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Numerous experimental observations have shown the existence of non-diffusive transportation in tokamak plasmas. We are interested here in the so-called 'side' turbulence located in the SOL (Scrape Off Layer), corresponding to the area where the open field lines intercept elements from the wall. Several sloping threshold instability mechanisms are likely to be responsible for this electrostatic turbulence, particularly the interchange mechanism. Studies at the CEA at Cadarache and at the University of Provence (cf. [1], [2]), have already shown an intermittent dynamism associated with occurrences of large-scale transportation in the radial direction of the core, called 'avalanches' or 'fronts'.

This report is concerned with the study of the transportation of test particles in these fluctuating power fields, with the initial aim of describing this transportation and of comparing it with the fluid description made. It was also concerned with studying the impact of these large occurrences on the trajectories of the test particles.

This report is broken down into 3 parts. We firstly recall the simplified fluid equations linked to the instability studied. These equations are not only supported by a classical forcing approach by the gradient but also by a new approach (cf [1]) based on forcing by flow. This approach, where the flow of particles coming from the heart of the plasma is set, does not presuppose any separability of scales between the balanced and the fluctuating part of physical sizes. Secondly, we present the equations which govern the trajectories of the test particles in such a flowing power. Finally, to end, we give the results obtained in the two simulations.

Additional information

Authors: GRANDGIRARD V ET AL, Equipe de Dynamique des Systemes Complexes, CNRS-Universite de Provence, PIIM, Case 321, 13397 Marseille (FR);GARBET X ET AL, Association EURATOM-CEA, CE Cadarache, DRFC, F-13108 St. Paul-lez-Durance (FR)
Bibliographic Reference: Report: EUR-CEA-FC-1704 (2000) 58pp., Euro:FREE of charge
Availability: Available from European Commission, DG XII Communication Unit rue de la Loi/Wetstraat 200, B-1049 Bruxelles (BE) Tel: +32-2-2950001 Fax:+32-2-2958220 email:
ISBN: ISBN Not available
Record Number: 200012915 / Last updated on: 2000-12-18
Original language: fr
Available languages: fr