Design of low energy backward wave oscillator

Summary form only given, as follows. A backward wave oscillator with the rippled-wall slow wave structure was designed to synchronize with low electron beam energy of 10 keV. The electron beam which is annular would interact with TM modes of periodic rippled-wall structure. To generate a X-band output signal, one-period's length of the rippled-wall SWS should be about 5mm for Cerenkov synchronism. The cold dispersion without electron beam by Swegle's theory and 10 kV beam line showed that the radiation would occur about 10 GHz.