Generation of powerful subnanosecond microwave pulses by intense electron bunches moving in a periodic backward wave structure in the superradiative regime

N S Ginzburg, N Y Novozhilova, I V Zotova, A S Sergeev, N Y Peskov, A D R Phelps, S M Wiggins, A W Cross, K Ronald, W He, V G Shpak, M I Yalandin, S A Shunailov, M R Ulmaskulov, V P Tarakanov