Description: Growth rates of coherent beam oscillations are faster than the natural damping mechanisms for the parameters of the PEP-II B-factory storage rings at nominal currents, even with damping of cavity higher order modes (HOM`s). With 165 8 bunches separated by 4.2 ns, and a large current of up to 3A (2.14 A nominal in the low energy ring), many coupled-bunch modes are excited by the resistive wall impedance and cavity higher order mode impedance. Fastest growth times of transverse rigid-bunch modes of approximately 300 ps are expected, two orders of magnitude faster than the radiation damping time. We will provide broadband, bunch-by-bunch feedback to suppress this coherent motion of the beam. Experience gained with a prototype system, installed and successfully operating at the LBNL Advanced Light Source (ALS), has been used extensively in developing the design of the PEP-II systems.
Date: October 1, 1995
Creator: Corlett, J.N.; Barry, W.; Byrd, J.M.; Lambertson, G.; Johnson, J. & Fahmie, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department