Experiment and Power Capacity Investigation of Collector in the 50-kW-Average-Power Q-Band Gyro-TWT

To further increase the average output power of the Q-band gyrotron traveling wave tube (gyro-TWT), the power capacity and stability of the collector are investigated. In this article, the characteristics of the electron collection, the modeling of the cooling system, and the suppression of stray electrons are analyzed. The dissipated power is associated with the transverse energy of the electron beam. When the gyro-TWT operates at zero drive, the collector has a maximum dissipated power density of 2 kW/cm(2) for a high average power state. Thermal results indicate a maximum temperature of 381 degrees C on the collector with an optimized cooling system. By applying a transverse magnetic field, the stray electrons can be completely intercepted by the collector. The hot experiment results indicate that the gyro-TWT (45% duty cycle), driven by a 60-kV-9.82-A electron beam, can withstand a maximum beam power of 265 kW at zero drive. Then, a pulse power of 111 kW, with an average power of 50 kW and an efficiency of 18.8% at 47 GHz, is measured stably. The simulation and experimental results demonstrate the high-power capacity and high stability of the curved collector.