Does magnetic shear stabilize drift waves
Abstract
Shear in the magnetic field of conventional planeslab models is known to have a damping effect on plasma drift waves. However, in a more realistic system in which conditions vary over a magnetic surface, waves associated with different surfaces become coupled together. Damping due to shear is reexamined, and it is shown that it may be completely eliminated if either the field strength or the shear itself is sufficiently nonuniform across a magnetic surface. If the nonuniformity is sufficient, the drift wave becomes completely nonpropagating, even in the presence of strong shear. A study of model examples leads to the conclusion that shear stabilization in a real system may be ineffective and drift waves may be unstable even if the conventional criteria for shear stabilization are well satisfied.
 Publication:

Plasma Physics and Controlled Nuclear Fusion Research 1976, Volume 2
 Pub Date:
 1977
 Bibcode:
 1977ppcf....2..323T
 Keywords:

 Magnetic Effects;
 Magnetohydrodynamic Stability;
 Plasma Waves;
 Shear Flow;
 Drift;
 Magnetic Mirrors;
 Mathematical Models;
 Toroidal Plasmas;
 Plasma Physics