Community Research and Development Information Service - CORDIS


The implementation of super-conducting field coils in future fusion devices will lead to significant extended discharge duration but will also require new techniques for the wall conditioning, because glow discharges are not compatible with the permanent magnetic fields.

This report is dedicated to the investigation of microwave generated plasmas in a toroidal magnetic field. In the first part the discharge is characterised in dependence on the selectable parameters magnetic field strength, neutral gas pressure and microwave input power. Spatial measurements of the electron density and temperature were done for different process gases to allow an extrapolation of the results on the plasma parameter during the layer deposition in reactive gaseous like methane (CH(4)) or acetylene (C(2)H(2)).

As a result of the application of various diagnostics, the spatial distribution of the film thickness on the wall of the vessel could be distinguished. Further on, the composition of the layers by carbon and hydrogen could be analysed and the thermal stability of the films was investigated ex-situ. The results of these measurements leads to an improved understanding of the film growth and the influence of neutral radicals and charged hydrocarbons on it. In addition, the erosion of the deposited layers by discharges in hydrogen, deuterium and oxygen has been characterised by mass spectrometry and investigation of the layer thickness by interference colour analysis.

Additional information

Authors: IHDE J, Institut für Plasmaphysik, EURATOM Association, Trilateral Euregio Cluster, Forschungszentrum Jülich, Jülich (DE)
Bibliographic Reference: Berichte des Forschungszentrums Jülich no. 3935, December 2001, pp.169. Free of charge
Availability: Available from Forschungszentrum Jülich GmBh - Zentralbibliothek Tel: (+49) (2461) 61-5220 Fax: (+49) (2461) 61-6103 E-mail:
ISBN: ISSN: 0944-2952
Record Number: 200215343 / Last updated on: 2002-10-22
Original language: de
Available languages: de