RESONATOR FOR CYCLOTRON

PROBLEM TO BE SOLVED: To provide a resonator of a simple structure for a cyclotron which can be easily adjusted in which equalized contact of a short plate can be maintained even when an outer cylinder and an inner cylinder in the resonator are eccentric. SOLUTION: A short plate 9 is composed as a two-separated one comprising a circular outer plate 10 and an inner plate 11. An outer circumference of the outer plate 10 is pressed to get in contact with an outer cylinder 7 by an overhang member 28, and an inner circumferential edge is put to get in contact with an outer circumferential edge of the inner plate 11 to overlap with it in a specified range. An inner circumference of the inner plate 11 is pressed to get in contact with an inner cylinder 8. An overlap part of the outer plate 10 with the inner plate 11 is tightened by a tightening bolt 21 and a tightening ring 41 to be jointed to be freely released. When the outer plate 10 and the inner plate 1 are eccentric because of eccentricity of the outer cylinder 7 and the inner cylinder 8, this eccentricity is absorbed by the overlap part, thereby equalized contact of the outer plate 10 and the inner plate 11 with the inner cylinder 8 and the outer cylinder 7 is secured.