Hydrogen and deuterium depth profiling in divertor tiles of a fusion experiment by micro-ERDA


Hydrogen and deuterium depth profiling in divertor tiles of a fusion experiment by micro-ERDA

Grambole, D.; Herrmann, F.; Behrisch, R.; Hauffe, W.

Depth profiling of light elements in the surface layer of solids by means of ERDA is limited to depths smaller than about 1 mu m. In order to measure the distributions
of hydrogen isotopes in larger depth regions such as needed for the divertor tiles from the tokamak fusion experiment ASDEX-Upgrade in the Max-Planck-Institut
fur Plasmaphysik, samples cut from the divertor tiles (about 0.6 mm tungsten on carbon) were bevelled at different angles by mechanical cutting and polishing or by
ion beam slope cutting. The mechanically cut slopes were additionally cleaned and polished by oblique incidence ion beam sputtering with target rotation to avoid
anisotropic etching.
The surface composition along the slope was measured by ERDA with the Rossendorf Nuclear Microprobe, A 10 MeV Si ion beam was focused to about 3 mu m
and scanned linearly across the slope. The hydrogen and deuterium recoils were detected by a surface barrier detector at a recoil angle of 30 degrees after passing
through a 10 mu m thick Al foil for stopping scattered primary ions. Deuterium was found at depths up to about 25 mu m and hydrogen up to 750 mu m on the
samples analysed.

Keywords: micro-ERDA; elastic recoil detection; depth profiling; hydrogen; deuterium

  • Lecture (Conference)
    6th Int. Conf. on Nucl. Microprobe Technology and Applications, Stellenbosch, South Africa, Oct. 11 - 16, 1998
  • Nuclear Instruments and Methods in Physics Research B 158(1999) 647-652

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Publ.-Id: 2217