Experimental investigation and modelling of electrostatic fluctuations in the scrape-off layer of the ASDEX tokamak and the Wendelstein 7-AS stellarator
In recent years it has become widely accepted that the processes of energy transport, not only in the centre of the plasma but also in the scrape-off layer at the plasma edge, directly affect the feasibility of nuclear fusion. In this project, fluctuations in plasma density and electric potential in the plasma edge layers in the ASDEX tokamak and the W7-AS stellarator were measured using H(alpha) fluctuation diagnostics of high spatial (poloidal) and temporal resolution. The nature of the spatial and temporal correlation between fluctuations of the floating potential and the ion saturation current presents a picture of fluctuation events, eddies of short duration, which cause at least a sizeable portion of the radial transport of particles within the scrape-off layer. It should be possible to exert a degree of control over the fluctuations and the anomalous transport, for which there is no theoretical explanation, and thus to optimise radial profiles in this part of the plasma for the operation of a fusion reactor.
Bibliographic Reference: Report: IPP 111/197 DE (1994) 256 pp.
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199411560 / Last updated on: 1995-01-10
Original language: de
Available languages: de