“…At the present time, intensive development of sources of electromagnetic radiation (gyrotrons, ortrons, traveling wave tube, power amplifiers also develop) could be found [1][2][3][4][5]. It is attracted an interests increasing power of emitting of eletromagnetic radiation, increasing of electronic efficiency, decreasing of dimensions of devices, development of mathematical approaches to improve prognosis of operating of the considered devices [6][7][8][9][10][11][12][13][14][15]. In this paper we introduce an analytical approach for analysis of processes in traveling wave tube type O and determination of operation conditions of the tube (see Figure 1).…”