1. Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
2. Utrecht University, H. R. Kruyt Building, Padualaan 8, 3584 CH Utrecht, The Netherlands
3. FEI Electron Optics, Achtseweg Noord 5, 5600 KA Eindhoven, The Netherlands