High frequency mode cascades in the ASDEX Upgrade tokamak
Using a novel diagnostic, cascades of high frequency modes have been observed in the core plasma of the ASDEX Upgrade tokamak. Their mode numbers obey the relation m = n+1, with n up to 23. The appearance of cascades is always related to a region of low shear, which is ascribed to previous (m,n) = (1, 1) mode activity and leads to the instability of tearing modes with high mode numbers. The destabilization and stabilization of modes resulting in the cascade process can be reproduced by a simple quasilinear model.
Bibliographic Reference: Article: Physical Review Letters, Vol. 80 (1998) No. 2, pp. 293-296
Record Number: 199810524 / Last updated on: 1998-05-05
Original language: en
Available languages: en