Study On W-band Quasi-optical Cavity Radiation Source

Diffraction radiation oscillator, called DRO for short or Orotron, is a sort ofvacuum electronic radiation source with an open resonator and a reflecting grating inmillimeter and submillmeter band. The device is based on the Smith-Purcel effect. TheDRO progress goes in the direction of DRO enhancement towards a low-voltage devicewith high output power and frequency stability and a narrow spectral line width of thegeneration signal in the frequency region up to300GHz and above. To improve thefield distribution across the strip beam, the DRO-orbictron was put forward. TheDRO-orbictron had a better factor of resonance field utilization by the beam at shorterwavelengths, small size, low voltage, low current and other characteristics. It has a goodapplication prospects.Based on the principle of the electronic sheet beam，a sheet beam electron gun andthe magnetic focusing system was designed. The gun was investigated detailed in PICsimulation. The effects of the magnetic field, the distance of two electrodes, thethickness of the superstratum and the voltage of the anode on the transmissioncharacteristic of the sheet beam were studied, respectively. Based on the summary of thevarious advantages and disadvantages of uniform magnetic field generation methods,the Halbach permanent magnet was used. The distribution of magnetic field along the Zaxis and X axis was analyzed in electromagnetic simulation. The PIC simulation wascarried out with the magnetic field and beam transmission of100%was obtained.In addition, the cold characteristics of the DRO-orbictron was studied. The fielddistribution and the influence of resonant structure parameters on Q factor and the factorψ of resonance field utilization by the electron beam were analyzed. Finally, based onthe preliminary analysis, the physical process of the DRO-orbictron was simulated inPIC simulation and the impact of the electrical parameters on the output of theoscillator was analyzed.