Global simulations of ion turbulence with magnetic shear reversal

Garbet, X., Bourdelle, C., Hoang, G.T., Maget, P., Benkadda, S., Beyer, P., Figarella, C., Voitsekovitch, I., Agullo, O. and Bian, N.H. (2001) Global simulations of ion turbulence with magnetic shear reversal. Physics of Plasmas, 8(6), p. 2793. (doi: 10.1063/1.1367320)

Abstract

This paper presents the results of three-dimensional fluid global simulations of electrostatic ion turbulence in tokamaks with reversed magnetic shear. It is found that a transport barrier appears at the location of magnetic shear reversal. This is due to a rarefaction of resonant surfaces in this region. For the same reason, the barrier is more pronounced when the minimum of the safety factor is a simple rational number. The barrier is broadened by velocity shear effects. It is also found that large-scale transport events hardly cross a transport barrier. Finally, a significant amount of toroidal rotation is generated by the turbulence. This rotation changes its sign at the position of magnetic shear reversal, as expected from a quasi-linear estimate of the Reynolds stresstensor.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Bian, Dr Nicolas Horace
• Authors: Garbet, X., Bourdelle, C., Hoang, G.T., Maget, P., Benkadda, S., Beyer, P., Figarella, C., Voitsekovitch, I., Agullo, O., and Bian, N.H.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physics of Plasmas
• Publisher: American Institute of Physics
• ISSN: 1070-664X
• ISSN (Online): 1089-7674