Author: Connolly, R.
Paper Title Page
MOOCN3 RHIC Polarized Proton Operation 41
 
  • H. Huang, L. A. Ahrens, I.G. Alekseev, E.C. Aschenauer, G. Atoian, M. Bai, A. Bazilevsky, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, A. Dion, K.A. Drees, W. Fischer, C.J. Gardner, J.W. Glenn, X. Gu, M. Harvey, T. Hayes, L.T. Hoff, R.L. Hulsart, J.S. Laster, C. Liu, Y. Luo, W.W. MacKay, Y. Makdisi, M. Mapes, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, S. Nemesure, A. Poblaguev, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, F. Severino, D. Smirnov, K.S. Smith, D. Steski, D. Svirida, S. Tepikian, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, M. Wilinski, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
RHIC operation as the polarized proton collider presents unique challenges since both luminosity and spin polarization are important. With longitudinally polarized beams at the experiments, the figure of merit is LP4. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system has been installed to improve longitudinal match at injection and to increase luminosity. The beam dumps were upgraded to allow for increased bunch intensities. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control has also been improved this year. Additional efforts were put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point was chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper.
 
slides icon Slides MOOCN3 [2.331 MB]  
 
MOP194 A Laser-Wire Beam-Energy and Beam-Profile Monitor at the BNL Linac 456
 
  • R. Connolly, L. DeSanto, C. Degen, R.J. Michnoff, M.G. Minty, D. Raparia
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work performed under Contract #DE-AC02-98CH10886 under the auspices of the US Department of Energy.
In 2009 a beam-energy monitor was installed in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. This device measures the energies of electrons stripped from the 40mA H beam by background gas. Electrons are stripped by the 1.7x10-7torr residual gas at a rate of ~2.4x10-8/cm. Since beam electrons have the same velocities as beam protons, the beam proton energy is deduced by multiplying the electron energy by mp/me=1836. A 183.6MeV H beam produces 100keV electrons. In 2010 we installed an optics plates containing a laser and optics to add beam-profile measurement capability via photodetachment. Our 100mJ/pulse, Q-switched laser neutralizes 70% of the beam during its 10ns pulse. The chamber in which the laser light passes through the ion beam is upstream of a dipole magnet which deflects the electrons into a biased retarding-grid (V<125kV) Faraday-cup detector. To measure beam profiles, a narrow laser beam is stepped across the ion beam removing electrons from the portion of the H beam intercepted by the laser. The laser also gives us energy measurements on the 0.2mA polarized proton beam.
 
 
THP054 Medium Energy Heavy Ion Operations at RHIC 2220
 
  • K.A. Drees, L. A. Ahrens, M. Bai, J. Beebe-Wang, I. Blackler, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, J.J. Butler, C. Carlson, R. Connolly, T. D'Ottavio, W. Fischer, W. Fu, D.M. Gassner, M. Harvey, T. Hayes, H. Huang, R.L. Hulsart, P.F. Ingrassia, N.A. Kling, M. Lafky, J.S. Laster, R.C. Lee, V. Litvinenko, Y. Luo, W.W. MacKay, M. Mapes, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, F.C. Pilat, V. Ptitsyn, G. Robert-Demolaize, T. Roser, P. Sampson, T. Satogata, V. Schoefer, C. Schultheiss, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, M. Wilinski, A. Zaltsman, K. Zeno, S.Y. Zhang
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n.