Low Voltage Folded Waveguide Multiple Beam Mini-Twts: Design and Modeling

Abstract

Multiple beam vacuum electronic devices are attractive for many applications since they are able to produce high output power at moderate or low operating voltages. Multiple Beam Traveling Wave Tubes (MB-TWT) based on folded waveguide slow wave structures (FW-SWS) are new devices suitable for efficient interaction with spatially distributed multiple electron beams. At the same time, increase in the transverse size of an area occupied by the electron beams leads to reduction of starting currents of higher order modes spurious oscillations in comparison with single beam TWTs. Therefore, design of MB-TWTs should address both the interaction of the operating mode with the spatially distributed beam as well as stability with respect to spurious modes excitation. To address these issues the NRL design codes TESLA and CHRISTINE has been developed and verified to be suitable for modeling and design of MB-TWTs with FW SWS.