D.R. Belichko, T.E. Konstantinova, A.V. Maletsky, G.K. Volkova, M.V. Lakusta, (Donetsk; Institute for Physics and Engineering named after O.O. Galkin, Kiev, Ukraine), D. Mardare, C. Mita, N. Cornei (Alexandru IoanCuza University of Iasi, Faculty of Physics, Romania)