1. CERN, Geneva 23, Switzerland
2. CERN, Université Jean Monnet, Saint-Étienne, France
3. CERN, Institute d’Électronique et des Systèmes, Université de Montpellier, Montpellier, France
4. GSI, Darmstadt, Germany
5. European Space Agency, Noordwijk, AZ, The Netherlands
6. Physik-Institut—Medical Physics and Radiation Research, University of Zurich, Zurich, Switzerland