Dynamics of cold pulses induced by super-sonic molecular beam injection in the EAST tokamak

Yong Liu, Yuejiang Shi, Tao Zhang, Chu Zhou*, Xiaolan Zou, Hailin Zhao, Ahdi Liu, Tianfu Zhou, Xiang Liu, Shoubiao Zhang, Bin Cao, Volker Naulin

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Evolution of electron temperature, electron density and its fluctuation with high spatial and temporal resolutions are presented for the cold pulse propagation induced by super-sonic molecular beam injection (SMBI) in ohmic plasmas in the EAST tokamak. The non-local heat transport occurs for discharges with plasma current Ip = 450 kA (q95 ∼ 5.55), and electron density ne0 below a critical value of (1.35 ± 0.25) x 1019 m-3. In contrary to the response of core electron temperature and electron density (roughly 10ms after SMBI), the electron density fluctuation in the plasma core increases promptly after SMBI and reaches its maximum around 15 ms after SMBI. The electron density fluctuation in the plasma core begins to decrease before the core electron temperature reaches its maximum (roughly 30ms). It was also observed that the turbulence perpendicular velocity close to the inversion point of the temperature perturbation changes sign after SMBI.

Original languageEnglish
Article number044005
JournalNuclear Fusion
Volume59
Issue number4
Number of pages6
ISSN0029-5515
DOIs
Publication statusPublished - 2019

Keywords

  • Non-local transport
  • Turbulence measurement
  • High spatial and temporal resolutions
  • Turbulence spreading

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