PRESERVATION OF ELECTRON POLARIZATION IN THE MEIC COLLIDER RING

Conference · Tue Jul 01 00:00:00 EDT 2014

DOI:https://doi.org/10.18429/JACoW-IPAC2015-TUPTY010· OSTI ID:1968594

Lin, F. ^[1]; Derbenev, Y.S. ^[1]; Morozov, V.S. ^[1]; Zhang, Y. ^[1]; Barber, D.P. ^[2]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2. DESY, Hamburg, Germany

A highly longitudinally-polarized (over 70%) electron beam is required by the nuclear physics programme of the Medium Energy Electron-Ion Collider (MEIC) at Jefferson Lab (JLab). To achieve this goal, a highly vertically-polarized electron beam is injected from the CEBAF. The polarization will be vertical in the arcs to avoid spin diffusion, and longitudinal at the collision points. The polarization rotation will be accomplished by using a total of four spin rotators, each of which consists of a set of solenoids and dipoles, placed at the ends of two arcs. The polarization configuration cancels the 1st order spin perturbation in the solenoids for the off-momentum particles and significantly reduces the synchrotron sideband resonances. In order to compensate the net Sokolov-Ternov depolarization effect, especially at higher energies, a continuous injection of a polarized electron beam from the CEBAF is being considered. We consider to perform a moderate spin matching in some key regions to extend the polarization lifetime so that the continuous injection can work more efficiently, while not imposing a burden on the optics design of the collider ring.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1968594
• Report Number(s): JLAB-ACP-14-2000; DOE/OR/23177-3401
• Resource Relation: Conference: IPAC2014 - Proceedings, Dresden, Germany, June 16-20, 2014
• Country of Publication: United States
• Language: English