Experimental investigation of PDI bifurcation of lower hybrid waves during electron density ramp-up in EAST

Yan, G. H.; Ding, B. J.; Wu, C. B.; Li, M. H.; Baek, S. G.; Napoli, F.; Zhou, T. T.; Geng, K. N.; Yan, N.; Wang, M.; Zhang, X. J.; Xu, H. D.; Yang, J. H.; Ma, W. Q.

doi:10.1088/1741-4326/ad4fa0

Title: Experimental investigation of PDI bifurcation of lower hybrid waves during electron density ramp-up in EAST

Journal Article · 19 June 2024 · Nuclear Fusion

DOI: https://doi.org/10.1088/1741-4326/ad4fa0 · OSTI ID:2375890

;

; Wu, C. B.;

; Baek, S. G.;

;

; Wang, M.; Zhang, X. J.; Xu, H. D.; Yang, J. H.; Ma, W. Q.

Abstract The effect of parametric decay instability (PDI) on the current drive efficiency of 4.6 GHz lower hybrid (LH) waves in EAST is investigated experimentally, showing the PDI channel bifurcation of LH waves for the first time in EAST. First, experiments with three platforms of LH power were performed, achieving the LH power required for the PDI occurrence. Second, PDI bifurcation experiments were further carried out by ramping up the plasma electron density. The loop voltage increases with an increase in density, implying a decrease in the current driven by the LH wave. PDI bifurcation during electron density ramp-up was studied by analyzing the parallel refractive index ( $n_{∥}$ ) and the frequency spectrum broadening, which is measured with a radio frequency magnetic probe array recently installed close to the LH antenna. It is observed for the first time that they both first increase with density, then there is not much variation and a clear sideband in the frequency spectrum is also observed when the density is up to $4 \times 10^{19} m^{- 3}$ , suggesting a change in the PDI channel. Calculation of the mode growth rate driven by PDI shows that when the edge electron density is up to $1.9 \times 10^{18} m^{- 3}$ , the growth rate of the ion cyclotron quasi-mode (ICQM) will exceed that of the ion sound quasi-mode (ISQM), quantitively explaining that with an increase in density, the PDI channel partly transits from the ISQM to the ICQM channel. Studies provide a possible way to reduce the power deposition in the edge region and improve drive capability by means of mitigating PDI behavior.

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Sponsoring Organization:: USDOE

Grant/Contract Number:: SC0010492; SC0010492

OSTI ID:: 2375890

Alternate ID(s):: OSTI ID: 2361144

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 8 Vol. 64; ISSN 0029-5515

Publisher:: IOP PublishingCopyright Statement

Country of Publication:: IAEA

Language:: English

References (37)

Absorption of lower hybrid waves in the scrape off layer of a diverted tokamak Wallace, G. M.; Parker, R. R.; Bonoli, P. T. Physics of Plasmas, Vol. 17, Issue 8 https://doi.org/10.1063/1.3465662	journal	August 2010
Lower-Hybrid Current Drive in the PLT Tokamak Bernabei, S.; Daughney, C.; Efthimion, P. Physical Review Letters, Vol. 49, Issue 17 https://doi.org/10.1103/PhysRevLett.49.1255	journal	October 1982
Parametric instability and lower hybrid current drive at plasma densities required for thermonuclear reactors Cesario, R.; Amicucci, L.; Arcangelis, D. De Journal of Physics: Conference Series, Vol. 260 https://doi.org/10.1088/1742-6596/260/1/012008	journal	November 2010
Experimental investigation on spectral broadening of lower hybrid waves with different frequencies in the EAST long-pulse plasmas Li, M. H.; Ding, B. J.; Liu, F. K. Plasma Physics and Controlled Fusion, Vol. 61, Issue 6 https://doi.org/10.1088/1361-6587/aaf9da	journal	April 2019
Consequence of filamentation on stimulated Raman scattering Liu, C. S.; Tripathi, V. K. The Physics of Fluids, Vol. 29, Issue 12 https://doi.org/10.1063/1.865710	journal	December 1986
Theory of parametric instability near the lower-hybrid frequency Porkolab, Miklos Physics of Fluids, Vol. 17, Issue 7 https://doi.org/10.1063/1.1694910	journal	January 1974
Theory of current drive in plasmas Fisch, Nathaniel J. Reviews of Modern Physics, Vol. 59, Issue 1 https://doi.org/10.1103/RevModPhys.59.175	journal	January 1987
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
Fast reciprocating probe system on the EAST superconducting tokamak Zhang, W.; Chang, J. F.; Wan, B. N. Review of Scientific Instruments, Vol. 81, Issue 11 https://doi.org/10.1063/1.3499237	journal	November 2010
Density fluctuations and spectral broadening during the lower hybrid current drive experiment on ASDEX Cesario, R.; Bartiromo, R.; Cardinali, A. Nuclear Fusion, Vol. 32, Issue 12 https://doi.org/10.1088/0029-5515/32/12/I04	journal	December 1992
Toroidal and scattering effects on lower-hybrid wave propagation Bonoli, Paul T. Physics of Fluids, Vol. 25, Issue 2 https://doi.org/10.1063/1.863744	journal	January 1982
Transport modeling of L- and H-mode discharges with LHCD on EAST Li, M. H.; Ding, B. J.; Imbeaux, F. Plasma Physics and Controlled Fusion, Vol. 55, Issue 4 https://doi.org/10.1088/0741-3335/55/4/045014	journal	March 2013
Experimental investigations of LHW–plasma coupling and current drive related to achieving H-mode plasmas in EAST Ding, B. J.; Kong, E. H.; Li, M. H. Nuclear Fusion, Vol. 53, Issue 11 https://doi.org/10.1088/0029-5515/53/11/113027	journal	October 2013
Development of the quasi-optical combiner systems for density profile reflectometers on the EAST tokamak Wang, Y. M.; Zhang, T.; Liu, X. M. Fusion Engineering and Design, Vol. 148 https://doi.org/10.1016/j.fusengdes.2019.111286	journal	November 2019
Correlation between the onset of parametric instability of lower hybrid waves and modification in edge plasma current profile on EAST Ding, B. J.; Li, M. H.; Li, Y. C. Nuclear Fusion, Vol. 58, Issue 12 https://doi.org/10.1088/1741-4326/aae027	journal	September 2018
Parameter study of parametric instabilities during lower hybrid wave injection into tokamaks Zhao, Aihui; Gao, Zhe Nuclear Fusion, Vol. 53, Issue 8 https://doi.org/10.1088/0029-5515/53/8/083015	journal	July 2013
Modeling of the nonlinear mode coupling of lower hybrid waves in tokamak plasmas Napoli, F.; Castaldo, C.; Cesario, R. Plasma Physics and Controlled Fusion, Vol. 55, Issue 9 https://doi.org/10.1088/0741-3335/55/9/095004	journal	July 2013
Spectral broadening of parametric instability in lower hybrid current drive at a high density Cesario, R.; Amicucci, L.; Cardinali, A. Nuclear Fusion, Vol. 54, Issue 4 https://doi.org/10.1088/0029-5515/54/4/043002	journal	March 2014
Coupling characteristics of the ITER-relevant lower hybrid antenna in Tore Supra: experiments and modelling Preynas, M.; Ekedahl, A.; Fedorczak, N. Nuclear Fusion, Vol. 51, Issue 2 https://doi.org/10.1088/0029-5515/51/2/023001	journal	January 2011
Isotopic effect of parametric instabilities during lower hybrid waves injection into hydrogen/deuterium plasmas Zhao, Aihui; Gao, Zhe Physics of Plasmas, Vol. 24, Issue 1 https://doi.org/10.1063/1.4974173	journal	January 2017
Study on lower hybrid current drive efficiency at high density towards long-pulse regimes in Experimental Advanced Superconducting Tokamak Li, M. H.; Ding, B. J.; Zhang, J. Z. Physics of Plasmas, Vol. 21, Issue 6 https://doi.org/10.1063/1.4883640	journal	June 2014
A Parametric Analysis of Nonlinear Lower Hybrid Effects Napoli, F.; Castaldo, C.; Cesario, R. Journal of Physics: Conference Series, Vol. 401 https://doi.org/10.1088/1742-6596/401/1/012016	journal	December 2012
RF current drive and plasma fluctuations Peysson, Yves; Decker, Joan; Morini, L. Plasma Physics and Controlled Fusion, Vol. 53, Issue 12 https://doi.org/10.1088/0741-3335/53/12/124028	journal	November 2011
Spectral broadening of lower hybrid waves produced by parametric instability in current drive experiments of tokamak plasmas Cesario, R.; Cardinali, A.; Castaldo, C. Nuclear Fusion, Vol. 46, Issue 4 https://doi.org/10.1088/0029-5515/46/4/007	journal	March 2006
Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST Ding, B. J.; Li, Y. C.; Zhang, L. Nuclear Fusion, Vol. 55, Issue 9 https://doi.org/10.1088/0029-5515/55/9/093030	journal	August 2015
Modeling the spectral modification of lower hybrid wave in the presence of drift-wave type density fluctuation in the scrape-off-layer of the EAST tokamak Wu, C. B.; Ding, B. J.; Li, M. H. Physics of Plasmas, Vol. 28, Issue 8 https://doi.org/10.1063/5.0053459	journal	August 2021
Initial measurements of plasma current and electron density profiles using a polarimeter/interferometer (POINT) for long pulse operation in EAST (invited) Liu, H. Q.; Qian, J. P.; Jie, Y. X. Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4963378	journal	October 2016
Modeling of a Lower-Hybrid Current Drive by Including Spectral Broadening Induced by Parametric Instability in Tokamak Plasmas Cesario, R.; Cardinali, A.; Castaldo, C. Physical Review Letters, Vol. 92, Issue 17 https://doi.org/10.1103/PhysRevLett.92.175002	journal	April 2004
Simulation model for lower hybrid current drive Bonoli, Paul T.; Englade, Ronald C. Physics of Fluids, Vol. 29, Issue 9 https://doi.org/10.1063/1.865494	journal	September 1986
Lower hybrid current drive efficiency in tokamaks and wave scattering by density fluctuations at the plasma edge Ridolfini, V. Pericoli; Apicella, M. L.; Calabrò, G. Nuclear Fusion, Vol. 51, Issue 11 https://doi.org/10.1088/0029-5515/51/11/113023	journal	November 2011
Parametric decay instabilities of lower hybrid wave current drive on CFETR Zhou, T. T.; Xiang, N.; Chen, J. L. 23RD TOPICAL CONFERENCE ON RADIOFREQUENCY POWER IN PLASMAS https://doi.org/10.1063/5.0013618	conference	January 2020
Parametric instabilities excited by ion sound and ion cyclotron quasi-modes during lower hybrid heating of tokamak plasmas Cesario, R.; Cardinali, A. Nuclear Fusion, Vol. 29, Issue 10 https://doi.org/10.1088/0029-5515/29/10/005	journal	October 1989
Diagnostic development for parallel wave-number measurement of lower hybrid waves in EAST Wang, Y. F.; Ding, B. J.; Li, M. H. Review of Scientific Instruments, Vol. 91, Issue 7 https://doi.org/10.1063/1.5144673	journal	July 2020
Creating an Asymmetric Plasma Resistivity with Waves Fisch, N. J.; Boozer, A. H. Physical Review Letters, Vol. 45, Issue 9 https://doi.org/10.1103/PhysRevLett.45.720	journal	September 1980
Lower hybrid current drive efficiency at high density on Tore Supra Goniche, M.; Sharma, P. K.; Basiuk, V. AIP Conference Proceedings https://doi.org/10.1063/1.3665003	conference	January 2011
Lower hybrid current drive experiments with different launched wave frequencies in the EAST tokamak Li, M. H.; Ding, B. J.; Liu, F. K. Physics of Plasmas, Vol. 23, Issue 10 https://doi.org/10.1063/1.4965904	journal	October 2016
Whistlers, helicons, and lower hybrid waves: The physics of radio frequency wave propagation and absorption for current drive via Landau damping Pinsker, R. I. Physics of Plasmas, Vol. 22, Issue 9 https://doi.org/10.1063/1.4930135	journal	September 2015

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