W7-AS Contributions to the 13th International Conference on Plasma Surface Interactions in San Diego/USA, May 18-22, 1998. W7-AS Contributions to the 25th EPS Conference on Controlled Fusion and Plasma Physics in Prague, June 29 to July 3, 1998. W/-AS Contributions to the 17th IAEA Fusion Energy Conference in Yokohama, Oct. 19-24, 1998