Patent attributes
The present invention provides a particle beam accelerator for accelerating charged particles along a traveling direction of the charged particles. The invention provides a particle beam accelerator, in which the charged particle beam deflected by spiral-shaped-deflecting electromagnet 3, is accelerated by an accelerating unit 5, the charged particle beam circulating in an annular vacuum passageway of a vacuum duct 1 a plurality of times differing in orbit. And gap 9 is formed in the accelerating unit 5 of the vacuum duct 1, and gap-constituting face of the vacuum duct 1 is formed to be perpendicular to each of the traveling directions of the charged particle beam orbiting on a first orbit and on a second orbit. In the above accelerator, vibrations of the charged particle beam can be brought under control and loss of the charged particle beam can be reduced.