1. Ludwig Maximilians Universität (LMU) München, Medical Physics Department, Am Coulombwall 1, Garching, Germany
2. LMU München, Medical Physics Department, Germany
3. University of Hamburg, Department of Physics, Germany
4. LMU München, Department of Medical Physics, Germany
5. King Saud University, Department of Physics and Astronomy, Ryiadh, Saudi Arabia
6. Università degli Studi di Milano, Department of Physics, Italy
7. Delft University of Technology, Netherlands