-mode plasma after ECRH termination in EAST Du, Hongfei; Ding, Siye; Chen, Jiale Nuclear Fusion, Vol. 58, Issue 6 https://doi.org/10.1088/1741-4326/aabaab	journal	April 2018
Confining a Tokamak Plasma with rf-Driven Currents Fisch, Nathaniel J. Physical Review Letters, Vol. 41, Issue 13 https://doi.org/10.1103/PhysRevLett.41.873	journal	September 1978
Enhancement of Absorption of Lower Hybrid Wave by Filling the Spectral Gap Ide, S.; Naito, O.; Kondoh, T. Physical Review Letters, Vol. 73, Issue 17 https://doi.org/10.1103/PhysRevLett.73.2312	journal	October 1994
Synergy of Electron-Cyclotron and Lower-Hybrid Current Drive in Steady-State Plasmas Giruzzi, G.; Artaud, J. F.; Dumont, R. J. Physical Review Letters, Vol. 93, Issue 25 https://doi.org/10.1103/PhysRevLett.93.255002	journal	December 2004
Confining a Tokamak Plasma with rf-Driven Currents. Fisch, Nathaniel J. Physical Review Letters, Vol. 42, Issue 6 https://doi.org/10.1103/physrevlett.42.410.2	journal	February 1979
Linear Theory of Lower Hybrid Heating Bonoli, Paul IEEE Transactions on Plasma Science, Vol. 12, Issue 2 https://doi.org/10.1109/TPS.1984.4316302	journal	January 1984
Vlasov Simulations of Spectral and Fast Electron Features in Lower Hybrid Current Drive Karttunen, S. J.; Pättikangas, T. J. H.; Salomaa, R. R. E. Physica Scripta, Vol. 60, Issue 4 https://doi.org/10.1238/Physica.Regular.060a00356	journal	October 1999
Theory of Synergy between Electron Cyclotron and Lower Hybrid Waves Dumont, R. J.; Giruzzi, G. arXiv https://doi.org/10.48550/arxiv.physics/0312092	text	January 2003

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