RHIC spin project -- Acceleration of polarized protons

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:195688

Roser, T

To achieve high energy polarized proton collisions polarized beams first have to be accelerated which requires an understanding of the evolution of spin during acceleration and the tools to control it. The acceleration of polarized beams in circular accelerators is complicated by the presence of numerous depolarizing resonances. During acceleration, a depolarizing resonance is crossed whenever the spin precession frequency equals the frequency with which spin-perturbing magnetic fields are encountered. There are two main types of depolarizing resonances corresponding to the possible sources of such fields: imperfection resonances, which are driven by magnet errors and misalignments, and intrinsic resonances, driven by the focusing fields. By introducing a Siberian Snake, which is a 180{degree} spin rotator of the spin about a horizontal axis, the stable spin direction remains unperturbed at all times as long as the spin rotation from the Siberian Snake is much larger than the spin rotation due to the resonance driving fields. Therefore the beam polarization is preserved during acceleration. Such a spin rotator can be constructed by using either solenoidal magnets for low energy beams or a sequence of interleaved horizontal and vertical dipole magnets producing only a local orbit distortion for high energy beams. Polarized proton acceleration at the AGS and the RHIC is discussed.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 195688
• Report Number(s): BNL--62448; CONF-951269--1; ON: DE96003666
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM DYNAMICS
BROOKHAVEN AGS
BROOKHAVEN RHIC
DIPOLES
ELECTROMAGNETS
EQUATIONS OF MOTION
ORBITS
POLARIMETERS
POLARIZED BEAMS
PROTON BEAMS