Shabanov D. S. RussiaMoskow Moscow Insitute of Electronics and Mathematics of National Research University "Higher School of Economics", Trekhsvyatitel`skii per. 3/12, Moscow, 109028, Russia deepgmail@gmail.com Additional info Студент МИЭМ НИЭ ВШЭ. Author's articles STUDY OF DISCRETE ELECTRON-WAVE INTERACTION IN THE PASSBAND AND STOPBAND OF SLOW-WAVE SYSTEMS