Sputtering of boron doped graphite USB15 : Investigation of the origin of low chemical erosionFunded under: EAEC-FUSION 12C
The changes in the surface composition of USB15 - a boron doped graphite containing 15 wt% of boron - during bombardment with D-ions were determined by in situ Auger electron spectroscopy at temperatures from 300 to 1000 K. For energies above 100 eV no strong increase of the boron surface concentration could be observed even around 800 K (the maximum for chemical erosion of pure graphite). The carbidic fraction of carbon atoms was much larger than expected. Thus boron has more influence on carbon atoms in their chemical reactivity with deuterium ions than predicted for the stoichiometric B(4)C precipitates. For ion energies below 100 eV a strong increase of boron surface concentration with decreasing ion energy at room temperature was observed. The chemical erosion of carbon in this energy regime is not suppressed by boron doping and indicates a different, surface related release process of hydrocarbon molecules.
Bibliographic Reference: Article : Journal of Plasma Physics, Vol. 77 (1995) No. 8, pp. 3812-3817
Record Number: 199510851 / Last updated on: 1995-08-03
Original language: en
Available languages: en