An analysis of oblique angle stimulated Cherenkov radiation with some experimental results

This paper considers the possible amplification in a dielectric medium of a plane wave intersected by an electron beam at the Cherenkov angle. An oscillator is designed in which a Fabry-Perot resonator's axis is placed at this angle. The gain is found to be inversely proportional to the wavelength, suggesting the possibility of a vacuum ultraviolet or soft X-ray laser. The randomization of the phase coherence between the wave and the electrons due to multiple scattering of the electrons by the atoms of the dielectric is minimized by limiting the length of interaction, and increasing the electron beam energy. Early unpublished experiments are given in which quartz resonators were placed in the Mark III Linear Accelerator's electron beam at Stanford University. From this, other subsequent experimental work, and the theory derived here. two devices are considered which utilize gas as a dielectric instead of a solid.