GB1350986A - High-frequency electrical resonators for particle acceleration - Google Patents

Abstract

1350986 Particle accelerators; resonators PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 26 April 1971 [29 April 1970] 11368/71 Headings H1D and H1W A high frequency resonator for an accelerator comprises a waveguide 26, an s./c. plate 15 slidable in the waveguide, and two accelerating electrodes 3, 5-6, the waveguide comprising two coaxial parts 18 and 22, one inside the other, the electrodes being selectively connected for high frequency currents to one of the waveguide parts so as to provide two frequency ranges. The inner and outer conductors 17 and 19 of the inner part are connected for H.F. currents at the end of waveguide 26 remote from electrodes 3 and 5, 6 to the outer and inner conductors 21 and 20 respectively of the outer part by connections 24 and 25. The inner conductor 17 is connected through a lead-in insulator 11 to the cyclotron "D" electrode 3 and electrodes 5, 6 forming "dummy D" electrodes are connected via conductive coatings on poles 2 and a conductive coating 9 in the cyclotron vacuum chamber 1 to the outer conductor 21 of the waveguide 26. The waveguide conductors are preferably rectangular in crosssection and conductors 19, 20 are connected at end 12 adjacent to the electrodes and pivotal connections 13, 14 connect points 12 selectively to the outer conductor 21 or the inner conductor 17. The two resonator frequency ranges thus provided are preferably made to overlap by suitable choice of waveguide dimensions. As shown, a second similar resonator 27 is provided, the "D" electrodes 3 and 4 being connected at the centre point 30. The conductors 19 and 20 may be one assembly, mechanically, consisting of two conductors with the interposition of a further material, preferably lightweight, or may be constituted by a single conductor in which H.F. currents flow in the outer and inner surface layers because of the skin effect. The s./c. plate, when in the inner part, may be moved by a mechanism connected through slots in the appropriate conductors. Dimensions are given, and conductor 19 may be of variable height.