Kinetic theory of helical instabilities in a cylindrical tokamak

Sanae Itoh, K. Itoh

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The kinetic theory of the drift-tearing mode in a finite-β, collisionless inhomogeneous cylindrical tokamak is investigated. It is found that 1) when the density is low, the kinetic drift-tearing modes are unstable whereas they become stabilized as the density increases, 2) the medium-m (poloidal mode number) modes have a smaller growth rate, and 3) the electron temperature gradient further stabilizes these modes. Because of the magnetic shear and the finite β value, the outgoing drift wave is associated with the tearing mode, and hence the ion Landau damping stabilizes the mode when β increases. The local current density is found to be crucial for the instability. It is noted that the stability criterion for the MHD tearing mode, [formatted text] is the jump of the logarithmic derivative of Br across the mode rational surface), is lo longer valid for kinetic tearing mode. - For future tokamak parameters, low- and medium-m (2 ≤m ≲ 50) kinetic drift-tearing modes are found to be stable in cylindrical geometry.

Original languageEnglish
Pages (from-to)3-13
Number of pages11
JournalNuclear Fusion
Volume21
Issue number1
DOIs
Publication statusPublished - Jan 1 1981

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kinetic theory
kinetics
Landau damping
temperature gradients
electron energy
current density
shear
geometry
ions

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

Kinetic theory of helical instabilities in a cylindrical tokamak. / Itoh, Sanae; Itoh, K.

In: Nuclear Fusion, Vol. 21, No. 1, 01.01.1981, p. 3-13.

Research output: Contribution to journalArticle

Itoh, Sanae ; Itoh, K. / Kinetic theory of helical instabilities in a cylindrical tokamak. In: Nuclear Fusion. 1981 ; Vol. 21, No. 1. pp. 3-13.
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