Title :
Higher-order modes in the APS storage ring waveguides
Author :
Brauer, S.O. ; Kustom, R.L.
Author_Institution :
Adv. Photon Source, Argonne Nat. Lab., IL, USA
Abstract :
Twelve higher-order modes (HOMs) in the single-cell accelerating cavities for the Advanced Photon Source (APS) storage ring were calculated to have complex impedances that will cause coupled-bunched instabilities near or below the 300 mA positron current which is the design goal. Some of these modes couple, through the coupling loop, from the storage ring cavity into the waveguide. This study investigates the transmission of these modes from the cavity into the waveguide. The standing wave ratio (VSWR) of a WR2300 hybrid waveguide component has been measured at each HOM frequency, and its effect on the transmitted modes in the waveguide is studied
Keywords :
cavity resonators; electron accelerators; particle beam diagnostics; storage rings; waveguide couplers; waveguides; 300 mA; APS storage ring waveguides; Advanced Photon Source; WR2300 hybrid waveguide component; coupled-bunched instabilities; higher-order modes; positron current; single-cell accelerating cavities; standing wave ratio; Damping; Electromagnetic waveguides; Impedance; Laboratories; Particle beams; Radio frequency; Shock absorbers; Stability; Storage rings; Threshold current;
Conference_Titel :
Particle Accelerator Conference, 1993., Proceedings of the 1993
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-1203-1
DOI :
10.1109/PAC.1993.308638
