Polarization of a stored electron beam
Synchrotron radiation by a point charge is a familiar subject in classical electrodynamics. Perhaps less familiar are some quantum mechanical corrections to the classical results. Some of those quantum aspects of synchrotron radiation are described. One of the quantum effects leads to the expectation that electrons in a storage ring will polarize themselves to 92% - a surprisingly high value. A semi-classical derivation of the quantum effects is given. An effort has been made to minimize the need of using quantum mechanics. Results are put together to derive a final expression of beam polarization. Conditions under which the expected 92% polarization is destroyed are found and attributed to depolarization resonances. The various depolarization mechanisms are first illustrated by an idealized example and then systematically treated by a matrix formalism. It is shown that the strength of depolarization is specified by a key quantity called the spin chromaticity. Finally as an application of the obtained results, an estimate of the achievable level of beam polarization for two existing electron storage rings, SPEAR and PEP, is given.
- Research Organization:
- Stanford Linear Accelerator Center, CA (USA)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 5686471
- Report Number(s):
- SLAC-PUB-2781; CONF-810774-1; ON: DE82003566; TRN: 82-005103
- Resource Relation:
- Conference: Summer school on high energy particle accelerators, Batavia, IL, USA, 13 Jul 1981
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ELECTRON BEAMS
POLARIZATION
STORAGE RINGS
POLARIZED BEAMS
SYNCHROTRON RADIATION SOURCES
SYNCHROTRON RADIATION
QUANTUM MECHANICS
DEPOLARIZATION
PEP STORAGE RINGS
SPEAR
SPIN FLIP
SPIN ORIENTATION
BEAMS
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
LEPTON BEAMS
MECHANICS
ORIENTATION
PARTICLE BEAMS
RADIATION SOURCES
RADIATIONS
430400* - Particle Accelerators- Storage Rings