Acceleration of polarized protons in the AGS

Tsoupas, N. ; Ahrens, L. ; Bai, M. ; Brown, K. ; Courant, E. ; Glenn, J.W. ; Huang, H. ; Luccio, A. ; MacKay, W.W. ; Roser, T. ; Schoefer, V. ; Zeno, K.

Brookhaven National Laboratory (BNL) Alternating Gradient Synchrotron

关键词: Acceleration;    Protons;    43 Particle Accelerators;    Preservation;    Polarization;   

DOI  :  10.2172/973141
RP-ID  :  BNL--91116-2010-IR
RP-ID  :  DE-AC02-98CH10886
RP-ID  :  973141

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来源: UNT Digital Library

【 摘 要 】

The high energy (s{sup 1/2} = 500 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the proton beam. With the AGS used as the pre-injector to RHIC, one of the main tasks is to preserve the polarization of the proton beam, during the beam acceleration in the AGS. The polarization preservation is accomplished by the two partial helical magnets [1,2,3,4,5,6,7] which have been installed in AGS, and help overcome the imperfection and the intrinsic spin resonances which occur during the acceleration of protons. This elimination of the intrinsic resonances is accomplished by placing the vertical tune Q{sub y} at a value close to 8.98, within the spin-tune stop-band created by the snake. At this near integer tune the perturbations caused by the partial helical magnets is large resulting in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have introduced compensation quads[2] in the AGS. In this paper we present the beam optics of the AGS which ameliorates this effect of the partial helices.