Minimization of spin tune spread by matching dispersion prime at RHIC
- Brookhaven National Lab. (BNL), Upton, NY (United States)
At RHIC, the spin polarization is preserved with a pair of Siberian snakes on the oppo- site sides in each ring. The polarized proton beam with finite spin tune spread might cross spin resonances multiple times in two cases, one is when beam going through strong spin intrinsic resonances during acceleration, the other is when sweeping spin flipper’ frequency across the spin tune to flip the direction of spin polarization. The consequence is loss of spin polarization in both cases. Therefore, a scheme of min- imizing the spin tune spread by matching the dispersion primes at the two snakes was introduced based on the fact that the spin tune spread is proportional to the difference of dispersion primes at the two snakes. The scheme was implemented at fixed energies for the spin flipper study and during beam acceleration for better spin polarization transmission efficiency. The effect of minimizing the spin tune spread by matching the dispersion primes was observed and confirmed experimentally. The principle of minimizing the spin tune spread by matching the dispersion primes, the impact on the beam optics, and the effect of a narrower spin tune spread are presented in this report.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider (RHIC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- DOE Contract Number:
- SC0012704
- OSTI ID:
- 1392255
- Report Number(s):
- BNL-114288-2017-IR; R&D Project: KBCH139; KB0202011
- Country of Publication:
- United States
- Language:
- English
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