1. Laboratory of Biomedical Technologies, Agenzia Nazionale per le Nuove Tecnologie, l’Energia e lo Sviluppo Economico Sostenibile (ENEA), CR-Casaccia, Rome, Italy
2. Department of Science, University Roma Tre, Rome, Italy
3. Department of Radiation Physics, Università degli Studi Guglielmo Marconi, Rome, Italy
4. Technical Unit of Energetic Efficiency, ENEA, Rome, Italy
5. Department of Physics, University of Pavia, Pavia, Italy