Kiel 2004 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

P: Plasmaphysik

P 8: Plasma-Wand-Wechselwirkung I

P 8.3: Fachvortrag

Tuesday, March 9, 2004, 16:05–16:25, H\"orsaal D

A new active charge-exchange diagnostic for measuring the poloidal plasma rotation at the tokamak TEXTOR — •C. Busch, A. Kreter, B. Schweer, B. Unterberg, and U. Samm — Institut für Plasmaphysik, Forschungszentrum Jülich GmbH, Trilateral Euregio Cluster, EURATOM Association, 52425 Jülich, Germany

The Dynamic Ergodic Divertor (DED) installed recently in the TEXTOR tokamak consists of 16 magnetic coils wound helically around the torus at the high field side. A resonant perturbation of the magnetic field is induced at the plasma edge where an ergodic zone (long magnetic connection lengths to the wall) and a laminar zone (short connection lengths) are formed. In the laminar zone the DED forms a helical divertor. The study of the impact of the DED on the transport properties is one major topic of research. In particular the AC operation at frequencies up to 10 kHz is expected to increase the rotation of the plasma.

The observed charge-exchange recombination processes via the CVI emission line (n= 8 → 7, λ₀= 5290.5 Å) are provided by a diagnostic hydrogen beam. It has already been used to determine radial profiles of the ion temperature and impurity densities and is now also deployed to measure the plasma rotation from the doppler shift of the CVI line. For this the low field side observation (r/a = 1.0 − 0.5) has been equipped with lines of sight looking at the beam from the top and from the bottom which provides an in-situ measurement of λ₀. The system consists of 20 radial channels with a spatial resolution of 1 cm at the plasma edge, a best spectral resolution of 0.05 Å and a time resolution of 50 ms according to the modulation period of the beam. Initial results will be given.