1Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Leninskie gory, RU-119991 Moscow, Russia
2Federal State Unitary Enterprise “State Scientific Centre of the Russian Federation, Institute for Physics and Power Engineering named after A. I. Leypunsky,” Bondarenko sq. 1, RU-249033 Obninsk, Kaluga Region, Russia
3National Nanotechnology Laboratory (NNL), Istituto Nanoscienze-CNR, Via per Arnesano 16, I-73100 Lecce, Italy