A NOVEL HYBRID SLOW-WAVE FAST-WAVE TRAVELING-WAVE AMPLIFIER/

We introduce a new broad-band amplifier configuration which contains e lements of both linear and cyclotron resonance maser microwave tubes, A helix slow-wave structure is used to bunch a linearly streaming annu lar electron beam, A nonadiabatic magnetic transition, which is placed after a drift region at the point where the ac beam current is nearly maximized, converts much of the beam's axial momentum to rotational m omentum, The beam then travels through a tapered right-circular wavegu ide, where microwave energy is extracted via the gyrotron interaction, The design of a proof-of-principle X-band amplifier is given, and the codes that are used in the simulation are described, The nominal beam voltage and current are 45 kV and 8 ii, respectively. The tube is pre dicted to be stable, to possess a peak efficiency above 43%, and to ha ve an instantaneous bandwidth of over 9%.