Global linear gyrokinetic simulations in quasi-symmetric configurations

Citation
G. Jost et al., Global linear gyrokinetic simulations in quasi-symmetric configurations, PHYS PLASMA, 8(7), 2001, pp. 3321-3333
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICS OF PLASMAS
ISSN journal
1070-664X → ACNP
Volume
8
Issue
7
Year of publication
2001
Pages
3321 - 3333
Database
ISI
SICI code
1070-664X(200107)8:7<3321:GLGSIQ>2.0.ZU;2-Q
Abstract
First global linear study of electrostatic drift waves in two realistic qua sisymmetric configurations, namely the Quasi-Axially symmetric Stellarator with three fields periods (QAS3) [P. Garabian and L. P. Ku, Phys. Plasma 6, 645 (1999)] and the Helically Symmetric eXperiment (HSX) [F. S. B. Anderso n , Trans. Fusion Technol. 27, 273 (1995)], are presented. Effects of the s hape of the plasma on the growth rate and frequency of the ion temperature gradient (ITG) driven mode are investigated by varying the quasi-symmetric configurations to an equivalent symmetric system. The calculations have bee n performed using a three-dimensional (3D) global gyrokinetic code in the m agnetic configurations provided by the magnetohydrodynamic (MHD) equilibriu m code VMEC [S. P. Hirshman and D. K. Lee, Comput. Phys. Commun. 39, 161 (1 986)]. The plasma is modeled by gyrokinetic ions and adiabatic electrons. I n QAS3, results are very close to those obtained for a tokamak. The drift w aves are only slightly affected by the shape of the plasma or the local mag netic shear. On the other hand, results for the HSX configuration show a cl ear 3D effect, namely a strong toroidal variation of the drift wave mode st ructure. This variation is a clear structure of the 3D plasma shape. Howeve r, first results show that the growth rate of the ITG driven mode is largel y unaffected by this effect. (C) 2001 American Institute of Physics.