1. Fraunhofer Institute for Material and Beam Technology, Winterbergstraße 28, DE-01277 Dresden, Germany
2. Department of Materials Technology, Technische Universität Dresden, Helmholtzstr. 7, DE-01069 Dresden, Germany
3. ESA/ESTEC, European Space Research and Technology Centre, NL-2201 AZ Noordwijk, The Netherlands
4. Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-971 87 Luleå, Sweden