Polarized beams in LEP

Conference · Fri May 05 04:00:00 EDT 1989 · AIP Conference Proceedings (American Institute of Physics); (USA)

OSTI ID:5034206

Blondel, A; Jowett, J M; Keil, E; Koutchouk, J P; Limberg, T ^[1]; Buon, J ^[2]

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1. CERN, Ch-1211 Geneva 23 (XC)
2. Laboratoire de l'accelerateur lineaire, F-91405 Orsay (France)

The renewed interest in polarized beams at the {ital Z} energy has stimulated a new round of studies. The asymptotic polarization degree, as calculated with the first-order theory, now reaches 85%, with the help of new asymmetric wigglers and polarization maximisation. Further spin tracking shows a strong excitation of higher-order satellite resonances due to the large beam energy spread in LEP. However they can be weakened by a refined compensation of the linear spin resonances. The resulting polarization degree is larger than 50% with a rise time of 36 minutes. A spin rotator of the Richter-Schwitters type has been designed for installation in the LEP straight sections. Magic phase advances for the rotator magnets have allowed an almost complete spin-matching. After optical matching, the optics is unaffected except for a tilt of the closed orbit of 15 mrad and a non-vanishing derivative of the vertical dispersion at hte interaction point (IP). The residual depolarization calculated with SLIM is found to be insignificant. Although various aspects need to be studied in more depth, the set of results obtained so far tend to show that polarized beams should be possible in LEP.

• OSTI ID: 5034206
• Report Number(s): CONF-880983--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (USA) Journal Volume: 187:2
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430100 -- Particle Accelerators-- Design
Development
& Operation
430400* -- Particle Accelerators-- Storage Rings
BEAMS
BREMSSTRAHLUNG
COMPUTER CALCULATIONS
DEPOLARIZATION
DESIGN
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
ELECTROMAGNETS
ELECTRON BEAMS
EQUIPMENT
LEP STORAGE RINGS
LEPTON BEAMS
MAGNETS
OPTICAL SYSTEMS
ORIENTATION
PARTICLE BEAMS
POLARIZED BEAMS
RADIATIONS
SPIN ORIENTATION
STORAGE RINGS
SYNCHROTRON RADIATION
TESTING
WIGGLER MAGNETS