Design of a Novel Spherical TWT Multistage Depressed Collector

THz wave is one of the most important technologies today, and the traveling wave tube (TWT) is a common amplifier for THz wave. Because the efficiency of the TWT is inferior to expected, most of the energy of the electron beam will be wasted if the TWT doesn’t collect and reuse them. Thus, the multistage depressed collector (MDC) is a necessary component in the TWT to improve the energy efficiency of the TWT and prevent the energy dissipation. The generation of secondary electrons is always a problem that can decrease the collector efficiency and affect the lifetime of the material. To suppress the emission of the secondary electrons, this paper designs a novel MDC with a spherical collector. This structure finally obtains a high collector efficiency and low electron reflux rate as 91.6% and 0.064% respectively when collecting the electrons from a G-band TWT. The spherical structure can reduce the amount of the material compared with the traditional structure.