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Oddo, P.

Paper Title Page
MOPEC030 High Precision Tune and Coupling Feedback and Beam Transfer Function Measurements in RHIC 522
 
  • M.G. Minty, A.J. Curcio, W.C. Dawson, C. Degen, Y. Luo, G.J. Marr, B. Martin, A. Marusic, K. Mernick, P. Oddo, T. Russo, V. Schoefer, R. Schroeder, C. Schultheiss, M. Wilinski
    BNL, Upton, Long Island, New York
  
 

Precision measurement and control of the betatron tunes and betatron coupling in the Relativistic Heavy Ion Collider (RHIC) are required for establishing and maintaining both good operating conditions and, particularly during the ramp to high beam energies, high proton beam polarization. While the proof-of-principle for simultaneous tune and coupling feedback was successfully demonstrated earlier, routine application of these systems has only become possible recently. Following numerous modifications for improved measurement resolution and feedback control, the time required to establish full-energy beams with the betatron tunes and coupling regulated by feedback was reduced from several weeks to a few hours. A summary of these improvements, select measurements benefitting from the improved resolution and a review of system performance are the subject of this report.

  
MOPE103 Commissioning of RHIC Spin Flipper 1224
 
  • M. Bai, W.C. Dawson, Y. Makdisi, W. Meng, S. Nayak, P. Oddo, C. Pai, P.H. Pile, T. Roser
    BNL, Upton, Long Island, New York
  • F. Méot
    CEA, Gif-sur-Yvette
  
 

Commissioning of spin flipper in the RHIC (Relativistic Heavy Ion Collider) Blue ring during the 2009 RHIC polarized proton run showed significant global vertical coherent betatron oscillations induced by a two AC dipole plus four DC dipole configuration. These global orbital coherent oscillations affected collision rates and Yellow beam polarization when beams were in collision. The measured depolarizing strength of of the two AC dipoles at a phase difference of 180 degrees at injection with a different spin tune also confirmed that a single isolated spin resonance can not be induced in the presence of this global vertical coherent betatron oscillation. Hence, a new design was proposed to eliminate the coherent orbital oscillation outside the spin flipper with three additional AC dipoles. This paper presents the new design and supporting numerical simulations. In the RHIC 2010 Au run, only one AC dipole was inserted between the two original AC dipoles; and the measured closure of this AC dipole bump is also presented.


This work is under the auspices of the US Department of Energy