Later analysis with alternative methods confirmed the XPS-results that none of the graphite had been seriously contaminated in the incident. Afterwards they were analyzed by XPS with respect to the composition of the boronization layer. Peaks with significant intensities could be detected only for boron, carbon and oxygen. Traces of other elements were probably present, but their signals were so weak that assignment and even more so quantification are not possible with any certainty. The average compositions of the two samples did not deviate much from each other.
Carbon is incorporated in a form with only little bonding to other partners.
In addition carbon is found as a post-deposition contamination on the surface of the as received samples. The increased content of carbon in the film compared to values found on samples from earlier boronization procedures reflects the enlarged carbon surface in the TCV, although other possible influences will have to be ruled out. Our work on TCV samples greatly depends on schedule and requirements at that facility. For this reason our plans focus on further in situ experiments with amorphous carbon.