Institution: | a Department of Atomic Physics, Eötvös University, Puskin u 5-7, 1088, Budapest, Hungary b Department of Applied Physics, Faculty of Engineering, Nagoya University, Nagoya 464-01, Japan c Computer and Automation Institute of HAS, P.O.B. 63, 1518, Budapest, Hungary d Institute for Technical Physics, P.O.B. 76, 1325, Budapest, Hungary |