CHARACTERISATION OF FILMS DEPOSITED BY IN-SITU WALL CARBONISATION IN TEXTOR
Carbonaceous films as produced for in-situ wall conditioning purposes in the TEXTOR tokamak have been investigated with SIMS (Secondary Ion Mass Spectroscopy) and AES (Auger Electron Spectroscopy). The measurements were supplemented by optical analyses and mechanical thickness measurements. The exposure to the in-situ carbonization process has been performed by placing the samples (Si, graphite, glassy carbon, Ni, Cr, and inconel) in liner positions. Independent of the substrate material the obtained films were homogeneous in thickness and composition. Depth profiles revealed impurity-free films with constant C/H ratio and slightly contaminated interfaces. The contaminants, i.e. metals (Fe, Ni, Cr) and O as detected on appropriate substrates, are supposed to be deposited due to sputtering of wall material during the initial period of the carbonization process. It is shown that the hydrogen in the carbon film is strongly bound. Exchange processes of the incorporated hydrogen during plasma discharges have been investigated. Blistering of the carbon films during noble gas ion bombardment have been observed.
Bibliographic Reference: JOURNAL OF NUCLEAR MATERIALS, PP 651-654, 1987
Record Number: 1989126073400 / Last updated on: 1989-05-01
Available languages: en