1. Engineering Department, Lancaster University, Bailrigg, Lancaster, Lancashire LA1 4YR, UK
2. Radiation and Genomic Stability Unit, Medical Research Council, Harwell, Didcot, Oxfordshire, OX11 ORD, UK
3. Computational Dosimetry Research Group, Physics Department, Clatterbridge Centre for Oncology, Bebington, Wirral, Merseyside CH63 4YY, UK
4. National Microelectronics Research Centre, Cork, Ireland
5. Instrument Development Services, SMITE, BAE SYSTEMS (Marine), Barrow-in-Furness, Cumbria, LA14 1AF, UK