A. Yu. Ignatovskiy (NIC "Kurchatov Institute", Moscow Institute of Physics and Technology), I. V. Panov (NIC "Kurchatov Institute"), A. V. Yudin (NIC "Kurchatov Institute")
J. Speicher (Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology), D. R. Ballantyne (Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology), P. C. Fragile (Department of Physics & Astronomy, College of Charleston)