Photocathode high-frequency electron-gun cavity apparatus

Abstract

A photocathode high-frequency electron-gun cavity apparatus of the present invention is provided with a high-frequency acceleration cavity (), a photocathode (), a laser entering port (), a high-frequency power input coupler port (), and a high-frequency resonant tuner (). Here, the apparatus adopts an ultra-small high-frequency accelerator cavity which contains a cavity cell formed only with a smooth and curved surface at an inner face thereof without having a sharp angle part for preventing discharging, obtaining higher strength of high-frequency electric field, and improving high-frequency resonance stability. Further, the photocathode is arranged at an end part of a half cell () of the high-frequency acceleration cavity for maximizing electric field strength at the photocathode face, perpendicular incidence of laser is ensured by arranging a laser entering port at a position facing to the photocathode behind an electron beam extraction port of the high-frequency acceleration cavity for maximizing quality of short-bunch photoelectrons, and a high-frequency power input coupler port is arranged at a side part of the cell of the high-frequency acceleration cavity for enhancing high-frequency electric field strength. According to the above, it is possible to provide a small photocathode high-frequency electron-gun cavity apparatus capable of generating a high-strength and high-quality electron beam.