Polarization Preservation in the AGS

Abstract

The successful operation of a high energy polarized beam at the Argonne Zero Gradient Synchrotron with the concommitant development of depolarizing resonance correction techniques has led to the present project of commissioning such a beam at the Brookhaven AGS. A description of the project was presented at the 1981 National Accelerator Conference. The current paper presents a more detailed description of how Brookhaven personnel plan to preserve the polarization during acceleration and how they intend to tune through some 50 resonances and reach their goal of a 26 GeV polarized proton beam with greater than 60% polarization. Some aspects of their resonance correction techniques are to cross resonances by fast passage and not rely on spin-flip; to use the slow AGS tune shifting quadrupoles to avoid hitting integer or half-integer resonances at v = 9.0 and 8.5; and to pulse the ring sextupoles in order to flatten the vertical tune profile and keep the total tune shift constant as a function of radius. They are also prepared to use a compensating horizontal (v /SUB x/ ) shift during the correction time should this prove necessary.