Curved Geometry Collector Design for High-Power Gyrotraveling Wave Tubes

The collector is an important component in a gyrotraveling wave tube (gyro-TWT) and its performance influences the overall capability of the tube. In our previous W-band gyro-TWT, the collector melted due to high thermal dissipation of the spent beam electrons. To improve collector performance, a curved geometry has been employed to distribute the dissipated heat power more uniformly. In simulations, compared with the previous cylindrical geometry collector, the maximum dissipated power in the curved collector was reduced from 0.83 to 0.396 kW/cm² and the maximum temperature in the collector was reduced from 395 °C to 194 °C (using an average output power of 96 kW). Thus, the thermal capability of the collector was improved. The curved geometry collector was validated in the experiment, and the gyro-TWT was operated stably with a peak output power of 110 kW.