Title :
Higher-order modes of storage ring RF cavities and their interaction with the beam at the Advanced Photon Source (APS)
Author :
Song, J.J. ; Harkay, K.C. ; Kang, Y.W. ; Kustom, R.L. ; Nassiri, A.
Author_Institution :
Argonne Nat. Lab., IL, USA
Abstract :
The higher-order modes (HOMs) of APS storage ring (SR) RF cavities and waveguides were measured under various operating conditions. The HOMs of the 352-MHz RF cavity can be one of the major contributors to the coupled bunch instability. The distribution of HOMs under various conditions of beam current, cavity temperature, cavity tuning, single-bunch and multi-bunch operation, and fill patterns, are presented. The HOMs´ shunt impedance of the loaded cavities were also measured. The effect of stagger tuning of the 16 cavities and their waveguide system is compared, and the HOM dampers are examined
Keywords :
accelerator RF systems; accelerator cavities; electron accelerators; particle beam stability; storage rings; APS; Advanced Photon Source; HOM; RF cavities; beam current; cavity temperature; cavity tuning; coupled bunch instability; dampers; fill patterns; higher-order modes; loaded cavities; multi-bunch operation; shunt impedance; single-bunch operation; stagger tuning; waveguide system; waveguides; Damping; Frequency measurement; Impedance; Probes; Radio frequency; Shock absorbers; Storage rings; Strontium; Temperature distribution; Undulators;
Conference_Titel :
Particle Accelerator Conference, 1997. Proceedings of the 1997
Conference_Location :
Vancouver, BC
Print_ISBN :
0-7803-4376-X
DOI :
10.1109/PAC.1997.753069
