John E. D. Fox

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PEP-II is an e + e-B-Factory Collider located at SLAC operating at the Upsilon 4S resonance (3.1 GeV x 9 GeV). PEP-II has delivered, over the past five years, an integrated luminosity to the BaBar detector of about 240 fb-1 and has reached a luminosity of 9.21x10 33 /cm 2 /s. Steady progress is being made in reaching higher luminosity. The goal over the(More)
An electronic system is presented which detects synchrotron oscillations of individual bunches with 4 ns separation. The system design and performance are motivated by the requirements of the proposed B Factory facility at SLAC. A comb generator is used to produce an eight cycle coherent tone burst at 3 GHz from each bunch. The phase of the coherent burst(More)
The PEP-II High and Low energy rings require active longitudinal feedback to control coupled-bunch instabilities. The driving impedances originate from higher order modes as well as the accelerating fundamental impedance. The PEP-II RF systems use direct and comb loop feedback to reduce the cavity fundamental impedance, though the remaining low-mode(More)
Over the past year, we have worked out a baseline design for PEP-X, as an ultra-low emittance storage ring that could reside in the existing 2.2-km PEP-II tunnel. The design features a hybrid lattice with double bend achromat (DBA) cells in two arcs and theoretical minimum emittance (TME) cells in the remaining four arcs. Damping wigglers are used to reduce(More)
Parameters are being studied for a high luminosity e + e-collider operating at the Upsilon 4S that would deliver a luminosity in the range of 7 to 10 x 10 35 /cm 2 /s. Particle physics studies dictate that a much higher luminosity collider than the present B-Factory accelerators will be needed to answer future new key physics questions. The success of the(More)
A modal decomposition is used to study the coupled longitudinal motion of electron bunches in a storage ring. The decomposition allows the simultaneous measurement o f g r o wth rates and feedback induced damping rates of all unstable beam modes via a time-domain transient technique. The damping rates of naturally stable modes are measured via a related(More)
A programmable longitudinal feedback system based on four AT&T 1610 digital signal processors has been developed as a component of the PEP-II R&D program. This Longitudinal Quick Prototype is a proof of concept for the PEP-II system and implements full speed bunch-by-bunch signal processing for storage rings with bunch spacings of 4 ns. The design(More)