1. Canberra Packard Ltd, 18 Clejani St., 051036 Bucharest 5, Romania
2. Bucharest Polytechnical University, Faculty of Applied Sciences, Splaiul Independenţei nr 313, Bucharest, Romania
3. National Institute for Nuclear Physics and Engineering ‘Horia Hulubei’—IFIN-HH, Bucharest—30 Reactorului St, Măgurele, Ilfov County, Romania
4. National Institute for Lasers, Plasma and Radiation Physics, Bucharest—409 Atomistilor St., Măgurele, Ilfov County, Romania