Gyrokinetic analysis of linear microinstabilities for the stellarator Wendelstein 7-X

Journal Article · Sun Apr 15 04:00:00 EDT 2007 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2714328· OSTI ID:20974930

Xanthopoulos, P; Jenko, F ^[1]

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1. Max-Planck-Institut fuer Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, D-17491 Greifswald (Germany)

A linear collisionless gyrokinetic investigation of ion temperature gradient (ITG) modes--considering both adiabatic and full electron dynamics--and trapped electron modes (TEMs) is presented for the stellarator Wendelstein 7-X (W7-X) [G. Grieger et al., Plasma Physics and Controlled Nuclear Fusion Research 1990 (International Atomic Energy Agency, Vienna, 1991), Vol. 3, p. 525]. The study of ITG modes reveals that in W7-X, microinstabilities of distinct character coexist. The effect of changes in the density gradient and temperature ratio is discussed. Substantial differences with respect to the axisymmetric geometry appear in W7-X, concerning the relative separation of regions with a large fraction of helically trapped particles and those of pronounced bad curvature. For both ITG modes and TEMs, the dependence of their linear growth rates on the background gradients is studied along with their parallel mode structure.

• OSTI ID: 20974930
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 14; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AXIAL SYMMETRY
ELECTRON TEMPERATURE
GEOMETRY
ION TEMPERATURE
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA SIMULATION
STELLARATORS
TEMPERATURE GRADIENTS
TRAPPED ELECTRONS