Relationship between the H-mode in tokamaks and the finite-Larmor-radius (FLR) modified Beltrami/Taylor state
ORAL
Abstract
It has been shown that the radial electric field at the H-mode pedestal is the result of charge separation between the ions and electrons due to the FLR effects in the presence of a sharp pressure gradient [1]. The resulting radial electric field, which compares well with many of the experiments as shown in Ref. [1], then gives rise to the ${\bf E} \times {\bf B}$ drift for both the electrons and the ions. Again, because of the FLR effects, it results in a net current in the poloidal direction, which modifies the gyrokinetic vorticity equation [2]. In the Beltrami/Taylor state [3], this current vanishes and the resulting gyrokinetic MHD equations [4] resemble those of Strauss [5], which are MHD stable for $q > 1$. Details will be presented.
[1] W. W. Lee and R. B. White, Phys. Plasmas {\bf 24}, 081204 (2017);
[2] W. W. Lee, Phys. Plasmas {\bf 23}, 070705 (2016);
[3] Z. Yoshida, S. M. Mahajan, S. Ohsaki, M. Iqbal and N. Shatashivili, Phys. Plasmas {\bf 8}, 2125 (2001).
[4] W. W. Lee, S. R. Hudson and C. H. Ma, Phys. Plasmas {\bf 24}, 124508 (2017);
[5] H. R. Strauss, Phys. Fluids {\bf 19}, 134 (1976).
[1] W. W. Lee and R. B. White, Phys. Plasmas {\bf 24}, 081204 (2017);
[2] W. W. Lee, Phys. Plasmas {\bf 23}, 070705 (2016);
[3] Z. Yoshida, S. M. Mahajan, S. Ohsaki, M. Iqbal and N. Shatashivili, Phys. Plasmas {\bf 8}, 2125 (2001).
[4] W. W. Lee, S. R. Hudson and C. H. Ma, Phys. Plasmas {\bf 24}, 124508 (2017);
[5] H. R. Strauss, Phys. Fluids {\bf 19}, 134 (1976).
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Presenters
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Wei-li W Lee
Princeton Plasma Phys Lab
Authors
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Wei-li W Lee
Princeton Plasma Phys Lab
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Roscoe B White
Princeton Plasma Phys Lab