1. Contribution from the Division of Ion Physics, Department of Materials Science, Uppsala University, Box 534, S-751 21 Uppsala, Sweden, Vapor Technologies Inc., Boulder Tech Center, 6400 Dry Creek Parkway, Boulder, Colorado 80503, Manne Siegbahn Laboratory, Frescativägen 24, S-104 05 Stockholm, Sweden, Neuroscience Research Institute, University of California, Santa Barbara, California 93106, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany, Department of Molecular Biology,...