[1] Russian Acad Sci, PN Lebedev Phys Inst, Opt Dept, Lab Xray Astron Sun, Moscow, Russia
[2] Royal Observ Belgium, Solar Terr Ctr Excellence IDC, Brussels, Belgium
[3] Polish Acad Sci, Space Res Ctr, Warsaw, Poland
[4] Russian Acad Sci, Inst Phys Microstruct, Nizhnii Novgorod, Russia