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Abstract

Recent work on JT -60U and JET indicates that ELM occurrences sometimes exhibit behaviour that is characteristic of a deterministic, non-linear dynamical system in a chaotic state. The ELM time-series of some discharge were found to contain a specific type of short sequence known as an Unstable Periodic Orbit (UPO). This result opens the door to a new way of characterising the dynamics of ELMs, and also is extremely encouraging from the point of view of controlling the ELM amplitudes by controlling the ELM period. We extend this previous work by examining the ELM time-series from a large number of ELMy H-mode discharges from the TCV tokamak for occurrences of UPOs. Further, we investigate how the properties of UPOs found vary with plasma parameters, pointing the way to establishing the necessary requirements for candidate models of ELM dynamics.

Additional information

Authors: DEGELING A.W, Centre de Recherches en Physique des Plasmas, EURATOM Association-Confederation Suisse, Ecole Polytechnique Federale de Lausanne (CH);MARTIN Y.R, Centre de Recherches en Physique des Plasmas, EURATOM Association-Confederation Suisse, Ecole Polytechnique Federale de Lausanne (CH);LISTER J.B, Centre de Recherches en Physique des Plasmas, EURATOM Association-Confederation Suisse, Ecole Polytechnique Federale de Lausanne (CH);LLOBET X, Centre de Recherches en Physique des Plasmas, EURATOM Association-Confederation Suisse, Ecole Polytechnique Federale de Lausanne (CH);BAK P.E, JAERI Naka Fusion Research Establishment, Ibarak-ken (JP)
Bibliographic Reference: An oral report given at: The 28th EPS Conference of Controlled Fusion and Plasma Physics. Held in: Madeira (PT) June 2001
Record Number: 200013694 / Last updated on: 2001-09-18
Category: PUBLICATION
Original language: en
Available languages: en