IPAC2014 - List of Authors (Barber, D.P.)

Paper	Title	Page
THPRO061	New and Unifying Formalism for Study of Particle-Spin Dynamics Using Tools Distilled From Theory of Bundles	3014
	K.A. Heinemann, J.A. Ellison UNM, Albuquerque, New Mexico, USA D.P. Barber Cockcroft Institute, Warrington, Cheshire, United Kingdom D.P. Barber, M. Vogt DESY, Hamburg, Germany
	Funding: The work of JAE and KH was supported by DOE under DE-FG-99ER41104 and the work of DPB and MV was supported by DESY. We summarize our recent work on spin motion in storage rings . In fact we return to our study * of spin motion in storage rings. We again focus on spin tunes, polarization fields etc. but in contrast to ** we base the description on one turn maps and refine and expand our toolset from that in * by using a rather modern method from Dynamical-Systems theory, developed in the 1980's by R. Zimmer and others based on bundles , . With this we obtain new insights into invariant spin fields, invariant frame fields, spin tunes and spin-orbit resonances. At the same time we get a unified way to treat spin-1/2 and spin-1 particles. The bundle aspect is pointed out and we briefly mention the relation to Yang-Mills Theory as well. K.Heinemann, D.P.Barber, J.A.Ellison, M.Vogt. To be submitted. D.P.B., J.A.E., K.H., PRSTAB 7 (2004) 124002. * K.Heinemann, PhD Thesis, University of New Mexico, 2010 (available on the web).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO061
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MOPRO006	Preservation of Electron Polarization in the MEIC Collider Ring	74
	F. Lin, Y.S. Derbenev, V.S. Morozov, Y. Zhang JLab, Newport News, Virginia, USA D.P. Barber DESY, Hamburg, Germany
	Funding: U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. 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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

New and Unifying Formalism for Study of Particle-Spin Dynamics Using Tools Distilled From Theory of Bundles

3014

K.A. Heinemann, J.A. Ellison
UNM, Albuquerque, New Mexico, USA
D.P. Barber
Cockcroft Institute, Warrington, Cheshire, United Kingdom
D.P. Barber, M. Vogt
DESY, Hamburg, Germany

Funding: The work of JAE and KH was supported by DOE under DE-FG-99ER41104 and the work of DPB and MV was supported by DESY.
We summarize our recent work on spin motion in storage rings *. In fact we return to our study ** of spin motion in storage rings. We again focus on spin tunes, polarization fields etc. but in contrast to ** we base the description on one turn maps and refine and expand our toolset from that in * by using a rather modern method from Dynamical-Systems theory, developed in the 1980's by R. Zimmer and others based on bundles **, ***. With this we obtain new insights into invariant spin fields, invariant frame fields, spin tunes and spin-orbit resonances. At the same time we get a unified way to treat spin-1/2 and spin-1 particles. The bundle aspect is pointed out and we briefly mention the relation to Yang-Mills Theory as well.
* K.Heinemann, D.P.Barber, J.A.Ellison, M.Vogt. To be submitted.
** D.P.B., J.A.E., K.H., PRSTAB 7 (2004) 124002.
*** K.Heinemann, PhD Thesis, University of New Mexico, 2010 (available on the web).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO061

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRO006

Preservation of Electron Polarization in the MEIC Collider Ring

74

F. Lin, Y.S. Derbenev, V.S. Morozov, Y. Zhang
JLab, Newport News, Virginia, USA
D.P. Barber
DESY, Hamburg, Germany

Funding: U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO006

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)