Stabilized radio frequency quadrupole

Claim 1

A stabilized radio frequency quadrupole resonator of the long-vane type for simultaneously bunching, focusing and accelerating charged particles along a linear central path through said resonator, comprising: means defining a radio frequency resonator cavity; four radially equally spaced vanes elongated and continuous in the axial direction of said means, said vanes having a base end and a tip end, said base end being mounted on said defining means and extending therefrom for dividing said cavity into four equal sections to form the two pairs of opposing vanes; and means electrically interconnecting opposing ones of said plurality of vanes at substantially the same longitudinal axial point along said central path for stabilizing said resonator, said interconnecting means enabling said resonator to be tuned by adjustment of any one of said vanes to affect the resonant frequency, said interconnecting means eliminating undesirable dipole modes from the resonant frequency; wherein said interconnecting means between opposing vanes electrically interconnects the tip ends of opposing vanes, said interconnecting means extending from opposing vanes through adjacent sections and holes in adjacent elongated vanes; and wherein said interconnecting means includes at least one pair of full-ring segments.