1. Centre for Environmental Radioactivity (CERAD), Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway
2. Swiss Light Source, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
3. AXIS Group, NANOlab Center of Excellence, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
4. Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Brehova 7, 166 36 Prague 1, Czech Republic