1. Institute for Scintillation Materials of the National Academy of Sciences of Ukraine 1 , Kharkiv 61001, Ukraine
2. B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine, Kharkiv 61103 2 , Ukraine
3. Max-Planck-Institut für Physik komplexer Systeme 3 , D-01187, Dresden, Germany
4. V. N. Karazin Kharkiv National University 4 , Kharkiv 61022, Ukraine