1. Separated Sector Cyclotron (SSC) Laboratory, Radiation Biophysics Division, National Research Foundation (NRF)-iThemba Laboratories for Accelerator Based Sciences (LABS), Cape Town 7100, South Africa
2. Department of Medical Biosciences (MBS), Faculty of Natural Sciences, University of the Western Cape (UWC), Cape Town 7530, South Africa
3. Biophysics Department, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
4. Dr Willem Burger Consulting, Mossel Bay 6503, South Africa
5. Institut für Physik Kondensierter Materie, Technische Universität (TU) Darmstadt, 64289 Darmstadt, Germany
6. Genetics Department and Biodosimetry Service, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay