title: Achieving 99.9% proton spin-flip efficiency at higher energy with a small RF dipole.
abstract: We recently used a new ferrite rf dipole to study spin flipping of a 2.1 GeV/c vertically polarized proton beam stored in the COSY Cooler Synchrotron in Jülich, Germany. We swept the rf dipole's frequency through an rf-induced spin resonance to flip the beam's polarization direction. After determining the resonance's frequency, we varied the frequency range, frequency ramp time, and number of flips. At the rf dipole's maximum strength and optimum frequency range and ramp time, we measured a spin-flip efficiency of 99.92+/-0.04%. This result, along with a similar 0.49 GeV/c IUCF result, indicates that, due to the Lorentz invariance of an rf dipole's transverse integralBdl and the weak energy dependence of its spin-resonance strength, an only 35% stronger rf dipole should allow efficient spin flipping in the 100 GeV BNL RHIC Collider or even the 7 TeV CERN Large Hadron Collider.
authors.affiliation: Spin Physics Center, University of Michigan, Ann Arbor, Michigan 48109-1120, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Leonova
authors.forename: A D
authors.initials: AD
authors.lastname: Krisch
authors.forename: V S
authors.initials: VS
authors.lastname: Morozov
authors.forename: R S
authors.initials: RS
authors.lastname: Raymond
authors.forename: V K
authors.initials: VK
authors.lastname: Wong
authors.forename: R
authors.initials: R
authors.lastname: Gebel
authors.forename: A
authors.initials: A
authors.lastname: Lehrach
authors.forename: B
authors.initials: B
authors.lastname: Lorentz
authors.forename: R
authors.initials: R
authors.lastname: Maier
authors.forename: D
authors.initials: D
authors.lastname: Prasuhn
authors.forename: A
authors.initials: A
authors.lastname: Schnase
authors.forename: H
authors.initials: H
authors.lastname: Stockhorst
authors.forename: D
authors.initials: D
authors.lastname: Eversheim
authors.forename: F
authors.initials: F
authors.lastname: Hinterberger
authors.forename: K
authors.initials: K
authors.lastname: Ulbrich