Longitudinal multibunch instabilities in the Advanced Photon Source storage ring
- Argonne National Lab., IL (United States). Advanced Photon Source
A longitudinal coupled-bunch (CB) instability was encountered in the 7-GeV Advanced Photon Source (APS) positron storage ring whose threshold depends on the bunch fill pattern in a nontrivial way. The beam spectrum exhibited a coupled-bunch signature, which could be reproduced by an analytical model. The beam fluctuations were found to be correlated with the rf cavity temperatures, consistent with the measured temperature dependence of the higher-order mode (HOM) frequencies. Fast beam loss due to a multibunch effect was observed with other patterns of very long bunch trains. The nature of these instabilities has not yet been characterized. Multibunch instabilities had not been observed previously with electrons, although such patterns of long bunch trains were not studied systematically in this case.
- Research Organization:
- Argonne National Lab., IL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 554878
- Report Number(s):
- ANL/ASD/CP--94766; CONF-970792--; ON: DE98050335
- Country of Publication:
- United States
- Language:
- English
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