On the calculation of the feeding coefficient of an open resonator of a diffraction radiation oscillator

For the oscillatory circuit, the diffraction radiation oscillator (DRO) uses a high-Q open resonator (OR), with electron-wave processes of the energy exchange proceeding on OR eigenoscillations. Given the wavelength and the OR geometry, wave types of the excitation can be both theoretically predicted and practically measured . The power transfer to the volume wave component of the OR oscillation comes about by virtue of the electron beam interaction with surface harmonics of the volume wave. When the resonator is open, the interaction gets more complex since a nonresonant noise associated with the electromagnetic energy radiation from the resonator is produced by an active power rather than reactive