Standing-wave accelerating structure with different diameter bores in bunching and regular cavity sections

摘要

A standing-wave accelerating structure for accelerating charged particles wherein a converging force and a diverging force of an electric field to an electron beam are checked to improve the transmittivity of the electron beam through the accelerating structure and production of X-ray leakage is eliminated or minimized. The accelerating structure comprises a buncher section including at least one cavity for mainly bunching charged particles, and a regular section including at least one cavity. The diameter of a bore in the buncher section is smaller than the diameter of another bore in the regular section. A shorting bar for stopping propagation of microwaves is inserted in at least one of the cavities, and a means for accelerating the charged particles and for converging a beam is provided forwardly or rearwardly of the cavity in which the shorting bar is inserted.