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Tepikian, S.

Paper Title Page
MOPEC031 Chromaticity Feedback at RHIC 525
 
  • A. Marusic, M.G. Minty, S. Tepikian
    BNL, Upton, Long Island, New York
  
 

Chro­matic­i­ty feed­back dur­ing the ramp to high beam en­er­gies has been demon­strat­ed in the Rel­a­tivis­tic Heavy Ion Col­lid­er (RHIC). In this re­port we re­view the feed­back de­sign and mea­sure­ment tech­nique. Com­mis­sion­ing ex­pe­ri­ences in­clud­ing in­ter­ac­tion with ex­ist­ing tune and cou­pling feed­back are pre­sent­ed to­geth­er with sup­port­ing ex­per­i­men­tal data.

  
MOPEC034 Experience with Split Transition Lattices at RHIC 534
 
  • C. Montag, M. Blaskiewicz, J.M. Brennan, S. Tepikian
    BNL, Upton, Long Island, New York
  
 

Dur­ing the ac­cel­er­a­tion pro­cess, heavy ion beams in RHIC cross the tran­si­tion en­er­gy. When RHIC was col­lid­ing deuterons and gold ions dur­ing Run-8, lat­tices with dif­fer­ent in­te­ger tunes were used for the two rings. This re­sult­ed in the two rings cross­ing tran­si­tion at dif­fer­ent times, which proved ben­e­fi­cial for the "Yel­low" ring, the RF sys­tem of which is slaved to the "Blue" ring. For the sym­met­ric gold-gold run in FY2010, lat­tices with dif­fer­ent tran­si­tion en­er­gies but equal tunes were im­ple­ment­ed. We re­port the op­tics de­sign con­cept as well as op­er­a­tional ex­pe­ri­ence with this con­fig­u­ra­tion.

  
MOPEC023 RHIC Performance for FY10 200 GeV Au+Au Heavy Ion Run 507
 
  • K.A. Brown, L. Ahrens, M. Bai, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, D. Bruno, C. Carlson, R. Connolly, T. D'Ottavio, R. De Maria, K.A. Drees, W. Fischer, W. Fu, C.J. Gardner, D.M. Gassner, J.W. Glenn, Y. Hao, M. Harvey, T. Hayes, L.T. Hoff, H. Huang, 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, S. Nemesure, B. Oerter, F.C. Pilat, V. Ptitsyn, G. Robert-Demolaize, T. Roser, T. Russo, P. Sampson, J. Sandberg, T. Satogata, V. Schoefer, C. Schultheiss, F. Severino, K. Smith, D. Steski, S. Tepikian, C. Theisen, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, M. Wilinski, A. Zaltsman, K. Zeno, S.Y. Zhang
    BNL, Upton, Long Island, New York
  
 

Since the last suc­cess­ful RHIC Au+Au run in 2007 (Run7), the RHIC ex­per­i­ments have made nu­mer­ous de­tec­tor im­prove­ments and up­grades. In order to ben­e­fit from the en­hanced de­tec­tor ca­pa­bil­i­ties and to in­crease the yield of rare events in the ac­quired heavy ion data a sig­nif­i­cant in­crease in lu­mi­nos­i­ty is es­sen­tial. In Run7 RHIC achieved an av­er­age store lu­mi­nos­i­ty of <L>=12x1026 cm-2 s-1 by op­er­at­ing with 103 bunch­es (out of 110 pos­si­ble), and by squeez­ing to β*=0.8 m. Our goal for this year's run, Run10, was to achieve an av­er­age of <L>=27x1026 cm-2 s-1. The mea­sures taken were de­creas­ing β* to 0.6 m, and re­duc­ing lon­gi­tu­di­nal and trans­verse emit­tances by means of bunched-beam stochas­tic cool­ing. In ad­di­tion we in­tro­duced a lat­tice to sup­press in­tra-beam scat­ter­ing (IBS) in both RHIC rings, up­grad­ed the RF sys­tem, and sep­a­rat­ed tran­si­tion cross­ings in both rings while ramp­ing. We pre­sent an overview of the changes and the re­sults in terms of Run10 in­creased in­stan­ta­neous lu­mi­nos­i­ty, lu­mi­nos­i­ty life­time, and in­te­grat­ed lu­mi­nos­i­ty.

  
MOPEC033 RHIC Performance as a 100 GeV Polarized Proton Collider in Run-9 531
 
  • C. Montag, L. Ahrens, M. Bai, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, A.V. Fedotov, W. Fischer, G. Ganetis, C.J. Gardner, J.W. Glenn, H. Hahn, M. Harvey, T. Hayes, H. Huang, P.F. Ingrassia, J.P. Jamilkowski, A. Kayran, J. Kewisch, R.C. Lee, D.I. Lowenstein, A.U. Luccio, Y. Luo, W.W. MacKay, Y. Makdisi, N. Malitsky, G.J. Marr, A. Marusic, M.P. Menga, R.J. Michnoff, M.G. Minty, J. Morris, B. Oerter, F.C. Pilat, P.H. Pile, E. Pozdeyev, V. Ptitsyn, G. Robert-Demolaize, T. Roser, T. Russo, T. Satogata, V. Schoefer, C. Schultheiss, F. Severino, M. Sivertz, K. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang
    BNL, Upton, Long Island, New York
  
 

Dur­ing the sec­ond half of Run-9, the Rel­a­tivis­tic Heavy Ion Col­lid­er (RHIC) pro­vid­ed po­lar­ized pro­ton col­li­sions at two in­ter­ac­tion points with both lon­gi­tu­di­nal and ver­ti­cal spin di­rec­tion. De­spite an in­crease in the peak lu­mi­nos­i­ty by up to 40%, the av­er­age store lu­mi­nos­i­ty did not in­crease com­pared to pre­vi­ous runs. We dis­cuss the lu­mi­nos­i­ty lim­i­ta­tions and po­lar­iza­tion per­for­mance dur­ing Run-9.

  
THPE103 Sorting Chromatic Sectupoles for Second Order Chromaticity Correction in the RHIC 4761
 
  • Y. Luo, W. Fischer, G. Robert-Demolaize, S. Tepikian, D. Trbojevic
    BNL, Upton, Long Island, New York
  
 

In this ar­ti­cle, based on the con­tri­bu­tions of the chro­mat­ic sex­tupole fam­i­lies to the half-in­te­ger res­o­nance driv­ing terms, we dis­cuss how to sort the chro­mat­ic sex­tupoles in the arcs of the Rel­a­tivis­tic Heavy Ion Col­lid­er (RHIC) to eas­i­ly and ef­fec­tive­ly cor­rect the sec­ond order chro­matic­i­ties. We pro­pose an on­line method with 4 knobs or 4 pairs of chro­mat­ic sex­tupole fam­i­lies to cor­rect sec­ond order chro­matic­i­ties. Nu­mer­i­cal sim­u­la­tions sup­port this method and shows that it im­proves the bal­ance of cor­rec­tion strengths among the sex­tupole fam­i­lies and avoids re­ver­sal of sex­tupole po­lar­i­ties, as well as yield­ing larg­er dy­nam­ic aper­tures for the 2009 RHIC 100 GeV po­lar­ized pro­ton run.