Nuclear Fusion (Jan 2024)

Ti/Te effects on transport in EAST low q95 plasmas

  • Y.F. He,
  • J.P. Qian,
  • J.G. Li,
  • P. Li,
  • X.Z. Gong,
  • B. Zhang,
  • J.Y. Zhang,
  • J.L. Chen,
  • Cheonho Bae,
  • M.Q. Wu,
  • X.D. Yang,
  • T.Q. Jia,
  • G.S. Li,
  • Y.F. Jin,
  • Z.C. Lin,
  • S.Y. Fu,
  • G.L. Lin,
  • Q. Zang,
  • G.Q. Zhong,
  • S.X. Wang,
  • X. Li,
  • J. Huang

DOI
https://doi.org/10.1088/1741-4326/ad5363
Journal volume & issue
Vol. 64, no. 7
p. 076064

Abstract

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Enhanced confinement is observed in EAST low ${q_{95}}$ ( ${q_{95}} < 3.5$ ) plasmas with the temperature ratio ( ${T_i}/{T_e}$ ) increasing. A statistically significant positive correlation between ${H_{98y2}}$ and ${T_i}/{T_e}$ has been established. Increased ${T_i}\,$ triggerd by Neutral Beam Injection in experiments maintaining constant ${T_e}$ leads initially to an improved ${T_i}/{T_e}$ ratio, which subsequently mitigates heat transport in the ion channel. The Trapped Gyro–Landau Fluid transport model was applied to analyse the dependence of the turbulent transport on ${T_i}/{T_e}$ . Simulation results demonstrate that the Ion Temperature Gradient mode is stabilized in high ${T_i}/{T_e}$ plasma, with ion flux results from predictive modelling further validating this effect. These findings corroborate the Weiland model and complement one another. This study contributes to a deeper understanding of how the dimensionless parameter ${T_i}/{T_e}$ influences plasma transport, and helps demonstrate the feasibility of operations under the low ${q_{95}}$ condition required for the ITER-inductive scenario in the new ${T_i}/{T_e}$ regime.

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