SPIN-COSY: Spin-Manipulating Polarized Deuterons and Protons

Journal Article · Tue Aug 04 00:00:00 EDT 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3215625· OSTI ID:21316889

Leonova, M A; Chao, A W; Krisch, A D; Morozov, V S; Raymond, R S; Sivers, D W; Wong, V K ^[1]; Garishvili, A; Gebel, R; Lehrach, A; Lorentz, B; Maier, R; Prasuhn, D; Stockhorst, H; Welsch, D ^[2]; Hinterberger, F; Ulbrich, K ^[3]; Derbenev, Ya S ^[4]; Kondratenko, A M ^[5]; Stephenson, E J ^[6]

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1. Spin Physics Center, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)
2. Forschungszentrum Juelich, Institut fuer Kernphysik, Postfach 1913, D-52425 Juelich (Germany)
3. Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, D-53115 Bonn (Germany)
4. Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)
5. GOO Zaryad, Russkaya St. 41, Novosibirsk, 630058 (Russian Federation)
6. IUCF, Indiana University, Bloomington, Indiana 47408-0768 (United States)

We studied spin manipulation of 1.85 GeV/c polarized deuteron beam stored in COSY obtaining a spin-flip efficiency of 97{+-}1%. We first discovered experimentally and then explained theoretically interesting behavior of the deuteron tensor polarization. We, for the first time, studied systematically spin resonance strengths induced by rf dipoles and solenoids. We found huge disagreements between the strengths measured in controlled Froissart-Stora sweeps and the theoretical values calculated using the well-known formulae. These data instigated re-examination of these formulae. We tested Chao's proposed new matrix formalism for describing the spin dynamics due to a single spin resonance, which may be the first fundamental improvement of the Froissart-Stora equation in that it allows analytic calculation of the beam polarization's behavior inside a resonance. Our measurements of the deuteron's polarization near and inside the resonance agreed precisely with the Chao formalism's predicted oscillations. We tested Kondratenko's proposal to overcome depolarizing resonances by ramping through them with a crossing pattern, which should force the depolarizing contributions to cancel themselves. Our first test of this idea with 2.1 GeV/c protons was not conclusive but a later test with 1.85 GeV/c deuterons demonstrated a rather substantial reduction in the depolarization compared to the tune jump at the same rate.

• OSTI ID: 21316889
• Journal Information: AIP Conference Proceedings, Vol. 1149, Issue 1; Conference: 18. international spin physics symposium, Charlottesville, VA (United States), 6-11 Oct 2008; Other Information: DOI: 10.1063/1.3215625; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM DYNAMICS
BEAM MONITORING
BEAM PULSERS
COSY STORAGE RING
DEPOLARIZATION
DEUTERON BEAMS
DIPOLES
GEV RANGE
OSCILLATIONS
POLARIZATION
POLARIZED BEAMS
RESONANCE
SOLENOIDS
SPIN
SPIN FLIP
TENSORS