PAC 2005 - List of Authors

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Peggs, S.

Paper	Title	Page
TPAP051	Principle of Global Decoupling with Coupling Angle Modulation	3132
	Y. Luo, S. Peggs, F.C. Pilat, T. Roser, D. Trbojevic BNL, Upton, Long Island, New York
	Funding: Work supported by U.S. DOE under contract No. DE-AC02-98CH10886. The global betatron decoupling on the ramp is an important issue for the operation of the Relativistic Heavy Ion Collider (RHIC). A new scheme coupling phase modulation is found. It introduces a rotating extra coupling into the coupled machine to detect the residual coupling. The eigentune responses are measured with a high resolution phase lock loop (PLL) system. From the minimum and maximum tune splits, the correction strengths are given. The time period occupied by one coupling phase modulation is less than 10 seconds. So it is a very promising solution for the global decoupling on the ramp. In this article the principle of the coupling phase modulation is given. The simulation with the smooth accelerator model is also done. The practical issues concerning its applications are discussed.
TPAP052	Possible Phase Loop for the Global Decoupling	3182
	Y. Luo, P. Cameron, A. Della Penna, A. Marusic, S. Peggs, T. Roser, D. Trbojevic BNL, Upton, Long Island, New York O.R. Jones CERN, Geneva
	Funding: Work supported by U.S. DOE under contract No. DE-AC02-98CH10886. Besides two eigentunes Q1 and Q2 , two amplitude ratios r1 and r2 and two phase differences ∆ φ₁ and ∆ φ₂ are introduced for the global coupling observation. Simulations are carried out to check their behaviors in the process of the skew quadrupole strength scans. Some attractive features of the phase differences ∆ φ_1,2 have been found, which are possibly useful for the global decoupling phase loop, or future global decoupling feedback. Analytical descriptions to these 6 quantities are described in the Twiss parameters through the linear coupling's action-angle parameterization, or in coupling coefficient through the linear coupling's Hamiltonian perturbation theory. Dedicated beam experiments are carried out at the Relativistic Heavy Ion Collider (RHIC) to check the global coupling observables from the phase lock loop (PLL) system. The six observables are measured under PLL driving oscillations during the 1-D and 2-D skew quadrupole scans. The experimental results are reported and discussions are given.
TPAT095	Beam Induced Pressure Rise at RHIC	4308
	S.Y. Zhang, J.G. Alessi, M. Bai, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, J. Gullotta, P. He, H.-C. Hseuh, H. Huang, U. Iriso, R.C. Lee, V. Litvinenko, W.W. MacKay, T. Nicoletti, B. Oerter, S. Peggs, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, L. Smart, L. Snydstrup, P. Thieberger, D. Trbojevic, L. Wang, J. Wei, K. Zeno BNL, Upton, Long Island, New York
	Beam induced pressure rise in RHIC warm sections is currently one of the machine intensity and luminosity limits. This pressure rise is mainly due to electron cloud effects. The RHIC warm section electron cloud is associated with longer bunch spacings compared with other machines, and is distributed non-uniformly around the ring. In addition to the countermeasures for normal electron cloud, such as the NEG coated pipe, solenoids, beam scrubbing, bunch gaps, and larger bunch spacing, other studies and beam tests toward the understanding and counteracting RHIC warm electron cloud are of interest. These include the ion desorption studies and the test of anti-grazing ridges. For high bunch intensities and the shortest bunch spacings, pressure rises at certain locations in the cryogenic region have been observed during the past two runs. Beam studies are planned for the current 2005 run and the results will be reported. Work performed under the auspices of the US Department of Energy.
TPPP022	The eRHIC Ring-Ring Collider Design	1766
	F. Wang, M. Farkhondeh, W.A. Franklin, W. Graves, R. Milner, C. Tschalaer, D. Wang, A. Zolfaghari, T. Zwart, J. van der Laan MIT, Middleton, Massachusetts D.P. Barber DESY, Hamburg J. Beebe-Wang, A. Deshpande, V. Litvinenko, W.W. MacKay, C. Montag, S. Ozaki, B. Parker, S. Peggs, V. Ptitsyn, T. Roser, S. Tepikian, D. Trbojevic BNL, Upton, Long Island, New York
	The eRHIC ring-ring collider is the main design option of the future lepton-ion collider at Brookhaven National Laboratory. We report the revisions of the ring-ring collider design features to the baseline design presented in the eRHIC Zeroth Design Report (ZDR). These revisions have been made during the past year. They include changes of the interaction region which are required from the modifications in the design of the main detector. They also include changes in the lepton storage ring for high current operations as a result of better understandings of beam-beam interaction effects. The updated collider luminosity and beam parameters also take into account a more accurate picture of current and future operational aspects of RHIC.
TPPP043	ERL Based Electron-Ion Collider eRHIC	2768
	V. Litvinenko, L. Ahrens, M. Bai, J. Beebe-Wang, I. Ben-Zvi, M. Blaskiewicz, J.M. Brennan, R. Calaga, X.Y. Chang, A.V. Fedotov, W. Fischer, D. Kayran, J. Kewisch, W.W. MacKay, C. Montag, B. Parker, S. Peggs, V. Ptitsyn, T. Roser, A. Ruggiero, T. Satogata, B. Surrow, S. Tepikian, D. Trbojevic, V. Yakimenko, S.Y. Zhang BNL, Upton, Long Island, New York A. Deshpande Stony Brook University, Stony Brook M. Farkhondeh MIT, Middleton, Massachusetts
	Funding: Work performed under Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy. We present the designs of a future polarized electron-hadron collider, eRHIC* based on a high current super-conducting energy-recovery linac (ERL) with energy of electrons up to 20 GeV. We plan to operate eRHIC in both dedicated (electron-hadrons only) and parallel(with the main hadron-hadron collisions) modes. The eRHIC has very large tunability range of c.m. energies while maintaining very high luminosity up to 1034 cm-2 s-1 per nucleon. Two of the most attractive features of this scheme are full spin transparency of the ERL at all operational energies and the capability to support up to four interaction points. We present two main layouts of the eRHIC, the expected beam and luminosity parameter, and discuss the potential limitation of its performance. *http://www.agsrhichome.bnl.gov/eRHIC/, Appendix A: Linac-Ring Option.