Tungsten coating on JET divertor tiles for erosion/deposition studies

Six Joint European Torus (JET) divertor tiles were coated with tungsten marker stripes for erosion/deposition studies. The average thickness was 3.4 mum and the film was uniform within 5% across and within 10% along the stripe. Small amounts of impurities C, Fe, Ni and Cr were found and the in-plane stress was 965 MPa. Resistance to high heat loads was tested in the Neutral Beam Test-bed at JET where a coated carbon fibre composite block was exposed to a total of 113 pulses with a maximum peak power density of 15.7 MW m(-2) and a maximum surface temperature of 1280 degreesC. No visible changes as a result of thermal cycling nor sputtering of the film by deuterium could be detected. (C) 2003 Elsevier Science B.V. All rights reserved.