1. Institute of Physics of National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine
2. Laboratoire de Physique des Lasers, Atomes et Molecules (PhLAM) Faculté des Sciences et Technologies, L’Université de Lille, Sis 42, Rue Paul Duez, 59800 Lille, France
3. V.I. Vernadsky Institute of General and Inorganic Chemistry of National Academy of Sciences of Ukraine, 03142 Kyiv, Ukraine
4. Department of Physics and Engineering Physics, Central Connecticut State University, New Britain, CT 06050, USA