Higher-Order Spin Resonances in 2.1 GeV/c Polarized Proton Beam
Spin resonances can cause partial or full depolarization or spin-flip of a polarized beam. We studied 1st-, 2nd- and 3rd-order spin resonances with a 2.1 GeV/c vertically polarized proton beam stored in the COSY Cooler Synchrotron. We observed almost full spin-flip when crossing the 1st-order G*gamma=8-nu<sub>y</sub> vertical-betatron-tune spin resonance and partial depolarization near some 2nd- and 3rd-order resonances. We observed almost full depolarization near the 1st-order G*gamma=8-nu<sub>x</sub> horizontal spin resonance and partial depolarization near some 2nd- and 3rd-order resonances. Moreover, we found that a 2nd-order nu<sub>x</sub> resonance seems about as strong as some 3rd-order nu<sub>x</sub> resonances, while some 3rd-order nu<sub>y</sub> resonances seem much stronger than a 2nd-order nu<sub>y</sub> resonance. It was thought that, for flat accelerators, vertical spin resonances are stronger than horizontal, and lower order resonances are stronger than higher order ones. The data suggest that many higher-order spin resonances, both horizontal and vertical, must be overcome to accelerate polarized protons to high energies; the data may help RHIC to better overcome its snake resonances between 100 and 250 GeV/c.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1020988
- Report Number(s):
- JLAB-ACC-11-1343; DOE/OR/23177-1631; TRN: US201116%%659
- Resource Relation:
- Conference: 2011 Particle Accelerator Conference (PAC'11), New York, NY, 28 Mar - 1 Apr 2011
- Country of Publication:
- United States
- Language:
- English
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