Patent ID: 7276708

Claim:
A diagnostic resonant cavity for use in determining characteristics of a charged particle beam traveling along a beam line of a charged particle accelerator, comprising two electrically conductive opposing end walls spaced apart from one another by an electrically conductive tubular wall, said end walls having openings centered therein for interposition of the cavity in the beam line by connection of said end walls to a beam tube having a central longitudinal axis defining the nominal path of travel of the charged particle beam, and an even plurality of at least four pairs of electrically conductive rods extending into said cavity from said end walls, each of said pairs of rods consisting of two rods extending inwardly and coaxially toward one another from said two opposing end walls and extending parallel to said central longitudinal axis said of said beam tube, said two rods of each pair of opposing rods being spaced from one another so as to form a capacitative gap between one another, and wherein said pairs of rods are equally spaced azimuthally in a symmetrical array around said central longitudinal axis of said beam tube.