1. Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
2. Belgien Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol, Belgium
3. Nofer Institute of Occupational Medicine (NIOM), St Teresa 8, 91-348 Lodz, Poland