title: Evidence for high-m secondary islands induced by large low-m islands in a tokamak plasma.
abstract: 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.
authors.affiliation: FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, PO Box 1207, 3430 BE Nieuwegein, The Netherlands. donne@rijnh.nl
authors.forename: A J H
authors.initials: AJ
authors.lastname: Donné
authors.forename: J C
authors.initials: JC
authors.lastname: van Gorkom
authors.forename: V S
authors.initials: VS
authors.lastname: Udintsev
authors.forename: C W
authors.initials: CW
authors.lastname: Domier
authors.forename: A
authors.initials: A
authors.lastname: Krämer-Flecken
authors.forename: N C
authors.initials: NC
authors.lastname: Luhmann
authors.forename: F C
authors.initials: FC
authors.lastname: Schüller