Paper | Title | Page |
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WEPPR090 | A 4.2 GS/s Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback | 3144 |
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Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP). A 4.2 GS/s beam excitation system with accelerator synchronization and power stages is described. The system is capable of playing unique samples (32 samples/bunch) for 15,000 turns on selected bunch(es) in the SPS in synchronism with the injection and acceleration cycle. The purpose of the system is to excite internal modes of single-bunch vertical motion, and study the bunch dynamics in the presence of developing Electron cloud or TMCI effects. The system includes a synchronized master oscillator, SPS timing functions, an FPGA based arbitrary waveform generator, 4.2 GS/sec. D/A system and four 80W 20 -1000 MHz amplifiers driving a tapered stripline pickup/kicker. A software GUI allows specification of various modulation signals and selection of bunches and turns to excite, while a remote control interface allows simple control/monitoring of the RF power stages located in the tunnel. Excitation signals developed to excite head-tail and other modes of vertical motion are illustrated. The successful use of this system for SPS MD measurements in August and November 2011 is a vital proof-of-principle for wideband feedback using similar functions to correct the beam motion. |
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