Calculation of Impedance from Multibunch Synchronous Phases: Theory and Experimental Results
A novel beam-based method for measuring the longitudinal impedance spectrum is demonstrated using experimental data from the PEP-II High Energy Ring (HER). The method uses a digital longitudinal feedback system from which the charge and synchronous phase are measured for every bucket. Calculation of the transfer function from fill shape to synchronous phase yields the impedance seen by the beam at revolution harmonics. The experimentally-derived longitudinal impedance function and lab measurements of the impedance of parked RF cavities are compared to suggest a mechanism for the occasional instability of low-order coupled bunch modes observed in the HER during commissioning in October 1997.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 9945
- Report Number(s):
- SLAC-PUB-7979; TRN: US0103240
- Resource Relation:
- Other Information: PBD: 20 Oct 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Multi-Bunch Longitudinal Dynamics and Diagnostics via a Digital Feedback System at PEP-II, DAFNE, ALS and SPEAR
Commissioning experience from PEP-II HER longitudinal feedback
Commissioning experience from PEP-II HER longitudinal feedback
Technical Report
·
Mon Apr 19 00:00:00 EDT 1999
·
OSTI ID:9945
Commissioning experience from PEP-II HER longitudinal feedback
Journal Article
·
Thu Dec 10 00:00:00 EST 1998
· AIP Conference Proceedings
·
OSTI ID:9945
+3 more
Commissioning experience from PEP-II HER longitudinal feedback
Conference
·
Mon Jun 01 00:00:00 EDT 1998
·
OSTI ID:9945
+3 more