Impurity coverage and deuterium inventory of beryllium and carbon first wall components after beryllium operation in JET

During 1989, following a brief all carbon phase, JET are operated with an evaporated beryllium film on all the plasma facing surfaces and then, in a third phase, with bulk beryllium used for the belt limiters and one set of antenna protection tiles. Subsequent analysis of wall components and long term samples (LTS) using Beta Backscatter and Ion Beam Analysis has been conducted to determine the condition of the First Wall and its deuterium inventory after beryllium operation. Ex-situ analysis of components where deposition occurs during operation shows mixed carbon and beryllium layers with an approximate ratio 1:1 and some localised higher Z components. The deuterium inventory situation is little changed by the introduction of beryllium. Similar surface levels of deuterium, ≅ 1x1022 atoms m-2, have been seen for both carbon and beryllium belt limiter tiles. (orig.)