Investigation of a Ka-Band High-Power Sheet Beam Relativistic Extended Interaction Oscillator

The sheet beam relativistic extended interaction oscillator (REIO) is a very important high-power millimeter-wave source for many actual and potential applications. A Ka-band sheet beam REIO is designed by means of particle-in-cell (PIC) simulation. In the design, we adopt a sheet electron beam with dimensions of 45 mm × 1.5 mm to reduce the space charge effect and the extended interaction cavities to increase the power capacity. The results of the PIC simulation demonstrate the device can generate an output power of 404 MW at 30 GHz with an efficiency of 20%. In addition, we develop the experiment on a short-pulse accelerator. In the experiment, the oscillator generates a millimeterwave power of 125 MW with a beam current of 4 kA, a beam voltage of 500 kV, and guiding magnetic field of 1 T. The frequency of the output millimeter wave is 30.6 GHz and the pulsewidth is 16 ns. The experiment proves that millimeter wave of over 100 MW can be generated with the sheet beam REIO.