Chemical sputtering measurements in Tore Supra by aftershot mass spectrometry outgassing studies J. Vac. Sci. Technol. A 15, 2597 (1997 Fabrication of cross-linked polymer shells for inertial confinement fusion experiments J. Vac. Sci. Technol. A 15, 683 (1997) Tritium permeation and inventory in an international thermonuclear experimental reactor divertor J. Vac. Sci. Technol. A 15, 169 (1997) Measurements of tritium retention and removal on the Tokamak Fusion Test ReactorAmorphous C:D ͑or C:H͒ films were deposited on the inner surface of a spherical ultrahigh vacuum chamber by means of a direct current glow discharge in a ϳ75% D 2 ͑or H 2 ͒ and ϳ25% CD 4 ͑CH 4 ͒ gas mixture. Laser Raman spectroscopy analysis of the film exhibited the absence of a diamond peak at 1334.3 cm Ϫ1 . The general appearance of the spectra was indicative of a polymerlike film. Upon exposure of the C:D film to 18 O 2 , almost all of the released deuterium was seen to be in the D 2 18O chemical form, with less than 1% released as D 2 . C 18 O 2 was observed to be the main C-containing reaction product of the 18 O 2 exposure. No methane release was detected. x-ray photoelectron spectroscopy and secondary ion mass spectroscopy analyses of the films indicated the appearance of carbonyl groups ͑ϾCvO͒ and an increase in the concentration of hydroxyl groups ͑-COD͒ due to surface oxidation. The generally accepted scheme for simple thermal oxidation of hydrocarbon polymers was used to provide a plausible reaction mechanism leading to emissions of the reaction products D 2 O, CO 2 , and CO.

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Surface properties of Kapton@ were analysed after different exposures to ground state fast atomic oxygen (FAO) and vacuum ultraviolet radiation in the atomic oxygen beam facility at the University of Toronto Institute for Aerospace Studies. X-ray photoelectron spectroscopy, scanning electron microscopy and contact angle measurements were used to characterize the chemical and physical changes to the surfaces of the materials analysed. The most important changes in the surface chemistry of Kapton induced by the various exposures to F A 0 were oxidative degradation of the polymer and substantial changes in supermolecular organization and morphology of the surface layer. A very weak adhesion of the rough top layer to the original Kapton has been observed after an atomic oxygen irradiation with a total fluence of 1.3 x 10" atoms cm-', which is comparable to some low earth orbit (LEO) exposures. Comparison was made between pristine samples and the cleaned surface of samples that had been exposed in the atomic oxygen beam facility and in the LEO environment. An ageing effect was observed in the surface layer of exposed samples after a prolonged storage. For several polymer materials, a correlation was found between the erosion yield when exposed to F A 0 and the dispersion component of the surface tension of the pristine material.

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