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G. Marr,
L. Ahrens,
M. Bai,
J. Beebe-Wang,
I. Blackler,
M. Blaskiewicz,
J.M. Brennan,
K.A. Brown,
D. Bruno,
J. Butler, [......],
P. Thieberger,
D. Trbojevic,
N. Tsoupas,
J.E. Tuozzolo,
B. VanKuik,
G. Wang,
M. Wilinski,
A. Zaltsman,
K. Zeno,
S.Y. Zhang
[show abstract]
[hide abstract]
ABSTRACT: Following the Fiscal Year (FY) 2010 (Run-10) Relativistic Heavy Ion Collider (RHIC) Au+Au run, 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. At the conclusion of the FY 2011 polarized proton run, preparations for heavy ion run proceeded on April 18, with Au+Au collisions continuing through June 28. Our standard operations at 100 GeV/nucleon beam energy was bracketed by two shorter periods of collisions at lower energies (9.8 and 13.5 GeV/nucleon), continuing a previously established program of low and medium energy runs. Table 1 summarizes our history of heavy ion operations at RHIC.
09/2011
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K.A. Drees,
L. Ahrens,
M. Bai,
J. Beebe-Wang,
I.M.C. Blackler,
M. Blaskiewicz,
K.A. Brown,
M. Brennan,
D. Bruno,
J. Butler, [......],
S. Tepikian,
P. Thieberger,
D. Trbojevic,
N. Tsoupas,
J. Tuozzolo,
B. van Kuik,
M. Wilinski,
A. Zaltsman,
K. Zeno,
S.Y. Zhang
[show abstract]
[hide abstract]
ABSTRACT: 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. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.
03/2011
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M Minty,
A Curcio,
C Dawson,
C Degen,
Y Luo, G Marr,
B Martin,
A Marusic,
K Mernick,
P Oddo,
Others
BNL C-AD AP Note. 01/2010; 366(August).
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T. Satogata,
L. Ahrens,
M. Bai,
J.M. Brennan,
D. Bruno,
J Butler,
A Drees,
A Fedotov,
W. Fischer,
M Harvey, [......],
N. Malitsky, G. Marr,
R. Michnoff,
B. Oerter,
E. Pozdeyev,
T. Roser,
F. Severino,
K Smith,
S. Tepikian,
N. Tsoupas
[show abstract]
[hide abstract]
ABSTRACT: There is significant interest in RHIC heavy ion collisions at $\sqrt{s_{NN}}=$5--50 GeV, motivated by a search for the QCD phase transition critical point. The lowest energies for this search are well below the nominal RHIC gold injection collision energy of $\sqrt{s_{NN}}=19.6$ GeV. There are several operations challenges at RHIC in this regime, including longitudinal acceptance, magnet field quality, lattice control, and luminosity monitoring. We report on the status of work to address these challenges, including results from beam tests of low energy RHIC operations with protons and gold, and potential improvements from different beam cooling scenarios.
11/2007;
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[show abstract]
[hide abstract]
ABSTRACT: Centralization of information pertaining to accelerators can benefit accelerator operation and development. Further, retention and the changeable nature of information present challenges to accelerator operation, particularly in instances of turnover. MediaWiki is free, server-based software licensed under the GNU general public license that uses PHP to render data stored in a MySQL database as interactive web documents, and is designed to produce a collaborative document known as a wiki. The MediaWiki engine was implemented at BNL, and this paper describes the first year of use by the operations, controls, and RF groups at the collider- accelerator department, including code modifications, common practices, and use as a training tool.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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L. Ahrens,
J. Alessi,
J. Benjamin,
M. Blaskiewicz,
J.M. Brennan,
K.A. Brown,
C. Carlson,
W. Fischer,
C.J. Gardner,
J.W. Glenn, [......],
J. Morris,
F. Pilat,
T. Roser,
F. Severino,
K.S. Smith,
D. Steski,
P. Thieberger,
N. Tsoupas,
A. Zaltsman,
K. Zeno
[show abstract]
[hide abstract]
ABSTRACT: Gold ions for the 2007 run [1] of the relativistic heavy ion collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem,Booster and AGS prior to injection into RHIC. The setup and performance of this chain of accelerators is reviewed with a focus on improvements in the quality of beam delivered to RHIC. In particular,more uniform stripping foils between Booster and AGS,and a new bunch merging scheme in AGS have provided beam bunches with reduced longitudinal emittance for RHIC.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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A. Drees,
L. Ahrens,
J. Alessi,
M. Bai,
D. Barton,
J. Beebe-Wang,
M. Blaskiewicz,
K. Brown,
M. Brennan,
D. Bruno, [......],
T. Satogata,
C. Schultheiss,
F. Severino,
K. Smith,
S. Tepikian,
D. Trbojevic,
N. Tsoupas,
J. Tuozzolo,
A. Zaltsman,
S.Y. Zhang
[show abstract]
[hide abstract]
ABSTRACT: After the last successful RHIC Au-Au run in 2004 (Run-4), RHIC experiments now require significantly enhanced luminosity to study very rare events in heavy ion collisions. RHIC has demonstrated its capability to operate routinely above its design average luminosity per store of 2times10<sup>26</sup> cm<sup>-2</sup> s<sup>-1</sup>. In Run-4 we already achieved 2.5 times the design luminosity in RHIC. This luminosity was achieved with only 40% of the total possible number of bunches filled, and with beta* = 1 m. However, the goal is to reach 4 times the design luminosity, an average of 8times10<sup>26</sup> cm<sup>-2</sup> s<sup>-1</sup>, by reducing the beta* value and increasing the number of bunches to the accelerator maximum of 111. In addition, the average time at store was expected to be increased by a factor of 1.1 to about 60% of calendar time. We present an overview of the changes that increased the instantaneous luminosity, luminosity lifetime and integrated luminosity of RHIC Au-Au operations during Run-7 even though the goal of 60% time at store could not be reached.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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T. Satogata,
L. Ahrens,
M. Bai,
J.M. Brennan,
D. Bruno,
J. Butler,
A. Drees,
A. Fedotov,
W. Fischer,
M. Harvey, [......],
N. Malitsky, G. Marr,
R. Michnoff,
B. Oerter,
E. Pozdeyev,
T. Roser,
F. Severino,
K. Smith,
S. Tepikian,
N. Tsoupas
[show abstract]
[hide abstract]
ABSTRACT: There is significant interest in RHIC heavy ion collisions at radics =5-50 GeV/u, motivated by a search for the QCD phase transition critical point. The lowest energies are well below the nominal RHIC gold injection radics = 19.6 GeV/u. There are several challenges that face RHIC operations in this regime, including longitudinal acceptance, magnet field quality, lattice control, and luminosity monitoring. We report on the status of work to address these challenges, including results from beam tests of low energy RHIC operations with protons and gold.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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M. Bai,
L. Ahrens,
I.G. Alekseev,
J. Alessi,
J. Beebe-Wang,
M. Blaskiewicz,
A. Bravar,
J.M. Brennan,
K. Brown,
D. Bruno, [......],
D.N. Svirida,
D. Trbojevic,
N. Tsoupas,
J. Tuozzolo,
M. Wilinski,
S. Tepikian,
A. Zaltsman,
A. Zelenski,
K. Zeno,
S.Y. Zhang
[show abstract]
[hide abstract]
ABSTRACT: The relativistic heavy ion collider (RHIC) as the first high energy polarized proton collider was designed to provide polarized proton collisions at a maximum beam energy of 250 GeV. It has been providing collisions at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during the acceleration from injection to 100 GeV with careful control of the betatron tunes and the vertical orbit distortions. However, the intrinsic spin resonances beyond 100 GeV are about a factor of two stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were accelerated to the record energy of 250 GeV in RHIC with a polarization of 46% measured at top energy in 2006. The polarization measurement as a function of beam energy also shows some polarization loss around 136 GeV, the first strong intrinsic resonance above 100 GeV. This paper presents the results and discusses the sensitivity of the polarization survival to orbit distortions.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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R.F. Conde,
K.A. Potocki,
A. Szabo,
K.W. Kirby,
H.M. Maldonado,
P.B. Adamsen,
R.S. Bokulic,
G. Dakermanji,
W.F. Dellinger,
J.P. Downing, [......],
B.A. Leary,
W.S. Lewis,
S.X. Ling, G. Marr,
P.M. Malouf,
D.H. Napollilo,
D.F. Persons,
J.R. Troll,
R.E. Wallis,
R.P. Lin
[show abstract]
[hide abstract]
ABSTRACT: The Sentinels mission is a key component of NASA's Living With a Star (LWS) program. The Sentinels Science and Technology Definition Team (STDT) has completed a study to define the science objectives, measurement requirements and observational strategies, and mission design for the Sentinels mission. The Inner Heliospheric Sentinels (IHS) are one of the three flight elements (the others are the Near Earth Sentinel and Far Side Sentinel) that make up the Sentinels mission. The four spin-stabilized IHS spacecraft are in elliptical heliocentric orbit with perihelia at ~0.25 AU and aphelia at ~0.75 AU. This orbit presents unique spacecraft thermal control and power challenges. This study has demonstrated mission feasibility by developing a spacecraft design concept using conventional technologies that satisfy the science and mission requirements defined by the Sentinels STDT. Numerous trade studies were performed to optimize the spacecraft design. The trade studies and their results are discussed.
Aerospace Conference, 2007 IEEE; 04/2007
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Proceedings of the 2007 Particle Accelerator Conference, Albuquerque, NM, USA; 01/2007
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L. Ahrens,
J. Alessi,
J. Benjamin,
M. Blaskiewicz,
J.M. Brennan,
K.A. Brown,
C. Carlson,
J. DeLong,
C.J. Gardner,
J.W. Glenn, [......],
W.W. MacKay, G. Marr,
J. Morris,
T. Roser,
F. Severino,
K.S. Smith,
D. Steski,
N. Tsoupas,
A. Zaltsman,
K. Zeno
[show abstract]
[hide abstract]
ABSTRACT: Copper ions for the 2005 run [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of these accelerators with copper are reviewed in this paper.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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F. Pilat,
L. Ahrens,
M. Bai,
D.S. Barton,
J. Beebe-Wang,
M. Blaskiewicz,
J.M. Brennan,
D. Bruno,
P. Cameron,
R. Connolly, [......],
S. Tepikian,
R. Tomas,
D. Trbojevic,
N. Tsoupas,
J. Tuozzolo,
K. Vetter,
A. Zaltsman,
K. Zeno,
S.Y. Zhang,
W. Zhang
[show abstract]
[hide abstract]
ABSTRACT: The 5<sup>th</sup>year of RHIC operations, started in November 2004 and expected to last till June 2005, consists of a physics run with Cu-Cu collisions at 100 GeV/u followed by one with polarized protons (pp) at 100 GeV [1]. We will address here the overall performance of the RHIC complex used for the first time as a Cu-Cu collider, and compare it with previous operational experience with Au, PP and asymmetric d-Au collisions. We will also discuss operational improvements, such as a squeeze to 85cm in the high luminosity interaction regions from the design value of 1m, system improvements, machine performance and limitations, and address reliability and uptime issues.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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L. Ahrens,
J. Alessi,
J. Benjamin,
M. Blaskiewicz,
J.M. Brennan,
K.A. Brown,
C. Carlson,
J. DeLong,
T. D'Ottavio,
B. Frak, [......],
J. Morris,
T. Roser,
T. Satogata,
G. Smith,
K.S. Smith,
D. Steski,
N. Tsoupas,
P. Thieberger,
K. Zeno,
S.Y. Zhang
[show abstract]
[hide abstract]
ABSTRACT: The RHIC 2003 Physics Run required collisions between gold ions and deuterons. The injector necessarily had to deliver adequate quality (transverse and longitudinal emittance) and quantity of both species. For gold this was a continuing evolution from past work. For deuterons it was new territory. For the filling of the RHIC the injector not only had to deliver quality beams but also had to switch between these species quickly. This paper details the collider requirements and our success in meeting these. Some details of the configurations employed are given.
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the; 06/2003
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K.A. Brown,
L. Ahrens,
S. Bellavia,
S. Binello,
B. Brelsford,
D. DuMont,
W. Eng,
C. Gardner,
D. Gassner,
J.W. Glenn, [......],
S. Nemesure,
D. Phillips,
A. Rusek,
J. Ryan,
T. Shrey,
L. Snydstrup,
N. Tsoupas,
B. VanKuik,
S. Zahariou-Cohen,
K. Zeno
[show abstract]
[hide abstract]
ABSTRACT: Brookhaven's AGS Booster has been modified to deliver slow extracted beam to a new beam line, the NASA Space Radiation Laboratory (NSRL). This facility was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The design of the resonant extraction system has been described. A more detailed description, which includes predictions of the slow extracted beam time structure has been described. In this report we present results of the system commissioning and performance.
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the; 06/2003
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K A Brown,
L Ahrens,
M Bai,
J Beebe-Wang,
M Blaskiewicz,
J M Brennan,
D Bruno,
C Carlson,
R Connolly,
R De Maria, [......],
C Theisen,
P Thieberger,
D Trbojevic,
N Tsoupas,
J Tuozzolo,
G Wang,
M Wilinski,
A Zaltsman,
K Zeno,
S Y Zhang
[show abstract]
[hide abstract]
ABSTRACT: Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous de-tector 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 in-crease in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of < L >= 12 × 10 26 cm −2 s −1 by operating with 103 bunches (out of 111 possible), and by squeezing to β * = 0.85 m. This year, Run-10, we achieved < L >= 20 × 10 26 cm −2 s −1 , which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased β * to 0.75 m, operated with 111 bunches per ring, and reduced longitudi-nal 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 control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.
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C J Gardner,
N P Abreu,
L Ahrens,
J Alessi,
M Bai,
D Barton,
J Beebe-Wang,
M Blaskiewicz,
J M Brennan,
K A Brown, [......],
D Steski,
S Tepikian,
Y Than,
P Thieberger,
D Trbojevic,
N Tsoupas,
J Tuozzolo,
A Zaltsman,
K L Zeno,
S Y Zhang
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L Ahrens,
J Alessi,
J Benjamin,
M Blaskiewicz,
J M Brennan,
K A Brown,
C Carlson,
W Fischer,
C J Gardner,
J W Glenn, [......],
J Morris,
F Pilat,
T Roser,
F Severino,
K S Smith,
D Steski,
P Thieberger,
N Tsoupas,
A Zaltsman,
K Zeno
[show abstract]
[hide abstract]
ABSTRACT: Gold ions for the 2007 run [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of this chain of accelerators is reviewed with a focus on im-provements in the quality of beam delivered to RHIC. In particular, more uniform stripping foils between Booster and AGS, and a new bunch merging scheme in AGS have provided beam bunches with reduced longitudinal emit-tance for RHIC.
-
L Ahrens,
J Alessi,
J Benjamin,
M Blaskiewicz,
J M Brennan,
K A Brown,
C Carlson,
J Delong,
T D 'ottavio,
B Frak, [......],
J Morris,
T Roser,
T Satogata,
G Smith,
K S Smith,
D Steski,
N Tsoupas,
P Thieberger,
K Zeno,
S Y Zhang
[show abstract]
[hide abstract]
ABSTRACT: The RHIC 2003 Physics Run [1] required collisions be-tween gold ions and deuterons. The injector necessarily had to deliver adequate quality (transverse and longitudinal emittance) and quantity of both species. For gold this was a continuing evolution from past work [2]. For deuterons it was new territory. For the filling of the RHIC the injector not only had to deliver quality beams but also had to switch between these species quickly. This paper details the col-lider requirements and our success in meeting these. Some details of the configurations employed are given.
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L Ahrens,
J Alessi,
J Benjamin,
M Blaskiewicz,
J M Brennan,
K A Brown,
C Carlson,
J Delong,
C J Gardner,
J W Glenn,
T Hayes,
W W Mackay, G Marr,
J Morris,
T Roser,
F Severino,
K S Smith,
D Steski,
N Tsoupas,
A Zaltsman
