Carbon sputtering of a thin carbon film, a pure graphite sample and a part of an exposed limiter sample from JET

Carbon ions were accelerated to energies in the range 1 to 14 keV, and were used to bombard three different carbon samples (two bulk graphite targets and one evaporated thin carbon film) in order to compare the carbon self-sputtering yields. Sputtered particles were collected on a surface situated in the backward direction. A second, high energy beam was used in quantitative analysis of collected carbon, which could be performed without breaking or changing the vacuum conditions. In thin carbon film case, the change of the film thickness was also monitored. The residual gas composition was continuously studied with a quadrupole mass spectrometer.