Evidence for high-m secondary islands induced by large low-m islands in a tokamak plasma.
Small-scale structures with high poloidal mode numbers (m=10-20) have been observed in the TEXTOR tokamak plasma with pulsed radar reflectometry and an electron cyclotron emission diagnostic, in conjunction with large 2/1 and 1/1 islands. The small islands have a peaked density profile, similar to that of the simultaneously observed large-scale 2/1 islands. This together with the observation that high-frequency density and temperature fluctuations are very pronounced near the X points of the large islands hints to a strongly perturbed magnetic topology around the X points.
Donné
A J H
AJ
FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, PO Box 1207, 3430 BE Nieuwegein, The Netherlands. donne@rijnh.nl
van Gorkom
J C
JC
Udintsev
V S
VS
Domier
C W
CW
Krämer-Flecken
A
A
Luhmann
N C
NC
Schüller
F C
FC