Non linear drift wave turbulence
Many features of a drift wave turbulence are in agreement with the measurements of fluctuations and transport in tokamaks. However, the traditional model of a drift wave driven by trapped electrons fails to explain some well reproducible experimental behaviours. In this work, the possibility of non linear radial localisation of Fourier modes near their associated resonant surfaces is emphasised. Such a localisation would enhance the coupling between modes and electrons, including circulating electrons, and therefore decrease the turbulence threshold. It is shown that the required localisation effect is possible through a soliton-like effect. It is also demonstrated numerically that such a turbulence can propagate over macroscopic scales in transient situations. In a stationary regime, it can also exhibit correlations over large distances, even if the Fourier mode is strongly localised near its resonant surface, leading to a non-local behaviour.
Bibliographic Reference: Paper presented: 1993 International Sherwood Fusion Theory Conference, Newport, Rhode Island (US), March 28-31, 1993
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Record Number: 199310616 / Last updated on: 1994-11-29
Original language: en
Available languages: en