IPAC2011 - List of Authors (Roser, T.)

Paper	Title	Page
TUPZ037	Momentum Aperture for the Low Beta* Lattices in RHIC Au-Au Runs	1891
	Y. Luo, K.A. Brown, W. Fischer, X. Gu, G. Robert-Demolaize, T. Roser, V. Schoefer, S. Tepikian, D. Trbojevic 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. In this article we calculate the momentum apertures with the low beta* lattices of 100 GeV RHIC Au-Au run. With RF re-bucketing, the maximum off-momentum spread reaches 1.7 ·10^-03 at store. To improve the momentum aperture, we need to reduce the nonlinear chromaticities. The methods to correct second order chromaticities in RHIC rings are presented. We also scan beta* at IP6 and IP8 and working point. The challenges to further reduce beta* in the RHIC Au-Au operation are discussed.

TUPZ039	Modelling of the AGS Using Zgoubi - Status	1897
	F. Méot, L. A. Ahrens, Y. Dutheil, J.W. Glenn, H. Huang, T. Roser, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Models of the Alternating Gradient Synchrotron, based on stepwise ray-tracing methods using both mathematical modelling or ﬁeld maps so to represent the optical elements, including the siberian snakes, are being developed based on stepwise ray-tracing numerical tools. The topic is introduced in earlier PAC and IPAC publications, a status is given here.

MOPO022	Precision Beam Instrumentation and Feedback-Based Beam Control at RHIC	526
	M.G. Minty, W. Fischer, H. Huang, R.L. Hulsart, C. Liu, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, V. Ptitsyn, G. Robert-Demolaize, T. Roser, V. Schoefer, S. Tepikian, M. Wilinski 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. In this report we present advances in beam instrumentation required for feedback-based beam control at the Relativistic Heavy Ion Collider (RHIC). Improved resolution has contributed to enabling now routine acceleration with multiple feedback loops. Better measurement and control of the beam’s properties have allowed acceleration at a new working point and have facilitated challenging experimental studies.

TUPZ035	RHIC Polarized Proton Status and Operation Highlights	1888
	H. Huang, L. A. Ahrens, I.G. Alekseev, E.C. Aschenauer, G. Atoian, M. Bai, A. Bazilevsky, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, A. Dion, K.A. Drees, W. Fischer, J.W. Glenn, X. Gu, L.T. Hoff, C. Liu, Y. Luo, W.W. MacKay, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, M.G. Minty, C. Montag, J. Morris, A. Poblaguev, V. Ptitsyn, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, D. Smirnov, S. Tepikian, J.E. Tuozzolo, G. Wang, K. Yip, A. Zaltsman, A. Zelenski, S.Y. Zhang BNL, Upton, Long Island, New York, USA D. Svirida ITEP, Moscow, Russia
	RHIC operation as the polarized proton collider presents unique challenges since both luminosity and spin polarization are important. 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. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control has also been improved this year. AGS polarization transfer efficiency is improved by a horizontal tune jump system. To preserve polarization on the ramp, a new working point was chosen with the vertical tune near a third order resonance. The orbit and tune control are essential for polarization preservation. To calibrate the polarization level at 250 GeV, polarized protons were accelerated up to 250GeV and decelerated back to 100GeV. The tune, orbit and chromaticity feedback is essential for this operation. The new record of luminosity was achieved with higher polarization at 250 GeV in this run. The overview of the changes and operation results are presented in this paper.

TUPZ038	RHIC Performance for FY2011 Au+Au Heavy Ion Run	1894
	G.J. Marr, 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, K.A. Drees, A.V. Fedotov, W. Fischer, W. Fu, C.J. Gardner, D.M. Gassner, J.W. Glenn, X. Gu, M. Harvey, T. Hayes, L.T. Hoff, H. Huang, P.F. Ingrassia, J.P. Jamilkowski, N.A. Kling, M. Lafky, J.S. Laster, C. Liu, Y. Luo, M. Mapes, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, S. Polizzo, V. Ptitsyn, G. Robert-Demolaize, T. Roser, P. Sampson, J. Sandberg, V. Schoefer, C. Schultheiss, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, B. Van Kuik, G. Wang, 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. Following the Fiscal Year (FY) 2010 (Run-10) Relativistic Heavy Ion Collider (RHIC) Au+Au run [1], RHIC experiment upgrades sought to improve detector capabilities. In turn, accelerator improvements were made to improve the luminosity available to the experiments for this run (Run-11). These improvements included: a redesign of the stochastic cooling systems for improved reliability; a relocation of “common” RF cavities to alleviate intensity limits due to beam loading; and an improved usage of feedback systems to control orbit, tune and coupling during energy ramps as well as while colliding at top energy. We present an overview of changes to the Collider and review the performance of the collider with respect to instantaneous and integrated luminosity goals.

THPS009	Coherent Electron Cooling Demonstration Experiment	3442
	V. Litvinenko, S.A. Belomestnykh, I. Ben-Zvi, J. Bengtsson, A.V. Fedotov, Y. Hao, D. Kayran, G.J. Mahler, W. Meng, T. Rao, T. Roser, B. Sheehy, R. Than, J.E. Tuozzolo, G. Wang, V. Yakimenko BNL, Upton, Long Island, New York, USA G.I. Bell, D.L. Bruhwiler, V.H. Ranjbar, B.T. Schwartz Tech-X, Boulder, Colorado, USA A. Hutton, G.A. Krafft, M. Poelker, R.A. Rimmer JLAB, Newport News, Virginia, USA M.A. Kholopov, P. Vobly BINP SB RAS, Novosibirsk, Russia
	Coherent electron cooling (CEC) is considered to be on of potential candidates capable of cooling high-energy, high-intensity hadron beams to very small emittances. It also has a potential to significantly boost luminosity of high-energy hadron-hadron and electron-hadron colliders. In a CEC system, a perturbation of the electron density caused by a hadron is amplified and fed back to the hadrons to reduce the energy spread and the emittance of the beam. Following the funding decision by DoE office of Nuclear Physics, we are designing and building coherent electron cooler for a proof-of-principle experiment at RHIC to cool 40 GeV heavy ion beam. In this paper, we describe the layout of the CeC installed into IP2 interaction region at RHIC. We present the design of the CeC cooler and results of preliminary simulations.

THPZ019	High Luminosity Electron-hadron Collider eRHIC	3726
	V. Ptitsyn, E.C. Aschenauer, J. Beebe-Wang, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, X. Chang, A.V. Fedotov, H. Hahn, L.R. Hammons, Y. Hao, P. He, A.K. Jain, E.C. Johnson, D. Kayran, J. Kewisch, V. Litvinenko, G.J. Mahler, W. Meng, B. Parker, A.I. Pikin, T. Rao, T. Roser, B. Sheehy, J. Skaritka, R. Than, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, Q. Wu, W. Xu BNL, Upton, Long Island, New York, USA
	We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan adding 20 (30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10³4 cm^-2s⁻¹ can be achieved in eRHIC using the low-beta interaction region which a 10 mrad crab crossing. A natural staging scenario of step-by-step increases of the electron beam energy by builiding-up of eRHIC's SRF linacs. We report on the eRHIC design and cost estimates for it stages. We discuss the progress of eRHC R&D projects from the polarized electron source to the coherent electron cooling.

Paper

Title

Page

Momentum Aperture for the Low Beta* Lattices in RHIC Au-Au Runs

1891

Y. Luo, K.A. Brown, W. Fischer, X. Gu, G. Robert-Demolaize, T. Roser, V. Schoefer, S. Tepikian, D. Trbojevic
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.
In this article we calculate the momentum apertures with the low beta* lattices of 100 GeV RHIC Au-Au run. With RF re-bucketing, the maximum off-momentum spread reaches 1.7 ·10^-03 at store. To improve the momentum aperture, we need to reduce the nonlinear chromaticities. The methods to correct second order chromaticities in RHIC rings are presented. We also scan beta* at IP6 and IP8 and working point. The challenges to further reduce beta* in the RHIC Au-Au operation are discussed.

TUPZ039

Modelling of the AGS Using Zgoubi - Status

1897

F. Méot, L. A. Ahrens, Y. Dutheil, J.W. Glenn, H. Huang, T. Roser, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Models of the Alternating Gradient Synchrotron, based on stepwise ray-tracing methods using both mathematical modelling or ﬁeld maps so to represent the optical elements, including the siberian snakes, are being developed based on stepwise ray-tracing numerical tools. The topic is introduced in earlier PAC and IPAC publications, a status is given here.

MOPO022

Precision Beam Instrumentation and Feedback-Based Beam Control at RHIC

526

M.G. Minty, W. Fischer, H. Huang, R.L. Hulsart, C. Liu, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, V. Ptitsyn, G. Robert-Demolaize, T. Roser, V. Schoefer, S. Tepikian, M. Wilinski
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.
In this report we present advances in beam instrumentation required for feedback-based beam control at the Relativistic Heavy Ion Collider (RHIC). Improved resolution has contributed to enabling now routine acceleration with multiple feedback loops. Better measurement and control of the beam’s properties have allowed acceleration at a new working point and have facilitated challenging experimental studies.

TUPZ035

RHIC Polarized Proton Status and Operation Highlights

1888

H. Huang, L. A. Ahrens, I.G. Alekseev, E.C. Aschenauer, G. Atoian, M. Bai, A. Bazilevsky, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, A. Dion, K.A. Drees, W. Fischer, J.W. Glenn, X. Gu, L.T. Hoff, C. Liu, Y. Luo, W.W. MacKay, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, M.G. Minty, C. Montag, J. Morris, A. Poblaguev, V. Ptitsyn, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, D. Smirnov, S. Tepikian, J.E. Tuozzolo, G. Wang, K. Yip, A. Zaltsman, A. Zelenski, S.Y. Zhang
BNL, Upton, Long Island, New York, USA
D. Svirida
ITEP, Moscow, Russia

RHIC operation as the polarized proton collider presents unique challenges since both luminosity and spin polarization are important. 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. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control has also been improved this year. AGS polarization transfer efficiency is improved by a horizontal tune jump system. To preserve polarization on the ramp, a new working point was chosen with the vertical tune near a third order resonance. The orbit and tune control are essential for polarization preservation. To calibrate the polarization level at 250 GeV, polarized protons were accelerated up to 250GeV and decelerated back to 100GeV. The tune, orbit and chromaticity feedback is essential for this operation. The new record of luminosity was achieved with higher polarization at 250 GeV in this run. The overview of the changes and operation results are presented in this paper.

TUPZ038

RHIC Performance for FY2011 Au+Au Heavy Ion Run

1894

G.J. Marr, 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, K.A. Drees, A.V. Fedotov, W. Fischer, W. Fu, C.J. Gardner, D.M. Gassner, J.W. Glenn, X. Gu, M. Harvey, T. Hayes, L.T. Hoff, H. Huang, P.F. Ingrassia, J.P. Jamilkowski, N.A. Kling, M. Lafky, J.S. Laster, C. Liu, Y. Luo, M. Mapes, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, S. Polizzo, V. Ptitsyn, G. Robert-Demolaize, T. Roser, P. Sampson, J. Sandberg, V. Schoefer, C. Schultheiss, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, B. Van Kuik, G. Wang, 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.
Following the Fiscal Year (FY) 2010 (Run-10) Relativistic Heavy Ion Collider (RHIC) Au+Au run [1], RHIC experiment upgrades sought to improve detector capabilities. In turn, accelerator improvements were made to improve the luminosity available to the experiments for this run (Run-11). These improvements included: a redesign of the stochastic cooling systems for improved reliability; a relocation of “common” RF cavities to alleviate intensity limits due to beam loading; and an improved usage of feedback systems to control orbit, tune and coupling during energy ramps as well as while colliding at top energy. We present an overview of changes to the Collider and review the performance of the collider with respect to instantaneous and integrated luminosity goals.

THPS009

Coherent Electron Cooling Demonstration Experiment

3442

V. Litvinenko, S.A. Belomestnykh, I. Ben-Zvi, J. Bengtsson, A.V. Fedotov, Y. Hao, D. Kayran, G.J. Mahler, W. Meng, T. Rao, T. Roser, B. Sheehy, R. Than, J.E. Tuozzolo, G. Wang, V. Yakimenko
BNL, Upton, Long Island, New York, USA
G.I. Bell, D.L. Bruhwiler, V.H. Ranjbar, B.T. Schwartz
Tech-X, Boulder, Colorado, USA
A. Hutton, G.A. Krafft, M. Poelker, R.A. Rimmer
JLAB, Newport News, Virginia, USA
M.A. Kholopov, P. Vobly
BINP SB RAS, Novosibirsk, Russia

Coherent electron cooling (CEC) is considered to be on of potential candidates capable of cooling high-energy, high-intensity hadron beams to very small emittances. It also has a potential to significantly boost luminosity of high-energy hadron-hadron and electron-hadron colliders. In a CEC system, a perturbation of the electron density caused by a hadron is amplified and fed back to the hadrons to reduce the energy spread and the emittance of the beam. Following the funding decision by DoE office of Nuclear Physics, we are designing and building coherent electron cooler for a proof-of-principle experiment at RHIC to cool 40 GeV heavy ion beam. In this paper, we describe the layout of the CeC installed into IP2 interaction region at RHIC. We present the design of the CeC cooler and results of preliminary simulations.

THPZ019

High Luminosity Electron-hadron Collider eRHIC

3726

V. Ptitsyn, E.C. Aschenauer, J. Beebe-Wang, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, X. Chang, A.V. Fedotov, H. Hahn, L.R. Hammons, Y. Hao, P. He, A.K. Jain, E.C. Johnson, D. Kayran, J. Kewisch, V. Litvinenko, G.J. Mahler, W. Meng, B. Parker, A.I. Pikin, T. Rao, T. Roser, B. Sheehy, J. Skaritka, R. Than, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, Q. Wu, W. Xu
BNL, Upton, Long Island, New York, USA

We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan adding 20 (30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10³4 cm^-2s⁻¹ can be achieved in eRHIC using the low-beta interaction region which a 10 mrad crab crossing. A natural staging scenario of step-by-step increases of the electron beam energy by builiding-up of eRHIC's SRF linacs. We report on the eRHIC design and cost estimates for it stages. We discuss the progress of eRHC R&D projects from the polarized electron source to the coherent electron cooling.