Title :
The center-of-mass energy of PEP-II
Author :
Sullivan, M. ; Donald, M. ; Placidi, M.
Author_Institution :
SLAC Collaboration, Stanford Univ., CA, USA
Abstract :
The PEP-II B-factory is designed to operate at a center-of-mass energy (Ecm) of 10.58 GeV, the mass value of the upsilon 4S resonance. It is important to set and maintain the Ecm to the peak of this resonance in order to maximize the production of B mesons that enable the BaBar detector to measure CP violation. There are several elements in the determination of the beam energies. Aside from the strength of the main bending magnets, there is a contribution to the beam energy from horizontal correctors. In addition, the frequency of the RF system also influences the ring energies by controlling the closed orbit circumference. The low-energy ring (LER) in PEP-II has a wiggler magnet for emittance control that also contributes to the beam energy of the LER. We discuss these aspects of beam energy determination and the algorithms used to monitor the beam energies
Keywords :
accelerator RF systems; accelerator magnets; colliding beam accelerators; electromagnets; electron accelerators; electron beams; particle beam diagnostics; particle beam extraction; storage rings; wigglers; B meson production; BaBar detector; CP violation; LER; PEP-II; beam energies; beam energy determination; beam energy monitoring; center-of-mass energy; closed orbit circumference; emittance control; horizontal correctors; low-energy ring; main bending magnets; radiofrequency system; ring energies; upsilon(4S) resonance; wiggler magnet; Control systems; Detectors; Extraterrestrial measurements; Magnets; Mesons; Monitoring; Production; Radio frequency; Resonance; Undulators;
Conference_Titel :
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-7191-7
DOI :
10.1109/PAC.2001.988181
