1. Fisica de les Radiacions, Departament de Fisica, Facultat de Ciencies, Universität Autönoma de Barcelona, 08193 Bellaterra, Spain
2. Quimica Analitica, Departament de Quimica, Facultat de Ciräcies, Universität Autönoma de Barcelona, 08193 Bellaterra, Spain
3. Laboratory of Radiation Physics, Physics Department, University College, Dublin, Ireland