Title :
Observation of radiative spin-polarization at 60.6 GeV
Author :
Assmann, R. ; Dehning, B. ; Hildreth, M. ; Matheson, J. ; Mugnai, G. ; Placidi, M. ; Roncarolo, F. ; Torrence, E. ; Sonnermann, F. ; Uythoven, J. ; Wenninger, J. ; Blondel, A.
Author_Institution :
SL Div., CERN, Geneva, Switzerland
Abstract :
Radiative spin-polarization has been used extensively at LEP to accurately measure the beam energy around the Z resonance. As the LEP physics has moved on to the W boson the calibration based on polarization must be extended towards higher beam energies. This is difficult as the depolarizing effects of spin resonances grow rapidly with beam energy. At LEP it has been possible for the first time to measure transverse beam polarization at 60.6 GeV. To allow a build-up of polarization the tunes and the energy were chosen accurately. A low phase advance optics was used and careful orbit correction was carried out using dynamic beam based alignment data. Harmonic spin matching was applied both in a deterministic and a novel semi-empirical way
Keywords :
calibration; colliding beam accelerators; electron accelerators; particle beam diagnostics; storage rings; 60.6 GeV; LEP; Z resonance; calibration; depolarizing effects; dynamic beam based alignment data; harmonic spin matching; low phase advance optics; orbit correction; radiative spin-polarization; spin resonances; transverse beam polarization; Extraterrestrial measurements; Large Hadron Collider; Optical polarization; Physics; Resonance; Storage rings;
Conference_Titel :
Particle Accelerator Conference, 1999. Proceedings of the 1999
Conference_Location :
New York, NY
Print_ISBN :
0-7803-5573-3
DOI :
10.1109/PAC.1999.792125
