Sawtooth-triggered limit-cycle oscillations and I-phase in the HL-2A tokamak

K. J. Zhao, J. Cheng, P. H. Diamond, J. Q. Dong, L. W. Yan, W. Y. Hong, M. Xu, G. Tynan, K. Miki, Z. H. Huang, K. Itoh, S. I. Itoh, A. Fujisawa, Y. Nagashima, S. Inagaki, Z. X. Wang, L. Wei, X. M. Song, G. J. Lei, Q. LiX. Q. Ji, Yi Liu, Q. W. Yang, X. T. Ding, X. R. Duan

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Transitions between low (L-mode) and intermediate (I-phase) confinement regimes triggered by sawteeth are investigated using multiple Langmuir probe arrays in the edge plasmas of the HL-2A tokamak. The I-phase is characterized by limit-cycle oscillations (LCOs). Repeated L-I-L transitions induced by sawtooth heat pulses are also observed. Statistical analyses show that the delay time of the L-I transition relative to sawtooth crashes is less than ∼1 ms. The intensity of turbulence bursts in the I-phase is stronger than those observed in L-mode plasmas. Measurements are consistent with zonal flow reducing turbulence intensity in the frequency band ∼20-100 kHz, while the LCO turbulence of frequency higher than 100 kHz has more power than that in the L-mode. The analyses of time-resolved power transfers between turbulence and zonal flows suggest that power transfers exist between turbulence and zonal flows. The direction of the power transfers is from turbulence into geodesic acoustic modes in ohmic plasmas.

Original languageEnglish
Article number123015
JournalNuclear Fusion
Volume53
Issue number12
DOIs
Publication statusPublished - Dec 1 2013

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turbulence
oscillations
cycles
crashes
electrostatic probes
bursts
time lag
heat
acoustics
pulses

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

Zhao, K. J., Cheng, J., Diamond, P. H., Dong, J. Q., Yan, L. W., Hong, W. Y., ... Duan, X. R. (2013). Sawtooth-triggered limit-cycle oscillations and I-phase in the HL-2A tokamak. Nuclear Fusion, 53(12), [123015]. https://doi.org/10.1088/0029-5515/53/12/123015

Sawtooth-triggered limit-cycle oscillations and I-phase in the HL-2A tokamak. / Zhao, K. J.; Cheng, J.; Diamond, P. H.; Dong, J. Q.; Yan, L. W.; Hong, W. Y.; Xu, M.; Tynan, G.; Miki, K.; Huang, Z. H.; Itoh, K.; Itoh, S. I.; Fujisawa, A.; Nagashima, Y.; Inagaki, S.; Wang, Z. X.; Wei, L.; Song, X. M.; Lei, G. J.; Li, Q.; Ji, X. Q.; Liu, Yi; Yang, Q. W.; Ding, X. T.; Duan, X. R.

In: Nuclear Fusion, Vol. 53, No. 12, 123015, 01.12.2013.

Research output: Contribution to journalArticle

Zhao, KJ, Cheng, J, Diamond, PH, Dong, JQ, Yan, LW, Hong, WY, Xu, M, Tynan, G, Miki, K, Huang, ZH, Itoh, K, Itoh, SI, Fujisawa, A, Nagashima, Y, Inagaki, S, Wang, ZX, Wei, L, Song, XM, Lei, GJ, Li, Q, Ji, XQ, Liu, Y, Yang, QW, Ding, XT & Duan, XR 2013, 'Sawtooth-triggered limit-cycle oscillations and I-phase in the HL-2A tokamak', Nuclear Fusion, vol. 53, no. 12, 123015. https://doi.org/10.1088/0029-5515/53/12/123015
Zhao KJ, Cheng J, Diamond PH, Dong JQ, Yan LW, Hong WY et al. Sawtooth-triggered limit-cycle oscillations and I-phase in the HL-2A tokamak. Nuclear Fusion. 2013 Dec 1;53(12). 123015. https://doi.org/10.1088/0029-5515/53/12/123015
Zhao, K. J. ; Cheng, J. ; Diamond, P. H. ; Dong, J. Q. ; Yan, L. W. ; Hong, W. Y. ; Xu, M. ; Tynan, G. ; Miki, K. ; Huang, Z. H. ; Itoh, K. ; Itoh, S. I. ; Fujisawa, A. ; Nagashima, Y. ; Inagaki, S. ; Wang, Z. X. ; Wei, L. ; Song, X. M. ; Lei, G. J. ; Li, Q. ; Ji, X. Q. ; Liu, Yi ; Yang, Q. W. ; Ding, X. T. ; Duan, X. R. / Sawtooth-triggered limit-cycle oscillations and I-phase in the HL-2A tokamak. In: Nuclear Fusion. 2013 ; Vol. 53, No. 12.
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