Collisionless drift waves in the H-mode edge
The magnetic shear stabilisation criteria of collisionless drift waves for steep density gradients, as observed in H-mode edges, are considered in this report. The criteria are found to be severely restricted in the H-mode edge plasma. The effect of a radially sheared transverse equilibrium velocity field on collisionless electron drift waves is then investigated. The drift wave is found to be linearly stabilised by a velocity profile corresponding to that found in the region a few centimetres inside the separatrix of an H-mode plasma. However, a velocity profile corresponding to the L-mode is shown to have a destabilising effect in the experimental range of parameters, even though the magnetic shear continues to play its stabilising role.
Bibliographic Reference: Report: AEA FUS 245 EN (1993) 14 pp.
Availability: Available from the Librarian, UKAEA, Culham Laboratory, Abingdon, Oxon. OX14 3DB (GB)
Record Number: 199311246 / Last updated on: 1994-11-29
Original language: en
Available languages: en