Turbulence associated with the sawtooth internal disruption
Specific turbulence associated with the sawtooth internal disruption has been observed on TFR tokamak plasmas by analysing density fluctuations with CO(2) laser light scattering. The time localisation is clearly connected with the successive phases of the relaxation process. Some specific turbulence appears in relation to the kink motion, but the main burst corresponds to the collapse phase. The study concentrates on this strong burst, showing its frequency and wave number spectral properties and the corresponding pseudo dispersion relation. The specific tubulence is spatially localised. It is within the interior of the q = 1 surface and extends approximately 120 degrees azimuthally. Taking into account the twisting of the central plasma during the turbulent kink phase, this location agrees with the azimuthal position of the "sooner and faster" outgoing heat flux. The power level of this turbulence is two orders of magnitude larger than the local quasi-stationary turbulence. These observations are in fair agreement with the predictions of the sawtooth disruption model previously proposed by Andreoletti. The observed specific turbulence shows several similarities with the so called "magnetodrift turbulence" described in the model.
Bibliographic Reference: Report: EUR-CEA-FC-1365 EN (1989)
Availability: Available from CEA, Département de Recherches sur la Fusion Contrôlée, Saint-Paul-lez-Durance (FR)
Record Number: 198911025 / Last updated on: 1994-12-01
Original language: en
Available languages: en