IBIC2012 - List of Authors (Van Winkle, D.)

Paper	Title	Page
TUPA32	Signal Equalizer for SPS Ecloud/TMCI Instability Feedback Control System	424
	K.M. Pollock, J.E. Dusatko, J.D. Fox, C.H. Rivetta, D. Van Winkle SLAC, Menlo Park, California, USA R. Secondo CERN, Geneva, Switzerland
	Funding: Work supported by the U.S. Department of Energy under contract #DE-AC02-76F00515 and the US LHC Accelerator Research Program. The 4GS/sec electron cloud and transverse mode coupled instability (TMCI) control system in development for the CERN Super Proton Synchrotron (SPS) requires 1.5GHz of processing bandwidth for the beam pickups and signal digitizer. An exponentially tapered stripline pickup has sufficient bandwidth, but has a phase response that distorts the beam signal in the time domain. We report on results from the design and implementation of an equalizer for the front end signal processing with correction for the pickup and cable responses. Using a model of the transfer functions for the pickups and the cabling, we determine a desired frequency response for the equalizer. Design for the circuitry, component value fitting is discussed as well as board construction and reduction of parasitic impedances. Finally, we show results from the measurement of an assembled equalizer, compare them with simulations and show beam signals from use at the SPS.

Paper

Title

Page

Signal Equalizer for SPS Ecloud/TMCI Instability Feedback Control System

424

K.M. Pollock, J.E. Dusatko, J.D. Fox, C.H. Rivetta, D. Van Winkle
SLAC, Menlo Park, California, USA
R. Secondo
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract #DE-AC02-76F00515 and the US LHC Accelerator Research Program.
The 4GS/sec electron cloud and transverse mode coupled instability (TMCI) control system in development for the CERN Super Proton Synchrotron (SPS) requires 1.5GHz of processing bandwidth for the beam pickups and signal digitizer. An exponentially tapered stripline pickup has sufficient bandwidth, but has a phase response that distorts the beam signal in the time domain. We report on results from the design and implementation of an equalizer for the front end signal processing with correction for the pickup and cable responses. Using a model of the transfer functions for the pickups and the cabling, we determine a desired frequency response for the equalizer. Design for the circuitry, component value fitting is discussed as well as board construction and reduction of parasitic impedances. Finally, we show results from the measurement of an assembled equalizer, compare them with simulations and show beam signals from use at the SPS.