Measurement and computation of the higher order modes of the ALS 500 MHz accelerating cavities

Author

Corlett, J.N. ; Byrd, J.M.

Author_Institution

Lawrence Berkeley Lab., CA, USA

fYear

1993

fDate

17-20 May 1993

Firstpage

3408

Abstract

Higher order modes in the accelerating cavities are expected to drive coupled bunch instabilities in the ALS, which will be overcome by a bunch-by-bunch feedback system. Computations of the cavity higher order modes using the URMEL-T and MAFIA codes are presented. Damping of the higher order modes is achieved by filters in the high power feeder waveguide which is aperture coupled to the cavity. Measurements of the modes in an ALS 500 MHz cavity are presented and compared with the computed values for an isolated, un-damped cavity. The resources of the Lambertson Beam Electrodynamics Laboratory of the Center for Beam Physics at LBL were used to perform these studies

Keywords

beam handling equipment; cavity resonators; damping; electron accelerators; particle beam diagnostics; physics computing; storage rings; 500 MHz; ALS; MAFIA; URMEL-T; accelerating cavities; bunch-by-bunch feedback system; coupled bunch instabilities; damping; filters; high power feeder waveguide; higher order modes; Acceleration; Apertures; Bifurcation; Damping; Electromagnetic waveguides; Feedback; Filters; Impedance; Radio frequency; Storage rings;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1993., Proceedings of the 1993

Conference_Location

Washington, DC

Print_ISBN

0-7803-1203-1

Type

conf

DOI

10.1109/PAC.1993.309666

Filename

309666