1. Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Košice, Slovakia
2. Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow region, Russia
3. Physics Department, Taras Shevchenko Kyiv National University, Volodymyrska 64, 01601 Kyiv, Ukraine
4. GKSS Research Centre, Max-Planck-Str. 1, 21502 Geesthacht, Germany