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Abstract

Preparation of the internal walls of tokamaks by plasma enhanced chemical vapour deposition of boron containing films has now been implemented on several machines since its development on TEXTOR. More recently, such films were deposited on the internal walls of TdeV using not only this procedure but also two new approaches; solid target boronisation (STB) which consisted of inserting a low-density boronised carbon-carbon (C-C) composite into the tokamak plasma, and TMB fuelling where trimethylboron was used as fuelling gas during the plasma discharge. These approaches resulted in a rapid shot to shot improvement of important parameters such as the volume averaged resistivity and radiated power over the first dozen shots when the boron source is present. The radiated power relative to the ohmic power is reduced from 20 to 10 %. When the boron source, present during STB or TMB fuelling, is removed, these plasma parameters start increasing. Within a few tens of shots, they have reverted to their preconditioning values, a situation which previously required hundreds of shots.

Additional information

Authors: BOUCHER C ET AL., Centre Canadien de Fusion Magnétique, Varennes (CA);HIROOKA Y, University of California in Los Angeles, Institute of Plasma and Fusion Research (US);CONN R W, University of California in Los Angeles, Institute of Plasma and Fusion Research (US);MATSUDA T, Toya Tanso Co. Ltd., Osaka (JP);ESSER H G, Forschungszentrum Jülich GmbH, Institut für Plasmaphysik (DE);WINTER J, Forschungszentrum Jülich GmbH, Institut für Plasmaphysik (DE)
Bibliographic Reference: Article: Journal of Nuclear Materials, Vol. 196-198 (1992) pp. 587-591
Record Number: 199310265 / Last updated on: 1994-11-29
Category: PUBLICATION
Original language: en
Available languages: en