Downsampled bunch-by-bunch feedback for PEP II

Conference · Tue Sep 01 04:00:00 EDT 1992

OSTI ID:7178890

Hindi, H A; Briggs, D; Fox, J; Hosseini, W; Hutton, A

The PEP II B Factory requires a feedback system to damp out longitudinal synchrotron oscillations. A time-domain bunch-by-bunch feedback system has been proposed in which each bunch is treated as an oscillator being driven by disturbances from the other bunches. The phase is detected, filtered, and the feedback correction signal is applied by the kicker. Since we are damping energy oscillations using measurements of phase, the required feedback signal must be proportional to the amplitude of the phase oscillations but phase shifted by 90 degrees. This signal must be calculated for each of the 1658 bunches, in parallel. In the original proposal, it was estimated that a farm of approximately 480 digital signal processors (DIPS) would be required to implement the feedback system. However, using the technique of downsampling, this number can be reduced to about 50 DIPS. In what follows, we will briefly explain the basic idea of downsampling and its implementation.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 7178890
• Report Number(s): SLAC-PUB-5919; CONF-9204126--17; ON: DE93004090
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200 -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
430303* -- Particle Accelerators-- Experimental Facilities & Equipment
BEAM BUNCHING
BEAM DYNAMICS
DAMPING
FEEDBACK
MATHEMATICAL SPACE
OSCILLATIONS
PEP STORAGE RINGS
PHASE SPACE
SAMPLING
SPACE
STORAGE RINGS
SYNCHROTRON OSCILLATIONS