Abstract
In this paper, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97−GeV/c deuteron beam. The IPP magnitude was measured by continuously monitoring the down-up scattering asymmetry (sensitive to sideways polarization) in an in-beam, carbon-target polarimeter and unfolding the precession of the IPP due to the magnetic anomaly of the deuteron. The optimum operating conditions for a long IPP lifetime were made by scanning the field of the storage ring sextupole magnet families while observing the rate of IPP loss during storage of the beam. The beam was bunched and electron cooled. The IPP losses appear to arise from the change of the orbit circumference, and consequently the particle speed and spin tune, due to the transverse betatron oscillations of individual particles in the beam. The effects of these changes are canceled by an appropriate sextupole field setting.16 MoreReceived 23 October 2017DOI:https://doi.org/10.1103/PhysRevAccelBeams.21.024201Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBeam diagnosticsBeam polarizationLow-energy multiple-particle dynamicsAccelerators & Beams
Highlights
A recent paper [1] reports the achievement of a 1000second lifetime for the in-plane polarization (IPP) of a spinpolarized deuteron beam circulating at 0.97-GeV/c in the COSY storage ring [2]
This is likely a result of the deliberate horizontal heating that was applied to the beam. This spreads the distribution of betatron oscillation amplitudes and spin tunes, making it harder to obtain a good match for the various settings of the sextupole fields
The search for an electric dipole moment (EDM) using a storage ring requires that we begin with the polarization of the beam parallel to the velocity, a situation that is unstable against momentum spread and depolarizing effects arising from betatron oscillations
Summary
A recent paper [1] reports the achievement of a 1000second lifetime for the in-plane polarization (IPP) of a spinpolarized deuteron beam circulating at 0.97-GeV/c in the COSY storage ring [2]. This lifetime was made possible through a combination of beam bunching, electron cooling, trimming of sextupole field components, and limiting the beam current (< 109 deuterons/fill). This demonstration fulfills a requirement [3], albeit at a lower circulating beam current, for the use of a storage ring to search for an intrinsic electric dipole moment (EDM) on the nuclei in a circulating charged-particle beam. The features of an EDM storage ring experiment have been reviewed elsewhere [1,3,5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
