Low-intermediate-high confinement transition in HL-2A tokamak plasmas

J. Cheng, J. Q. Dong, K. Itoh, L. W. Yan, W. Y. Hong, K. J. Zhao, Z. H. Huang, X. Q. Ji, W. L. Zhong, D. L. Yu, Sanae Itoh, L. Nie, X. M. Song, Q. W. Yang, X. T. Ding, X. L. Zou, X. R. Duan, Yong Liu

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

The dynamics of low-intermediate-high confinement transitions was studied using a four-step Langmuir probe in the HL-2A edge plasma. Two types (dubbed type-Y and type-J) of limit cycle oscillations (LCOs) with opposite temporal ordering between the radial electric field and turbulence were first observed. In type-Y, the turbulence grows first, followed by the localized electric field. In contrast, the electric field leads turbulence in type-J. In addition, the Reynolds stress gradient is found not enough to drive the LCO flow and the three-wave nonlinear coupling is weak there. The continuously increasing amplitude of magnetic fluctuations and the significant correlation between the magnetic fluctuation and the electron pressure gradient indicate an important role of diamagnetic drifts in the L-H transition. Mode numbers of magnetic fluctuations in the LCO frequency are identified to be m/n=1/0.

Original languageEnglish
Article number114004
JournalNuclear Fusion
Volume54
Issue number11
DOIs
Publication statusPublished - Nov 1 2014

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turbulence
oscillations
cycles
electric fields
electron pressure
Reynolds stress
electrostatic probes
pressure gradients
gradients

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

Cheng, J., Dong, J. Q., Itoh, K., Yan, L. W., Hong, W. Y., Zhao, K. J., ... Liu, Y. (2014). Low-intermediate-high confinement transition in HL-2A tokamak plasmas. Nuclear Fusion, 54(11), [114004]. https://doi.org/10.1088/0029-5515/54/11/114004

Low-intermediate-high confinement transition in HL-2A tokamak plasmas. / Cheng, J.; Dong, J. Q.; Itoh, K.; Yan, L. W.; Hong, W. Y.; Zhao, K. J.; Huang, Z. H.; Ji, X. Q.; Zhong, W. L.; Yu, D. L.; Itoh, Sanae; Nie, L.; Song, X. M.; Yang, Q. W.; Ding, X. T.; Zou, X. L.; Duan, X. R.; Liu, Yong.

In: Nuclear Fusion, Vol. 54, No. 11, 114004, 01.11.2014.

Research output: Contribution to journalArticle

Cheng, J, Dong, JQ, Itoh, K, Yan, LW, Hong, WY, Zhao, KJ, Huang, ZH, Ji, XQ, Zhong, WL, Yu, DL, Itoh, S, Nie, L, Song, XM, Yang, QW, Ding, XT, Zou, XL, Duan, XR & Liu, Y 2014, 'Low-intermediate-high confinement transition in HL-2A tokamak plasmas', Nuclear Fusion, vol. 54, no. 11, 114004. https://doi.org/10.1088/0029-5515/54/11/114004
Cheng J, Dong JQ, Itoh K, Yan LW, Hong WY, Zhao KJ et al. Low-intermediate-high confinement transition in HL-2A tokamak plasmas. Nuclear Fusion. 2014 Nov 1;54(11). 114004. https://doi.org/10.1088/0029-5515/54/11/114004
Cheng, J. ; Dong, J. Q. ; Itoh, K. ; Yan, L. W. ; Hong, W. Y. ; Zhao, K. J. ; Huang, Z. H. ; Ji, X. Q. ; Zhong, W. L. ; Yu, D. L. ; Itoh, Sanae ; Nie, L. ; Song, X. M. ; Yang, Q. W. ; Ding, X. T. ; Zou, X. L. ; Duan, X. R. ; Liu, Yong. / Low-intermediate-high confinement transition in HL-2A tokamak plasmas. In: Nuclear Fusion. 2014 ; Vol. 54, No. 11.
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