[1] SAS, Inst Expt Phys, Watsonova 47, Kosice 04001, Slovakia
[2] Joint Inst Nucl Res, Frank Lab Neutron Phys, Joliot Curie 6, Dubna 141980, Moscow Region, Russia
[3] Helmholtz Zentrum Geesthacht Zentrum Mat & Kstenf, Max Plank Strae 1, D-216502 Geesthacht, Germany
[4] Taras Shevchenko Kyiv Natl Univ, Phys Dept, Volodymyrska St 64, UA-01601 Kiev, Ukraine