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Sample records for bnl ags rhic

  1. Highlights from BNL-RHIC

    CERN Document Server

    Tannenbaum, M J

    2012-01-01

    Recent highlights from Brookhaven National Laboratory and the Relativistic Heavy Ion Collider (RHIC) are reviewed and discussed. Topics include: Discovery of the strongly interacting Quark Gluon Plasma (sQGP) in 2005; RHIC machine operation in 2011 as well as latest achievements from the superconducting Magnet Division and the National Synchrotron Light Source II project. Highlights from QGP physics at RHIC include: comparison of new measurements of charged multiplicity in A+A collisions by ALICE at the LHC to previous RHIC measurements; Observation of the anti-alpha particle by the STAR experiment; Collective Flow, including the Triangular Flow discovery and the latest results on v3; the RHIC beam energy scan in search of the QCD critical point. The pioneering use at RHIC of hard-scattering as a probe of the sQGP will also be reviewed and the latest results presented including: jet-quenching via suppression of high pT particles and two particle correlations; new results on fragmentation functions using gamma...

  2. Highlights from BNL and RHIC 2015

    CERN Document Server

    Tannenbaum, M J

    2016-01-01

    Highlights of news from Brookhaven National Laboratory (BNL) and results from the Relativistic Heavy Ion Collider (RHIC) in the period July 2014-June 2015 are presented. The news this year was mostly very positive. The major event at BNL was the startup and dedication of the new NSLS II, "the World's brightest Synchrotron Light Source". The operation of RHIC was outstanding with a polarized p+p run at $\\sqrt{s}=200$ GeV with integrated luminosity that exceeded the sum of all previous p+p integrated luminosity at this $\\sqrt{s}$. For the first time at RHIC asymmetric p+Au and p+Al runs were made but the p+Al run caused damage in the PHENIX forward detectors from quenches that were inadequately shielded for this first p+A run. This was also the 10th anniversary of the 2005 announcement of the Perfect Liquid Quark Gluon Plasma at RHIC and a review is presented of the discoveries leading to this claim. A new result on net-charge fluctuations (with no particle identification) from PHENIX based on previous scans ov...

  3. Highlights from BNL and RHIC 2014

    CERN Document Server

    Tannenbaum, M J

    2015-01-01

    Highlights of news from Brookhaven National Laboratory (BNL) and results from the Relativistic Heavy Ion Collider (RHIC) in the period July 2013-June 2014 are presented. It was a busy year for news, most notably a U. S. Government shutdown for 16 days beginning October 1, 2013 due to the lack of an approved budget for FY2014. Even with this unusual government activity, the $\\sqrt{s_{NN}}=200$ GeV Au+Au Run14 at RHIC was the best ever with integrated luminosity exceeding the sum of all previous runs. Additionally there was a brief He$^3$+Au run to continue the study of collective flow in small systems which was reinforced by new results presented on identified particle flow in d+Au. The other scientific highlights are also mostly concerned with ``soft (low $p_T$)'' physics complemented by the first preliminary results of reconstructed jets from hard-scattered partons in Au+Au collisions at RHIC . The measurements of transverse energy ($E_T$) spectra in p-p, d+Au and Au+Au collisions, which demonstrated last ye...

  4. Heavy Ion results from RHIC-BNL

    Directory of Open Access Journals (Sweden)

    Esumi Shinlchi

    2013-05-01

    Full Text Available Recent results from heavy ion collision experiments from RHIC at BNL are presented and discussed in terms of Quark Gluon Plasm properties, such as partonic collectivity and partonic energy loss. The experimental results with direct photons and heavy quarks have given important additional insights of the plasma on top of what has been known with light hadrons. Higher order event anisotropies and the related results have provided the geometrical, temporal and dynamical information of the plasma. The beam energy dependence of the various measurements could reveal the structure of QCD phase diagram and possibly the critical point in the diagram, where the properties of phase transition are expected to change drastically.

  5. Highlights from BNL-RHIC-2012

    CERN Document Server

    Tannenbaum, M J

    2013-01-01

    Recent highlights from Brookhaven National Laboratory and the Relativistic Heavy Ion Collider (RHIC) are reviewed and discussed in the context of the discovery of the strongly interacting Quark Gluon Plasma (sQGP) at RHIC in 2005 as confirmed by results from the CERN-LHC Pb+Pb program. Outstanding RHIC machine operation in 2012 with 3-dimensional stochastic cooling and a new EBIS ion source enabled measurements with Cu+Au, U+U, for which multiplicity distributions are shown, as well as with polarized p-p collisions. Differences of the physics and goals of p-p versus A+A are discussed leading to a review of RHIC results on pi0 suppression in Au+Au collisions and comparison to LHC Pb+Pb results in the same range 5 30 GeV. Improved measurements of direct photon production and correlation with charged particles at RHIC are shown, including the absence of a low pT (thermal) photon enhancement in d+Au collisions. Attempts to understand the apparent equality of the energy loss of light and heavy quarks in the QGP by...

  6. RHIC FY15 pp Run RHIC and AGS polarization analysis

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Adams, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-20

    The polarization information is important for the spin physics program in Relativistic Heavy Ion Collider (RHIC). There are discrepancies between AGS and RHIC polarization measurements. First, the face value of AGS polarization is higher than RHIC ones in general. Second, the measured polarization profile (described by the profile ratio R) is stronger in AGS than in RHIC. This note analyzes the polarization data from FY15 pp run period. The results show that the differences between AGS and RHIC polarization measurements are reasonable, but the R value difference is puzzling. The difference between blue and yellow ring is worth of spin simulation to explain.

  7. Proceedings of RIKEN BNL Research Center workwhop on RHIC spin

    Energy Technology Data Exchange (ETDEWEB)

    SOFFER,J.

    1999-10-06

    This RHIC Spin Workshop is the 1999 annual meeting of the RHIC Spin Collaboration, and the second to be hosted at Brookhaven and sponsored by the RIKEN BNL Research Center. The previous meetings were at Brookhaven (1998), Marseille (1996), MIT in 1995, Argonne 1994, Tucson in 1991, and the Polarized Collider Workshop at Penn State in 1990. As noted last year, the Center provides a home for combined work on spin by theorists, experimenters, and accelerator physicists. This proceedings, as last year, is a compilation of 1 page summaries and 5 selected transparencies for each speaker. It is designed to be available soon after the workshop is completed. Speakers are welcome to include web or other references for additional material. The RHIC spin program and RHIC are rapidly becoming reality. RHIC has completed its first commissioning run, as described here by Steve Peggs. The first Siberian Snake for spin has been completed and is being installed in RHIC. A new polarized source from KEK and Triumf with over 1 milliampere of polarized H{sup minus} is being installed, described by Anatoli Zelenski. They have had a successful test of a new polarimeter for RHIC, described by Kazu Kurita and Haixin Huang. Spin commissioning is expected next spring (2000), and the first physics run for spin is anticipated for spring 2001. The purpose of the workshop is to get everyone together about once per year and discuss goals of the spin program, progress, problems, and new ideas. They also have many separate regular forums on spin. There are spin discussion sessions every Tuesday, now organized by Naohito Saito and Werner Vogelsang. The spin discussion schedule and copies of presentations are posted on http://riksg01.rhic.bnl.gov/rsc. Speakers and other spinners are encouraged to come to BNL and to lead a discussion on your favorite idea. They also have regular polarimeter and snake meetings on alternate Thursdays, led by Bill McGahern, the lead engineer for the accelerator spin

  8. RHIC/AGS Online Model Environments: Experiences and Design for AGS Modeling

    International Nuclear Information System (INIS)

    The RHIC/AGS online modeling environment, a general client-server modeling package that supports cdev and straightforward integration of diverse computational modeling engines (CMEs), is being adapted to model the AGS and Booster at BNL. This implementation uses a version of MAD modified at BNL that allows traditional lattice structure analysis, single pass beam line analysis, multi-particle tracking, interactive graphics, and the use of field maps. The on-line model system is still under development, a real working prototype exists and is being tested. This paper describes the system and experience with its design and use for AGS and AGS Booster online modeling

  9. Proceedings of RIKEN BNL Research Center Workshop: Progress in High-pT Physics at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Bazilevsky, A.; Bland, L.; Vogelsang, W.

    2010-03-17

    This volume archives the presentations at the RIKEN BNL Research Center workshop 'Progress in High-PT Physics at RHIC', held at BNL in March 2010. Much has been learned from high-p{sub T} physics after 10 years of RHIC operations for heavy-ion collisions, polarized proton collisions and d+Au collisions. The workshop focused on recent progress in these areas by both theory and experiment. The first morning saw review talks on the theory of RHIC high-p{sub T} physics by G. Sterman and J. Soffer, and on the experimental results by M. Tannenbaum. One of the most exciting recent results from the RHIC spin program is the first observation of W bosons and their associated single-spin asymmetry. The new preliminary data were reported on the first day of our workshop, along with a theoretical perspective. There also were detailed discussions on the global analysis of polarized parton distributions, including the knowledge on gluon polarization and the impact of the W-data. The main topic of the second workshop day were single-transverse spin asymmetries and their analysis in terms of transverse-momentum dependent parton distributions. There is currently much interest in a future Drell-Yan program at RHIC, thanks to the exciting physics opportunities this would offer. This was addressed in some of the talks. There also were presentations on the latest results on transverse-spin physics from HERMES and BELLE. On the final day of the workshop, the focus shifted toward forward and small-x physics at RHIC, which has become a cornerstone of the whole RHIC program. Exciting new data were presented and discussed in terms of their possible implications for our understanding of strong color-field phenomena in QCD. In the afternoon, there were discussions of nuclear parton distributions and jet observables, among them fragmentation. The workshop was concluded with outlooks toward the near-term (LHC, JLab) and longer-term (EIC) future. The workshop has been a great success

  10. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 65, RHIC SPIN COLLABORATION MEETINGS XXVII, XXVIII, and XXX

    International Nuclear Information System (INIS)

    The RIKEN BNL Research Center (RSRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the 'Rikagaku Kenkyusho' (RIKEN, The Institute of Physical and Chemical Research) of Japan. The Center is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has both a theory and experimental component. At present the theoretical group has 4 Fellows and 3 Research Associates as well as 11 RHIC Physics/University Fellows (academic year 2003-2004). To date there are approximately 30 graduates from the program of which 13 have attained tenure positions at major institutions worldwide. The experimental group is smaller and has 2 Fellows and 3 RHIC Physics/University Fellows and 3 Research Associates, and historically 6 individuals have attained permanent positions. Beginning in 2001 a new RIKEN Spin Program (RSP) category was implemented at RBRC. These appointments are joint positions of RBRC and RIKEN and include the following positions in theory and experiment: RSP Researchers, RSP Research Associates, and Young Researchers, who are mentored by senior RBRC Scientists, A number of RIKEN Jr. Research Associates and Visiting Scientists also contribute to the physics program at the Center. RBRC has an active workshop program on strong interaction physics with each workshop focused on a specific physics problem. Each workshop speaker is encouraged to select a few of the most important transparencies from his or her presentation, accompanied by a page of explanation. This material is collected at the end of the workshop by the organizer to form proceedings, which can therefore be available within a short time. To date there are sixty nine proceedings volumes available. The construction of a 0.6 teraflops parallel processor, dedicated to lattice QCD, begun at the Center on February 19, 1998, was completed on August 28, 1998 and is still

  11. SynapSense Wireless Environmental Monitoring System of the RHIC & ATLAS Computing Facility at BNL

    Science.gov (United States)

    Casella, K.; Garcia, E.; Hogue, R.; Hollowell, C.; Strecker-Kellogg, W.; Wong, A.; Zaytsev, A.

    2014-06-01

    RHIC & ATLAS Computing Facility (RACF) at BNL is a 15000 sq. ft. facility hosting the IT equipment of the BNL ATLAS WLCG Tier-1 site, offline farms for the STAR and PHENIX experiments operating at the Relativistic Heavy Ion Collider (RHIC), the BNL Cloud installation, various Open Science Grid (OSG) resources, and many other small physics research oriented IT installations. The facility originated in 1990 and grew steadily up to the present configuration with 4 physically isolated IT areas with the maximum rack capacity of about 1000 racks and the total peak power consumption of 1.5 MW. In June 2012 a project was initiated with the primary goal to replace several environmental monitoring systems deployed earlier within RACF with a single commercial hardware and software solution by SynapSense Corporation based on wireless sensor groups and proprietary SynapSense™ MapSense™ software that offers a unified solution for monitoring the temperature and humidity within the rack/CRAC units as well as pressure distribution underneath the raised floor across the entire facility. The deployment was completed successfully in 2013. The new system also supports a set of additional features such as capacity planning based on measurements of total heat load, power consumption monitoring and control, CRAC unit power consumption optimization based on feedback from the temperature measurements and overall power usage efficiency estimations that are not currently implemented within RACF but may be deployed in the future.

  12. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER, VOLUME 37, RHIC SPIN COLLABORATION MEETING VI (PART 2).

    Energy Technology Data Exchange (ETDEWEB)

    BLAND, L.; SAITO, N.

    2001-11-15

    The second part of the sixth RHIC Spin Collaboration (RSC) meeting was held on November 15, 2001 at Brookhaven National Laboratory. Previous meetings have elaborated on the new generation of proton spin-structure studies (e.g. gluon polarization and flavor separation of q and {bar q} polarizations via real W{sup {+-}} production) enabled by studying polarized proton collisions at energies and momentum transfers where perturbative QCD models are expected to be applicable. The focus of this meeting was on many of the experimental issues that must be resolved to achieve these physics goals. This summary is written with the benefit of hindsight following the completion of the first-ever run of a polarized proton collider. This first run can be considered as a successfully completed milestone of the RHIC Spin Collaboration. Other milestones remain important. Long term machine items were identified in Waldo Mackay's talk, the most important being the completion of the spin rotator magnets that will be installed in 2002 to allow the flexible orientation of the proton beam polarization at the PHENM and STAR experiments. At the meeting Waldo discussed a stronger partial snake magnet for the AGS as a means of producing highly polarized proton beams to inject into RHIC. Developments subsequent to this meeting suggest that a superconducting helical dipole magnet may be feasible for the AGS, and is likely to be needed to achieve the 70% beam polarization in RHIC. Longer term items were also presented, including potential increases in luminosity by the addition of electron cooling to RHIC and the possibility of increasing the collision energy by {approx}20% by replacement of the DX magnets. These items could be considered for a second generation of RHIC spin experiments. The other topics covered at the meeting were related to polarimetry and to the absolute calibration of the proton beam polarization in RHIC. These topics were divided into short- and long-term solutions to

  13. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER, VOLUME 37, RHIC SPIN COLLABORATION MEETING VI (PART 2)

    International Nuclear Information System (INIS)

    The second part of the sixth RHIC Spin Collaboration (RSC) meeting was held on November 15, 2001 at Brookhaven National Laboratory. Previous meetings have elaborated on the new generation of proton spin-structure studies (e.g. gluon polarization and flavor separation of q and bar q polarizations via real W± production) enabled by studying polarized proton collisions at energies and momentum transfers where perturbative QCD models are expected to be applicable. The focus of this meeting was on many of the experimental issues that must be resolved to achieve these physics goals. This summary is written with the benefit of hindsight following the completion of the first-ever run of a polarized proton collider. This first run can be considered as a successfully completed milestone of the RHIC Spin Collaboration. Other milestones remain important. Long term machine items were identified in Waldo Mackay's talk, the most important being the completion of the spin rotator magnets that will be installed in 2002 to allow the flexible orientation of the proton beam polarization at the PHENM and STAR experiments. At the meeting Waldo discussed a stronger partial snake magnet for the AGS as a means of producing highly polarized proton beams to inject into RHIC. Developments subsequent to this meeting suggest that a superconducting helical dipole magnet may be feasible for the AGS, and is likely to be needed to achieve the 70% beam polarization in RHIC. Longer term items were also presented, including potential increases in luminosity by the addition of electron cooling to RHIC and the possibility of increasing the collision energy by ∼20% by replacement of the DX magnets. These items could be considered for a second generation of RHIC spin experiments. The other topics covered at the meeting were related to polarimetry and to the absolute calibration of the proton beam polarization in RHIC. These topics were divided into short- and long-term solutions to polarimetry issues

  14. Hadron spin-flip at RHIC energies: Volume 3. Proceedings of RIKEN BNL Research Center workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    From July 21 to August 22, 1997 a working group sponsored by the RIKEN BNL Research Center was convened to consider ``Hadron Spin-Flip at RHIC Energies.`` The original motivation for this arose from the importance of understanding the hadronic part of the proton-proton spin flip amplitude in using the Coulomb-Nuclear Interference for polarimetry. This is a very difficult, non-perturbative problem and it is not possible to make a calculation with controlled approximations, so a number of approaches were followed: (1) methods to extract the necessary information from past experiments and from RHIC experiments were examined; (2) phenomenological, Regge models--some of them very old--were reviewed; (3) the predictions of several non-perturbative theoretical models were evaluated; (4) the use of nuclei for the CNI experiment was quantitatively considered; (5) alternative methods of polarimetry were critically studied. These included Primikoff effect, large-t pp scattering, and pe double spin asymmetry.

  15. Hadron spin-flip at RHIC energies: Volume 3. Proceedings of RIKEN BNL Research Center workshop

    International Nuclear Information System (INIS)

    From July 21 to August 22, 1997 a working group sponsored by the RIKEN BNL Research Center was convened to consider ''Hadron Spin-Flip at RHIC Energies.'' The original motivation for this arose from the importance of understanding the hadronic part of the proton-proton spin flip amplitude in using the Coulomb-Nuclear Interference for polarimetry. This is a very difficult, non-perturbative problem and it is not possible to make a calculation with controlled approximations, so a number of approaches were followed: (1) methods to extract the necessary information from past experiments and from RHIC experiments were examined; (2) phenomenological, Regge models--some of them very old--were reviewed; (3) the predictions of several non-perturbative theoretical models were evaluated; (4) the use of nuclei for the CNI experiment was quantitatively considered; (5) alternative methods of polarimetry were critically studied. These included Primikoff effect, large-t pp scattering, and pe double spin asymmetry

  16. eRHIC Design Study: An Electron-Ion Collider at BNL

    CERN Document Server

    Aschenauer, E C; Bazilevsky, A; Boyle, K; Belomestnykh, S; Ben-Zvi, I; Brooks, S; Brutus, C; Burton, T; Fazio, S; Fedotov, A; Gassner, D; Hao, Y; Jing, Y; Kayran, D; Kiselev, A; Lamont, M A C; Lee, J -H; Litvinenko, V N; Liu, C; Ludlam, T; Mahler, G; McIntyre, G; Meng, W; Meot, F; Miller, T; Minty, M; Parker, B; Pinayev, I; Ptitsyn, V; Roser, T; Stratmann, M; Sichtermann, E; Skaritka, J; Tchoubar, O; Thieberger, P; Toll, T; Trbojevic, D; Tsoupas, N; Tuozzolo, J; Ullrich, T; Wang, E; Wang, G; Wu, Q; Xu, W; Zheng, L

    2014-01-01

    This document presents BNL's plan for an electron-ion collider, eRHIC, a major new research tool that builds on the existing RHIC facility to advance the long-term vision for Nuclear Physics to discover and understand the emergent phenomena of Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction that binds the atomic nucleus. We describe the scientific requirements for such a facility, following up on the community wide 2012 white paper, "Electron-Ion Collider: the Next QCD Frontier", and present a design concept that incorporates new, innovative accelerator techniques to provide a cost-effective upgrade of RHIC with polarized electron beams colliding with the full array of RHIC hadron beams. The new facility will deliver electron-nucleon luminosity of $\\sim10^{33} cm^{-2}sec^{-1}$ for collisions of 15.9 GeV polarized electrons on either 250 GeV polarized protons or 100 GeV/u heavy ion beams. The facility will also be capable of providing an electron beam energy of 21.2 GeV, at reduc...

  17. PROCEEDINGS FROM RIKEN-BNL RESEARCH CENTER WORKSHOP: PARITY-VIOLATING SPIN ASYMMETRIES AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    VOGELSANG,W.; PERDEKAMP, M.; SURROW, B.

    2007-04-26

    The RHIC spin program is now fully underway. Several runs have been successfully completed and are producing exciting first results. Luminosity and polarization have improved remarkably and promising advances toward the higher RHIC energy of {radical}s = 500 GeV have been made. At this energy in particular, it will become possible to perform measurements of parity-violating spin asymmetries. Parity violation occurs in weak interactions, and in combination with the unique polarization capabilities at RHIC fascinating new opportunities arise. In particular, parity-violating single- and double-spin asymmetries give new insights into nucleon structure by allowing probes of up and down sea and anti-quark polarizations. Such measurements at RHIC are a DOE performance milestone for the year 2013 and are also supported by a very large effort from RIKEN. With transverse polarization, charged-current interactions may be sensitive to the Sivers effect. Parity-violating effects at RHIC have been proposed even as probes of physics beyond the Standard Model. With the era of measurements of parity-violating spin asymmetries at RHIC now rapidly approaching, we had proposed a small workshop that would bring together the main experts in both theory and experiment. We are very happy that this worked out. The whole workshop contained 17 formal talks, both experiment (10) and theory (7), and many fruitful discussions. The physics motivations for, the planned measurements were reviewed first. The RHIC machine prospects regarding polarized 500 GeV running were discussed, as well as the plans by the RHIC experiments for the vital upgrades of their detectors needed for the W physics program. We also had several talks on the topic of ''semi-inclusive deep-inelastic scattering'', which provides different access to related physics observables. On the theory side, new calculations were presented, for example in terms of QCD all-order resummations of perturbation theory

  18. The new BNL AGS phase, radial and synchronization loops

    Energy Technology Data Exchange (ETDEWEB)

    Onillon, E.; Brennan, J.M.

    1996-07-01

    The AGS and the RHIC must be synchronized before bunch-to-bucket transfer of the beam. A feedback loop has been designed and an improvement has been made to the AGS phase and radial loops. In both cases, the design uses a state variable representation to achieve greater stability and smaller errors. The state variables are beam phase, frequency and radius , the integral of the difference between the radius and its reference and the phase deviation of the bunch from the synchronous phase. Furthermore, the feedback gains are programmed as a function of the beam parameters to keep the same loop performances through the acceleration cycle.

  19. A combined model for pseudorapidity distributions in Cu-Cu collisions at BNL-RHIC energies

    CERN Document Server

    Jiang, Zhjin; Huang, Yan

    2016-01-01

    The charged particles produced in nucleus-nucleus collisions come from leading particles and those frozen out from the hot and dense matter created in collisions. The leading particles are conventionally supposed having Gaussian rapidity distributions normalized to the number of participants. The hot and dense matter is assumed to expand according to the unified hydrodynamics, a hydro model which unifies the features of Landau and Hwa-Bjorken model, and freeze out into charged particles from a space-like hypersurface with a proper time of Tau_FO . The rapidity distribution of this part of charged particles can be derived out analytically. The combined contribution from both leading particles and unified hydrodynamics is then compared against the experimental data performed by BNL-RHIC-PHOBOS Collaboration in different centrality Cu-Cu collisions at sqrt(s_NN)=200 and 62.4 GeV, respectively. The model predictions are in well consistent with experimental measurements.

  20. The RHIC polarized source upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Zelenski, A.; Atoian, G.; Davydenko, V.; Ivanov, A.; Kolmogorov, A.; Ritter, J.; Steski, D.; Zubets, V.

    2010-09-27

    The RHIC polarized H{sup -} ion source is being upgraded to higher intensity (5-10 mA) and polarization for use in the RHIC polarization physics program at enhanced luminosity RHIC operation. The higher beam peak intensity will allow reduction of the transverse beam emittance at injection to AGS to reduce polarization losses in AGS. There is also a planned RHIC luminosity upgrade by using the electron beam lens to compensate the beam-beam interaction at collision points. This upgrade is also essential for future BNL plans for a high-luminosity electron - proton (ion) Collider eRHIC.

  1. Results from the experiment E895 at the BNL AGS

    CERN Document Server

    Rai, G; Alexander, J; Anderson, M; Best, D; Brady, F P; Case, T; Caskey, W; Cebra, D A; Chance, J L; Chung, P; Cole, B; Crowe, K; Das, A; Draper, J E; Gilkes, M L; Gushue, S; Heffner, M; Hirsch, A S; Hjort, E L; Huo, L; Justice, M; Kaplan, M; Keane, D; Kintner, J; Klay, J; Krofcheck, D; Lacey, R; Lisa, M A; Liu, H; Liu, Y M; McGrath, R; Milosevich, Z; Odyniec, Grazyna Janina; Olson, D L; Panitkin, S Y; Pinkenburg, C H; Porile, N T; Ritter, H G; Romero, J L; Scharenberg, R P; Schröder, L S; Srivastava, B K; Stone, N T B; Symons, T J M; Wang, S; Wells, R; Whitfield, J; Wienold, T; Witt, R; Wood, L; Yang, X; Zhang, W; Zhang, Y

    1999-01-01

    We present some of the latest results from the E895 experiment conducted at the BNL AGS accelerator. Au+Au collisions were recorded by the EOS Time Projection Chamber (TPC) at beam energies of 2, 4, 6, and 8 A GeV. The TPC detector permitted the reconstruction of individual collision events with almost 4 pi acceptance and good particle identification. This capability allowed E895 to study global observables and two particle correlations with respect to symmetries of the event. Flow excitation functions are examined and discussed in the context of the Nuclear Equation of State.

  2. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER, RHIC SPIN COLLABORATION MEETING VI, VOLUME 36.

    Energy Technology Data Exchange (ETDEWEB)

    BLAND,L.; SAITO,N.

    2001-10-10

    The sixth meeting of the RHIC Spin Collaboration (RSC) took place on October 1, 2001 at Brookhaven National Laboratory. RHIC is now in its second year of operation for physics production and the first polarized proton collision run at {radical}s=200 GeV is expected to start in eight weeks. The RSC has developed a plan for this coming run through two previous meetings, RHIC Spin Physics III (August 3, 2000) and IV (October 13-14, 2000). We requested the following: two weeks of polarized proton studies in AGS, three weeks of polarized collider commissioning, and five weeks of polarized proton physics run. As a result, we have obtained all we asked and the above plans are implemented in the current operation schedule. The focus of the present meeting was to bring all involved in the RHIC Spin activities up-to-date on the progress of machine development, theory issues, and experimental issues. This meeting was right after the Program Advisory Committee (PAC) meeting and it started with the comments on the PAC discussion by Gerry Bunce, who was informed about the PAC deliberations by Tom Kirk. The PAC was fully supportive to complete the proposed spin program within the currently available budget for RHIC run 2 operations. Gerry further explained the expected luminosity to be {integral} Ldt = 0.5 pb{sup -1} per week, reflecting the current machine status. The introductory session also had a talk from Werner Vogelsang that reviewed the progress in perturbative QCD theory focused on spin effects.

  3. Transverse impedance measurements in RHIC and the AGS

    CERN Document Server

    Biancacci, N; Blaskiewicz, M; Liu, C; Mernick, K; Minty, M; White, S

    2014-01-01

    The RHIC luminosity upgrade program aims for an increase of the polarized proton luminosity by a factor 2. To achieve this goal a significant increase in the beam intensity is foreseen. The beam coupling impedance represents a source of detrimental effects for beam quality and stability at high bunch intensities. In this paper, we evaluate the global transverse impedance in both the AGS and RHIC with measurements of tune shift as a function of bunch intensity. The results are compared to past measurements and the present impedance model. First attempts at transverse impedance localization are as well presented for the RHIC Blue ring.

  4. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, RHIC SPIN COLLABORATION MEETINGS XII AND XIII, SEPTEMBER 16, 2002, OCTOBER 22, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    FOX,B.

    2003-03-06

    Since its inception, the RHIC Spin Collaboration (RSC) has held semi-regular meetings each year to discuss the physics possibilities and the operational details of the program. Having collected our first data sample of polarized proton-proton collisions in Run02 of RHIC, we are now in the process of examining the performance of both the accelerator and the experiments. During the PAC meeting on August 29, 2002, the beam use proposal with a four week, polarized proton physics run was approved as part of the plan for Run-03. So, we meet at BNL on September 16, 2002 to discuss the concrete plans for this proton-proton run.

  5. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, RHIC SPIN PHYSICS V, VOLUME 32, FEBRUARY 21, 2001.

    Energy Technology Data Exchange (ETDEWEB)

    BUNCE,G.; SAITO,N.; VIGDOR,S.; ROSER,T.; SPINKA,H.; ENYO,H.; BLAND,L.C.; GURYN,W.

    2001-02-21

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkysho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan. The Center is dedicated to the study of strong interactions, including spin physics, lattice QCD and RHIC physics through the nurturing of a new generation of young physicists. During the fast year, the Center had only a Theory Group. In the second year, an Experimental Group was also established at the Center. At present, there are seven Fellows and nine post dots in these two groups. During the third year, we started a new Tenure Track Strong Interaction Theory RHIC Physics Fellow Program, with six positions in the academic year 1999-2000; this program will increase to include eleven theorists in the next academic year, and, in the year after, also be extended to experimental physics. In addition, the Center has an active workshop program on strong interaction physics, about ten workshops a year, with each workshop focused on a specific physics problem. Each workshop speaker is encouraged to select few of the most important transparencies from his or her presentation, accompanied by a page of explanation. This material is collected at the end of the workshop by the organizer to form proceedings, which can therefore be available within a short time. The construction of a 0.6 teraflop parallel processor, which was begun at the Center on February 19, 1998, was completed on August 28, 1998.

  6. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 72, RHIC SPIN COLLABORATION MEETINGS XXXI, XXXII, XXXIII.

    Energy Technology Data Exchange (ETDEWEB)

    OGAWA, A.

    2005-04-11

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkyusho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan. The Center is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has both a theory and experimental component. At present the theoretical group has 4 Fellows and 3 Research Associates as well as 11 RHIC Physics/University Fellows (academic year 2003-2004). To date there are approximately 30 graduates from the program of which 13 have attained tenure positions at major institutions worldwide. The experimental group is smaller and has 2 Fellows and 3 RHIC Physics/University Fellows and 3 Research Associates, and historically 6 individuals have attained permanent positions. Beginning in 2001 a new RIKEN Spin Program (RSP) category was implemented at RBRC. These appointments are joint positions of RBRC and RIKEN and include the following positions in theory and experiment: RSP Researchers, RSP Research Associates, and Young Researchers, who are mentored by senior RBRC Scientists. A number of RIKEN Jr. Research Associates and Visiting Scientists also contribute to the physics program at the Center. RBRC has an active workshop program on strong interaction physics with each workshop focused on a specific physics problem. Each workshop speaker is encouraged to select a few of the most important transparencies from his or her presentation, accompanied by a page of explanation. This material is collected at the end of the workshop by the organizer to form proceedings, which can therefore be available within a short time. To date there are seventy-two proceeding volumes available. The construction of a 0.6 teraflops parallel processor, dedicated to lattice QCD, begun at the Center on February 19, 1998, was completed on August

  7. Transverse impedance measurement in RHIC and the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Biancacci, Nicolo [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mernick, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-05-12

    The RHIC luminosity upgrade program aims for an increase of the polarized proton luminosity by a factor 2. To achieve this goal a significant increase in the beam intensity is foreseen. The beam coupling impedance could therefore represent a source of detrimental effects for beam quality and stability at high bunch intensities. For this reason it is essential to quantify the accelerator impedance budget and the major impedance sources, and possibly cure them. In this MD note we summarize the results of the 2013 transverse impedance measurements in the AGS and RHIC. The studies have been performed measuring the tune shift as a function of bunch intensity and deriving the total accelerator machine transverse impedance. For RHIC, we could obtain first promising results of impedance localization measurements as well.

  8. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 57, HIGH PT PHYSICS AT RHIC, DECEMBER 2-6, 2003

    Energy Technology Data Exchange (ETDEWEB)

    Kretzer, Stefan; Venugopalan, Raju; Vogelsang, Werner

    2004-02-18

    The AuAu, dAu, and pp collision modes of the RHIC collider at BNL have led to the publication of exciting high p{perpendicular} particle production data. There have also been two physics runs with polarized protons, and preliminary results on the double-spin asymmetry for pion production had been presented very recently. The ontological questions behind these measurements are fascinating: Did RHIC collisions create a Quark-Gluon-Plasma phase and did they verify the Color Glass Condensate as the high energy limit of QCD? Will the Spin Crisis finally be resolved in terms of gluon polarization and what new surprises are we yet to meet for Transverse Spin? Phenomena related to sub-microscopic questions as important as these call for interpretations that are footed in solid theory. At large p{perpendicular}, perturbative concepts are legitimately expected to provide useful approaches. The corresponding hard parton dynamics are, in several ways, key to unraveling the initial or final state and collisional phase of hard scattering events in vacuum as well as in hot or cold nuclear matter. Before the advent of RHIC data, a RIKEN-BNL workshop had been held at BNL in March 1999 on ''Hard Parton Physics in High Energy Nuclear Collisions''. The 2003 workshop on ''High p{perpendicular} Physics at RHIC'' was a logical continuation of this previous workshop. It gave the opportunity to revisit the 1999 expectations in the light of what has been found in the meantime and, at the same time, to critically discuss the underlying theoretical concepts. We brought together theorists who have done seminal work on the foundations of parton phenomenology in field theory, with theorists and experimentalists who are presently working on RHIC phenomenology. The participants were both from a high-energy physics and nuclear physics background and it remains only to be said here that this chemistry worked perfectly and the workshop was a great success.

  9. p-Carbon CNI polarimetry in the AGS and RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    Huang,H.; Alekseev, I.; Bazilevsky, A.; Bravar, A.; Bunce, G.; Dhawan, S.; Gill, R.; Makdisi, Y.; Morozov, B.; Roser, T.; Steski, D.; Sivertz, M.; Svirida, D.; Wood, J.; Yip, K.; Zelenski, A.

    2008-06-23

    Proton polarization measurements in the AGS (Alternate Gradient Synchrotron) and RHIC (Relativistic Heavy Ion Collider) are based on proton-carbon(pC) and proton-proton elastic scattering in the Coulomb Nuclear Interference (CNI) region. The CNI polarimeters are the essential tools for polarized proton acceleration setup and operation. High intensity recoil nuclei from the scattering of the circulating proton beam in the thin carbon target is efficiently utilized in the silicon strip detectors and data acquisition system, which is capable to analyze the event rate up to a few millions/second. This makes it possible for the fast, practically non-destructive polarization measurements. The polarization measurement on the beam energy ramp was implemented in AGS and RHIC, providing locations of polarization losses. Polarimeter operation in the scanning mode also gives polarization profile and beam profile (including bunch by bunch values for the later one). This paper summarizes the recent modifications. Results of polarization measurements are also discussed.

  10. The Unified Hydrodynamics and the Pseudorapidity Distributions in Heavy Ion Collisions at BNL-RHIC and CERN-LHC Energies

    Directory of Open Access Journals (Sweden)

    Z. J. Jiang

    2015-01-01

    Full Text Available The charged particles produced in nucleus-nucleus collisions are divided into two parts. One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand according to unified hydrodynamics and freezes out into charged particles from a space-like hypersurface with a fixed proper time of τFO. The leading particles are conventionally taken as the particles which inherit the quantum numbers of colliding nucleons and carry off most of incident energy. The rapidity distributions of the charged particles from these two parts are formulated analytically, and a comparison is made between the theoretical results and the experimental measurements performed in Au-Au and Pb-Pb collisions at the respective BNL-RHIC and CERN-LHC energies. The theoretical results are well consistent with experimental data.

  11. Twenty years of space radiation physics at the BNL AGS and NASA Space Radiation Laboratory.

    Science.gov (United States)

    Miller, J; Zeitlin, C

    2016-06-01

    Highly ionizing atomic nuclei HZE in the GCR will be a significant source of radiation exposure for humans on extended missions outside low Earth orbit. Accelerators such as the LBNL Bevalac and the BNL AGS, designed decades ago for fundamental nuclear and particle physics research, subsequently found use as sources of GCR-like particles for ground-based physics and biology research relevant to space flight. The NASA Space Radiation Laboratory at BNL was constructed specifically for space radiation research. Here we review some of the space-related physics results obtained over the first 20 years of NASA-sponsored research at Brookhaven. PMID:27345198

  12. Twenty years of space radiation physics at the BNL AGS and NASA Space Radiation Laboratory

    Science.gov (United States)

    Miller, J.; Zeitlin, C.

    2016-06-01

    Highly ionizing atomic nuclei HZE in the GCR will be a significant source of radiation exposure for humans on extended missions outside low Earth orbit. Accelerators such as the LBNL Bevalac and the BNL AGS, designed decades ago for fundamental nuclear and particle physics research, subsequently found use as sources of GCR-like particles for ground-based physics and biology research relevant to space flight. The NASA Space Radiation Laboratory at BNL was constructed specifically for space radiation research. Here we review some of the space-related physics results obtained over the first 20 years of NASA-sponsored research at Brookhaven.

  13. Proceedings of RIKEN BNL Resarch Center Workshop: Fluctuations, Correlations and RHIC Low Energy Runs

    Energy Technology Data Exchange (ETDEWEB)

    Karsch, F.; Kojo, T.; Mukherjee, S.; Stephanov, M.; Xu, N.

    2011-10-27

    Most of our visible universe is made up of hadronic matter. Quantum Chromodynamics (QCD) is the theory of strong interaction that describes the hadronic matter. However, QCD predicts that at high enough temperatures and/or densities ordinary hadronic matter ceases to exist and a new form of matter is created, the so-called Quark Gluon Plasma (QGP). Non-perturbative lattice QCD simulations shows that for high temperature and small densities the transition from the hadronic to the QCD matter is not an actual phase transition, rather it takes place via a rapid crossover. On the other hand, it is generally believed that at zero temperature and high densities such a transition is an actual first order phase transition. Thus, in the temperature-density phase diagram of QCD, the first order phase transition line emanating from the zero temperature high density region ends at some higher temperature where the transition becomes a crossover. The point at which the first order transition line turns into a crossover is a second order phase transition point belonging to three dimensional Ising universality class. This point is known as the QCD Critical End Point (CEP). For the last couple of years the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been performing experiments at lower energies in search of the elusive QCD CEP. In general critical behaviors are manifested through appearance of long range correlations and increasing fluctuations associated with the presence of mass-less modes in the vicinity of a second order phase transition. Experimental signatures of the CEP are likely to be found in observables related to fluctuations and correlations. Thus, one of the major focuses of the RHIC low energy scan program is to measure various experimental observables connected to fluctuations and correlations. On the other hand, with the start of the RHIC low energy scan program, a flurry of activities are taking place to provide solid theoretical

  14. The feature study on the π and proton rapidity distributions at AGS, SPS and RHIC

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGS and SPS, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of <βγ >L with log s is given at AGS and SPS. Non-uniform flow model may explain the features of the distribution at AGS and SPS, but may not ex- plain those of at RHIC.

  15. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ENTITLED "ODDERON SEARCHES AT RHIC" (VOLUME 76)

    Energy Technology Data Exchange (ETDEWEB)

    ORGANIZERS: GURYN, W.; KOVCHEGOV, Y.; VOGELSANG, W.; TRUEMAN, L.

    2005-10-25

    The Odderon, a charge-conjugation-odd partner of the Pomeron, has been a puzzle ever since its introduction in 1973. The Pomeron describes a colorless exchange with vacuum quantum numbers in the t-channel of hadronic scattering at high energies. The concept was originally formulated for the non-perturbative regime of Quantum Chromodynamics (QCD). In perturbation theory, the simplest picture of the Poineron is that of a two-gluon exchange process, whereas an Odderon can be thought of as an exchange of three gluons. Both the Pomeron and the Odderon are expected in QCD. However, while there exists plenty of experimental data that could be successfully described by Pomeron exchanges (for example in electron-proton and hadron-hadron scattering at high energies), no experimental sign of the Odderon has been observed. One of the very few hints so far is the difference in the diffractive minima of elastic proton-proton and proton-antiproton scattering measured at the ISR. The Odderon has recently received renewed attention by QCD researchers, mainly for the following two reasons. First of all, RHIC has entered the scene, offering exciting unique new opportunities for Odderon searches. RHIC provides collisions of nuclei at center-of-mass energies far exceeding those at all previous experiments. RHIC also provides collisions of protons of the highest center-of-mass energy, and in the interval, which has not been explored previously in p {bar p} collisions. In addition, it also has the unique feature of polarization for the proton beams, promising to become a crucial tool in Odderon searches. Indeed, theorists have proposed possible signatures of the Odderon in some spin asymmetries measurable at RHIC. Qualitatively unique signals should be seen in these observables if the Odderon coupling is large. Secondly, the Odderon has recently been shown to naturally emerge from the Color Glass Condensate (CGC), a theory for the high-energy asymptotics of QCD. It has been argued that

  16. Open charm meson production at BNL RHIC within $k_{t}$-factorization approach and revision of their semileptonic decays

    CERN Document Server

    Maciula, Rafal; Luszczak, Marta

    2015-01-01

    We discuss inclusive production of open charm mesons in proton-proton scattering at the BNL RHIC. The calculation is performed in the framework of $k_t$-factorization approach which effectively includes higher-order pQCD corrections. Different models of unintegrated gluon distributions (UGDF) from the literature are used. We focus on UGDF models favoured by the LHC data and on a new up-to-date parametrizations based on the HERA collider DIS high-precision data. Results of the $k_t$-factorization approach are compared to next-to-leading order collinear predictions. The hadronization of heavy quarks is done by means of fragmentation function technique. The theoretical transverse momentum distributions of charmed mesons are compared with recent experimental data of the STAR collaboration at $\\sqrt{s} = 200$ and $500$ GeV. Theoretical uncertainties related to the choice of renormalization and factorization scales as well as due to the quark mass are discussed. Very good description of the measured integrated cros...

  17. New dynamics information from experimental results obtained in d-Au collisions at RHIC-BNL energies

    International Nuclear Information System (INIS)

    During the last runs d-Au collisions at √sNN = 200 GeV have been investigated at RHIC-BNL using the BRAHMS Experiment. Some interesting experimental results on charged particle multiplicities, rapidity distributions, transverse momentum spectra, antiparticle to particle ratios, participant spectator evolution have been obtained. In this work the most interesting results are presented for different rapidity and collision centrality ranges. Taking into account the importance of the collision geometry and collision symmetry in the collision dynamics, comparisons with the similar experimental results obtained in Au-Au collisions have been done. New interesting results can be reported. The most significant are related to the evolution of the nuclear modification factor with rapidity and collision centrality. The high transverse momentum suppression and the behaviours in different rapidity and centrality ranges suggest strong initial state effects. These effects could be related to the gluonic structure of the colliding nuclei. Some insights on the Color Glass Condensate formation are possible. (author)

  18. EDDY CURRENT EFFECT OF THE BNL-AGS VACUUM CHAMBER ON THE OPTICS OF THE BNL-AGS SYNCHROTRON.

    Energy Technology Data Exchange (ETDEWEB)

    TSOUPAS,N.; AHRENS,L.; BROWN,K.A.; GLENN,J.W.; GARDNER,K.

    1999-03-29

    During the acceleration cycle of the AGS synchrotron, eddy currents are generated within the walls of the vacuum chambers of the AGS main magnets. The vacuum chambers have elliptical cross section, are made of inconel material with a wall thickness of 2 mm and are placed within the gap of the combined-function main magnets of the AGS synchrotron. The generation of the eddy currents in the walls of the vacuum chambers, creates various magnetic multipoles, which affect the optics of the AGS machine. In this report these magnetic multipoles are calculated for various time interval starting at the acceleration cycle, where the magnetic field of the main magnet is {approx}0.1 T, and ending before the beam extraction process, where the magnetic field of the main magnet is almost constant at {approx}1.1 T. The calculations show that the magnetic multipoles generated by the eddy-currents affect the optics of the AGS synchrotron during the acceleration cycle and in particular at low magnetic fields of the main magnet. Their effect is too weak to affect the optics of the AGS machine during beam extraction at the nominal energies.

  19. Polarized proton collider at RHIC

    International Nuclear Information System (INIS)

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to √s=500 GeV

  20. Longitudinal emittance measurements in the Booster and AGS during the 2014 RHIC gold run

    International Nuclear Information System (INIS)

    This note describes longitudinal emittance measurements that were made in the Booster and AGS during the 2014 RHIC Gold run. It also contains an overview of the longitudinal aspects of their setup during this run. Each bunch intended for RHIC is composed of beam from 4 Booster cycles, and there are two of them per AGS cycle. For each of the 8 Booster cycles required to produce the 2 bunches in the AGS, a beam pulse from EVIS is injected into the Booster and captured in four h=4 buckets. Then those bunches are accelerated to a porch where they are merged into 2 bunches and then into 1 bunch.

  1. Longitudinal emittance measurements in the Booster and AGS during the 2014 RHIC gold run

    Energy Technology Data Exchange (ETDEWEB)

    Zeno, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-08-18

    This note describes longitudinal emittance measurements that were made in the Booster and AGS during the 2014 RHIC Gold run. It also contains an overview of the longitudinal aspects of their setup during this run. Each bunch intended for RHIC is composed of beam from 4 Booster cycles, and there are two of them per AGS cycle. For each of the 8 Booster cycles required to produce the 2 bunches in the AGS, a beam pulse from EVIS is injected into the Booster and captured in four h=4 buckets. Then those bunches are accelerated to a porch where they are merged into 2 bunches and then into 1 bunch.

  2. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, RHIC SPIN COLLABORATION MEETINGS VIII, IX, X, XI, APRIL 12, MAY, 22, JUNE 17, JULY 29, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    FOX,B.

    2003-03-06

    Since its inception, the RHIC Spin Collaboration (RSC) has held semi-regular meetings each year to discuss the physics possibilities and the operational details of the program. Having collected our first data sample of polarized proton-proton collisions in Run02 of RHIC, we are now in the process of examining the performance of both the accelerator and the experiments. From this evaluation, we not only aim to formulate a consensus plan for polarized proton-proton during Run03 of RHIC but also to look more forward into the future to ensure the success of the spin program. In the second meeting of this series (which took place at BNL on April 12, 2002), we focused on Run02 polarization issues. This meeting opened with a presentation by Thomas Roser about his reflections on the outcome from the RHIC retreat during which the Run02 performance was evaluated. Of particular importance, Thomas pointed out that, with the expected beam time and his estimates for machine-tuning requirements, the experiments should limit their beam requests to two or three programs.

  3. The abstract geometry modeling language (AgML): experience and road map toward eRHIC

    International Nuclear Information System (INIS)

    The STAR experiment has adopted an Abstract Geometry Modeling Language (AgML) as the primary description of our geometry model. AgML establishes a level of abstraction, decoupling the definition of the detector from the software libraries used to create the concrete geometry model. Thus, AgML allows us to support both our legacy GEANT 3 simulation application and our ROOT/TGeo based reconstruction software from a single source, which is demonstrably self- consistent. While AgML was developed primarily as a tool to migrate away from our legacy FORTRAN-era geometry codes, it also provides a rich syntax geared towards the rapid development of detector models. AgML has been successfully employed by users to quickly develop and integrate the descriptions of several new detectors in the RHIC/STAR experiment including the Forward GEM Tracker (FGT) and Heavy Flavor Tracker (HFT) upgrades installed in STAR for the 2012 and 2013 runs. AgML has furthermore been heavily utilized to study future upgrades to the STAR detector as it prepares for the eRHIC era. With its track record of practical use in a live experiment in mind, we present the status, lessons learned and future of the AgML language as well as our experience in bringing the code into our production and development environments. We will discuss the path toward eRHIC and pushing the current model to accommodate for detector miss-alignment and high precision physics.

  4. The abstract geometry modeling language (AgML): experience and road map toward eRHIC

    Science.gov (United States)

    Webb, Jason; Lauret, Jerome; Perevoztchikov, Victor

    2014-06-01

    The STAR experiment has adopted an Abstract Geometry Modeling Language (AgML) as the primary description of our geometry model. AgML establishes a level of abstraction, decoupling the definition of the detector from the software libraries used to create the concrete geometry model. Thus, AgML allows us to support both our legacy GEANT 3 simulation application and our ROOT/TGeo based reconstruction software from a single source, which is demonstrably self- consistent. While AgML was developed primarily as a tool to migrate away from our legacy FORTRAN-era geometry codes, it also provides a rich syntax geared towards the rapid development of detector models. AgML has been successfully employed by users to quickly develop and integrate the descriptions of several new detectors in the RHIC/STAR experiment including the Forward GEM Tracker (FGT) and Heavy Flavor Tracker (HFT) upgrades installed in STAR for the 2012 and 2013 runs. AgML has furthermore been heavily utilized to study future upgrades to the STAR detector as it prepares for the eRHIC era. With its track record of practical use in a live experiment in mind, we present the status, lessons learned and future of the AgML language as well as our experience in bringing the code into our production and development environments. We will discuss the path toward eRHIC and pushing the current model to accommodate for detector miss-alignment and high precision physics.

  5. New experimental results obtained in Au-Au collisions at the energies available to the RHIC-BNL using BRAHMS experimental setup

    International Nuclear Information System (INIS)

    Many experimental data for Au-Au collisions at √sNN = 130 GeV and √sNN = 200 GeV have been obtained in the last two years at the Relativistic Heavy Ion Collider (RHIC) from Brookhaven National Laboratory, Upton, New York, USA. The experimental setup BRAHMS is one of the five experimental setups used at RHIC-BNL. Interesting experimental results on many physical quantities with dynamic signification have been obtained. In the present work we report the new results on charged particle multiplicities, pseudorapidities, rapidities, transverse, momentum spectra, and particle to antiparticle ratios. These experimental results lead to nuclear temperatures and nuclear densities at different collision centralities and rapidities. Some interesting results on collective flow velocities of the nuclear matter are also obtained. Dependencies on the collision centrality, pseudorapidity and beam energy, in the center-of-mass system, are included in the work. The highest multiplicities (more than 5000 charged particles per event) and the highest pionic, kaonic and protonic temperatures obtained up to now are reported for the most central collisions (0-6%). The Coulomb effects are very low at very small velocities. A significant increase of the negative kaon to positive kaon ratio appears at rapidities around y = 0.0. Similar results are obtained for antiproton to proton ratio. The stopping of the nuclear matter is reflected by the high collective velocities obtained in the same rapidity range (up to 0.6 c). All these experimental results, as well as the experimental results obtained in the frame of other collaborations, including the RHIC-BNL collaboration, will be used to obtain new information on the behaviour of the highly excited and dense nuclear matter and the formation conditions for the quark-gluon plasma. Interesting information on the Universe behaviour in the first microsecond after Big Bang can also be obtained. (authors)

  6. FY2014 Parameters for Helions and Gold Ions in Booster, AGS, and RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, C. J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-08-15

    The nominal parameters for helions (helion is the bound state of two protons and one neutron, the nucleus of a helium-3 atom) and gold ions in Booster, AGS, and RHIC are given for the FY2014 running period. The parameters are found using various formulas to derive mass, helion anomalous g-factor, kinetic parameters, RF parameters, ring parameters, etc..

  7. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ENTITLED "GLOBAL ANALYSIS OF POLARIZED PARTON DESTRIBUTIONS IN THE RHIC ERA" (VOLUME 86).

    Energy Technology Data Exchange (ETDEWEB)

    DESHPANDE,A.; VOGELSANG, W.

    2007-10-08

    The determination of the polarized gluon distribution is a central goal of the RHIC spin program. Recent achievements in polarization and luminosity of the proton beams in RHIC, has enabled the RHIC experiments to acquire substantial amounts of high quality data with polarized proton beams at 200 and 62.4 GeV center of mass energy, allowing a first glimpse of the polarized gluon distribution at RHIC. Short test operation at 500 GeV center of mass energy has also been successful, indicating absence of any fundamental roadblocks for measurements of polarized quark and anti-quark distributions planned at that energy in a couple of years. With this background, it has now become high time to consider how all these data sets may be employed most effectively to determine the polarized parton distributions in the nucleon, in general, and the polarized gluon distribution, in particular. A global analysis of the polarized DIS data from the past and present fixed target experiments jointly with the present and anticipated RHIC Spin data is needed.

  8. FY2014 Parameters for Gold Ions in Booster, AGS, and RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, C. J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-07-30

    The nominal parameters for gold ions in Booster, AGS, and RHIC are given for the FY2014 running period. The parameters are worked out using various formulas to derive mass, kinetic parameters, RF parameters, ring parameters, etc.. The ''standard setup'', ''medium-energy'', and ''low-energy'' parameters are summarized in separate sections.

  9. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON SPIN PHYSICS AT RHIC IN YEAR-1 AND BEYOND.

    Energy Technology Data Exchange (ETDEWEB)

    BLAND, L.; BOER, D.; SAITO, N.; VOGELSANG, W.

    2001-05-14

    The much anticipated RHIC spin physics program will commence this fall when the first physics run with colliding beams of polarized protons is expected. More specifically, the planned year-1 RHIC-Spin measurements are (1) the double-spin asymmetry A{sub LL}{sup {pi}} in production of pions by collisions of longitudinally polarized protons (in order to obtain first information on the proton's spin-dependent gluon density, {Delta}g); (2) the transverse single-spin asymmetry A{sub N}{sup {pi}} for pion production. These two reactions provided part of the motivation for our workshop. On the first day there were informative talks on the specific plans of STAR (by Rakness) and PHENIX (by Goto) for the polarized run of Year-1. Some of the theoretical questions related to the double-spin asymmetry A{sub LL}{sup {pi}} were discussed on the first day by Vogelsang and Kretzer, which centered mostly around the questions of how well the unpolarized fragmentation functions are known, the need for next-to-leading order calculations, and on how sensitive the asymmetry is to the possible {Delta}g distributions. Vetterli presented HERMES measurements of fragmentation functions, which overlap in Q{sup 2} with the future lower-p{sub T} measurements at RHIC.

  10. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON SPIN PHYSICS AT RHIC IN YEAR-1 AND BEYOND

    International Nuclear Information System (INIS)

    The much anticipated RHIC spin physics program will commence this fall when the first physics run with colliding beams of polarized protons is expected. More specifically, the planned year-1 RHIC-Spin measurements are (1) the double-spin asymmetry ALLπ in production of pions by collisions of longitudinally polarized protons (in order to obtain first information on the proton's spin-dependent gluon density, Δg); (2) the transverse single-spin asymmetry ANπ for pion production. These two reactions provided part of the motivation for our workshop. On the first day there were informative talks on the specific plans of STAR (by Rakness) and PHENIX (by Goto) for the polarized run of Year-1. Some of the theoretical questions related to the double-spin asymmetry ALLπ were discussed on the first day by Vogelsang and Kretzer, which centered mostly around the questions of how well the unpolarized fragmentation functions are known, the need for next-to-leading order calculations, and on how sensitive the asymmetry is to the possible Δg distributions. Vetterli presented HERMES measurements of fragmentation functions, which overlap in Q2 with the future lower-pT measurements at RHIC

  11. High density matter in AGS, SPS and RHIC collisions: Proceedings. Volume 9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This 1-day workshop focused on phenomenological models regarding the specific question of the maximum energy density achievable in collisions at AGS, SPS and RHIC. The idea was to have 30-minute (or less) presentations of each model--but not the model as a whole, rather then that strongly narrowed to the above physics question. The key topics addressed were: (1) to estimate the energy density in heavy-ion collisions within a model, and to discuss its physical implications; (2) to suggest experimental observables that may confirm the correctness of a model approach--with respect to the energy density estimate; (3) to compare with existing data from AGS and SPS heavy-ion collisions, and to give predictions for the future RHIC experiments. G. Ogilvie started up the workshop with a critical summary of experimental manifestations of high-density matter at the AGS, and gave a personal outlook on RHIC physics. R. Mattiello talked about his newly developed hadron cascade model for applications to AGS and SPS collisions. Next, D. Kharzeev gave a nice introduction of the Glauber approach to high-energy collisions and illustrated the predictive power of this approach in nucleus-nucleus collisions at the SPS. It followed S. Vance with a presentation of the baryon-junction model to explain the observed baryon stopping phenomenon in collisions of heavy nuclei. S. Bass continued with a broad perspective of the UrQMD model, and provided insight into the details of the microscopic dynamical features of nuclear collisions at high energy. J. Sandweiss and J. Kapusta addressed the interesting aspect of photon production in peripherical nuclear collisions due to intense electromagnetic bremstrahlung by the highly charged, fast moving ions. Finally, H. Sorge closed up the one-day workshop with a presentation of his recent work with the RQMD model. This report consists of a summary and vugraphs of the presentations.

  12. High density matter in AGS, SPS and RHIC collisions. Proceedings. Volume 9

    International Nuclear Information System (INIS)

    This 1-day workshop focused on phenomenological models regarding the specific question of the maximum energy density achievable in collisions at AGS, SPS and RHIC. The idea was to have 30-minute (or less) presentations of each model--but not the model as a whole, rather then that strongly narrowed to the above physics question. The key topics addressed were: (1) to estimate the energy density in heavy-ion collisions within a model, and to discuss its physical implications; (2) to suggest experimental observables that may confirm the correctness of a model approach--with respect to the energy density estimate; (3) to compare with existing data from AGS and SPS heavy-ion collisions, and to give predictions for the future RHIC experiments. G. Ogilvie started up the workshop with a critical summary of experimental manifestations of high-density matter at the AGS, and gave a personal outlook on RHIC physics. R. Mattiello talked about his newly developed hadron cascade model for applications to AGS and SPS collisions. Next, D. Kharzeev gave a nice introduction of the Glauber approach to high-energy collisions and illustrated the predictive power of this approach in nucleus-nucleus collisions at the SPS. It followed S. Vance with a presentation of the baryon-junction model to explain the observed baryon stopping phenomenon in collisions of heavy nuclei. S. Bass continued with a broad perspective of the UrQMD model, and provided insight into the details of the microscopic dynamical features of nuclear collisions at high energy. J. Sandweiss and J. Kapusta addressed the interesting aspect of photon production in peripherical nuclear collisions due to intense electromagnetic bremstrahlung by the highly charged, fast moving ions. Finally, H. Sorge closed up the one-day workshop with a presentation of his recent work with the RQMD model. This report consists of a summary and vugraphs of the presentations

  13. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON BARYON DYNAMICS AT RHIC, MARCH 28-30, 2002, BROOKHAVEN NATIONAL LABORATORY.

    Energy Technology Data Exchange (ETDEWEB)

    GYULASSY,M.; KHARZEEV,D.; XU,N.

    2002-03-28

    One of the striking observations at RHIC is the large valence baryon rapidity density observed at mid rapidity in central Au+Au at 130 A GeV. There are about twice as many valence protons at mid-rapidity than predicted based on extrapolation from p+p collisions. Even more striking PHENIX observed that the high pt spectrum is dominated by baryons and anti-baryons. The STAR measured event anisotropy parameter v2 for lambdas are as high as charged particles at pt {approx} 2.5 GeV/c. These are completely unexpected based on conventional pQCD parton fragmentation phenomenology. One exciting possibility is that these observables reveal the topological gluon field origin of baryon number transport referred to as baryon junctions. Another is that hydrodynamics may apply up to high pt in A+A. There is no consensus on what are the correct mechanisms for producing baryons and hyperons at high pt and large rapidity shifts and the new RHIC data provide a strong motivation to hold a meeting focusing on this class of observables. The possible role of junctions in forming CP violating domain walls and novel nuclear bucky-ball configurations would also be discussed. In this workshop, we focused on all measured baryon distributions at RHIC energies and related theoretical considerations. To facilitate the discussions, results of heavy ion collisions at lower beam energies, results from p+A /p+p/e+e collisions were included. Some suggestions for future measurements have been made at the workshop.

  14. OPERATIONS ELECTRONIC LOGBOOK EXPERIENCE AT BNL.

    Energy Technology Data Exchange (ETDEWEB)

    SATOGATA,T.; CAMPBELL,I.; MARR,G.; SAMPSON,P.

    2002-06-02

    A web-based system for electronic logbooks, ''elog'', developed at Fermilab (FNAL), has been adopted for use by AGS and RHIC operations and physicists at BNL for the 2001-2 fixed target and collider runs. This paper describes the main functional and technical issues encountered in the first year of electronic logbook use, including security, search and indexing, sequencer integration, archival, and graphics management. We also comment on organizational experience and planned changes for the next facility run starting in September 2002.

  15. The PHENIX experiment at RHIC

    CERN Document Server

    Aronson, Samuel H

    2001-01-01

    PHENIX is a large detector at the Relativistic Heavy Ion Collider (RHIC) at BNL. RHIC and PHENIX have recently operated for the first time, producing and detecting collisions of gold ions at beam energies of 30 and 65 GeV per nucleon. The current performance and future plans of PHENIX and of RHIC are presented. (2 refs).

  16. Some comments on the phase diagram parameters for the nuclear matter formed in Au-Au collisions at RHIC-BNL energies

    International Nuclear Information System (INIS)

    The formation of highly excited dense nuclear matter in laboratory, with the possibility to evidence a phase transition to deconfined quark-gluon plasma, can be analysed in ultrarelativistic heavy ion collisions. The rapidity density and pseudorapidity density, respectively, are used to estimate energy density in Au-Au collisions at √sNN = 130 GeV and √sNN = 200 GeV. From transverse mass spectra and transverse momentum spectra - obtained in the same collision - pion, kaon, proton and antiproton temperatures are extracted. These quantities are important parameters of the phase diagram of the nuclear matter formed in such collisions. The mass dependence of the slope parameters provides evidence of collective transverse flow. Comparisons with the predictions with UrQMD and HIJING codes are included in this paper. Taking into account the fact that some information on the dynamics of high-energy Au-Au collisions is obtained from the analysis of the antiparticles to particles ratios, we calculated these ratios for different rapidities. We investigate the Coulomb interaction through the ratio of negative to positive pions produced in very high-energy heavy ion collisions at BRAHMS experiment. The study of Coulomb interaction could also provide information on the collision dynamics, such as collective expansion and the charge of the system produced in the central region of the collisions because the effect of the nuclear medium is not evident for particles related to the later collision stages. They can affect the phase diagram parameters. The values of the energy and baryonic densities - over 10 normal values - as well as the agreement between the experimental values on participants and phenomenological model estimations, represent a support for the estimated thermodynamic parameters of the nuclear matter in Au-Au collisions at RHIC-BNL energies. This information can be used to study the formation of the quark plasma and quark-gluon plasma in these collisions

  17. Freeze-Out Parameters in Heavy-Ion Collisions at AGS, SPS, RHIC, and LHC Energies

    International Nuclear Information System (INIS)

    We review the chemical and kinetic freeze-out conditions in high energy heavy-ion collisions for AGS, SPS, RHIC, and LHC energies. Chemical freeze-out parameters are obtained using produced particle yields in central collisions while the corresponding kinetic freeze-out parameters are obtained using transverse momentum distributions of produced particles. For chemical freeze-out, different freeze-out scenarios are discussed such as single and double/flavor dependent freeze-out surfaces. Kinetic freeze-out parameters are obtained by doing hydrodynamic inspired blast wave fit to the transverse momentum distributions. The beam energy and centrality dependence of transverse energy per charged particle multiplicity are studied to address the constant energy per particle freeze-out criteria in heavy-ion collisions

  18. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON RHIC SPIN PHYSICS III AND IV, POLARIZED PARTONS AT HIGH Q2 REGION, AUGUST 3, 2000 AT BNL, OCTOBER 14, 2000 AT KYOTO UNIVERSITY.

    Energy Technology Data Exchange (ETDEWEB)

    BUNCE, G.; VIGDOR, S.

    2001-03-15

    International workshop on II Polarized Partons at High Q2 region 11 was held at the Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan on October 13-14, 2000, as a satellite of the international conference ''SPIN 2000'' (Osaka, Japan, October 16-21,2000). This workshop was supported by RIKEN (The Institute of Physical and Chemical Research) and by Yukawa Institute. The scientific program was focused on the upcoming polarized collider RHIC. The workshop was also an annual meeting of RHIC Spin Collaboration (RSC). The number of participants was 55, including 28 foreign visitors and 8 foreign-resident Japanese participants, reflecting the international nature of the RHIC spin program. At the workshop there were 25 oral presentations in four sessions, (1) RHIC Spin Commissioning, (2) Polarized Partons, Present and Future, (3) New Ideas on Polarization Phenomena, (4) Strategy for the Coming Spin Running. In (1) the successful polarized proton commissioning and the readiness of the accelerator for the physics program impressed us. In (2) and (3) active discussions were made on the new structure function to be firstly measured at RHIC, and several new theoretical ideas were presented. In session (4) we have established a plan for the beam time requirement toward the first collision of polarized protons. These proceedings include the transparencies presented at the workshop. The discussion on ''Strategy for the Coming Spin Running'' was summarized by the chairman of the session, S. Vigdor and G. Bunce.

  19. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON RHIC SPIN PHYSICS III AND IV, POLARIZED PARTONS AT HIGH Q2 REGION (VOLUME 31)

    International Nuclear Information System (INIS)

    International workshop on II Polarized Partons at High Q2 region 11 was held at the Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan on October 13-14, 2000, as a satellite of the international conference ''SPIN 2000'' (Osaka, Japan, October 16-21,2000). This workshop was supported by RIKEN (The Institute of Physical and Chemical Research) and by Yukawa Institute. The scientific program was focused on the upcoming polarized collider RHIC. The workshop was also an annual meeting of RHIC Spin Collaboration (RSC). The number of participants was 55, including 28 foreign visitors and 8 foreign-resident Japanese participants, reflecting the international nature of the RHIC spin program. At the workshop there were 25 oral presentations in four sessions, (1) RHIC Spin Commissioning, (2) Polarized Partons, Present and Future, (3) New Ideas on Polarization Phenomena, (4) Strategy for the Coming Spin Running. In (1) the successful polarized proton commissioning and the readiness of the accelerator for the physics program impressed us. In (2) and (3) active discussions were made on the new structure function to be firstly measured at RHIC, and several new theoretical ideas were presented. In session (4) we have established a plan for the beam time requirement toward the first collision of polarized protons. These proceedings include the transparencies presented at the workshop. The discussion on ''Strategy for the Coming Spin Running'' was summarized by the chairman of the session, S. Vigdor and G. Bunce

  20. Evolution-dominated Hydrodynamic Model and the Pseudorapidity Distributions of the Charged Particles Pro duced in Cu-Cu Collisions at BNL-RHIC Energies%演化过程主导的流体力学模型与Cu-Cu在BNL-RHIC能量碰撞中带电粒子的赝快度分布

    Institute of Scientific and Technical Information of China (English)

    姜志进; 王杰; 张海丽; 马可

    2014-01-01

    The charged particles resulting in high energy heavy ion collisions consist of two parts: One is from the hot and dense matter produced in collisions. The other is the leading particles. We suppose that the hot and dense matter expands and freezes out into the charged particles according to the evolution-dominated hydrodynamics, and the leading particles are from participants with approximately the same energy. On the basis of this assumption, we get the pseudorapidity distributions of the charged particles produced in high energy heavy ion collisions, and make a comparison with the experimental data presented by PHOBOS Collaboration at BNL-RHIC in Cu-Cu collisions at√sNN=62.4 and 200 GeV. The theoretical predictions are in good accordance with experimental measurements.%高能重离子碰撞产生的带电粒子由两部分组成:一部分来源于碰撞产生的高温高密度物质,另一部分是带头粒子。假设高温高密度物质按照由演化过程主导的流体力学的规律膨胀并冻析为带电粒子,带头粒子来源于参与者且具有大致相同的能量。基于该假设,得到了高能重离子碰撞带电粒子的赝快度分布,并与BNL-RHIC上的PHOBOS合作组在√sNN=62.4与200 GeV的Cu-Cu碰撞中给出的实验结果相比较,理论与实验测量符合得很好。

  1. 演化过程主导的流体力学模型与Cu-Cu在BNL-RHIC能量碰撞中带电粒子的赝快度分布%Evolution-dominated Hydrodynamic Model and the Pseudorapidity Distributions of the Charged Particles Pro duced in Cu-Cu Collisions at BNL-RHIC Energies

    Institute of Scientific and Technical Information of China (English)

    姜志进; 王杰; 张海丽; 马可

    2014-01-01

    The charged particles resulting in high energy heavy ion collisions consist of two parts: One is from the hot and dense matter produced in collisions. The other is the leading particles. We suppose that the hot and dense matter expands and freezes out into the charged particles according to the evolution-dominated hydrodynamics, and the leading particles are from participants with approximately the same energy. On the basis of this assumption, we get the pseudorapidity distributions of the charged particles produced in high energy heavy ion collisions, and make a comparison with the experimental data presented by PHOBOS Collaboration at BNL-RHIC in Cu-Cu collisions at√sNN=62.4 and 200 GeV. The theoretical predictions are in good accordance with experimental measurements.%高能重离子碰撞产生的带电粒子由两部分组成:一部分来源于碰撞产生的高温高密度物质,另一部分是带头粒子。假设高温高密度物质按照由演化过程主导的流体力学的规律膨胀并冻析为带电粒子,带头粒子来源于参与者且具有大致相同的能量。基于该假设,得到了高能重离子碰撞带电粒子的赝快度分布,并与BNL-RHIC上的PHOBOS合作组在√sNN=62.4与200 GeV的Cu-Cu碰撞中给出的实验结果相比较,理论与实验测量符合得很好。

  2. PHYSICS OF POLARITY AT RHIC-VOLUME 10.

    Energy Technology Data Exchange (ETDEWEB)

    IMAI,K.; FIELDS,D.

    1998-08-04

    The RBRC Workshop on Physics of Polarimetry at RHIC was held from Aug 4 to 7, 1998 at BNL. The primary motive of the workshop is (1) to discuss the RHIC polarimeter using the elastic proton-carbon scattering at Coulomb-nuclear interference region (p-C CNI polarimeter) in detail and write a proposal for the test experiment a t the AGS, (2) to discuss the related physics, (3) and to discuss other options for the RHIC polarimetry. The idea of the p-C CNI polarimeter was proposed last year as a simple, inexpensive and efficient polarimeter for RHIC. In order to establish this polarimeter, we have decided to carry out a test experiment by using a polarized beam at the AGS. We have made a draft of the proposal during the workshop. For the p-C CNI polarimeter, a telescope detector using both the micro-channel plate (MCP) and the SSD was proposed to detect low energy recoil carbon ions, based on the test measurements at IUCF and Kyoto, where the carbon ions as low as 200 keV were successfully detected. The kinetic energy of carbon ion is measured with the SSD, and the velocity is measured by TOF between the two detectors and between the accelerator rf pulse and the two detectors. Counting rates for the background and true events were estimated. With the proposed polarimeter, one can expect to measure the beam polarization at the AGS and RHIC at an accuracy of 10% within a reasonable time period. We will test this detector system at Kyoto as soon as possible and install it in the AGS ring for the test measurement of A{sub N} during E880 which is scheduled early in the next year.

  3. Recent Results on High-Energy Spin Phenomena of Gluons and Sea-Quarks in Polarized Proton-Proton Collisions at Rhic at Bnl

    Science.gov (United States)

    Surrow, Bernd

    2014-01-01

    The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is carrying out a spin physics program in high-energy polarized proton collisions at √ {s} = 200 GeV and √ {s} = 500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. One of the main objectives of the spin physics program at RHIC is the precise determination of the polarized gluon distribution function. The STAR detector is well suited for the reconstruction of various final states involving jets, π0, π±, e± and γ, which allows to measure several different processes. Recent results suggest a gluon spin contribution to the proton spin at the same level as the quark spin contribution itself. The production of W bosons in polarized p+p collisions at √ {s} = 500 GeV opens a new era in the study of the spin-flavor structure of the proton. W-(+) bosons are produced in \\bar {u} + d (\\bar {d} + u) collisions and can be detected through their leptonic decays, e- + \\bar {ν }e (e++ν e), where only the respective charged lepton is measured. Results of W-(+) production suggest a large asymmetry between the polarization of anti-u and anti-d quarks.

  4. RHIC and quark matter: proposal for a relativistic heavy ion collider at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    This document describes the Brookhaven National Laboratory Proposal for the construction of a Relativistic Heavy Ion Collider (RHIC). The construction of this facility represents the natural continuation of the laboratory's role as a center for nuclear and high-energy physics research and extends and uses the existing AGS, Tandem Van de Graaff and CBA facilities at BNL in a very cost effective manner. The Administration and Congress have approved a project which will provide a link between the Tandem Van de Graaf and the AGS. Completion of this project in 1986 will provide fixed target capabilities at the AGS for heavy ions of about 14 GeV/amu with masses up to approx. 30 (sulfur). The addition of an AGS booster would extend the mass range to the heaviest ions (A approx. 200, e.g., gold); its construction could start in 1986 and be completed in three years. These two new AGS experimental facilities can be combined with the proposed Relativistic Heavy Ion Collider to extend the energy range to 100 x 100 GeV/amu for the heaviest ions. BNL proposes to start construction of RHIC in FY 86 with completion in FY 90 at a total cost of 134 M$

  5. RHIC and quark matter: proposal for a relativistic heavy ion collider at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1984-08-01

    This document describes the Brookhaven National Laboratory Proposal for the construction of a Relativistic Heavy Ion Collider (RHIC). The construction of this facility represents the natural continuation of the laboratory's role as a center for nuclear and high-energy physics research and extends and uses the existing AGS, Tandem Van de Graaff and CBA facilities at BNL in a very cost effective manner. The Administration and Congress have approved a project which will provide a link between the Tandem Van de Graaf and the AGS. Completion of this project in 1986 will provide fixed target capabilities at the AGS for heavy ions of about 14 GeV/amu with masses up to approx. 30 (sulfur). The addition of an AGS booster would extend the mass range to the heaviest ions (A approx. 200, e.g., gold); its construction could start in 1986 and be completed in three years. These two new AGS experimental facilities can be combined with the proposed Relativistic Heavy Ion Collider to extend the energy range to 100 x 100 GeV/amu for the heaviest ions. BNL proposes to start construction of RHIC in FY 86 with completion in FY 90 at a total cost of 134 M$.

  6. Spin at RHIC

    International Nuclear Information System (INIS)

    The relativistic Heavy Ion Collider (RHIC) at BNL is in its fourth year of construction. The target date for completion is March 1999. In this report, I will describe the accelerator complex and its status with special emphasis on its capability as a polarized proton collider, the proposed physics program, the detectors, and the expected sensitivities to physics signatures. copyright 1995 American Institute of Physics

  7. Polarized 3He+2 ions in the Alternate Gradient Synchrotron to RHIC transfer line

    Science.gov (United States)

    Tsoupas, N.; Huang, H.; Méot, F.; Ptitsyn, V.; Roser, T.; Trbojevic, D.

    2016-09-01

    The proposed electron-hadron collider (eRHIC) to be built at Brookhaven National Laboratory (BNL) will allow the collisions of 20 GeV polarized electrons with 250 GeV polarized protons, or 100 GeV /n polarized 3He+2 ions, or other unpolarized ion species. The large value of the anomalous magnetic moment of the 3He nucleus GHe=(g -2 )/2 =-4.184 (where g is the g -factor of the 3He nuclear spin) combined with the peculiar layout of the transfer line which transports the beam bunches from the Alternate Gradient Synchrotron (AGS) to the Relativistic Heavy Ion Collider (RHIC) makes the transfer and injection of polarized 3He ions from AGS to RHIC (AtR) a special case as we explain in the paper. Specifically in this paper we calculate the stable spin direction of a polarized 3He beam at the exit of the AtR line which is also the injection point of RHIC, and we discuss a simple modifications of the AtR beam-transfer-line, to perfectly match the stable spin direction of the injected polarized 3He beam to that of the circulating beam, at the injection point of RHIC.

  8. Spin physics at RHIC: Present and future

    Indian Academy of Sciences (India)

    Abhay Deshpande

    2003-11-01

    In 2001–2002 the relativistic heavy-ion collider (RHIC) at the Brookhaven National Laboratory (BNL) was first commissioned for polarized proton collisions. Polarized protons were injected into the RHIC, accelerated to 100 GeV, stored and the two beams were made to collide in four interaction regions. I will review the progress made by the RHIC spin program, followed by the physics goals for the next few years. After that I will present a brief overview of a proposal to build a high intensity polarized electron/positron beam facility at BNL which would enable deep inelastic scattering (DIS) experiments to be pursued at BNL by its collisions with the RHIC hadron beams.

  9. Proceedings of the third workshop on experiments and detectors for a relativistic heavy ion collider (RHIC)

    International Nuclear Information System (INIS)

    This report contains papers on the following topics: the RHIC Project; summary of the working group on calorimetry; J//Psi/ measurements in heavy ion collisions at CERN; QCD jets at RHIC; tracking and particle identification; a 4π tracking spectrometer for RHIC; Bose-Einstein measurements at RHIC in light of new data; summary of working group on read-out electronics; data acquisition for RHIC; summary of the working group on detector simulation; B-physics at RHIC; and CP violation revisited at BNL, B-physics at RHIC

  10. Polarized protons and RHIC

    International Nuclear Information System (INIS)

    RHIC, the heavy ion collider being built at Brookhaven, offers an exciting opportunity to collide highly polarized protons at high energy and luminosity. This new facility would combine the existing AGS polarized proton capability with the new Booster/Accumulator and spin rotators to achieve collisions between intense beams of polarized protons at a collision energy of 500 GeV. At this energy and the expected luminosity of 2 x 1032 cm2/second physics probes will include high PT jets, direct photons, Drell-Yan, W±, and heavy quarks. The accessible physics includes study of the spin content of the proton, particularly gluon and antiquark polarization, study of large PQCD-predicted asymmetries for parton-parton subprocesses, and parity violation studies and searches. The proton spin direction at a RHIC crossing can be longitudinal or transverse and can alternate bunch-to-bunch giving exquisite control of systematic errors. At RHIC double spin experiments can be done with pure beams and the energy and luminosity open a new domain for probing the physics of spin. An international collaboration is forming which proposes to exploit the unique physics available from a polarized RHIC. Important steps, leading to a polarized RHIC, have been taken. The AGS has already accelerated polarized protons. A new Booster/Accumulator has been commissioned. A beautiful series of machine experiments at Indian University have verified that spin rotators indeed remove spin resonance behavior, which is the key to achieving polarized proton acceleration to high energy. E880, an accelerator experiment which will build, install, and test a Siberian Snake in the AGS, was approved by the Brookhaven PAC in August 1991. The snake will be installed in the AGS in the summer of 1993. RHIC construction has started, with heavy ion experiments to begin in 1997

  11. Joining the RHIC Online and Offline Models

    CERN Document Server

    Malitsky, Nikolay; Fedotov, Alexei V; Kewisch, Jorg; Luccio, Alfredo U; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Satogata, Todd; Talman, Richard M; Tepikian, Steven; Wei, Jie

    2005-01-01

    The paper presents an interface encompassing the RHIC online ramp model and the UAL offline simulation framework. The resulting consolidated facility aims to minimize the gap between design and operational data, and to facilitate analysis of RHIC performance and future upgrades in an operational context. The interface is based on the Accelerator Description Exchange Format (ADXF), and represents a snapshot of the RHIC online model which is in turn driven by machine setpoints. This approach is also considered as an intermediate step towards integrating the AGS and RHIC modeling environments to produce a unified online and offline AGS model for operations.

  12. BNL Direct Wind Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  13. Excitation function of squared speed-of-sound extracted from (net-)proton rapidity spectra in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC

    CERN Document Server

    Gao, Li-Na; Sun, Yan; Sun, Zhu; Lacey, Roy A

    2016-01-01

    Experimental results of the rapidity distributions of protons and net-protons (protons minus antiprotons) emitted in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions, measured by a few collaborations at the alternating gradient synchrotron (AGS), super proton synchrotron (SPS), and relativistic heavy ion collider (RHIC), are described by a revised Landau hydrodynamic model. The values of squared speed-of-sound parameter $c^2_s$ are then extracted from the rapidity distribution widths of (net-)protons. The excitation function of $c^2_s$ of the interacting system in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC is obtained to show a local minimum or softest point in the equation of state (EoS) at the center-of-mass energy per nucleon pair $\\sqrt{s_{NN}}=8.8$ GeV which confirms our previous result.

  14. BNl 703 MHz superconducting RF cavity testing

    Energy Technology Data Exchange (ETDEWEB)

    Sheehy, B.; Altinbas, Z.; Burrill, A.; Ben-Zvi, I.; Gassner, D.; Hahn, H.; Hammons, L.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Laloudakis, N.; Lederle, D.; Litvinenko, V.; McIntyre, G.; Pate, D.; Phillips, D.; Schultheiss, C.; Seda,T.; Than, R.; Xu, W.; Zaltsman, A.; Schultheiss, T.

    2011-03-28

    The BNL 5-cell, 703 MHz superconducting accelerating cavity has been installed in the high-current ERL experiment. This experiment will function as a proving ground for the development of high-current machines in general and is particularly targeted at beam development for an electron-ion collider (eRHIC). The cavity performed well in vertical tests, demonstrating gradients of 20 MV/m and a Q{sub 0} of 1e10. Here we will present its performance in the horizontal tests, and discuss technical issues involved in its implementation in the ERL.

  15. The Future Of Spin Physics At BNL

    Science.gov (United States)

    Aronson, Samuel; Deshpande, Abhay

    2007-06-01

    The Relativistic Heavy Ion Collider (RHIC) at BNL is the world's only polarized proton-proton collider. Collisions at center-of-mass energies up to 500 GeV and beam polarizations approaching 70% (longitudinal or transverse) are provided to two experiments, STAR and PHENIX, at luminosities ⩾ 1032/cm2/sec. Transverse polarized beam has also been provided to the BRAHMS experiment. Measurements that bear on the important question of the spin content of the nucleon are beginning to appear. Over the next 10 years, as the performance of polarized proton running at RHIC is farmer developed, the Spin Physics program at RHIC will provide definitive measurements of the contributions to the proton's spin of the gluon, the sea quarks and the orbital motion of the partons in the proton's wave function. We plan to extend the reach of our study of the role of spin in QCD with the development of "eRHIC," which will provide polarized e-p collisions to a new detector.

  16. THE FUTURE OF SPIN PHYSICS AT BNL.

    Energy Technology Data Exchange (ETDEWEB)

    ARONSON, S.; DESHPANDE, A.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) at BNL is the world's only polarized proton-proton collider. Collisions at center-of-mass energies up to 500 GeV and beam polarizations approaching 70% (longitudinal or transverse) are provided to two experiments, STAR and PHENIX, at luminosities {ge} 10{sup 32}/cm{sup 2}/sec. Transverse polarized beam has also been provided to the BRAHMS experiment. Measurements that bear on the important question of the spin content of the nucleon are beginning to appear. Over the next 10 years, as the performance of polarized proton running at RHIC is further developed, the Spin Physics program at RHIC will provide definitive measurements of the contributions to the proton's spin of the gluon, the sea quarks and the orbital motion of the partons in the proton's wave function. We plan to extend the reach of our study of the role of spin in QCD with the development of ''eRHIC'', which will provide polarized e-p collisions to a new detector.

  17. LHeC and eRHIC

    CERN Document Server

    Litvinenko, Vladimir N

    2009-01-01

    This paper is focused on possible designs and predicted performances of two proposed highenergy, high-luminosity electron-hadron colliders: eRHIC at Brookhaven National Laboratory (BNL, Upton, NY, USA) and LHeC at Organisation Européenne pour la Recherche Nucléaire (CERN, Geneve, Switzerland). The Relativistic Heavy Ion Collider (RHIC, BNL) and the Large Hadron Collider (LHC, CERN) are designed as versatile colliders. RHIC is colliding various species of hadrons staring from polarized protons to un-polarized heavy ions (such as fully stripped Au (gold) ions) in various combinations: polarized p-p, d-Au, Cu-Cu, Au-Au. Maximum energy in RHIC is 250 GeV (per beam) for polarized protons and 100 GeV/n for heavy ions. There is planed expansion of the variety of species to include polarized He3 and unpolarized fully stripped U (uranium). LHeC is designed to collide both un-polarized protons with energy up to 7 TeV per beam and fully stripped Pb (lead) ions with energy up to 3 TeV/n. Both eRHIC and LHeC plan to add...

  18. Scientific articles of the RBRC/CCAST Symposium on Spin Physics Lattice QCD and RHIC Physics

    International Nuclear Information System (INIS)

    This volume comprises scientific articles of the symposium on spin physics, lattice QCD and RHIC physics organized by RIKEN BNL research center (RBRC) and China center of advanced science and technology (CCAST). The talks were discussing the spin structure of nucleons and other problems of RHIC physics

  19. Three lectures on the physics of RHIC

    International Nuclear Information System (INIS)

    Relativistic Heavy Ion Collider at BNL has just begun its operation, colliding the nuclei of Gold at unprecedented energies, RHIC is a dedicated QCD machine, and in these lectures I discuss some topics in the physics of hot and dense QCD matter that can be addressed there. The following subjects are considered in the present three lectures: introduction to the physics of RHIC; heavy quarkonium as a probe of QCD dynamics; topological fluctuations near the deconfinement phase transition and the possibility of P and CP violation in hot QCD. (author)

  20. Workshop on the RHIC performance

    Energy Technology Data Exchange (ETDEWEB)

    Khiari, F.; Milutinovic, J.; Ratti, A.; Rhoades-Brown, M.J. (eds.)

    1988-07-01

    The most recent conceptual design manual for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven was published in May 1986 (BNL 51932). The purpose of this workshop was to review the design specifications in this RHIC reference manual, and to discuss in detail possible improvements in machine performance by addressing four main areas. These areas are beam-beam interactions, stochastic cooling, rf and bunch instabilities. The contents of this proceedings are as follows. Following an overview of the workshop, in which the motivation and goals are discussed in detail, transcripts of the first day talks are given. Many of these transcripts are copies of the original transparencies presented at the meeting. The following four sections contain contributed papers, that resulted from discussions at the workshop within each of the four working groups. In addition, there is a group summary for each of the four working groups at the beginning of each section. Finally, a list of participants is given.

  1. Workshop on the RHIC performance

    International Nuclear Information System (INIS)

    The most recent conceptual design manual for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven was published in May 1986 (BNL 51932). The purpose of this workshop was to review the design specifications in this RHIC reference manual, and to discuss in detail possible improvements in machine performance by addressing four main areas. These areas are beam-beam interactions, stochastic cooling, rf and bunch instabilities. The contents of this proceedings are as follows. Following an overview of the workshop, in which the motivation and goals are discussed in detail, transcripts of the first day talks are given. Many of these transcripts are copies of the original transparencies presented at the meeting. The following four sections contain contributed papers, that resulted from discussions at the workshop within each of the four working groups. In addition, there is a group summary for each of the four working groups at the beginning of each section. Finally, a list of participants is given

  2. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 x 1032/cm2/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined

  3. Two particle interferometry at RHIC

    CERN Document Server

    Laue, F

    2002-01-01

    We present preliminary results from a pion interferometry analysis of Au+Au collisions at square root (S/sub NN/)=130 GeV, recorded with the STAR (Solenoidal Tracker At RHIC) detector at the Relativistic Heavy Ion Collider (RHIC). The evaluation of three-dimensional correlation functions indicates increasing source sizes with increasing event centrality. The dependence of the calculated HBT radii on transverse momentum is attributed to strong space-momentum correlations (transverse flow). In the study presented in this paper we have not observed anomalously large source sizes as have been predicted as a signal for quark-qluon plasma formation. However, the measured HBT radii seem to follow the trend established at lower energies (AGS/SPS). We find the ratio R/sub o//R/sub s/ approximately =1, suggesting a short duration of pion emission. The "universal" pion phase space density, observed at AGS/SPS, seems to hold also at RHIC. (26 refs).

  4. Polarized proton parameters for the 2015 PP-on-Aluminum setup in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, C. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-10-02

    Values are given for RHIC circumference shifts due to snakes for various situations. Relevant parameters are tabulated for polarized protons (PP) in the booster and in AGS and RHIC for PP-on-Aluminum stores.

  5. Polarized proton parameters for the 2015 PP-on-Au setup in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, C. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-08-25

    Values are given for RHIC circumference shifts due to snakes for various situations. Relevant parameters are tabulated for polarized protons (PP) in the booster and in AGS and RHIC for PP-on-Au stores.

  6. RHIC STATUS

    Energy Technology Data Exchange (ETDEWEB)

    ROSER, T.

    2007-01-29

    As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species. Machine operation and performance will be reviewed that includes high luminosity gold-on-gold and copper-on-copper collisions at design beam energy (100 GeVh), asymmetric deuteron-on-gold collisions as well as high energy polarized proton-proton collisions (100 GeV on 100 GeV) with beam polarization of up to 65%. Plans for future upgrades of RHIC will also be discussed.

  7. LHeC and eRHIC

    International Nuclear Information System (INIS)

    This paper is focused on possible designs and predicted performances of two proposed high-energy, high-luminosity electron-hadron colliders: eRHIC at Brookhaven National Laboratory (BNL, Upton, NY, USA) and LHeC at Organisation Europeenne pour la Recherche Nucleaire (CERN, Geneve, Switzerland). The Relativistic Heavy Ion Collider (RHIC, BNL) and the Large Hadron Collider (LHC, CERN) are designed as versatile colliders. RHIC is colliding various species of hadrons staring from polarized protons to un-polarized heavy ions (such as fully stripped Au (gold) ions) in various combinations: polarized p-p, d-Au, Cu-Cu, Au-Au. Maximum energy in RHIC is 250 GeV (per beam) for polarized protons and 100 GeV/n for heavy ions. There is planed expansion of the variety of species to include polarized He3 and unpolarized fully stripped U (uranium). LHeC is designed to collide both un-polarized protons with energy up to 7 TeV per beam and fully stripped Pb (lead) ions with energy up to 3 TeV/n. Both eRHIC and LHeC plan to add polarized electrons (or/and positrons) to the list of colliding species in these versatile hadron colliders. In eRHIC 10-20 GeV electrons would collide with hadrons circulating in RHIC. In LHeC 50-150 GeV polarized leptons will collided with LHC's hadron beams. Both colliders plan to operate in electron-proton (in RHIC case protons are polarized as well) and electron-ion collider modes. eRHIC and LHeC colliders are complimentary both in the energy reach and in their physics goals. I will discuss in this paper possible choices of the accelerator technology for the electron part of the collider for both eRHIC and LHeC, and will present predicted performance for the colliders. In addition, possible staging scenarios for these colliders will be discussed.

  8. The RHIC status update

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, S. [Brookhaven National Lab., Upton, NY (United States)

    1995-07-15

    The construction of the Relativistic Heavy Ion Collider (RHIC) began in 1991, with the completion date originally scheduled for 1997. Significant reduction of the funding levels in FY 1993 and 1994, and the funding level cap for FY 1995 and later years caused a 19-month stretchout of the construction period to the second quarter of FY 1999, and an increase of the total estimated cost (TEC) to $475 M. The Project, therefore, is now at the halfway mark of the construction period with actual cost and schedule performance tracking close to the DOE-approved baseline. Construction funding through FY 1994 reached close to 60% of the TEC. Incidentally, if one adds the current value of preexisting facilities which will be incorporated into RHIC, such as the injection system (Tandem Van de Graaff - the Booster - the AGS), the esixting 3.8 km tunnel, the 24 kW helium refrigerator, etc., the total value of the RHIC facility, when completed, will reach one billion dollars, if not more. The accelerator lattice design was finalized in 1992 after an intensive study was made to optimize the collider design for performance, operational flexibility, and value engineering. The civil construciton, including the collider enclosure, magnet access ports to the ring tunnel, and six service buildings for accelerator power supplies and cryogenic control boxes was completed.

  9. RHIC physics

    CERN Document Server

    Pajares, C

    1999-01-01

    A brief review of the hadronic phase transitions is presented by emphasizing the physical ideas and the main signatures of the transition in relation to the most significant results of the SPS experiments and the description of the RHIC experiments. (77 refs).

  10. Is there a role for fixed target heavy ion physics beyond RHIC startup?

    Energy Technology Data Exchange (ETDEWEB)

    Sandweiss, J. [Yale Univ., New Haven, CT (United States)

    1995-07-15

    The interesting and important physics opportunities provided by AGS and CERN fixed target facilities will be far from exhausted by the time of RHIC turn on. Given the need for the AGS to provide heavy ion beams for injection into RHIC, the cost effectiveness of fixed target experimentation with AGS beams will be high. Examples of the physics are given.

  11. RHIC Polarized proton operation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D' Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is 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. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  12. RHIC Polarized proton operation

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) 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 is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is 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. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above injection

  13. Nuclear Stopping:. Paving the way from Rhic to Lhc

    Science.gov (United States)

    Dalsgaard, Hans Hjersing

    Nuclear stopping has been measured at a range of different energies in heavy ion experiments. In this contribution proton data from the BRAHMS experiment at RHIC running at √ {SNN} = 62.4\\ GeV are presented. Furthermore data from AGS, SPS and RHIC are used to estimate the stopping, energy loss and multiplicity at LHC.

  14. Silicon drift-chamber studies for possible use at RHIC

    International Nuclear Information System (INIS)

    It is proposed to continue the program now underway at the University of Pittsburgh to study the feasibility of using silicon drift-chambers as particle tracking devices at RHIC. We are currently testing a UA6-type detector obtained from BNL and plan to also study a new device that will become available this year: a cylindrical geometry detector designed for NA45 (CERN). In addition we propose to fabricate and study a detector to be used in vertex determination for the RHIC OASIS experiment. The two-year budget for this proposal is $246.962. 5 refs., 12 figs

  15. Hypernucleus Production at RHIC and HIRFL-CSR Energy

    International Nuclear Information System (INIS)

    We calculated the hypertriton production at RHIC-STAR and HIRFL-CSR acceptance, with a multi-phase transport model (AMPT) and a relativistic transport model (ART), respectively. In specific, we calculated the Strangeness Population Factor S3 = Λ3H/(3He x Λ/p) at different beam energy. Our results from AGS to RHIC energy indicated that the collision system may change from hadronic phase at AGS energies to partonic phase at RHIC energies. Our calculation at HIRFL-CSR energy supports the proposal to measure hypertriton at HIRFL-CSR.

  16. BNL 56 MHz HOM damper prototype fabrication at JLAB

    Energy Technology Data Exchange (ETDEWEB)

    Huque, N.; McIntyre, G.; Daly, E. F.; Clemens, W.; Wu, Q.; Seberg, S.; Bellavia, S.

    2015-05-03

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider’s (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  17. BNL 56 MHz HOM Damper Prototype Fabrication at JLab

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Naeem A. [Jefferson Lab., Newport News, VA (United States); Daly, Edward F. [Jefferson Lab., Newport News, VA (United States); Clemens, William A. [Jefferson Lab., Newport News, VA (United States); McIntyre, Gary T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wu, Qiong [Brookhaven National Lab. (BNL), Upton, NY (United States); Seberg, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Bellavia, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-01

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider's (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  18. The Forward GEM Tracker of STAR at RHIC

    OpenAIRE

    Simon, F.; Balewski, J.; Fatemi, R.; Hasell, D.; Kelsey, J.; Majka, R.; Page, B.; Plesko, M.; Underwood, D.; Smirnov, N.; Sowinski, J.; Spinka, H.; Surrow, B.(Temple University, Philadelphia, PA, 19122, USA); Visser, G.

    2008-01-01

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is in the process of designing and constructing a forward tracking system based on triple GEM technology. This upgrade is necessary to give STAR the capability to reconstruct and identify the charge sign of W bosons over an extended rapidity range through their leptonic decay mode into an electron (positron) and a neutrino. This will allow a detailed study of the flavor-separated spin str...

  19. The Strongly Interacting Quark Gluon Plasma at RHIC and LHC

    Directory of Open Access Journals (Sweden)

    Tserruya Itzhak

    2014-04-01

    Full Text Available The study of heavy-ion collisions has currently unprecedented opportunities with two first class facilities, the Relativistic Heavy Ion Collider (RHIC at BNL and the Large Hadron Collider (LHC at CERN, and five large experiments ALICE, ATLAS, CMS, PHENIX and STAR producing a wealth of high quality data. Selected results recently obtained are presented on the study of flow, energy loss and direct photons.

  20. Measuring the Proton Beam Polarization From The Source To RHIC

    Science.gov (United States)

    Makdisi, Yousef I.

    2008-02-01

    Polarimeters are necessary tools for measuring the beam polarization during the acceleration process as well as a yardstick for performing spin physics experiments. In what follows, I will describe the principles of measuring the proton beam polarization and the techniques that are employed at various energies. I will present a tour of the polarimetry employed at the BNL Relativistic Heavy Ion collider (RHIC) polarized proton complex as it spans the full spectrum from the source to collider energies.

  1. Measuring the proton beam polarization from the source to RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    Makdisi,Y.

    2007-09-10

    Polarimeters are necessary tools for measuring the beam polarization during the acceleration process as well as a yardstick for performing spin physics experiments. In what follows, I will describe the principles of measuring the proton beam polarization and the techniques that are employed at various energies. I will present a tour of the polarimetry employed at the BNL Relativistic Heavy Ion collider (RHIC) polarized proton complex as it spans the full spectrum from the source to collider energies.

  2. Strangelet Search at the BNL Relativistic Heavy Ion Collider

    OpenAIRE

    Abelev, B. I.

    2008-01-01

    We have searched for strangelets in a triggered sample of 61 million central (top 4percent) Au+Au collisions at sqrt sNN = 200 GeV near beam rapidities at the STAR solenoidal tracker detector at the BNL Relativistic Heavy Ion Collider. We have sensitivity to metastable strangelets with lifetimes of order >_0.1 ns, in contrast to limits over ten times longer in BNL Alternating Gradient Synchrotron (AGS) studies and longer still at the CERN Super Proton Synchrotron (SPS). Upper limits of a few ...

  3. Cooling Scheme for BNL-Built LHC Magnets

    CERN Document Server

    Ostojic, R; Van Weelderen, R; Willen, E H; Wu, K C

    1999-01-01

    Brookhaven National Laboratory (BNL) will provide four types of magnets, identified as D1, D2, D3 and D4, for the Insertion Regions of the Large Hadron Collider (LHC) as part of an international collaboration. These magnets utilize the dipole coil design of the Relativistic Heavy Ion Collider (RHIC) at BNL, for performance, reliability and cost reasons. The magnet cold mass and cryostat have been designed to ensure that these magnets meet all performance requirements in the LHC sloped tunnel using its cryogenic distribution system. D1 is a RHIC arc dipole magnet. D2 and D4 are 2-in-1 magnets, two coils in one cold mass, in a cryostat. D3 is a 1-in-1 magnet, one coil in one cold mass, with two cold masses side by side in a cryostat. D1 and D4 will be cooled by helium II at 1.9 K using a bayonet heat exchanger similar to the main cooling system of LHC. D2 and D3 will be cooled by liquid helium at 4.5 K using a Two-Feed scheme. A detailed description of the cooling scheme for these magnets, their cryostats, spec...

  4. The RHIC polarized H- ion source

    Science.gov (United States)

    Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Steski, D.

    2016-02-01

    A novel polarization technique had been successfully implemented for the Relativistic Heavy Ion Collider (RHIC) polarized H- ion source upgrade to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gaseous ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically pumped Rb vapor. The use of high-brightness primary beam and large cross sections of charge-exchange cross sections resulted in production of high intensity H- ion beam of 85% polarization. The source very reliably delivered polarized beam in the RHIC Run-2013 and Run-2015. High beam current, brightness, and polarization resulted in 75% polarization at 23 GeV out of Alternating Gradient Synchrotron (AGS) and 60%-65% beam polarization at 100-250 GeV colliding beams in RHIC.

  5. The RHIC polarized H⁻ ion source.

    Science.gov (United States)

    Zelenski, A; Atoian, G; Raparia, D; Ritter, J; Steski, D

    2016-02-01

    A novel polarization technique had been successfully implemented for the Relativistic Heavy Ion Collider (RHIC) polarized H(-) ion source upgrade to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gaseous ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically pumped Rb vapor. The use of high-brightness primary beam and large cross sections of charge-exchange cross sections resulted in production of high intensity H(-) ion beam of 85% polarization. The source very reliably delivered polarized beam in the RHIC Run-2013 and Run-2015. High beam current, brightness, and polarization resulted in 75% polarization at 23 GeV out of Alternating Gradient Synchrotron (AGS) and 60%-65% beam polarization at 100-250 GeV colliding beams in RHIC. PMID:26932068

  6. Serpentine Coil Topology for BNL Direct Wind Superconducting Magnets

    CERN Document Server

    Parker, Brett

    2005-01-01

    BNL direct wind technology, with the conductor pattern laid out without need for extra tooling (no collars, coil presses etc.) began with RHIC corrector production. RHIC patterns were wound flat and then wrapped on cylindrical support tubes. Later for the HERA-II IR magnets we improved conductor placement precision by winding directly on a support tube. To meet HERA-II space and field quality goals took sophisticated coil patterns, (some wound on tapered tubes). We denote such patterns, topologically equivalent to RHIC flat windings, "planar patterns." Multi-layer planar patterns run into trouble because it is hard to wind across existing turns and magnet leads get trapped at poles. So we invented a new "Serpentine" winding style, which goes around 360 degrees while the conductor winds back and forth on the tube. To avoid making solenoidal fields, we wind Serpentine layers in opposite handed pairs. With a Serpentine pattern each turn can have the same projection on the coil axis and integral field harmonics t...

  7. Electron Cooling of RHIC

    CERN Document Server

    Ben-Zvi, Ilan; Barton, Donald; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Bruhwiler, David L; Burger, Al; Burov, Alexey; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Derbenev, Yaroslav S; Eidelman, Yury I; Favale, Anthony; Fedotov, Alexei V; Fischer, Wolfram; Funk, L W; Gassner, David M; Hahn, Harald; Harrison, Michael; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Koop, Ivan; Lambiase, Robert; Litvinenko, Vladimir N; MacKay, William W; Mahler, George; Malitsky, Nikolay; McIntyre, Gary; Meng, Wuzheng; Merminga, Lia; Meshkov, Igor; Mirabella, Kerry; Montag, Christoph; Nagaitsev, Sergei; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Parkhomchuk, Vasily; Parzen, George; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Sekutowicz, Jacek; Shatunov, Yuri; Sidorin, Anatoly O; Skrinsky, Aleksander Nikolayevich; Smirnov, Alexander V; Smith, Kevin T; Todd, Alan M M; Trbojevic, Dejan; Troubnikov, Grigory; Wang, Gang; Wei, Jie; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Zaltsman, Alex; Zhao, Yongxiang; ain, Animesh K

    2005-01-01

    We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...

  8. FPC conditioning cart at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W.; Ben-Zvi, I.; Altinbas, F.Z.; Belomestnykh, S.; Burrill, A.; Cole, M.; Deonarine, J.; Jamilkowski, J.; Kayran, D.; Laloudakis, N.; Masi Jr, L.; McIntyre, G.; Pate, D.; Philips, D.; Seda, T.; Steszyn, A.; Tallerico, T.; Todd, R.; Weiss, D.; White, G.; Zaltsman, A.

    2011-03-28

    The 703 MHz superconducting gun for the BNL Energy Recovery Linac (ERL) prototype has two fundamental power couplers (FPCs), and each of them will deliver up to 500 kW of CW RF power. In order to prepare the couplers for high power RF service and process multipacting, the FPCs should be conditioned prior to installation into the gun cryomodule. A conditioning cart based test stand, which includes a vacuum pumping system, controllable bake-out system, diagnostics, interlocks and data log system has been designed, constructed and commissioned by collaboration of BNL and AES. This paper presents FPC conditioning cart systems and the conditioning process.

  9. BNL Activities in Advanced Neutron Source Development: Past and Present

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, J.B.; Ludewig, H.; Montanez, P.; Todosow, M.; Smith, G.C.; Larese, J.Z.

    1998-06-14

    Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In this report we discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

  10. BNL ACTIVITIES IN ADVANCED NEUTRON SOURCE DEVELOPMENT: PAST AND PRESENT

    Energy Technology Data Exchange (ETDEWEB)

    HASTINGS,J.B.; LUDEWIG,H.; MONTANEZ,P.; TODOSOW,M.; SMITH,G.C.; LARESE,J.Z.

    1998-06-14

    Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In the sections below the authors discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

  11. Azimuthal Jet Tomography of Quark Gluon Plasmas at RHIC and LHC

    OpenAIRE

    Betz, Barbara; Gyulassy, Miklos

    2013-01-01

    Recent data on the azimuthal and transverse momentum dependence of high-pT>10 GeV pion nuclear modification factors in nuclear collisions at RHIC/BNL and LHC/CERN are analyzed in terms of a wide class of jet-energy loss models and a variety of transverse expanding collective flow backgrounds. RHIC data at 200 AGeV are found to be surprisingly consistent with rather different dE/dx models when coupled to recent 2+1D minimally viscous QGP flow field predictions. However, extrapolations to LHC, ...

  12. RHIC progress and future

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.

    2009-05-04

    The talk reviews RHIC performance, including unprecedented manipulations of polarized beams and recent low energy operations. Achievements and limiting factors of RHIC operation are discussed, such as intrabeam scattering, electron cloud, beam-beam effects, magnet vibrations, and the efficiency of novel countermeasures such as bunched beam stochastic cooling, beam scrubbing and chamber coatings. Future upgrade plans and the pertinent R&D program will also be presented.

  13. Entropy Production at RHIC

    OpenAIRE

    Pal, Subrata; Pratt, Scott

    2003-01-01

    For central heavy ion collisions at the RHIC energy, the entropy per unit rapidity dS/dy at freeze-out is extracted with minimal model dependence from available experimental measurements of particle yields, spectra, and source sizes estimated from two-particle interferometry. The extracted entropy rapidity density is consistent with lattice gauge theory results for a thermalized quark-gluon plasma with an energy density estimated from transverse energy production at RHIC.

  14. Opportunities for Polarized He-3 in RHIC and EIC

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer E.; Deshpande, A.; Fischer, W.; Derbenev, S.; Milner, R.; Roser, T.; Zelenski, A.

    2011-10-01

    The workshop on opportunities for polarized He-3 in RHIC and EIC was targeted at finding practical ways of implementing and using polarized He-3 beams. Polarized He-3 beams will provide the unique opportunity for first measurements, i.e, to a full quark flavor separation measuring single spin asymmetries for p{sup +}, p{sup -} and p{sup 0} in hadron-hadron collisions. In electron ion collisions the combination of data recorded with polarized electron proton/He-3 beams allows to determine the quark flavor separated helicity and transverse momentum distributions. The workshop had sessions on polarized He-3 sources, the physics of colliding polarized He-3 beams, polarimetry, and beam acceleration in the AGS Booster, AGS, RHIC, and ELIC. The material presented at the workshop will allow making plans for the implementation of polarized He-3 beams in RHIC.

  15. Gluon saturation and pseudo-rapidity distributions of charged hadrons at RHIC energy regions

    Institute of Scientific and Technical Information of China (English)

    WEI Xin-Bing; FENG Sheng-Qin

    2012-01-01

    We modified the gluon saturation model by rescaling the momentum fraction according to saturation momentum and introduced Cooper-Frye hydrodynamic evolution to systematically study the pseudorapidity distributions of final charged hadrons at different energies and different centralities for Au-Au collisions in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC).The features of both gluon saturation and hydrodynamic evolution at different energies and different centralities for Au-Au collisions are investigated in this paper.

  16. Progress on Test EBIS and the Design of an EBIS-Based RHIC Preinjector

    CERN Document Server

    Alessi, James; Gould, Omar; Kponou, Ahovi; Lockey, Robert; Pikin, Alexander I; Prelec, Krsto; Raparia, Deepak; Ritter, John; Snydstrup, Louis

    2005-01-01

    Following the successful development of the Test EBIS at BNL,* we now have a design for an EBIS-based heavy ion preinjector which would serve as an alternative to the Tandem Van de Graaffs in providing beams for RHIC and the NASA Space Radiation Laboratory. This baseline design includes an EBIS producing mA-level currents of heavy ions (ex. Au 32+) in ~ 10-20

  17. From SPS to RHIC: Maurice and the CERN heavy-ion programme

    OpenAIRE

    Heinz, Ulrich W.

    2008-01-01

    Maurice Jacob played a key role in bringing together different groups from the experimental and theoretical nuclear and particle physics communities to initiate an ultrarelativistic heavy-ion collision program at the CERN SPS, in order to search for the quark-gluon plasma. I review the history of this program from its beginnings to the time when the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) started operation. I close by providing a glimpse of the important...

  18. BNL heavy ion fusion program

    International Nuclear Information System (INIS)

    A principal attraction of heavy ion fusion is that existing accelerator technology and theory are sufficiently advanced to allow one to commence the design of a machine capable of igniting thermonuclear explosions. There are, however, a number of features which are not found in existing accelerators built for other purposes. The main thrust of the BNL Heavy Ion Fusion program has been to explore these features. Longitudinal beam bunching, very low velocity acceleration, and space charge neutralization are briefly discussed

  19. First test of BNL electron beam ion source with high current density electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, Alexander, E-mail: pikin@bnl.gov; Alessi, James G., E-mail: pikin@bnl.gov; Beebe, Edward N., E-mail: pikin@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973 (United States); Shornikov, Andrey; Mertzig, Robert; Wenander, Fredrik; Scrivens, Richard [CERN, CH-1211 Geneva 23 (Switzerland)

    2015-01-09

    A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm{sup 2} and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio < 4.5 are requested by many heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, the EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given.

  20. First test of BNL electron beam ion source with high current density electron beam

    International Nuclear Information System (INIS)

    A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm2 and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio < 4.5 are requested by many heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, the EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given

  1. RHIC PROGRESS REPORT

    Energy Technology Data Exchange (ETDEWEB)

    PEGGS, S.

    1998-06-26

    The design and construction status of the Relativistic Heavy Ion Collider, RHIC, which is in the eighth year of a nine year construction cycle, is discussed [1]. Those performance features of a heavy ion collider that are distinct from hadron colliders in general are noted. These features are derived from the experimental requirements of operation with a variety of ion species over a wide energy range, including collisions between ions of unequal energies, between protons and ions, and between polarized protons. Section 1 gives a brief introduction to the major parameters and overall layout of RHIC. A review of the superconducting magnet program is given in Section 2. Machine performance is reviewed in Section 3, and the plans for RHIC commissioning in 1999 are presented in Section 4.

  2. The RHIC vacuum systems

    Science.gov (United States)

    Burns, R.; Hseuh, H. C.; Lee, R. C.; McIntyre, G.; Pate, D.; Smart, L.; Sondericker, J.; Weiss, D.; Welch, K.

    2003-03-01

    There are three vacuum systems in RHIC: the insulating vacuum vessels housing the superconducting magnets, the cold beam tubes surrounded by the superconducting magnets, and the warm beam tube sections at the insertion regions and the experimental regions. These systems have a cumulative length over 10 km and a total volume over 3000 m 3. Conventional ultrahigh vacuum technology was used in the design and construction of the cold and warm beam vacuum systems with great success. The long and large insulating vacuum volumes without vacuum barriers require careful management of the welding and leak checking of the numerous helium line joints. There are about 1500 vacuum gauges and pumps serial-linked to eight PLCs distributed around RHIC, which allow the monitoring and control of these devices through Ethernet networks to remote control consoles. With the exception of helium leaks through the cryogenic valve boxes into the insulating vacuum volumes, the RHIC vacuum systems have performed well beyond expectations.

  3. RHIC prefire protection masks

    Energy Technology Data Exchange (ETDEWEB)

    Drees, A.; Biscardi, C.; Curcio, T.; Gassner, D.; DeSanto, L.; Fu, W.; Liaw, C. J.; Montag, C.; Thieberger, P.; Yip, K.

    2015-01-07

    The protection of the RHIC experimental detectors from damage due to beam hitting close upstream elements in cases of abort kicker prefires requires some dedicated precautionary measures with two general options: to bring the beam close to a limiting aperture (i.e. the beam pipe wall), as far upstream of the detector components as possible or, alternatively, to bring a limiting aperture close to the circulating beam. Spontaneous and random prefires of abort kicker modules (Pulse Forming Network, PFN) have a history as long as RHIC is being operated. The abort system consist of 5 kickers in per ring, each of them equipped with its own dedicated PFN.

  4. Loss maps of RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Robert-Demolaize,G.

    2007-10-01

    State-of-the-art tracking tools were recently developed at CERN to study the cleaning efficiency of the Large Hadron Collider (LHC) collimation system [1]. These tools are fully transportable, meaning that any accelerator lattice that includes a collimation system can be simulated. Each of the two Relativistic Heavy Ion Collider (RHIC) [2] beam lines features a multi-stage collimation system, therefore dedicated datasets from RHIC operations with proton beams can be used to benchmark the tracking codes and assess the accuracy of the predicted hot spots along the LHC.

  5. RHIC OPERATIONAL STATUS.

    Energy Technology Data Exchange (ETDEWEB)

    ROSER, T.

    2005-05-16

    As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species. Machine operation and performance will be reviewed that includes high luminosity gold-on-gold and copper-on-copper collisions at design beam energy (100 GeV/u), asymmetric deuteron-on-gold collisions as well as high energy polarized proton-proton collisions (100 GeV on 100 GeV). Plans for future upgrades of RHIC will also be discussed.

  6. RHIC SPIN FLIPPER

    Energy Technology Data Exchange (ETDEWEB)

    BAI,M.; ROSER, T.

    2007-06-25

    This paper proposes a new design of spin flipper for RHIC to obtain full spin flip with the spin tune staying at half integer. The traditional technique of using an rf dipole or solenoid as spin flipper to achieve full spin flip in the presence of full Siberian snake requires one to change the snake configuration to move the spin tune away from half integer. This is not practical for an operational high energy polarized proton collider like RHIC where beam lifetime is sensitive to small betatron tune change. The design of the new spin flipper as well as numerical simulations are presented.

  7. Why is the null HBT result at RHIC so interesting?

    CERN Document Server

    Gyulassy, M

    2003-01-01

    Pion interferometry (HBT of A+A) data have posed a thorn in the theoretical interpretation of AA collisions at RHIC (sq root s = 130 AGeV). How can R sub o sub u sub t approx R sub s sub i sub d sub e approx R sub l sub o sub n sub g and remain so between AGS and RHIC? Where is the QGP Stall? Can elephants hide along the x sub 0 sup + dimension? We rummage old hydrodynamic scenarios and uncover some previously ignored NULL solutions. (author)

  8. Analysis of polarimeter data for the 2001-2002 RHIC run

    International Nuclear Information System (INIS)

    The results of several studies of the 200-MeV (LINAC), AGS (E880), and RHIC polarimeter data from the polarized proton run in 2001/2002 are presented. Much of this work occurred during or immediately after the run. Some of these analyses have implications for the understanding of the performance of the polarized ion source, AGS, and RHIC with polarized protons. Some of the conclusions include: (A) A recalibration of the 200-MeV polarimeter gives results consistent with the older calibration, but high rates in the 200-MeV polarimeter are still a problem. (B) No evidence of sizable systematic effects was found in several tests of the AGS polarimeter with a thin carbon fiber target. (C) Significant polarization loss in the AGS was observed above Gγ = 7.5 but not between injection and Gγ = 7.5. (D) The magnitude of the flattop asymmetry in the RHIC polarimeters decreases with time in a fill. (E) The RHIC polarimeter analyzing power on flattop is greater than or equal to that at injection. (F) Unexplained systematic effects were observed in the RHIC polarimeter, but the implications for the measured polarization asymmetry are not clear. These effects were not isolated events, but occurred throughout the run. Conceivably the data could indicate that the present RHIC polarimeter design will not be able to achieve a goal of a ± 5% measurement of the beam polarization

  9. THE RHIC SEQUENCER.

    Energy Technology Data Exchange (ETDEWEB)

    VAN ZEIJTS,J.; DOTTAVIO,T.; FRAK,B.; MICHNOFF,R.

    2001-06-18

    The Relativistic Heavy Ion Collider (RHIC) has a high level asynchronous time-line driven by a controlling program called the ''Sequencer''. Most high-level magnet and beam related issues are orchestrated by this system. The system also plays an important task in coordinated data acquisition and saving. We present the program, operator interface, operational impact and experience.

  10. The RHIC polarized H{sup −} ion source

    Energy Technology Data Exchange (ETDEWEB)

    Zelenski, A., E-mail: zelenski@bnl.gov; Atoian, G.; Raparia, D.; Ritter, J.; Steski, D. [Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2016-02-15

    A novel polarization technique had been successfully implemented for the Relativistic Heavy Ion Collider (RHIC) polarized H{sup −} ion source upgrade to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gaseous ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically pumped Rb vapor. The use of high-brightness primary beam and large cross sections of charge-exchange cross sections resulted in production of high intensity H{sup −} ion beam of 85% polarization. The source very reliably delivered polarized beam in the RHIC Run-2013 and Run-2015. High beam current, brightness, and polarization resulted in 75% polarization at 23 GeV out of Alternating Gradient Synchrotron (AGS) and 60%-65% beam polarization at 100-250 GeV colliding beams in RHIC.

  11. Beam Loss Estimates and Control for the BNL Neutrino Facility

    CERN Document Server

    Weng, Wu-Tsung; Raparia, Deepak; Tsoupas, Nicholaos; Wei, Jie; Yung Lee, Yong; Zhang, S Y

    2005-01-01

    BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW for a very long baseline neutrino oscillation experiment. This increase in beam power is mainly due to the faster repetition rate of the AGS by a new 1.5 GeV superconductiong linac as injector, replacing the existing booster. The requirement for low beam loss is very important both to protect the beam component, and to make the hands-on maintenance possible. In this report, the design considerations for achieving high intensity and low loss will be presented. We start by specifying the beam loss limit at every physical process followed by the proper design and parameters for realising the required goals. The process considered in this paper include the emittance growth in the linac, the H-

  12. Synchrotron Radiation in eRHIC Interaction Region

    CERN Document Server

    Beebe-Wang, Joanne; Montag, Christoph; Rondeau, Daniel J; Surrow, Bernd

    2005-01-01

    The eRHIC currently under study at BNL consists of an electron storage ring added to the existing RHIC complex. The interaction region of this facility has to provide the required low-beta focusing while accommodating the synchrotron radiation generated by beam separation close to the interaction point. In the current design, the synchrotron radiation caused by 10GeV electrons bent by low-beta triplet magnets will be guided through the interaction region and dumped 5m downstream. However, it is unavoidable to stop a fraction of the photons at the septum where the electron and ion vacuum system are separated. In order to protect the septum and minimize the backward scattering of the synchrotron radiation, an absorber and collimation system will be employed. In this paper, we first present the overview of the current design of the eRHIC interaction region with special emphasis on the synchrotron radiation. Then the initial design of the absorber and collimation system, including their geometrical and physical p...

  13. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  14. The Cornell-BNL FFAG-ERL Test Accelerator: White Paper

    CERN Document Server

    Bazarov, Ivan; Dunham, Bruce; Hoffstaetter, Georg; Mayes, Christopher; Patterson, Ritchie; Sagan, David; Ben-Zvi, Ilan; Berg, Scott; Blaskiewicz, Michael; Brooks, Stephen; Brown, Kevin; Fischer, Wolfram; Hao, Yue; Meng, Wuzheng; Méot, François; Minty, Michiko; Peggs, Stephen; Ptitsin, Vadim; Roser, Thomas; Thieberger, Peter; Trbojevic, Dejan; Tsoupas, Nick

    2015-01-01

    The Cornell-BNL FFAG-ERL Test Accelerator (C$\\beta$) will comprise the first ever Energy Recovery Linac (ERL) based on a Fixed Field Alternating Gradient (FFAG) lattice. In particular, we plan to use a Non Scaling FFAG (NS-FFAG) lattice that is very compact and thus space- and cost- effective, enabling multiple passes of the electron beam in a single recirculation beam line, using the superconducting RF (SRF) linac multiple times. The FFAG-ERL moves the cost optimized linac and recirculation lattice to a dramatically better optimum. The prime accelerator science motivation for C$\\beta$ is proving that the FFAG-ERL concept works. This is an important milestone for the Brookhaven National Laboratory (BNL) plans to build a major Nuclear Physics facility, eRHIC, based on producing 21 GeV electron beams to collide with the RHIC ion beams. A consequence of the C$\\beta$ work would be the availability of significantly better, cost-effective, compact CW high-brightness electron beams for a plethora of scientific inves...

  15. PROCEEDINGS OF RIKEN/BNL RESEARCH CENTER WORKSHOP FUTURE TRANSVERSITY MEASUREMENTS (VOLUME 29).

    Energy Technology Data Exchange (ETDEWEB)

    Boer, D.; Grosse Perdekamp, M.

    2001-01-02

    The RIKEN-BNL Research Center workshop on ''Future Transversity Measurements'' was held at BNL from September 18-20, 2000. The main goal of the workshop was to explore future measurements of transversity distributions. This issue is of importance to the RHIC experiments, which will study polarized proton-proton collisions with great precision. One of the workshop's goals was to enhance interactions between the DIS community at HERA and the spin community at RHIC in this field. The workshop has been well received by the participants; the number of 69 registered participants demonstrates broad interest in the workshop's topics. The program contained 35 talks and there was ample time for lively discussions. The program covered all recent work in the field and in addition some very elucidating educational talks were given. At the workshop the present status of the field was discussed and it has succeeded in stimulating new experimental and theoretical studies (e.g. model calculations for interference fragmentation functions (IFF), IFF analysis at DELPHI). It also functioned to focus attention on the open questions that need to be resolved for near future experiments. In general, the conclusions were optimistic, i.e. measuring the transversity functions seems to be possible, although some new experimental hurdles will have to be taken.

  16. RHIC Power Supply Ramp Diagnostics*

    OpenAIRE

    Morris, J. T.; Clifford, T. S.; Frak, B.; Laster, J.; Marusic, A; van Zeijts, J.

    2001-01-01

    Reliable and reproducible performance of the more than 800 Relativistic Heavy Ion Collider (RHIC) magnet power supplies is essential to successful RHIC operation. In order to support power supply commissioning, a system was developed to capture detailed power supply measurements from all the RHIC ring power supplies during acceleration ramps. Diagnostic tools were developed to allow experts to assess ramp reproducibility and rapidly identify problems. The system has now become a routine part ...

  17. HARD PARTON PHYSICS IN HIGH ENERGY NUCLEAR COLLISIONS. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 17

    Energy Technology Data Exchange (ETDEWEB)

    CARROLL,J.

    1999-09-10

    The RIKEN-BNL center workshop on ''Hard parton physics in high energy nuclear collisions'' was held at BNL from March 1st-5th! 1999. The focus of the workshop was on hard probes of nucleus-nucleus collisions that will be measured at RHIC with the PHENIX and STAR detectors. There were about 45 speakers and over 70 registered participants at the workshop, with roughly a quarter of the speakers from overseas. About 60% of the talks were theory talks. A nice overview of theory for RHIC was provided by George Sterman. The theoretical talks were on a wide range of topics in QCD which can be classified under the following: (a) energy loss and the Landau-Pomeranchuk-Migdal effect; (b) minijet production and equilibration; (c) small x physics and initial conditions; (d) nuclear parton distributions and shadowing; (e) spin physics; (f) photon, di-lepton, and charm production; and (g) hadronization, and simulations of high pt physics in event generators. Several of the experimental talks discussed the capabilities of the PHENIX and STAR detectors at RHIC in measuring high pt particles in heavy ion collisions. In general, these talks were included in the relevant theory sessions. A session was set aside to discuss the spin program at RHIC with polarized proton beams. In addition, there were speakers from 08, HERA, the fixed target experiments at Fermilab, and the CERN fixed target Pb+Pb program, who provided additional perspective on a range of issues of relevance to RHIC; from jets at the Tevatron, to saturation of parton distributions at HERA, and recent puzzling data on direct photon production in fixed target experiments, among others.

  18. PHOBOS at RHIC 2000

    International Nuclear Information System (INIS)

    The relativistic heavy ion collider (RHIC) at Brookhaven national laboratory delivered in June 2000 the first collisions between Au nuclei at the highest center-of-mass energies achieved in a controlled environment to date. PHOBOS is one of the four experiments installed during this phase of RHIC running. This paper will describe the PHOBOS experiment, and discuss the results of the first physics measurement, thc pseudo rapidity densities of primary charged particles near mid rapidity in central Au + Au collisions at two different energies, √ SNN = 56 and 130 GeV. The observed densities are higher than those previously observed in any collisions, and the rate of increase between the two energies is larger than that for nucleon-nucleon collisions at comparable beam energies. This talk will describe the PHOBOS experiment, discuss the first physics measurement, and conclude with the present status of the experiment, the physics analysis and the perspectives fi the future. (Author)

  19. Electromagnetic Signals at RHIC

    CERN Document Server

    Turbide, S; Turbide, Simon; Gale, Charles

    2006-01-01

    We calculate the direct photon yield in central and mid-peripheral Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC). The processes involving the propagation of jets have been convolved with a leading order treatment of jet energy loss in the medium and a one dimensional hydrodynamic expansion. The quark-gluon plasma (QGP) contribution turns out to be important, especially the in-medium conversion of a jet into a photon, for successfully describing recent photon measurements.

  20. RHIC physics overview

    CERN Document Server

    Ruan, Lijuan

    2010-01-01

    The results from data taken during the last several years at the Relativistic Heavy-Ion Collider (RHIC) will be reviewed in the paper. Several selected topics that further our understanding of constituent quark scaling, jet quenching and color screening effect of heavy quarkonia in the hot dense medium will be presented. Detector upgrades will further probe the properties of Quark Gluon Plasma. Future measurements with upgraded detectors will be presented. The discovery perspectives from future measurements will also be discussed.

  1. Absolute polarimetry at RHIC

    OpenAIRE

    Okada, H.; Alekseev, I.; Bravar, A; Bunce, G.; Dhawan, S.; Eyser, K. O.; Gill, R; Haeberli, W.; Huang, H.; Jinnouchi, O.; Makdisi, Y.; Nakagawa, I.; Nass, A.; Saito, N; Stephenson, E.

    2007-01-01

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy of $\\Delta P_{beam}/P_{beam} < 5%$. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detector...

  2. RHIC spin program

    International Nuclear Information System (INIS)

    Colliding beams of high energy polarized protons at RHIC is an excellent way to probe the polarization of gluons, u and d quarks in a polarized proton. RHIC is the Relativistic Heavy Ion Collider being built now at Brookhaven in the ISABELLE tunnel. It is designed to collide gold ions on gold ions at 100 GeV/nucleon. Its goal is to discover the quark-gluon plasma, and the first collisions are expected in March, 1999. RHIC will also make an ideal polarized proton collider with high luminosity and 250 GeV x 250 GeV collisions. The RHIC spin physics program is: (1) Use well-understood perturbative QCD probes to study non-perturbative confining dynamics in QCD. We will measure - gluon and sea quark polarization in a polarized proton, polarization of quarks in a transversely polarized proton. (2) Look for additional surprises using the first high energy polarized proton collider. We will - look for the expected maximal parity violation in W and Z boson production, - search for parity violation in other processes, - test parton models with spin. This lecture is organized around a few of the key ideas: Siberian Snakes--What are they? High energy proton-proton collisions are scatters of quarks and leptons, at high x, a polarized proton beam is a beam of polarized u quarks, quark and gluon collisions are very sensitive to spin. We will discuss two reactions: how direct photon production measures gluon polarization, and how W+ boson production measures u and d quark polarization

  3. Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Nucleon Spin Physics

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer, A.; Qiu, Jianwei; Vogelsang, W.; Yuan, F.

    2011-08-02

    Understanding the structure of the nucleon is of fundamental importance in sub-atomic physics. Already the experimental studies on the electro-magnetic form factors in the 1950s showed that the nucleon has a nontrivial internal structure, and the deep inelastic scattering experiments in the 1970s revealed the partonic substructure of the nucleon. Modern research focuses in particular on the spin and the gluonic structure of the nucleon. Experiments using deep inelastic scattering or polarized p-p collisions are carried out in the US at the CEBAF and RHIC facilities, respectively, and there are other experimental facilities around the world. More than twenty years ago, the European Muon Collaboration published their first experimental results on the proton spin structure as revealed in polarized deep inelastic lepton-nucleon scattering, and concluded that quarks contribute very little to the proton's spin. With additional experimental and theoretical investigations and progress in the following years, it is now established that, contrary to naive quark model expectations, quarks and anti-quarks carry only about 30% of the total spin of the proton. Twenty years later, the discovery from the polarized hadron collider at RHIC was equally surprising. For the phase space probed by existing RHIC experiments, gluons do not seem to contribute any to the proton's spin. To find out what carries the remaining part of proton's spin is a key focus in current hadronic physics and also a major driving force for the new generation of spin experiments at RHIC and Jefferson Lab and at a future Electron Ion Collider. It is therefore very important and timely to organize a series of annual spin physics meetings to summarize the status of proton spin physics, to focus the effort, and to layout the future perspectives. This summer program on 'Nucleon Spin Physics' held at Brookhaven National Laboratory (BNL) on July 14-27, 2010 [http://www.bnl.gov/spnsp/] is the

  4. RHIC spin physics

    International Nuclear Information System (INIS)

    The physics potential of colliding beams of protons, polarized either longitudinally or transversely, at RHIC is remarkable. A luminosity of L = 2 x 1032 cm-2 sec-1 with 70% polarized beams will be available with up to 250 GeV energy in each beam. The proposal to collide polarized protons in RHIC was submitted in August 1992 and approved in October 1993, just after this workshop. The collaboration has been encouraged to complete R ampersand D on Siberian Snakes, so that RHIC will be able to accelerate polarized protons early in its program. The expected date of the first heavy ion collisions is 1999. The spin physics program includes measurement of gluon and sea quark polarization in the longitudinally polarized proton, measurement and then application of parity violation in W and Z production, measurement of hard scattering parton-parton asymmetries, and quark polarization or transversity in transversely polarized protons. Single spin asymmetries allow sensitive searches for parity violation (longitudinal polarization), and correlations between quark spin and gluons (transverse). Probes include direct photons (to pT = 20 GeV/c), jets (to pT > 50 GeV/c), Drell-Yan pairs (to mll = 9 GeV), W+/-, Z. Here, the collaboration emphasizes the new information included in the Update, given to the Brookhaven PAC this September

  5. An overview of Booster and AGS polarized proton operation during Run 15

    Energy Technology Data Exchange (ETDEWEB)

    Zeno, K. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-10-20

    This note is an overview of the Booster and AGS for the 2015 Polarized Proton RHIC run from an operations perspective. There are some notable differences between this and previous runs. In particular, the polarized source intensity was expected to be, and was, higher this year than in previous RHIC runs. The hope was to make use of this higher input intensity by allowing the beam to be scraped down more in the Booster to provide a brighter and smaller beam for the AGS and RHIC. The RHIC intensity requirements were also higher this run than in previous runs, which caused additional challenges because the AGS polarization and emittance are normally intensity dependent.

  6. Long baseline neutrino oscillation experiment at the AGS. Physics design report

    Energy Technology Data Exchange (ETDEWEB)

    Beavis, D.; Carroll, A.; Chiang, I. [Brookhaven National Lab., Long Island, NY (United States); E889 Collaboration

    1995-04-01

    The authors present a design for a multi-detector long baseline neutrino oscillation experiment at the BNL AGS. It has been approved by the BNL-HENP-PAC as AGS Experiment 889. The experiment will search for oscillations in the {nu}{sub {mu}}, disappearance channel and the {nu}{sub {mu}} {leftrightarrow} {nu}{sub e} appearance channel by means of four identical neutrino detectors located 1, 3, 24, and 68km from the AGS neutrino source. Observed depletion of the {nu}{sub {mu}} flux (via quasi-elastic muon neutrino events, {nu}{sub {mu}}n {yields} {mu}{sup {minus}}p) in the far detectors not attended by an observed proportional increase of the {nu}{sub e} flux (via quasi-elastic electron neutrino events, {nu}{sub e}n {yields} e{sup {minus}}p) in those detectors will be prima facie evidence for the oscillation channel {nu}{sub {mu}} {leftrightarrow} {nu}{sub {tau}}. The experiment is directed toward exploration of the region of the neutrino oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}, suggested by the Kamiokande and IMB deep underground detectors but it will also explore a region more than two orders of magnitude larger than that of previous accelerator experiments. The experiment will run in a mode new to BNL. It will receive the fast extracted proton beam on the neutrino target approximately 20 hours per day when the AGS is not filling RHIC. A key aspect of the experimental design involves placing the detectors 1.5 degrees off the center line of the neutrino beam, which has the important advantage that the central value of the neutrino energy ({approx} 1 GeV) and the beam spectral shape are, to a good approximation, the same in all four detectors. The proposed detectors are massive, imaging, water Cherenkov detectors similar in large part to the Kamiokande and IMB detectors. The design has profited from their decade-long experience, and from the detector designs of the forthcoming SNO and SuperKamiokande detectors.

  7. High-energy high-luminosity electron-ion collider eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, V.N.; Ben-Zvi, I.; Hammons, L.; Hao, Y.; Webb, S.; et al

    2011-08-09

    design of the high-luminosity eRHIC. In it, electrons from the polarized pre-injector will be accelerated to their top energy by passing six times through two SRF linacs. After colliding with the hadron beam in up to three detectors, the e-beam will be decelerated by the same linacs and dumped. The six-pass magnetic system with small-gap magnets will be installed from the start. We will stage the electron energy from 5 GeV to 30 GeV stepwise by increasing the lengths of the SRF linacs. We discuss details of eRHIC's layout in Section 3. We considered several IR designs for eRHIC. The latest one, with a 10 mrad crossing angle and {beta}* = 5 cm, takes advantage of newly commissioned Nb{sub 3}Sn quadrupoles. Section 4 details the eRHIC lattice and the IR layout. The current eRHIC design focuses on electron-hadron collisions. If justified by the EIC physics, we will add a 30 GeV polarized positron ring with full energy injection from eRHIC ERL. This addition to the eRHIC facility provide for positron-hadron collisions, but at a significantly lower luminosity than those attainable in the electron-hadron mode. As a novel high-luminosity EIC, eRHIC faces many technical challenges, such as generating 50 mA of polarized electron current. eRHIC also will employ coherent electron cooling (CeC) for the hadron beams. Staff at BNL, JLab, and MIT is pursuing vigorously an R&D program for resolving addressing these obstacles. In collaboration with Jlab, BNL plans experimentally to demonstrate CeC at the RHIC. We discuss the structure and the status of the eRHIC R&D in Section 5.

  8. RHIC: The World's First High-Energy, Polarized-Proton Collider (423rd Brookhaven Lecture)

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider (RHIC) at BNL has been colliding polarized proton at a beam energy of 100 billion electron volts (GeV) since 2001. In addition to reporting upon the progress of RHIC polarized-proton program, this talk will focus upon the mechanisms that cause the beam to depolarize and the strategies developed to overcome this. As the world first polarized-proton collider, RHIC is designed to collide polarized protons up to an energy of 250 GeV, thereby providing an unique opportunity to measure the contribution made by the gluon to a proton's spin and to study the spin structure of proton. Unlike other high-energy proton colliders, however, the challenge for RHIC is to overcome the mechanisms that cause partial or total loss of beam polarization, which is due to the interaction of the spin vector with the magnetic fields. In RHIC, two Siberian snakes have been used to avoid these spin depolarizing resonances, which are driven by vertical closed-orbit distortion and vertical betatron oscillations. As a result, polarized-proton beams have been accelerated to 100 GeV without polarization loss, although depolarization has been observed during acceleration from 100 GeV to 205 GeV.

  9. Calirimeter/absorber optimization for a RHIC dimuon experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aronson, S.H.; Murtagh, M.J.; Starks, M. [Brookhaven National Lab., Upton, NY (United States); Liu, X.T.; Petitt, G.A.; Zhang, Z. [Georgia State Univ., Atlanta (United States); Ewell, L.A.; Hill, J.C.; Wohn, F.K. [Iowa State Univ., Ames (United States); Costales, J.B.; Namboodiri, M.N., Sangster, T.C.; Thomas, J.H. [Lawrence Livermore National Lab., CA (United States); Gavron, A.; Waters, L. [Los Alamos National Lab., NM (United States); Kehoe, W.L.; Steadman, S.G. [Massachusetts Institute of Technology, Cambridge (United States); Awes, T.C.; Obenshain, F.E.; Saini, S.; Young, G.R. [Oak Ridge National Lab., TN (United States); Chang, J.; Fung, S.Y.; Kang, J.H. [Univ. of California, Riverside, CA (United States); Kreke, J.; He, Xiaochun, Sorensen, S.P. [Univ. of Tennessee, Knoxville (United States); Cornell, E.C.; Maguire, C.F. [Vanderbilt Univ., Nashville, TN (United States)

    1991-12-31

    The RD-10 R&D effort on calorimeter/absorber optimization for a RHIC experiment had an extended run in 1991 using the A2 test beam at the AGS. Measurements were made of the leakage of particles behind various model hadron calorimeters. Behavior of the calorimeter/absorber as a muon-identifier was studied. First comparisons of results from test measurements to calculated results using the GHEISHA code were made

  10. SCIENTIFIC PRESENTATION. 7TH MEETING OF THE MANAGEMENT STEERING COMMITTEE OF THE RIKEN BNL COLLABORATION.

    Energy Technology Data Exchange (ETDEWEB)

    LEE,T.D.

    2001-02-13

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkysho,'' (RIKEN) The Institute of Physical and Chemical Research, of Japan. The Center is dedicated to the study of strong 'interactions, including hard QCD/spin physics, lattice QCD and RHIC (Relativistic Heavy Ion Collider) physics through nurturing of a new generation of young physicists. The Director of RBRC is Professor T. D. Lee. The first years were dedicated to the establishment of a theory group. This has essentially been completed consisting of Fellows, Postdocs, and RHIC Physics/University Fellows, with an active group of consultants. The center also organizes an extensive series of workshops on specific topics in strong interactions with an accompanying series of published proceedings. In addition, a 0.6 teraflop parallel processor computer has been constructed and operational since August 1998. It was awarded the Supercomputer 1998 Gordon Bell Prize for price performance. An active experimental group centered around the spin physics program at RHIC has subsequently also been established at RBRC. It presently consists of five Fellows, one Postdoc and several scientific collaborators with more appointments being expected in the near future. Members and participants of RBRC on occasion will develop articles such as this one, in the nature of a status report or a general review.

  11. SCIENTIFIC PRESENTATION. 7TH MEETING OF THE MANAGEMENT STEERING COMMITTEE OF THE RIKEN BNL COLLABORATION.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T.D.

    2001-02-13

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkysho,'' (RIKEN) The Institute of Physical and Chemical Research, of Japan. The Center is dedicated to the study of strong interactions, including hard QCD/spin physics, lattice QCD and RHIC (Relativistic Heavy Ion Collider) physics through nurturing of a new generation of young physicists. The Director of RBRC is Professor T. D. Lee. The first years were dedicated to the establishment of a theory group. This has essentially been completed consisting of Fellows, Postdocs, and RHIC Physics/University Fellows, with an active group of consultants. The center also organizes an extensive series of workshops on specific topics in strong interactions with an accompanying series of published proceedings. In addition, a 0.6 teraflop parallel processor computer has been constructed and operational since August 1998. It was awarded the Supercomputer 1998 Gordon Bell Prize for price performance. An active experimental group centered around the spin physics program at RHIC has subsequently also been established at RBRC. It presently consists of five Fellows, one Postdoc and several scientific collaborators with more appointments being expected in the near future. Members and participants of RBRC on occasion will develop articles such as this one, in the nature of a status report or a general review.

  12. Proceedings of RIKEN BNL Research Center Workshop: The Physics of W and Z Bosons

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, S.; Okada, K.; Patwa, A.; Qiu, J.; Surrow, B.

    2010-06-24

    A two-day workshop on 'The Physics of Wand Z Bosons' Was held at the RIKEN BNL Research Center at Brookhaven National Laboratory on June 24-25, 2010. With the recent release of the first measurement of W bosons in proton-proton collisions at RHIC and the first observation of W events at the LHC, the workshop was a timely opportunity to bring together experts from both the high energy particle and nuclear physics communities to share their ideas and expertise on the physics of Wand Z bosons, with the aim of fully exploring the potential of the W/Z physics programs at RHIC and the LHC. The focus was on the production and measurement of W/Z bosons in both polarized and unpolarized proton-proton collisions, and the role of W/Z production in probing the parton flavor and helicity structure of the colliding proton and in the search for new physics. There were lively discussions about the potential and future prospects of W/Z programs at RHIC, Tevatron, and the LHC.

  13. RHIC Spin Flipper Commissioning Status

    Energy Technology Data Exchange (ETDEWEB)

    Bai, M.; Meot, F.; Dawson, C.; Oddo, P.; Pai, C.; Pile, P.; Makdisi, Y.; Meng, W.; Roser, T.

    2010-05-23

    The commissioning of the RHIC spin flipper in the RHIC Blue ring during the RHIC polarized proton run in 2009 showed the detrimental effects of global vertical coherent betatron oscillation induced by the 2-AC dipole plus 4-DC dipole configuration. This global orbital coherent oscillation of the RHIC beam in the Blue ring in the presence of collision modulated the beam-beam interaction between the two RHIC beams and affected Yellow beam polarization. The experimental data at injection with different spin tunes by changing the snake current also demonstrated that it was not possible to induce a single isolated spin resonance with the global vertical coherent betatron oscillation excited by the two AC dipoles. Hence, a new design was proposed to eliminate the coherent vertical betatron oscillation outside the spin flipper by adding three additional AC dipoles. This paper presents the experimental results as well as the new design.

  14. Fast Automated Decoupling at RHIC

    CERN Document Server

    Beebe-Wang, Joanne

    2005-01-01

    Coupling correction is essential for the operational performance of RHIC. The independence of the transverse degrees of freedom makes diagnostics and tune control easier, and it is advantageous to operate an accelerator close to the coupling resonance to minimize nearby nonlinear sidebands. An automated decoupling application has been developed at RHIC for coupling correction during routine operations. The application decouples RHIC globally by minimizing the tune separation through finding the optimal settings of two orthogonal skew quadrupole families. The program provides options of automatic, semi-automatic and manual decoupling operations. It accesses tune information from all RHIC tune measurement systems: the PLL (Phase Lock Loop), the high frequency Schottky system, and the tune meter. It also supplies tune and skew quadrupole scans, finding the minimum tune separation, display the real time results and interface with the RHIC control system. We summarize the capabilities of the decoupling application...

  15. EVENT GENERATOR FOR RHIC SPIN PHYSICS-VOLUME 11

    Energy Technology Data Exchange (ETDEWEB)

    SAITO,N.; SCHAEFER,A.

    1998-12-01

    This volume contains the report of the RIKEN BNL Research Center workshop on ''Event Generator for RHIC Spin Physics'' held on September 21-23, 1998 at Brookhaven National Laboratory. A major objective of the workshop was to establish a firm collaboration to develop suitable event generators for the spin physics program at RHIC. With the completion of the Relativistic Heavy Ion Collider (RHIC) as a polarized collider a completely new domain of high-energy spin physics will be opened. The planned studies address the spin structure of the nucleon, tests of the standard model, and transverse spin effects in initial and final states. RHIC offers the unique opportunity to pursue these studies because of its high and variable energy, 50 {le} {radical}s {le} 500 GeV, high polarization, 70%, and high luminosity, 2 x 10{sup 32} cm{sup -2} sec{sup -1} or more at 500 GeV. To maximize the output from the spin program at RHIC, the understanding of both experimental and theoretical systematic errors is crucial. It will require full-fledged event generators, to simulate the processes of interest in great detail. The history of event generators shows that their development and improvement are ongoing processes taking place in parallel to the physics analysis by various experimental groups. The number of processes included in the generators has been increasing and the precision of their predictions has been being improved continuously. Our workshop aims at getting this process well under way for the spin physics program at RHIC, based on the fist development in this direction, SPHINX. The scope of the work includes: (1) update of the currently existing event generator by including the most recent parton parameterizations as a library and reflecting recent progress made for spin-independent generators, (2) implementation of new processes, especially parity violating effects in high energy pp collisions, (3) test of the currently available event generator by

  16. Strangelet Search at RHIC

    CERN Document Server

    Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhasin, A; Bhati, A K; Bhatia, V S; Bichsel, H; Bielcik, J; Bielcikova, J; Billmeier, A; Bland, L C; Blyth, C O; Blyth, S L; Bonner, B E; Botje, M; Boucham, A; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Choi, H A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; De Moura, M M; De Phillips, M; Dedovich, T G; Derevshchikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta-Majumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Fornazier, K S F; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Geurts, F; Ghazikhanian, V; Ghosh, P; González, J E; Gorbunov, Y G; Gos, H; Grachov, O; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guo, Y; Gupta, N; Gutíerrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kowalik, K L; Kravtsov, P; Kravtsov, V I; Krämer, M; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Le Vine, M J; Lebedev, A; Lednicky, R; Lee, C H; Lehocka, S; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; López-Noriega, M; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnik, Yu M; Meschanin, A; Miller, M L; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D; Pruneau, C A; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Reinnarth, J; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Sen-Gupta, A; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimansky, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Sumbera, M; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Szeliga, B; Sørensen, P; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; Van Leeuwen, M; Van der Kolk, N; Van der Molen, A M; Varma, R; Vasilev, A N; Vasilevski, I M; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yoo, I K; Yurevich, V I; Zborovský, I; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2005-01-01

    We report results of the first strangelet search at RHIC. The measurement was done using a triggered data-set that sampled 61 million top 4% most central (head-on) Au+Au collisions at $\\sNN= 200 $GeV in the very forward rapidity region at the STAR detector. Upper limits at a level of a few $10^{-6}$ to $10^{-7}$ per central Au+Au collision are set for strangelets with mass ${}^{>}_{\\sim}30$ GeV/$c^{2}$.

  17. RHIC electron lenses upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Binello, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Costanzo, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Pikin, A. I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Shrey, T. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tan, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  18. Collective dynamics at RHIC

    International Nuclear Information System (INIS)

    The strong collective flow effects, 2> and t>, observed at RHIC (√SNN = 130 GeV) is discussed. It is shown that part of the collectivity could have already developed at partonic stage. To 'see' the partonic effects directly, measurements of multi-strange baryons like Ξ, Ω and charmed particles like J/ψ transverse momentum distributions are important. They provide one of the possible keys to the discovery of collective modes with the partonic (quarks and gluons) degrees of freedom. (author)

  19. Perturbative QCD as a probe of hadron structure: Volume 2. Proceedings of RIKEN BNL Research Center workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The workshop brought together about thirty invited participants from around the world, and an almost equal number of Brookhaven users and staff, to discuss recent developments and future prospects for hadronic strong interaction studies at high energy, particularly relating to the RHIC project at Brookhaven. RIKEN and Brookhaven have long traditions in and commitments to the study of the strong interactions, and the advent of the RHIC collider will open new opportunities both for relativistic heavy ion and polarized proton-proton studies. Activities at the RIKEN BNL Research Center are intended to focus on physics opportunities stimulated by this new facility. Thus, one of the purposes of the center is to provide a forum where workers in the field can gather to share and develop their ideas in a stimulating environment. The purpose of the workshop was both to delineate theoretical problems and stimulate collaborations to address them. The workshop focused primarily, but not exclusively, on spin and small-x physics.

  20. BNL ATF II beamlines design

    International Nuclear Information System (INIS)

    The Brookhaven National Laboratory. Accelerator Test Facility (BNL ATF) is currently undergoing a major upgrade (ATF-II). Together with a new location and much improved facilities, the ATF will see an upgrade in its major capabilities: electron beam energy and quality and CO2 laser power. The electron beam energy will be increased in stages, first to 100-150 MeV followed by a further increase to 500 MeV. Combined with the planned increase in CO2 laser power (from 1-100 TW), the ATF-II will be a powerful tool for Advanced Accelerator research. A high-brightness electron beam, produced by a photocathode gun, will be accelerated and optionally delivered to multiple beamlines. Besides the energy range (up to a possible 500 MeV in the final stage) the electron beam can be tailored to each experiment with options such as: small transverse beam size (<10 um), short bunch length (<100 fsec) and, combined short and small bunch options. This report gives a detailed overview of the ATFII capabilities and beamlines configuration.

  1. BWR stability analyses at BNL

    International Nuclear Information System (INIS)

    The March 9, 1988 instability at the LaSalle County-2 boiling water reactor power plant at Seneca, IL was simulated with Brookhaven National Laboratory's (BNL's) Engineering Plant Analyzer (EPA) for the purpose of demonstrating that the EPA is suitable for simulating large-amplitude, limit-cycle power and flow oscillations. It was shown in fall of 1988, by comparing all the available plant data from the STARTREC recording system of LaSalle-2 with EPA simulation results, that the EPA reproduces the LaSalle-2 oscillations without the use of stabilizing or destabilizing model or parameter modifications. The power vs. flow map of the LaSalle-2 plant was also reproduced at five lines of constant control rod positions. The LaSalle-2 stability boundary was established with the EPA and confirmed within ±15% accuracy by comparing the EPA results with the results of the frequency domain code LAPUR of Oak Ridge National Laboratory. Comparisons of EPA simulation results with plant data from three Peach Bottom stability tests show an agreement, based on mean and standard deviation, of -10±28%, -1±40% and +28±52% (low power) in the gain of the pressure to power transfer functions. This demonstrates that the time domain code HIPA in the EPA is capable of simulating instabilities

  2. BNL ATF II beamlines design

    Energy Technology Data Exchange (ETDEWEB)

    Fedurin, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Jing, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stratakis, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Swinson, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The Brookhaven National Laboratory. Accelerator Test Facility (BNL ATF) is currently undergoing a major upgrade (ATF-II). Together with a new location and much improved facilities, the ATF will see an upgrade in its major capabilities: electron beam energy and quality and CO2 laser power. The electron beam energy will be increased in stages, first to 100-150 MeV followed by a further increase to 500 MeV. Combined with the planned increase in CO2 laser power (from 1-100 TW), the ATF-II will be a powerful tool for Advanced Accelerator research. A high-brightness electron beam, produced by a photocathode gun, will be accelerated and optionally delivered to multiple beamlines. Besides the energy range (up to a possible 500 MeV in the final stage) the electron beam can be tailored to each experiment with options such as: small transverse beam size (<10 um), short bunch length (<100 fsec) and, combined short and small bunch options. This report gives a detailed overview of the ATFII capabilities and beamlines configuration.

  3. ABSOLUTE POLARIMETRY AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.

    2007-09-10

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.

  4. Absolute polarimetry at RHIC

    CERN Document Server

    Okada, H; Bravar, A; Bunce, G; Dhawan, S; Eyser, K O; Gill, R; Haeberli, W; Huang, H; Jinnouchi, O; Makdisi, Y; Nakagawa, I; Nass, A; Saitô, N; Stephenson, E; Sviridia, D; Wise, T; Wood, J; Zelenski, A

    2007-01-01

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy of $\\Delta P_{beam}/P_{beam} < 5%$. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features \\textit{proton-proton} elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power $A_N$ of this process has allowed us to achieve $\\Delta P_{beam}/P_{beam} =4.2%$ in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of $A...

  5. Partonic collectivity at RHIC

    Science.gov (United States)

    Shi, Shusu

    2009-10-01

    The measurement of event anisotropy, often called v2, provides a powerful tool for studying the properties of hot and dense medium created in high-energy nuclear collisions. The important discoveries of partonic collectivity and the brand-new process for hadronization - quark coalescence were obtained through a systematic analysis of the v2 for 200 GeV Au+Au collisions at RHIC [1]. However, early dynamic information might be masked by later hadronic rescatterings. Multistrange hadrons (φ, ξ and φ) with their large mass and presumably small hadronic cross sections should be less sensitive to hadronic rescattering in the later stage of the collisions and therefore a good probe of the early stage of the collision. We will present the measurement of v2 of π, p, KS^0, λ, ξ, φ and φ in heavy ion collisions. In minimum-bias Au+Au collisions at √sNN = 200 GeV, a significant amount of elliptic flow, almost identical to other mesons and baryons, is observed for φ and φ. Experimental observations of pT dependence of v2 of identified particles at RHIC support partonic collectivity. [4pt] [1] B. I. Abelev et al., (STAR Collaboration), Phys. Rev. C 77, 054901 (2008).

  6. Direct Photons at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gabor,D.

    2008-07-29

    Direct photons are ideal tools to investigate kinematical and thermodynamical conditions of heavy ion collisions since they are emitted from all stages of the collision and once produced they leave the interaction region without further modification by the medium. The PHENIX experiment at RHIC has measured direct photon production in p+p and Au+Au collisions at 200 GeV over a wide transverse momentum (p{sub T}) range. The p+p measurements allow a fundamental test of QCD, and serve as a baseline when we try to disentangle more complex mechanisms producing high p{sub T} direct photons in Au+Au. As for thermal photons in Au+Au we overcome the difficulties due to the large background from hadronic decays by measuring 'almost real' virtual photons which appear as low invariant mass e{sup +}e{sup -} pairs: a significant excess of direct photons is measured above the above next-to-leading order perturbative quantum chromodynamics calculations. Additional insights on the origin of direct photons can be gained with the study of the azimuthal anisotropy which benefits from the increased statistics and reaction plane resolution achieved in RHIC Year-7 data.

  7. RHIC spin flipper commissioning results

    Energy Technology Data Exchange (ETDEWEB)

    Bai M.; Roser, T.; Dawson, C.; Kewisch, J.; Makdisi, Y.; Oddo, P.; Pai, C.; Pile, P.

    2012-05-20

    The five AC dipole RHIC spin flipper design in the RHIC Blue ring was first tested during the RHIC 2012 polarized proton operation. The advantage of this design is to eliminate the vertical coherent betatron oscillations outside the spin flipper. The closure of each ac dipole vertical bump was measured with orbital response as well as spin. The effect of the rotating field on the spin motion by the spin flipper was also confirmed by measuring the suppressed resonance at Q{sub s} = 1 - Q{sub osc}.

  8. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP (VOLUME 55) COLLECTIVE FLOW AND QGP PROPERTIES.

    Energy Technology Data Exchange (ETDEWEB)

    BASS,S.ESUMI,S.HEINZ,U.KOLB,P.SHURYAK,E.XU,N.

    2003-11-17

    The first three years of RHIC physics, with Au/Au collisions induced at 65, 130 and 200 GeV per nucleon pair, produced dramatic results, particularly with respect to collective observables such as transverse flow and anisotropies in transverse momentum spectra. It has become clear that the data show very strong rescattering at very early times of the reaction, strong enough in fact to be described by the hydrodynamic limit. Therefore, with today's experiments, we are able to investigate the equation of state of hot quark gluon matter, discuss its thermodynamic properties and relate them to experimental observables. At this workshop we came together to discuss our latest efforts both in the theoretical description of heavy ion collisions as well as most recent experimental results that ultimately allow us to extract information on the properties of RHIC matter. About 50 participants registered for the workshop, but many more dropped in from the offices at BNL. The workshop lasted for three days, of which each day was assigned a special topic on which the talks focused. On the first day we dealt with the more general question what the strong collective phenomena observed in RHIC collisions tell us about the properties and the dynamics of RHIC matter. The second day covered all different aspects of momentum anisotropies, and interesting new experimental results were presented for the first time. On the third day, we focused on the late fireball dynamics and the breakdown of the assumption of thermalization. New experimental observables were discussed, which will deliver more information of how the expanding fireball breaks up, once the frequent interaction ceases.

  9. The AGS CNI polarimeter

    International Nuclear Information System (INIS)

    A new polarimeter is being installed in the Brookhaven AGS, based on the successful proton-carbon polarimeters in RHIC. The polarimeter will measure the left-right asymmetry for proton-carbon elastic scattering in the Coulomb-nuclear interference (CNI) region, for vertically polarized protons in the AGS. The polarimeter offers a much higher figure of merit than the existing AGS polarimeter which is based on larger angle proton-proton elastic scattering. We expect to measure the polarization in the AGS with a single or a few acceleration cycles. We also plan to measure the polarization in 2 ms bins during the AGS acceleration ramp. Multiple ramps will be necessary, probably over 30 minutes to an hour

  10. POLARIZED PROTON COLLISIONS AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; ET AL.

    2005-05-16

    The Relativistic Heavy Ion Collider provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC. In 2002, polarized proton beams were first accelerated to 100 GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. Optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limited conditions are reported.

  11. The RHIC gold rush

    CERN Document Server

    Schäfer, T

    2003-01-01

    Physicists are colliding gold nuclei to recreate the fireball that existed in the very early universe, and they may have found evidence for quark-gluon plasma. What happens to ordinary matter as you heat it to higher and higher temperatures, or compress it to greater and greater densities? This simple question underpins a major effort to create extreme conditions in the lab, which has recently taken the shape of the Relativistic Heavy Ion Collider (RHIC). This machine has been colliding gold nuclei since 2000, and has produced tantalizing hints that a new state of matter - the quark-gluon plasma - is created in the reactions. But it has also sparked surprises that are sending researchers back to the drawing board. (U.K.)

  12. Reconstructed Jets at RHIC

    CERN Document Server

    Salur, Sevil

    2010-01-01

    To precisely measure jets over a large background such as pile up in high luminosity p+p collisions at LHC, a new generation of jet reconstruction algorithms is developed. These algorithms are also applicable to reconstruct jets in the heavy ion environment where large event multiplicities are produced. Energy loss in the medium created in heavy ion collisions are already observed indirectly via inclusive hadron distributions and di-hadron correlations. Jets can be used to study this energy loss in detail with reduced biases. We review the latest results on jet-medium interactions as seen in A+A collisions at RHIC, focusing on the recent progress on jet reconstruction in heavy ion collisions.

  13. The Forward GEM Tracker of STAR at RHIC

    CERN Document Server

    Simon, F; Fatemi, R; Hasell, D; Kelsey, J; Majka, R; Page, B; Plesko, M; Underwood, D; Smirnov, N; Sowinski, J; Spinka, H; Surrow, B; Visser, G

    2008-01-01

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is in the process of designing and constructing a forward tracking system based on triple GEM technology. This upgrade is necessary to give STAR the capability to reconstruct and identify the charge sign of W bosons over an extended rapidity range through their leptonic decay mode into an electron (positron) and a neutrino. This will allow a detailed study of the flavor-separated spin structure of the proton in polarized p + p collisions uniquely available at RHIC. The Forward GEM Tracker FGT will consist of six triple GEM disks with an outer radius of ~39 cm and an inner radius of ~10.5 cm, arranged along the beam pipe, covering the pseudo-rapidity range from 1.0 to 2.0 over a wide range of collision vertices. The GEM foils will be produced by Tech-Etch, Inc. Beam tests with test detectors using 10 cm x 10 cm Tech-Etch GEM foils and a two dimensional orthogonal strip readout have demonstrated a spatial r...

  14. Performance on the low charge state laser ion source in BNL

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, M.; Alessi, J.; Beebe, E.; Costanzo, M.; DeSanto, L.; Jamilkowski, J.; Kanesue, T.; Lambiase, R.; Lehn, D.; Liaw, C. J.; McCafferty, D.; Morris, J.; Olsen, R.; Pikin, A.; Raparia, D.; Steszyn, A.; Ikeda, S.

    2015-09-07

    On March 2014, a Laser Ion Source (LIS) was commissioned which delivers high-brightness, low-charge-state heavy ions for the hadron accelerator complex in Brookhaven National Laboratory (BNL). Since then, the LIS has provided many heavy ion species successfully. The low-charge-state (mostly singly charged) beams are injected to the Electron Beam Ion Source (EBIS), where ions are then highly ionized to fit to the following accelerator’s Q/M acceptance, like Au32+. Recently we upgraded the LIS to be able to provide two different beams into EBIS on a pulse-to-pulse basis. Now the LIS is simultaneously providing beams for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL).

  15. Performance of the RHIC Injection Line Instrumentation Systems

    Science.gov (United States)

    Shea, T. J.; Witkover, R. L.; Cameron, P.; Connolly, R.; Ryan, W. A.; Smith, G.; Zitvogel, E.

    1997-05-01

    The beam injection line from the Alternating Gradient Synchrotron (AGS) to the Relativistic Heavy Ion Collider (RHIC) transports proton and heavy ion bunches. This line and the RHIC first sextant currently contain thefollowing complement of beam instrumentation: stripline position monitors, ionization loss monitors, video profile monitors, and commercial current transformers. Over several years, these systems have been designed and bench tested to assure a desired performance level. The design criteria will be briefly reviewed. Then, using data from laboratory tests and the recent single pass beam tests, desired performance and attained performance will be compared. Finally, experience from the beam based tests will be applied to the design criteria for the future collider ring instrumentation.

  16. 2013 BNL Site Environmental Report. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Ratel, K.; Remien, J.; Pohlot, P.; Williams, J.; Green, T.; Paquette, P.; Dorsch, W.; Welty, T.; Burke, J.

    2014-10-01

    A summary of Brookhaven National Laboratory’s (BNL) Site Environmental Report, meant to inform the public, regulators, employees, and other stakeholders of the Laboratory’s environmental performance in the lab’s surrounding area during the calendar year. The review is comprised of multiple volumes relevant to environmental data/environmental management performance and groundwater status report.

  17. RESEARCH PLAN FOR SPIN PHYSICS AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    AIDALA, C.; BUNCE, G.; ET AL.

    2005-02-01

    In this report we present the research plan for the RHIC spin program. The report covers (1) the science of the RHIC spin program in a world-wide context; (2) the collider performance requirements for the RHIC spin program; (3) the detector upgrades required, including timelines; (4) time evolution of the spin program.

  18. Configuration Manual Polarized Proton Collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S. Y.; Luccio, A.; MacKay, W. W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Svirida, D.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.

    2006-01-01

    In this report we present our design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. We provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  19. CONFIGURATION MANUAL POLARIZED PROTON COLLIDER AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    ROSER,T.; MACKAY,W.W.; ALEKSEEV,I.; BAI,M.; BROWN,K.; BUNCE,G.; CAMERON,P.; COURANT,E.; ET AL.

    2001-03-01

    In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  20. What hath RHIC wrought?

    CERN Document Server

    Brown, G E; Rho, M; Rho, Mannque

    2006-01-01

    The new form of matter found just above Tc by RHIC is made up of tightly bound quark-antiquark pairs, essentially 32 chirally restored (zero-mass) mesons pi, sigma, rho and a1. Taking the results of lattice gauge simulations (LGS) for the color Coulomb potential from the work of the Bielefeld group and feeding this into a relativistic two-body code, after modifying the heavy-quark lattice results so as to include the velocity-velocity interaction, all ground-state eigenvalues of the 32 mesons go to zero at Tc just as they do from below Tc as dictated by Brown-Rho scaling. This produces the rapid rise in entropy up to Tc found in LGS calculations. As the scale 4 pi f_pi ~ 1 GeV for chiral symmetry breaking is replaced at Tc by the zero mass of the chirally restored meson, the QCD Coulomb coupling moves far toward the infrared, producing an effective coupling of g ~ 8 just above Tc. Exactly how the dynamics work can be understood from the behavior of the hard and soft glue.

  1. Spin physics at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Tannenbaum, M.J.

    1996-09-06

    Operation of RHIC with two beams of highly polarized protons (70%, either longitudinal or transverse) at high luminosity L = 2 x 10{sup 32} cm{sup -2} sec{sup -1} for two months/year will allow the STAR and PHENIX detectors to perform high statististics studies of polarization phenomena in the perturbative region of hard scattering where both QCD and ElectroWeak theory make detailed predictions for polarization effects. The collision c.m. energy, {radical}s = 200 - 500 GeV, represents a new domain for the study of spin. Direct photon production will be used to measure the gluon polarization in the polarized proton. A new twist comes from W-boson production which is expected to be 100% parity violating and will thus allow measurements of flavor separated Quark and antiquark (u, {bar u}, d, {bar d}) polarization distributions. Searches for parity violation in strong interaction processes such as jet and leading particle production will be a sensitive way to look for new physics beyond the standard model, one possibility being quark substructure.

  2. NEUTRINO SUPER BEAM FACILITY FOR A LONG BASELINE EXPERIMENT FROM BNL TO HOMESTAKE.

    Energy Technology Data Exchange (ETDEWEB)

    KAHN,S.

    2002-10-21

    An upgrade to the BNL Alternate Gradient Synchrotron (AGS) could produce a very intense proton source at a relatively low cost. Such a proton beam could be used to generate a conventional neutrino beam with a significant flux at large distances from the laboratory. This provides the possibility of a very long baseline neutrino experiment at the Homestake mine. The construction of this facility would allow a program of experiments to study many of the aspects of neutrino oscillations including CP violations. This study examines a 1 MW proton source at BNL and a large 1 megaton detector positioned at the Homestake Mine as the ultimate goal of a staged program to study neutrino oscillations.

  3. High density matter at RHIC

    Indian Academy of Sciences (India)

    Thomas S Ullrich

    2004-02-01

    QCD predicts a phase transition between hadronic matter and a quark-gluon plasma at high energy density. The relativistic heavy ion collider (RHIC) at Brookhaven National Laboratory is a new facility dedicated to the experimental study of matter under extreme conditions. Already the first round of experimental results at RHIC indicated that the conditions to create a new state of matter are indeed reached in the collisions of heavy nuclei. Studies of particle spectra and their correlations at low transverse momenta provide evidence of strong pressure gradients in the highly interacting dense medium and hint that we observe a system in thermal equilibrium. Recent runs with high statistics allow us to explore the regime of hard-scattering processes where the suppression of hadrons at large transverse momentum, and quenching of di-jets are observed thus providing further evidence for extreme high density matter created in collisions at RHIC.

  4. Tracking algorithms in ultrarelativistic nuclear experiments applied at BRAHMS - RHIC (BNL)

    International Nuclear Information System (INIS)

    Considering the experimental results obtained in one of the major experiments at the Relativistic Heavy Ion Collider from Brookhaven National Laboratory - Upton, New York, USA - namely BRAHMS (Broad Range Hadron Magnetic Spectrometers) Experiment - which studies Au + Au collisions at 200 GeV/n (center of mass system), we study the collision geometry implications upon the experimental yields. Making use of the two spectrometers from BRAHMS - providing very accurate angular distributions - we find out the importance of vertex determination on the physical event reconstruction and on the centrality cuts. The vertex problem is of major importance in collider physics, showing wide distributions. In this analysis of the experimental data are used three groups of detectors, namely: the Beam - Beam Counters and the Zero Degree Calorimeters, providing vertex measurements by time-of-flight right-left methods, and the time projection chambers that reconstruct the vertex by the back-projection of the produced clusters. The methods used are presented and a qualitative comparison between the experimental data from Au + Au collisions at 130 GeV and 200 GeV energies is made. Finally, we present the main problems regarding the track reconstruction and also some visualization algorithms from peculiar tracking detectors from BRAHMS. (authors)

  5. Conceptual design of the Relativistic Heavy Ion Collider: RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Samios, Nicholas P.

    1986-05-01

    The complete Relativistic Heavy Ion Collider (RHIC) facility will be a complex set of accelerators and beam transfer equipment connecting them. A significant portion of the total facility either exists or is under construction. Two existing Tandem Van de Graaff accelerators will serve for the initial ion acceleration. Ions with a charge of -1 would be accelerated from ground to +15 MV potential, pass through a stripping foil, and accelerate back to ground potential, where they would pass through a second stripping foil. From there the ions will traverse a long transfer line to the AGS tunnel and be injected into the Booster accelerator. The Booster accelerates the ion bunch, and then the ions pass through one more stripper and then enter the Alternating Gradient Synchrotron (AGS), where they are accelerated to the top AGS energy and transferred to the collider. Bending and focusing of ion beams is to be achieved by superconducting magnets. The physics goals behind the RHIC are enumerated, particularly as regards the study of quark matter and the characteristics of high energy nucleus-nucleus collisions. The design of the collider and all its components is described, including the injector, the lattice, magnet system, cryogenic and vacuum systems, beam transfer, injection, and dump, rf system, and beam instrumentation and control system. Also given are cost estimates, construction schedules, and a management plan. (LEW)

  6. Conceptual design of the Relativistic Heavy Ion Collider: RHIC

    International Nuclear Information System (INIS)

    The complete Relativistic Heavy Ion Collider (RHIC) facility will be a complex set of accelerators and beam transfer equipment connecting them. A significant portion of the total facility either exists or is under construction. Two existing Tandem Van de Graaff accelerators will serve for the initial ion acceleration. Ions with a charge of -1 would be accelerated from ground to +15 MV potential, pass through a stripping foil, and accelerate back to ground potential, where they would pass through a second stripping foil. From there the ions will traverse a long transfer line to the AGS tunnel and be injected into the Booster accelerator. The Booster accelerates the ion bunch, and then the ions pass through one more stripper and then enter the Alternating Gradient Synchrotron (AGS), where they are accelerated to the top AGS energy and transferred to the collider. Bending and focusing of ion beams is to be achieved by superconducting magnets. The physics goals behind the RHIC are enumerated, particularly as regards the study of quark matter and the characteristics of high energy nucleus-nucleus collisions. The design of the collider and all its components is described, including the injector, the lattice, magnet system, cryogenic and vacuum systems, beam transfer, injection, and dump, rf system, and beam instrumentation and control system. Also given are cost estimates, construction schedules, and a management plan

  7. PHENIX Spinfest School 2009 at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Foster,S.P.; Foster,S.; Seidl, R.; Goto, Y.; Okada, K.

    2009-08-07

    Since 2005, the PHENIX Spin Physics Working Group has set aside several weeks each summer for the purposes of training and integrating recent members of the working group as well as coordinating and making rapid progress on support tasks and data analysis. One week is dedicated to more formal didactic lectures by outside speakers. The location has so far alternated between BNL and the RIKEN campus in Wako, Japan, with support provided by RBRC and LANL.

  8. BNL ENVIRONMENTAL MONITORING PLAN TRIENNIAL UPDATE, JANUARY 2003.

    Energy Technology Data Exchange (ETDEWEB)

    BROOKHAVEN NATIONAL LABORATORY

    2003-01-01

    Brookhaven National Laboratory (BNL) is a multi-program national laboratory operated by Brookhaven Science Associates for the U.S. Department of Energy (DOE) and is located on a 5,265-acre site in Suffolk County, Long Island, New York. BNL has a comprehensive Environmental Management System (EMS) in place, which meets the requirements of the International Organization for Standardization 14001 EMS Standard, as described in the BNL EMS Manual. BNL's extensive environmental monitoring program is one component of the EMS, and the BNL Environmental Monitoring Plan (EMP) describes this program in detail. The data derived from systematically monitoring the various environmental media on site enable BNL to make informed decisions concerning the protection of human health and the environment and to be responsive to community concerns.

  9. Target and orbit feedback simulations of a muSR beamline at BNL

    Energy Technology Data Exchange (ETDEWEB)

    MacKay, W. W. [Residence, 25 Rhododendron Circle, Asheville, NC (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pile, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    Well-polarized positive surface muons are a tool to measure the magnetic properties of materials since the precession rate of the spin can be determined from the observation of the positron directions when the muons decay. The use of the AGS complex at BNL has been explored for a muSR facility previously. Here we report simulations of a beamline with a target inside a solenoidal field, and of an orbit feed-back system with single muon beam positioning monitors based on technology available today

  10. First polarized proton collision at a beam energy of 250 GeV in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Bai,M.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; et al.

    2009-05-04

    After providing collisions of polarized protons at a beam energy of 100 GeV since 2001, the Relativistic Heavy Ion Collider (RHIC) at BNL had its first opportunity to collide polarized protons at its maximum beam energy of 250 GeV in the 2009 polarized proton operations. Equipped with two full Siberian snakes [1] in each ring, RHIC preserves polarization during acceleration from injection to 100 GeV with precise control of the betatron tunes and vertical orbit distortions. However, the strong intrinsic spin resonances beyond 100 GeV are more than two times stronger than those below 100 GeV, requiring much tighter tolerances on vertical orbit distortions and betatron tunes. With the currently achieved orbit correction and tune control, average polarizations of {approx_equal} 42% at top energy and average polarizations of {approx_equal} 55% at injection energy were achieved. Polarization measurements as a function of beam energy also indicated aU polarization losses occurred around three strong intrinsic resonances at 136 GeV, 199.3 GeV and 220.8 GeV Peak luminosity of 122 x 10{sup 30} cm{sup -2} s{sup -1} was also demonstrated. This paper presents the performance of the first RHIC 250 GeV operation and discusses the depolarization issues encountered during the run.

  11. Novel deflecting cavity design for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q.; Belomestnykh, S.; Ben-Zvi, I.

    2011-07-25

    To prevent significant loss of the luminosity due to large crossing angle in the future ERL based Electron Ion Collider at BNL (eRHIC), there is a demand for crab cavities. In this article, we will present a novel design of the deflecting/crabbing 181 MHz superconducting RF cavity that will fulfil the requirements of eRHIC. The quarter-wave resonator structure of the new cavity possesses many advantages, such as compact size, high R{sub t}/Q, the absence of the same order mode and lower order mode, and easy higher order mode damping. We will present the properties and characteristics of the new cavity in detail. As the accelerator systems grow in complexity, developing compact and efficient deflecting cavities is of great interest. Such cavities will benefit situations where the beam line space is limited. The future linac-ring type electron-ion collider requires implementation of a crab-crossing scheme for both beams at the interaction region. The ion beam has a long bunches and high rigidity. Therefore, it requires a low frequency, large kicking angle deflector. The frequency of the deflecting mode for the current collider design is 181 MHz, and the deflecting angle is {approx}5 mrad for each beam. At such low frequency, the previous designs of the crab cavities will have very large dimensions, and also will be confronted by typical problems of damping the Lower Order Mode (LOM), the Same Order Mode (SOM), and as usual, the Higher Order Modes (HOM). In this paper we describe how one can use the concept of a quarter-wave (QW) resonator for a deflecting/crabbing cavity, and use its fundamental mode to deflect the beam. The simplicity of the cavity geometry and the large separation between its fundamental mode and the first HOM make it very attractive.

  12. Beam emittance measurements in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Zelenski,A.; Bazilevsky, A.; Bunce, G.; Gill, R.; Huang, H.; Makdisi, Y.; Morozov, B.; Nemesure, S.; Russo, t.; Steski, D.; Sivertz, M.

    2009-05-04

    The RHIC proton polarimeters can operate in scanning mode, giving polarization profiles and transverse beam intensity profile (beam emittance) measurements. The polarimeters function as wire scanners, providing a very good signal/noise ratio and high counting rate. This allows accurate bunch-by-bunch emittance measurements during fast target sweeps (<1 s) through the beam. Very thin carbon strip targets make these measurements practically non-destructive. Bunch by bunch emittance measurements are a powerful tool for machine set-up; in RHIC, individual proton beam transverse emittances can only be measured by CNI polarimeter scans. We discuss the consistency of these measurements with Ionization Profile Monitors (IPMs) and vernier scan luminosity measurements. Absolute accuracy limitations and cross-calibration of different techniques are also discussed.

  13. High intensity protons in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.; Ahrens, L.; Blaskiewicz, M.; Brennan, J. M.; Drees, K. A.; Fischer, W.; Huang, H.; Minty, M.; Robert-Demolaize, G.; Thieberger, P.; Yip, K.

    2012-01-05

    During the 2012 summer shutdown a pair of electron lenses will be installed in RHIC, allowing the beam-beam parameter to be increased by roughly 50 percent. To realize the corresponding luminosity increase bunch intensities have to be increased by 50 percent, to 2.5 {center_dot} 10{sup 11} protons per bunch. We list the various RHIC subsystems that are most affected by this increase, and propose beam studies to ensure their readiness. The proton luminosity in RHIC is presently limited by the beam-beam effect. To overcome this limitation, electron lenses will be installed in IR10. With the help of these devices, the headon beam-beam kick experienced during proton-proton collisions will be partially compensated, allowing for a larger beam-beam tuneshift at these collision points, and therefore increasing the luminosity. This will be accomplished by increasing the proton bunch intensity from the presently achieved 1.65 {center_dot} 10{sup 11} protons per bunch in 109 bunches per beam to 2.5 {center_dot} 10{sup 11}, thus roughly doubling the luminosity. In a further upgrade we aim for bunch intensities up to 3 {center_dot} 10{sup 11} protons per bunch. With RHIC originally being designed for a bunch intensity of 1 {center_dot} 10{sup 11} protons per bunch in 56 bunches, this six-fold increase in the total beam intensity by far exceeds the design parameters of the machine, and therefore potentially of its subsystems. In this note, we present a list of major subsystems that are of potential concern regarding this intensity upgrade, show their demonstrated performance at present intensities, and propose measures and beam experiments to study their readiness for the projected future intensities.

  14. Monolithic readout circuits for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    O`Connor, P.; Harder, J. [Brookhaven National Laboratory, Upton, NY (United States)

    1991-12-31

    Several CMOS ASICs have been developed for a proposed RHIC experiment. This paper discusses why ASIC implementation was chosen for certain functions, circuit specifications and the design techniques used to meet them, and results of simulations and early prototypes. By working closely together from an early stage in the planning process, in-house ASIC designers and detector and data acquisition experimenters can achieve optimal use of this important technology.

  15. RHIC and its upgrade programmes.

    Energy Technology Data Exchange (ETDEWEB)

    Roser,T.

    2008-06-23

    As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species. After a brief review of the achieved performance the presentation will give an overview of the plans, challenges and status of machine upgrades, that range from a new heavy ion pre-injector and beam cooling at 100 GeV to a high luminosity electron-ion collider.

  16. VIBRATION MEASUREMENTS IN A RHIC QUADRUPOLE AT CRYOGENIC TEMPERATURES.

    Energy Technology Data Exchange (ETDEWEB)

    JAIN, A.; AYDIN, S.; HE, P.; ANERELLA, M.; GANETIS, G.; HARRISON, M.; PARKER, B.; PLATE, S.

    2005-10-17

    One of the concerns in using compact superconducting magnets in the final focus region of the ILC is the influence of the cryogen flow on the vibration characteristics. As a first step towards characterizing such motion at nanometer levels, a project was undertaken at BNL to measure the vibrations in a spare RHIC quadrupole under cryogenic conditions. Given the constraints of cryogenic operation, and limited space available, it was decided to use a dual head laser Doppler vibrometer for this work. The performance of the laser vibrometer was tested in a series of room temperature tests and compared with results from Mark L4 geophones. The laser system was then used to measure the vibration of the cold mass of the quadrupole with respect to the outside warm enclosure. These measurements were carried out both with and without the flow of cold helium through the magnet. The results indicate only a minor increase in motion in the horizontal direction (where the cold mass is relatively free to move).

  17. Proceedings of RIKEN BNL Research Center Workshop: Thermal Photons and Dileptons in Heavy-Ion Collisions. Volume 119

    Energy Technology Data Exchange (ETDEWEB)

    David, G. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Rapp, R. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Ruan, L. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Yee, H-U. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2014-09-11

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkyusho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan and the U. S. Department of Energy’s Office of Science. The RBRC is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has theory, lattice gauge computing and experimental components. It is presently exploring the possibility of an astrophysics component being added to the program. The primary theme for this workshop related to sharing the latest experimental and theoretical developments in area of low transverse momentum (pT) dielectron and photons. All the presentations given at the workshop are included in this proceedings, primarily as PowerPoint presentations.

  18. Proposal for Reduction of Transverse Emittance of BNL 200 MeV Linac

    CERN Document Server

    Alessi, J; Raparia, D; Weng, W T

    2004-01-01

    BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW and beyond for such a neutrino facility which consists of two major subsystems. First is a 1.2 GeV super-conducting linac (SCL) to replace the booster as injector for the AGS. Second is the performance upgrade for the AGS itself for the higher intensity and repetition rate. For high intensity proton accelerators, such as the upgraded AGS, there are very stringent limitations on uncontrolled beam losses. A direct effect of linac beam emittance is the halo/tail generation in the circulating beam. Studies show the estimated halo/tail generation in the beam for present normalized RMS emittance of linac beam is unacceptable. To reduce the transverse emittance of 200 MeV linac, the existing radio frequency quadrupole linac (RFQ) has to be relocated closer to drift tube linac (DTL) tank 1 to meet emittance requirement for the AGS injection with low loss. This paper will present the various options of matching between RFQ and DTL,...

  19. Production of Quarkonia at RHIC

    CERN Document Server

    Vertesi, Robert

    2015-01-01

    The production of different quarkonium states provides unique insight to the hot and cold nuclear matter effects in the strongly interacting medium that is formed in high energy heavy ion collisions. While LHC explores the energy frontier, RHIC has a broad physics program to explore the nuclear modification at different energies in a wide range of systems. Some of the most interesting recent results on $J/\\psi$ and $\\Upsilon$ production in p+p, d+Au and A+A collisions from PHENIX and STAR are summarized in this work.

  20. Unruh gamma radiation at RHIC?

    CERN Document Server

    Biro, T S; Schram, Z

    2011-01-01

    Varying the proposition that acceleration itself would simulate a thermal environment, we investigate the semiclassical photon radiation as a possible telemetric thermometer of accelerated charges. Based on the classical Jackson formula we obtain the equivalent photon intensity spectrum stemming from a constantly accelerated charge and demonstrate its resemblances to a thermal distribution for high transverse momenta. The inverse transverse slope differs from the famous Unruh temperature: it is larger by a factor of pi. We compare the resulting direct photon spectrum with experimental data for AuAu collisions at RHIC and speculate about further, analytically solvable acceleration histories.

  1. A description of the pseudorapidity distributions in heavy ion collisions at RHIC and LHC energies

    CERN Document Server

    Jiang, Z J; Zhang, H L; Deng, H P

    2015-01-01

    The charged particles produced in nucleus-nucleus collisions are classified into two parts,One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand and generate particles according to BJP hydrodynamics, a theory put forward by A. Bialas, R. A. Janik and R. Peschanski. The leading particles are argued to possess a Gaussian rapidity distribution with the normalization constant equaling the number of participants. A comparison is made between the theoretical results and the experimental measurements performed by BRAHMS and PHOBOS Collaboration at BNL-RHIC in Au-Au and Cu-Cu collisions at sqrt(s_NN)=200 GeV and by ALICE Collaboration at CERN-LHC in Pb-Pb collisions at sqrt(s_NN) =2.76 TeV. The theoretical results are well consistent with experimental data.

  2. A description of the pseudorapidity distributions in heavy ion collisions at RHIC and LHC energies

    Science.gov (United States)

    Jiang, Z. J.; Zhang, Y.; Zhang, H. L.; Deng, H. P.

    2015-09-01

    The charged particles produced in nucleus-nucleus collisions are classified into two parts: One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand and generate particles according to BJP hydrodynamics, a theory put forward by A. Bialas, R.A. Janik and R. Peschanski. The leading particles are argued to possess a Gaussian rapidity distribution with the normalization constant equaling the number of participants. A comparison is made between the theoretical results and the experimental measurements performed by BRAHMS and PHOBOS Collaborations at BNL-RHIC in Au-Au and Cu-Cu collisions at √{sNN} = 200 GeV and by ALICE Collaboration at CERN-LHC in Pb-Pb collisions at √{sNN} = 2.76 TeV. The theoretical results are well consistent with experimental data.

  3. Proceedings of RIKEN BNL Research Center Workshop: The Approach to Equilibrium in Strongly Interacting Matter. Volume 118

    Energy Technology Data Exchange (ETDEWEB)

    Liao, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Venugopalan, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berges, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaizot, J. -P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gelis, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-04-09

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory*. It is funded by the ''Rikagaku Kenkyusho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan and the U. S. Department of Energy’s Office of Science. The RBRC is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has theory, lattice gauge computing and experimental components. It is presently exploring the possibility of an astrophysics component being added to the program. The purpose of this Workshop is to critically review the recent progress on the theory and phenomenology of early time dynamics in relativistic heavy ion collisions from RHIC to LHC energies, to examine the various approaches on thermalization and existing issues, and to formulate new research efforts for the future. Topics slated to be covered include Experimental evidence for equilibration/isotropization, comparison of various approaches, dependence on the initial conditions and couplings, and turbulent cascades and Bose-Einstein condensation.

  4. Emergency response training with the BNL plant analyzer

    International Nuclear Information System (INIS)

    Presented in the experience in the use of the BNL plant analyzer for NRC emergency response training to simulated accidents in a BWR. The unique features of the BNL Plant Analyzer that are important for the emergency response training are summarized. A closed-loop simulation of all the key systems of a power plant in question was found essential to the realism of the emergency drills conducted at NRC. The faster than real-time simulation speeds afforded by the BNL Plant Analyzer have demonstrated its usefulness for the timely conduct of the emergency response training

  5. Transverse mode coupling in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Raka, E.

    1990-02-21

    In the Proceedings of the Workshop on the RHIC Performance, it was stated that the transverse mode coupling instability, posed a potential intensity limitation for protons. This was based on the expression I{sub b} = 4(E{sub t}/qe) Q{sub s} 4 {radical}{pi} {sigma} {ell}/(Im (Z{sub {perpendicular}}) < {beta}{sub {perpendicular}} > R 3) where E{sub t} is the total energy, q the charge state, Q{sub s} the synchrotron tune, < {beta}{sub {perpendicular}} > the average beta function, R the machine radius, and {sigma}{sub {ell}} the rms bunch length of a Gaussian distribution in longitudinal phase space. For a < {beta}{sub {perpendicular}} > of 55 m and 10{sup 11} protons/bunch, the allowed impedance Z{sub {perpendicular}} for protons at injection, where Q{sub s} = 0.11 {times} 10{sup {minus}3}, would be less than 1.2 M{Omega}/m. The purpose of this report is to discuss the consequences of two factors that were omitted in this equation, which comes from the ZAP program, to RHIC. These are the space charge impedance and the incoherent tune spread of the beam.

  6. MULTIPLE SINGLE BUNCH EXTRACTION TO THE AGS SWITCHYARD

    International Nuclear Information System (INIS)

    In this report we will describe the multiple single bunch extraction system as utilized to deliver beams to the Brookhaven's Alternating Gradient Synchrotron (AGS) switchyard area. We will describe modifications of the AGS switchyard, necessary to allow it to accept bunched beam, and results of the first commissioning of this system. The AGS Switchyard has for many years been used to simultaneously deliver (unbunched) resonant extracted beam to a set of fixed target experiments. In order to accommodate new fixed target experiments which require bunched beams, a method of sending the bunched beams to the AGS Switchyard was required. In addition, by using the AGS switchyard instead of the upstream section of the Brookhaven's Relativistic Heavy Ion Collider (RHIC) injection line the accelerators can be reconfigured quickly and efficiently for filling RHIC. We will present results of the commissioning of this system, which was done in January 2001

  7. A FLYING WIRE SYSTEM IN THE AGS.

    Energy Technology Data Exchange (ETDEWEB)

    HUANG,H.; BUXTON,W.; MAHLER,G.; MARUSIC,A.; ROSER,T.; SMITH,G.; SYPHERS,M.; WILLIAMS,N.; WITKOVER,R.

    1999-03-29

    As the AGS prepares to serve as the injector for RHIC, monitoring and control of the beam transverse emittance become a major and important topic. Before the installation of the flying wire system, the emittance was measured with ionization profile monitors in the AGS, which require correction for space charge effects. It is desirable to have a second means of measuring profile that is less depend on intensity. A flying wire system has been installed in the AGS recently to perform this task. This paper discusses the hardware and software setup and the capabilities of the system.

  8. RHIC OPERATION WITH LONGITUDINALLY POLARIZED PROTONS.

    Energy Technology Data Exchange (ETDEWEB)

    HUANG,H.BAI,M.BEEBE-WANG,J.ET AL.

    2004-07-05

    Polarized proton beams have been accelerated, stored and collided at 100GeV per beam in the Relativistic Heavy Ion Collider (RHIC) with longitudinal polarization. The essential equipment includes four Siberian snakes, eight spin rotators and fast relative polarimeters in each of the two RHIC rings as well as local polarimeters at the STAR and PHENIX detectors. This paper summarizes the performance of RHIC as a polarized proton collider in the FY03 run with emphasis on polarization issues. Preliminary data from the FY04 run is also shown.

  9. THE RHIC HYDROGEN JET LUMINESCENCE MONITOR.

    Energy Technology Data Exchange (ETDEWEB)

    RUSSO,T.; BELLAVIA, S.; GASSNER, D.; THIEBERGER, P.; TRBOJEVIC, D.; TSANG, T.

    2007-06-25

    A hydrogen jet polarimeter was developed for the RHIC accelerator to improve the process of measuring polarization. Particle beams intersecting with gas molecules can produce light by the process known as luminescence. This light can then be focused, collected, and processed giving important information such as size, position, emittance, motion, and other parameters. The RHIC hydrogen jet polarimeter was modified in 2005 with specialized optics, vacuum windows, light transport, and a new camera system making it possible to monitor the luminescence produced by polarized protons intersecting the hydrogen beam. This paper describes the configuration and preliminary measurements taken using the RHIC hydrogen jet polarimeter as a luminescence monitor.

  10. PHENIX EXPERIMENT AT RHIC: DECADAL PLAN 2004-2013

    Energy Technology Data Exchange (ETDEWEB)

    ZAJC,W.ET. AL.

    2003-11-30

    program is achievable using the present capabilities of PHENIX experimental apparatus, but the physics reach is considerably extended and the program made even more compelling by a proposed set of upgrades which include: (1) An aerogel and time-of-flight system to provide complete {pi}/K/p separation for momenta up to 10 GeV/c. (2) A vertex detector to detect displaced vertices from the decay of mesons containing charm or bottom quarks. (3) A hadron-blind detector to detect and track electrons near the vertex. (4) A micro-TPC to extend the range of PHENIX tracking in azimuth and pseudo-rapidity. (5) A forward detector upgrade for an improved muon trigger to preserve sensitivity at the highest projected RHIC luminosities. (6) A forward calorimeter to provide photon+jet studies over a wide kinematic range. The success of the proposed program is contingent upon several factors external to PHENIX. Implementation of the upgrades is predicated on the availability of R&D funds to develop the required detector technologies on a timely, and in some cases urgent, basis. The necessity for such funding, and the physics merit of the proposed PHENIX program, has been endorsed in the first meeting of BNL's Detector Advisory Committee in December, 2002. Progress towards the physics goals depends in an essential way on the development of the design values for RHIC luminosity, polarization and availability. An analysis based on the guidance from the Collider Accelerator Department indicates that moderate increases in the yearly running time lead to very considerable increases in progress toward the enunciated goals. Efficient access to the rarest probes in the proposed program is achieved via the order-of-magnitude increase in luminosity provided by RHIC-II.

  11. Radionuclide production and radiopharmaceutical chemistry with BNL cyclotrons

    International Nuclear Information System (INIS)

    The Brookhaven National Laboratory (BNL) radiopharmaceutical chemistry program focuses on production and utilization of radionuclides having a half-life of > 2 hr. However, a major portion of the BNL program is devoted to short-lived radionuclides, such as 11C and 18F. Activities encompassed in the program are classified into seven areas: cyclotron parameters, radiochemistry, design and rapid synthesis of radiopharmaceuticals and labeled compounds, radiotracer evaluation in animals, studies in humans, technology transfer, and several other areas

  12. Experts dismiss doomsday scenarios for RHIC

    CERN Multimedia

    Levi, B G

    2000-01-01

    A panel of particle physicists examining the possibility that operation of RHIC could generate blackholes or 'strangelets' which would consume ordinary matter, have declared that such scenarios are 'firmly excluded' (1 p).

  13. GLOBAL DECOUPLING ON THE RHIC RAMP.

    Energy Technology Data Exchange (ETDEWEB)

    LUO, Y.; CAMERON, P.; DELLA PENNA, A.; FISCHER, W.; ET AL.

    2005-05-16

    The global betatron decoupling on the ramp is an important issue for the operation of the Relativistic Heavy Ion Collider (RHIC), especially in the RHIC polarized proton (pp) run. To avoid the major betatron and spin resonances on the ramp, the betatron tunes are constrained. And the rms value of the vertical closed orbit should be smaller than 0.5mm. Both require the global coupling on the ramp to be well corrected. Several ramp decoupling schemes were found and tested at RHIC, like N-turn map decoupling, three-ramp correction, coupling amplitude modulation, and coupling phase modulation. In this article, the principles of these methods are shortly reviewed and compared. Among them, coupling angle modulation is a robust and fast one. It has been applied to the global decoupling in the routine RHIC operation.

  14. Summary of the RHIC Retreat 2007

    Energy Technology Data Exchange (ETDEWEB)

    Pilat,F.; Gardner, C.; Montag, C.; Roser, T.

    2008-08-01

    The RHIC Retreat 2007 took place on July 16-17 2007 at the Foxwoods Resort in CT, about 3 weeks after the end of the RHIC Run-7. The goal of the Retreat is traditionally to plan the upcoming run in the light of the results from the previous one, by providing a snapshot of the present understanding of the machine and a forum for free and frank discussion. A particular attention was paid to the challenge of increasing the time at store, and the related issue of system reliability. An interesting Session covered all new developments aimed to improve the machine performance and luminosity. In Section 2 we summarize the results from Run-7 for RHIC and the injectors and discuss the present objectives of the RHIC program and performance. Sections 3-6 are summaries of the Retreat sessions focused on preparation for deuteron gold and polarized protons, respectively, machine availability and new developments.

  15. Results from PHENIX at RHIC

    CERN Document Server

    Tannenbaum, M J

    2009-01-01

    Results from PHENIX at RHIC in p-p and Au+Au collisions are presented from the perspective of measurements in p-p collisions at the CERN ISR which serve as a basis for many of the techniques used. Notable results include the equality of the suppression of inclusive pi0 and direct electrons (from the decay of heavy quarks) in the range of transverse momentuum 4 < pT < 9 GeV/c in central Au+Au collisions. This result appears to strongly disfavor the explanation of suppression as due to radiative energy loss of partons traversing a Quark Gluon Plasma but opens up a fundamental discussion of how Fermions get mass, whether all six quarks are nearly massless in a QGP and how to test this.

  16. (Strange) meson interferometry at RHIC

    International Nuclear Information System (INIS)

    We make predictions for the kaon interferometry measurements in Au+Au collisions at the relativistic heavy ion collider (RHIC). A first-order phase transition from a thermalized quark-gluon plasma (QGP) to a gas of hadrons is assumed for the transport calculations. The fraction of kaons that are directly emitted from the phase boundary is considerably enhanced at large transverse momenta KT ∼ 1 GeV/c. In this kinematic region, the sensitivity of the Rout/Rside ratio to the QGP properties is enlarged. The results of the one-dimensional correlation analysis are presented. The extracted interferometry radii, depending on KT, are not unusually large and are strongly affected by finite momentum resolution effects. (author)

  17. RHIC heavy ion operations performance

    CERN Document Server

    Satogata, T; Ferrone, R; Pilat, F

    2006-01-01

    The Relativistic Heavy Ion Collider (RHIC) completed its fifth year of operation in 2005, colliding copper ion beams with ps=200 GeV/u and 62.4 GeV/u[1]. Previous heavy ion runs have collided gold ions at ps=130 GeV/u, 200 GeV/u, and 62.4 GeV/u[2], and deuterons and gold ions at ps=200 GeV/u[3]. This paper discusses operational performance statistics of this facility, including Cu- Cu delivered luminosity, availability, calendar time spent in physics stores, and time between physics stores. We summarize the major factors affecting operations efficiency, and characterize machine activities between physics stores.

  18. Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD project. Proceedings of RIKEN BNL Research Center workshop: Volume 13

    International Nuclear Information System (INIS)

    A workshop was held at the RIKEN-BNL Research Center on October 16, 1998, as part of the first anniversary celebration for the center. This meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. Many of the talks in the workshop were devoted to domain wall fermions, a discretization of the continuum description of fermions which preserves the global symmetries of the continuum, even at finite lattice spacing. This formulation has been the subject of analytic investigation for some time and has reached the stage where large-scale simulations in QCD seem very promising. With the computational power available from the QCDSP computers, scientists are looking forward to an exciting time for numerical simulations of QCD

  19. Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD project. Proceedings of RIKEN BNL Research Center workshop: Volume 13

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-16

    A workshop was held at the RIKEN-BNL Research Center on October 16, 1998, as part of the first anniversary celebration for the center. This meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. Many of the talks in the workshop were devoted to domain wall fermions, a discretization of the continuum description of fermions which preserves the global symmetries of the continuum, even at finite lattice spacing. This formulation has been the subject of analytic investigation for some time and has reached the stage where large-scale simulations in QCD seem very promising. With the computational power available from the QCDSP computers, scientists are looking forward to an exciting time for numerical simulations of QCD.

  20. RHIC Critical Point Search: Assessing STAR's Capabilities

    OpenAIRE

    Sorensen, Paul

    2007-01-01

    In this report we discuss the capabilities and limitations of the STAR detector to search for signatures of the QCD critical point in a low energy scan at RHIC. We find that a RHIC low energy scan will cover a broad region of interest in the nuclear matter phase diagram and that the STAR detector -- a detector designed to measure the quantities that will be of interest in this search -- will provide new observables and improve on previous measurements in this energy range.

  1. COMMISSIONING CNI PROTON POLARIMETERS IN RHIC

    International Nuclear Information System (INIS)

    Two polarimeters based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region have been installed and commissioned in the Blue and Yellow rings of RHIC during the first RHIC polarized proton collider run. Each polarimeter consists of ultra-thin carbon targets and six silicon detectors. With newly developed wave form digitizers, they provide fast and reliable polarization information for both rings

  2. RHIC Polarized proton performance in run-8

    International Nuclear Information System (INIS)

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the 'Yellow' RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8, and we discuss possible causes of the not as high as previously achieved polarization performance of the 'Yellow' ring.

  3. Results from STAR experiment at RHIC

    Indian Academy of Sciences (India)

    Bedangadas Mohanty; STAR Collaboration

    2006-11-01

    We present some of the important experimental results from nucleus–nucleus collision studies carried out by the STAR experiment at Relativistic Heavy Ion Collider (RHIC). The results suggests that central Au+Au collisions at RHIC has produced a dense and rapidly thermalizing matter with initial energy densities above the critical values predicted by lattice QCD for establishment of a quark-gluon plasma (QGP).

  4. ANALYSIS OF ELECTRON CLOUD AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    IRISO,U.; BLASKIEWICZ,M.; CAMERON,P.; DREES,A.; FISCHER,W.; ET AL.

    2004-07-05

    Pressure rises with high intense beams are among the main luminosity limitations at RHIC. Observations during the latest runs show beam induced electron multipacting as one of the causes for these pressure rises. Experimental studies are carried out at RHIC using devoted instrumentation to understand the mechanism leading to electron clouds. In the following, we report the experimental electron cloud data and the analyzed results using computer simulation codes.

  5. A luminosity model of RHIC gold runs

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.Y.

    2011-11-01

    In this note, we present a luminosity model for RHIC gold runs. The model is applied to the physics fills in 2007 run without cooling, and with the longitudinal cooling applied to one beam only. Having good comparison, the model is used to project a fill with the longitudinal cooling applied to both beams. Further development and possible applications of the model are discussed. To maximize the integrated luminosity, usually the higher beam intensity, smaller longitudinal and transverse emittance, and smaller {beta} are the directions to work on. In past 10 years, the RHIC gold runs have demonstrated a path toward this goal. Most recently, a successful commissioning of the bunched beam stochastic cooling, both longitudinal and transverse, has offered a chance of further RHIC luminosity improvement. With so many factors involved, a luminosity model would be useful to identify and project gains in the machine development. In this article, a preliminary model is proposed. In Section 2, several secondary factors, which are not yet included in the model, are identified based on the RHIC operation condition and experience in current runs. In Section 3, the RHIC beam store parameters used in the model are listed, and validated. In Section 4, the factors included in the model are discussed, and the luminosity model is presented. In Section 5, typical RHIC gold fills without cooling, and with partial cooling are used for comparison with the model. Then a projection of fills with more coolings is shown. In Section 6, further development of the model is discussed.

  6. Review: BNL graphite blanket design concepts

    International Nuclear Information System (INIS)

    A review of the Brookhaven National Laboratory (BNL) minimum activity graphite blanket designs is made. Three designs are identified and discussed in the context of an experimental power reactor (EPR) and commercial power reactor. Basically, the three designs employ a thick graphite screen (typically 30 cm or greater, depending on type as well as application-experimental power reactor or commercial reactor). Bremsstrahlung energy is deposited on the graphite surface and re-radiated away as thermal radiation. Fast neutrons are slowed down in the graphite, depositing most of their energy. This energy is then either radiated to a secondary blanket with coolant tubes, as in types A and B, or is removed by intermittent direct gas cooling (type C). In types A and B, radiation damage to the structural material of the coolant tubes in the secondary blanket is reduced by one or two orders of magnitude by the graphite screen, while in type C, the blanket is only cooled when the reactor is shut down, so that coolant cannot quench the plasma, whatever the degree of radiation damage

  7. BNL ALARA Center: ALARA Notes, No. 9

    Energy Technology Data Exchange (ETDEWEB)

    Khan, T.A.; Xie, J.W.; Beckman, M.C. [eds.] [and others

    1994-02-01

    This issue of the Brookhaven National Laboratory`s Alara Notes includes the agenda for the Third International Workshop on ALARA and specific instructions on the use of the on-line fax-on-demand service provided by BNL. Other topics included in this issue are: (1) A discussion of low-level discharges from Canadian nuclear plants, (2) Safety issues at French nuclear plants, (3) Acoustic emission as a means of leak detection, (4) Replacement of steam generators at Doel-3, Beaznau, and North Anna-1, (5) Remote handling equipment at Bruce, (6) EPRI`s low level waste program, (7) Radiation protection during concrete repairs at Savannah River, (8) Reactor vessel stud removal/repair at Comanche Peak-1, (9) Rework of reactor coolant pump motors, (10) Restoration of service water at North Anna-1 and -2, (11) Steam generator tubing problems at Mihama-1, (12) Full system decontamination at Indian Point-2, (13) Chemical decontamination at Browns Ferry-2, and (14) Inspection methodolody in France and Japan.

  8. BNL ALARA Center: ALARA Notes, No. 9

    International Nuclear Information System (INIS)

    This issue of the Brookhaven National Laboratory's Alara Notes includes the agenda for the Third International Workshop on ALARA and specific instructions on the use of the on-line fax-on-demand service provided by BNL. Other topics included in this issue are: (1) A discussion of low-level discharges from Canadian nuclear plants, (2) Safety issues at French nuclear plants, (3) Acoustic emission as a means of leak detection, (4) Replacement of steam generators at Doel-3, Beaznau, and North Anna-1, (5) Remote handling equipment at Bruce, (6) EPRI's low level waste program, (7) Radiation protection during concrete repairs at Savannah River, (8) Reactor vessel stud removal/repair at Comanche Peak-1, (9) Rework of reactor coolant pump motors, (10) Restoration of service water at North Anna-1 and -2, (11) Steam generator tubing problems at Mihama-1, (12) Full system decontamination at Indian Point-2, (13) Chemical decontamination at Browns Ferry-2, and (14) Inspection methodolody in France and Japan

  9. SNS RING STUDY AT THE AGS BOOSTER.

    Energy Technology Data Exchange (ETDEWEB)

    ZHANG, S.Y.; AHRENS, L.; BEEBE-WANG, J.; BLASKIEWICZ, M.; FEDOTOV, A.; GARDNER, C.; LEE, Y.Y.; LUCCIO, A.; MALITSKY, N.; ROSER, T.; WENG, W.T.; WEI, J.; ZENO, K.; REECE, K.; WANG, J.G.

    2000-06-30

    During the g-2 run at the BNL AGS in early 2000, a 200 MeV storage-ring-like magnetic cycle has been set-up and tuned at the Booster in preparing for the Spallation Neutron Source (SNS) accumulator ring study. In this article, we report the progress of the machine set-up, tuning, some preliminary studies, and the future plan.

  10. HOM absorbers for ERL cryomodules at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Hahn,H.; Ben-Zvi, I.; Hammons, L.; Xu, W.

    2009-09-20

    The physics needs and technical requirements for several future accelerator projects at the Relativistic Heavy Ion Collider (RHIC) all involve electron Energy Recovery Linacs (ERL). The required high-current, high-charge operating parameters make effective higher-order-mode (HOM) damping mandatory and the development of HOM dampers for a prototypical five-cell cavity is actively pursued. An experimental five-cell niobium cavity with ferrite dampers has been constructed, and effective HOM damping has been demonstrated at room and superconducting (SC) temperatures. A novel type of ferrite damper around a ceramic break has been developed for the ERL electron gun and prototype tests are also reported. Contemplated future projects are based on assembling a chain of superconducting cavities in a common cryomodule with the dampers placed in the cold space between the cavities, imposing severe longitudinal space constraints. Various damper configurations have been studied by placing them between two five-cell copper cavities. Measured and simulated copper cavity results, external Q-values of possible dampers and fundamental mode losses are presented.

  11. Target and orbit feedback simulations of a muSR beam line at BNL

    Energy Technology Data Exchange (ETDEWEB)

    MacKay, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pile, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-07-28

    Well-polarized positive surface muons are a tool to measure the magnetic properties of materials since the precession rate of the spin can be determined from the observation of the positron directions when the muons decay. For a dc beam an ideal µSR flux for surface µ+ should be about 40 kHz/mm2. In this report we show how this flux could be achieved in a beam line using the AGS complex at BNL for a source of protons. We also determined that an orbit feedback system with a pair of thin silicon position monitors and kickers would miss the desired flux by at least an order of magnitude, even with perfect time resolution and no multiple scattering.

  12. First large scale application of novel Si stripixel detector in real large experiment: Si VTX in PHENIX upgrade at RHIC

    Institute of Scientific and Technical Information of China (English)

    LI Zheng; H. ENYO; Y. GOTO; J. TOJO; Y. AKIBA; R. NOUICER; A. L. DESHPANDE; K. BOYLE; V. CIANCIOLO

    2006-01-01

    2D position sensitive,single-sided Si stripixel detector was selected as the one of the two main components of the Si vertex tracker (Si SVX) in the upgraded PHENIX detector at RHIC (relativistic heavy ion collider) in Brookhaven National Laboratory (BNL). This is the first large scale application of the novel Si stripixel detector in a real large experiment after many years of research and development at BNL. The first and second prototype fabrication runs of the SVX stripixel detectors were carried out successfully in BNL's Si detector development and processing Lab. The processing of these stripixel detectors is similar to that for the standard single-sided strip detectors: one-sided processing,single implant for the pixel (strip) electrodes,etc. The only additional processing step is the double metal process,a technology that is simple and well matured by many Si detector processing industries and labs,including BNL. The laser and beam tests on those prototype detectors show the 2D position sensitivity and good position resolution in both X and U coordinates (about 25 μm for 80 μm pitch). For the mass production of 400 sensors needed for the Si SVX,the processing technology has been successfully transferred to the industrial: Hamamatsu Photonics (HPK). HPK has produced a pre-production run of stripixel sensors with the full PHENIX SVX specification on 150 mm diameter wafers. The laser tests on these pre-production wafers show good signal to noise ratio (about 20:1).

  13. The RHIC p-Carbon CNI Polarimeter Upgrade For The Beam Polarization And Intensity Measurements

    International Nuclear Information System (INIS)

    Proton polarization measurements in the AGS and RHIC (Relativistic Heavy Ion Collider at the beam energies 24-250 GeV) are based on proton-carbon and proton-proton elastic scattering in the Coulomb Nuclear Interference (CNI) region. Polarimeter operation in the scanning mode also gives polarization profile and beam intensity profile (beam emittance) measurements. Bunch by bunch emittance measurement is a very powerful tool for machine setup. Presently, the polarization and beam intensity profile measurements (in both vertical and horizontal planes) are restricted by the long target switching time and possible target destruction during this complicated motion. The RHIC polarimeters were operated near the limit of the counting rate for present silicon strip detectors. The ongoing polarimeter upgrade for the 2009 run will address all these problems. The upgrade should allow significant reduction of the polarization measurement errors by making feasible the complete polarization measurements, which includes polarization profiles in both the horizontal and vertical planes.

  14. Acceleration of polarized protons in the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Tsoupas, N.; Ahrens, L.; Bai, M.; Brown, K.; Courant, E.; Glenn, J.W.; Huang, H.; Luccio, A.; MacKay, W.W.; Roser, T.; Schoefer, V.; Zeno, K.

    2010-02-25

    The high energy (s{sup 1/2} = 500 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the proton beam. With the AGS used as the pre-injector to RHIC, one of the main tasks is to preserve the polarization of the proton beam, during the beam acceleration in the AGS. The polarization preservation is accomplished by the two partial helical magnets [1,2,3,4,5,6,7] which have been installed in AGS, and help overcome the imperfection and the intrinsic spin resonances which occur during the acceleration of protons. This elimination of the intrinsic resonances is accomplished by placing the vertical tune Q{sub y} at a value close to 8.98, within the spin-tune stop-band created by the snake. At this near integer tune the perturbations caused by the partial helical magnets is large resulting in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have introduced compensation quads[2] in the AGS. In this paper we present the beam optics of the AGS which ameliorates this effect of the partial helices.

  15. BNL ACCELERATOR-BASED RADIOBIOLOGY FACILITIES

    Energy Technology Data Exchange (ETDEWEB)

    LOWENSTEIN,D.I.

    2000-05-28

    For the past several years, the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (USA) has provided ions of iron, silicon and gold, at energies from 600 MeV/nucleon to 10 GeV/nucleon, for the US National Aeronautics and Space Administration (NASA) radiobiology research program. NASA has recently funded the construction of a new dedicated ion facility, the Booster Applications Facility (BAF). The Booster synchrotron will supply ion beams ranging from protons to gold, in an energy range from 40--3,000 MeV/nucleon with maximum beam intensities of 10{sup 10} to 10{sup 11} ions per pulse. The BAF Project is described and the future AGS and BAF operation plans are presented.

  16. Proceedings of the symposium on RHIC detector R ampersand D

    International Nuclear Information System (INIS)

    This report contains papers on the following topics: Development of Analog Memories for RHIC Detector Front-end Electronic Systems; Monolithic Circuit Development for RHIC at Oak Ridge National Laboratory; Highly Integrated Electronics for the STAR TPC; Monolithic Readout Circuits for RHIC; New Methods for Trigger Electronics Development; Neurocomputing methods for Pattern Recognition in Nuclear Physics; The Development of a Silicon Multiplicity Detector System; A Transition Radiation Detector for RHIC Featuring Accurate

  17. Heavy Flavor Results at RHIC - A Comparative Overview

    CERN Document Server

    Dong, Xin

    2012-01-01

    I review the latest heavy flavor measurements at RHIC experiments. Measurements from RHIC together with preliminary results from LHC offer us an opportunity to systematically study the sQGP medium properties. In the end, I will outlook a prospective future on precision heavy flavor measurements with detector upgrades at RHIC.

  18. An impedance model of the relativistic heavy ion collider, RHIC

    International Nuclear Information System (INIS)

    This paper is an abbreviated version of a comprehensive and detailed analysis of RHIC instabilities soon to be published as a RHIC project report. It emphasises longitudinal impedance modeling and design choices in RHIC, wile a companion paper emphasises instability calculations

  19. Strangeness in STAR at RHIC

    CERN Document Server

    ,

    2016-01-01

    We present the recent results of strangeness production at the mid-rapidity in Au + Au collisions at RHIC, from $\\sqrt{s_{\\rm NN}}$ = 7.7 to 200 GeV. The $v_2$ of multi-strange baryon $\\Omega$ and $\\phi$ mesons are similar to that of pions and protons in the intermediate $p_T$ range (2 - 5 GeV/$c$) in $\\sqrt{s_{\\rm NN}}$ = 200 GeV Au + Au collisions, indicating that the major part of collective flow has been built up at partonic stage. The breaking of mass ordering between $\\phi$ mesons and protons in the low $p_T$ range ($<$ 1 GeV/$c$) is consistent with a picture that $\\phi$ mesons are less sensitive to later hadronic interaction. The nuclear modification factor $R_{\\rm CP}$ and baryon to meson ratio change dramatically when the collision energy is lower than 19.6 GeV. It suggests a possible change of medium property of the system compared to those from high energies.

  20. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP (VOLUME 70)

    Energy Technology Data Exchange (ETDEWEB)

    JACAK, B.; SHURYAK, E.; HALLMAN, T.; BASS, S.; DAVIDSON, R.

    2005-01-14

    The Relativistic Heavy Ion Collider (RHIC) was commissioned for heavy ion collisions and for polarized pp collisions in 2001. All principal components of the accelerator chain were operational by the 2003 RHIC run. Approximately 50 papers on RHIC experimental results have been published in refereed journals to date. This is a testament to the vast amount of exciting new information and the unprecedented analysis and publication rate from RHIC. A number of signals of creation of matter at extreme energy density, and of new physics in that matter, have been observed. The RHIC community has been heavily engaged in discussion about these signals, and about the appropriate level of proof for Quark Gluon Plasma discovery at the RHIC. In fact, such discussions were the subject of an earlier RBRC Workshop. One of the striking results from heavy ion collisions at RHIC is that the quark gluon plasma accessible appears to be strongly coupled. The properties of strongly coupled plasmas are of intense interest in the traditional Plasma Physics community, who have been developing tools to study such matter theoretically and experimentally. Despite the fact that one plasma interacts electromagnetically and the other through the strong interaction, there is tremendous commonality in the intellectual approach and even the theoretical and experimental tools. It is important to broaden the discussion of Quark Gluon Plasma discovery beyond possible signals of deconfinement to also encompass signals of plasma phenomena in heavy ion collisions. Thus it is imperative establish more direct contact among Nuclear, Plasma and Atomic physicists to share techniques and ideas. RHIC physicists will benefit from familiarity with typical plasma diagnostics and theoretical methods to study strongly coupled plasmas. Plasma and Atomic physicists may fmd new techniques parallel to the multi-particle correlations used in RHIC data analysis, and theoretical tools to study high energy density matter

  1. RHIC BPM System Modifications and Performance

    CERN Document Server

    Satogata, Todd; Cameron, Peter; Cerniglia, Phil; Cupolo, John; Curcio, Anthony J; Dawson, William C; Degen, Christopher; Gullotta, Justin; Mead, Joe; Michnoff, Robert; Russo, Thomas; Sikora, Robert

    2005-01-01

    The RHIC beam position monitor (BPM) system provides independent average orbit and turn-by-turn (TBT) position measurements. In each ring, there are 162 measurement locations per plane (horizontal and vertical) for a total of 648 BPM planes in the RHIC machine. During 2003 and 2004 shutdowns, BPM processing electronics were moved from the RHIC tunnel to controls alcoves to reduce radiation impact, and the analog signal paths of several dozen modules were modified to eliminate gain-switching relays and improve signal stability. This paper presents results of improved system performance, including stability for interaction region and sextupole beam-based alignment efforts. We also summarize performance of improved million-turn TBT acquisition channels for nonlinear dynamics and echo studies.

  2. Beam Induced Pressure Rise at RHIC

    CERN Document Server

    Zhang, S Y; Bai, Mei; Blaskiewicz, Michael; Cameron, Peter; Drees, Angelika; Fischer, Wolfram; Gullotta, Justin; He, Ping; Hseuh Hsiao Chaun; Huang, Haixin; Iriso, Ubaldo; Lee, Roger C; Litvinenko, Vladimir N; MacKay, William W; Nicoletti, Tony; Oerter, Brian; Peggs, Steve; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smart, Loralie; Snydstrup, Louis; Thieberger, Peter; Trbojevic, Dejan; Wang, Lanfa; Wei, Jie; Zeno, Keith

    2005-01-01

    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.

  3. ARTUS: THE TUNE MEASUREMENT SYSTEM AT RHIC

    Energy Technology Data Exchange (ETDEWEB)

    DREES,A.; BRENNAN,M.; CONNOLLY,R.; MICHNOFF,R.; DELONG,J.

    2000-05-08

    The super-conducting Relativistic Heavy Ion Collider (RHIC) with two separate rings and six combined interaction regions will provide collisions between equal and unequal heavy ion species up to Au ions in typically 60 bunches. The betatron tunes of the two beams are among the most important parameters to be measured. The tunes have to be acquired at any moment during accelerator operation and in particular during the acceleration process. At RHIC the tune measurement device (ARTUS) consists of a fast horizontal and vertical kicker magnet and a dedicated beam position monitor in each ring. The system layout is described and first experiences from operation is reported.

  4. RHIC Polarized proton performance in run-8

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.; Bai, M.; MacKay, W.W.; Roser, T.; Abreu, N.; Ahrens, L.; Barton, D.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Bunce, G.; Calaga, R.; Cameron, P.; Connolly, R.; D' Ottavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hayes, T.; Huang, H.; Ingrassia, P.; Kayran, D.A.; Kewisch, J.; Lee, R.C.; Lin, F.; Litvinenko, V.N.; Luccio, A.U.; Luo, Y.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Michnoff, R.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Robert-Demolaize, G.; Russo, T.; Satogata, T.; Schultheiss, C.; Sivertz, M.; Smith, K.; Tepikian, S.; D. Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2008-10-06

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the 'Yellow' RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8, and we discuss possible causes of the not as high as previously achieved polarization performance of the 'Yellow' ring.

  5. Global Decoupling on the RHIC Ramp

    CERN Document Server

    Luo, Yun; Della Penna, Al; Fischer, Wolfram; Laster, Jonathan S; Marusic, Al; Pilat, Fulvia Caterina; Roser, Thomas; Trbojevic, Dejan

    2005-01-01

    The global betatron decoupling on the ramp is an important issue for the operation of the Relativistic Heavy Ion Collider (RHIC). In the polarized proton run, the betatron tunes are required to keep almost constant on the ramp to avoid spin resonance line crossing and the beam polarization loss. Some possible correction schemes on the ramp, like three-ramp correction, the coupling amplitude modulation and the coupling phase modulaxtion, have been found. The principles of these schemes are shortly reviewed and compared. Operational results of their applications on the RHIC ramps are given.

  6. A prototype ionization profile monitor for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, R.; Cameron, P.; Ryan, W. [and others

    1997-07-01

    Transverse beam profiles in the Relativistic Heavy-Ion Collider (RHIC) will be measured with ionization profile monitors (IPM`s). Each IPM collects and measures the distribution of electrons in the beamline resulting from residual gas ionization during bunch passage. The electrons are swept transversely from the beamline and collected on strip anodes oriented parallel to the beam axis. At each bunch passage the charge pulses are amplified, integrated, and digitized for display as a profile histogram. A prototype detector was tested in the injection line during the RHIC Sextant Test. This paper describes the detector and gives results from the beam tests.

  7. Open heavy flavor production at RHIC

    CERN Document Server

    Suaide, A A P

    2007-01-01

    The study of heavy flavor production in relativistic heavy ion collisions is an extreme experimental challenge but provides important information on the properties of the Quark-Gluon Plasma (QGP) created in Au+Au collisions at RHIC. Heavy-quarks are believed to be produced in the initial stages of the collision, and are essential on the understanding of parton energy loss in the dense medium created in such environment. Moreover, heavy-quarks can help to investigate fundamental properties of QCD in elementary p+p collisions. In this work we review recent results on heavy flavor production and their interaction with the hot and dense medium at RHIC.

  8. Proceedings of RIKEN BNL Research Center Workshop: Understanding QGP through Spectral Functions and Euclidean Correlators (Volume 89)

    Energy Technology Data Exchange (ETDEWEB)

    Mocsy,A.; Petreczky, P.

    2008-06-27

    In the past two decades, one of the most important goals of the nuclear physics community has been the production and characterization of the new state of matter--Quark-Gluon Plasma (QGP). Understanding how properties of hadrons change in medium, particularly, the bound state of a very heavy quark and its antiquark, known as quarkonium, as well as determining the transport coefficients is crucial for identifying the properties of QGP and for the understanding of the experimental data from RHIC. On April 23rd, more than sixty physicists from twenty-seven institutions gathered for this three-day topical workshop held at BNL to discuss how to understand the properties of the new state of matter obtained in ultra-relativistic heavy ion collisions (particularly at RHIC-BNL) through spectral functions. In-medium properties of the different particle species and the transport properties of the medium are encoded in spectral functions. The former could yield important signatures of deconfinement and chiral symmetry restoration at high temperatures and densities, while the later are crucial for the understanding of the dynamics of ultra-relativistic heavy ion collisions. Participants at the workshop are experts in various areas of spectral function studies. The workshop encouraged direct exchange of scientific information among experts, as well as between the younger and the more established scientists. The workshops success is evident from the coherent picture that developed of the current understanding of transport properties and in-medium particle properties, illustrated in the current proceedings. The following pages show calculations of meson spectral functions in lattice QCD, as well as implications of these for quarkonia melting/survival in the quark gluon plasma; Lattice calculations of the transport coefficients (shear and bulk viscosities, electric conductivity); Calculation of spectral functions and transport coefficients in field theories using weak coupling

  9. Correlation between multiplicity and impact parameters in Au-Au nuclear collision at energies available at RHIC-BNL

    International Nuclear Information System (INIS)

    The nuclear collisions at high energies offer conditions for different phase transition in nuclear matter. One of main goal of the BRAHMS Experiment is establishing the collisions dynamics and the search for the experimental signals evidencing the quark-gluon plasma. Because the dynamics is in great extent dependent on the collision geometry we consider necessary a good correlation between the level of collision centrality and the behaviour of some specific physical quantities. The present work presents an analysis of the multiplicity distribution shape in relationship with the impact parameter and a comparison of the experimental results with the predictions of different simulation models. (authors)

  10. Data Model of the BNL Archive and Dissemination System

    Energy Technology Data Exchange (ETDEWEB)

    Heller, J; Osterer, L

    1977-02-01

    The Data Model, i.e., the information content of the data base as it is viewed by the users, of the BNL Archive and Dissemination System is presented. The syntax of the data model is stated in BNF form, and the semantic meaning is discussed. Examples of the use of the data model are given. 3 figs.

  11. BNL hypernuclear spectrometers and instrumentation present and future

    International Nuclear Information System (INIS)

    During the period 1981 to 1984 the BNL hypernuclear spectrometer system was upgraded resulting in an increase in kaon flux and an increase in solid angle and momentum acceptance. The modifications require drift chambers to be operated at rates up to 107 s-1. The performance of the spectrometer-drift chamber systems will be discussed

  12. RHIC Proton Luminosity and Polarization Improvement

    International Nuclear Information System (INIS)

    The RHIC proton beam polarization can be improved by raising the Booster scraping, which also helps to reduce the RHIC transverse emittance, and therefore to improve the luminosity. By doing this, the beam-beam effect would be enhanced. Currently, the RHIC working point is constrained between 2/3 and 7/10, the 2/3 resonance would affect intensity and luminosity lifetime, and the working point close to 7/10 would enhance polarization decay in store. Run 2013 shows that average polarization decay is merely 1.8% in 8 hours, and most fills have the luminosity lifetime better than 14 hours, which is not a problem. Therefore, even without beam-beam correction, there is room to improve for RHIC polarization and luminosity. The key to push the Booster scraping is to raise the Booster input intensity; for that, two approaches can be used. The first is to extend the LINAC tank 9 pulse width, which has been successfully applied in run 2006. The second is to raise the source temperature, which has been successfully applied in run 2006 and run 2012.

  13. Linear and chromatic optics measurements at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Aiba, M.; Calaga, R.; Aiba, M.; Tomas, R.; Vanbavinkove, G.

    2010-05-23

    Measurements of chromatic beta-beating were carried out for the first time in the RHIC accelerator during Run 2009. The analysis package developed for the LHC was used to extract the off-momentum optics for injection and top energy. Results from the beam experiments and compassion to the optics model are presented. The primary goal of the RHIC experiments were execute an on-line measurement of the optics using the tools developed for the LHC. Turn-by-turn BPM trajectories (typically 1000 turns) acquired immediately after an external dipole kick are numerically analyzed to determine the optical parameters at the location of the beam position monitors (BPMs). For chromatic optics, a similar analysis, but on a beam with finite momentum offset(s). Each optical measurement typically is calculated from multiple data sets to capture statistical variations and ensure reproducibility. The procedure of measurement and analysis is detailed in ref [1, 2]. Two dedicated experiments were performed at RHIC with protons during Run 2009. The first at injection energy and optics and the other at 250 GeV and squeezed optics. The basic RHIC parameters relevant for the two experiments are listed in Table 1.

  14. Heavy-flavour meson production at RHIC

    NARCIS (Netherlands)

    Mischke, A.

    2010-01-01

    Collisions of heavy atomic nuclei at very high beam energies allow to create and study hot QCD matter under laboratory-controlled conditions. Measurements at the SPS and RHIC facilities have yielded compelling evidence for the formation of this novel state of matter, the so-called Quark-Gluon Plasma

  15. Polarized proton beam for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    RHIC has provided polarized proton collisions from 31 GeV to 255 GeV in the past decade. To preserve polarization through numerous depolarizing resonances through the whole accelerator chain, harmonic orbit correction, partial snakes, horizontal tune jump system and full snakes have been used. In addition, close attentions have been paid to betatron tune control, orbit control and beam line alignment. The polarization of 60% at 255 GeV has been delivered to experiments with 1.8×1011 bunch intensity. For the eRHIC era, the beam brightness has to be maintained to reach the desired luminosity. Since we only have one hadron ring in the eRHIC era, existing spin rotator and snakes can be converted to six snake configuration for one hadron ring. With properly arranged six snakes, the polarization can be maintained at 70% at 250 GeV. This paper summarizes the effort and plan to reach high polarization with small emittance for eRHIC.

  16. First polarized proton collisions at RHIC

    International Nuclear Information System (INIS)

    We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180 deg. about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV

  17. FIRST POLARIZED PROTON COLLISIONS AT RHIC

    International Nuclear Information System (INIS)

    We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180o about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV

  18. Hybrid helical snakes and rotators for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.D.

    1995-06-13

    The spin rotators and Siberian snakes presently envisaged for RHIC utilize helical dipole magnets. The snakes and the rotators each consist of four helices, each with a full twist (360{degrees}) of the field. Here we investigate an alternate layout, namely combinations of helical and pure bending magnet, and show that this may have advantages.

  19. PHENIX Measurements of Correlations at RHIC

    Science.gov (United States)

    Taranenko, Arkadiy

    2016-01-01

    Relativistic heavy-ion collisions provide a unique opportunity to study the expansion dynamics and the transport properties of the produced strongly interacting quark gluon plasma (QGP). This article reviews the recent soft physics results obtained via correlation measurements from the PHENIX experiment at RHIC: space-time extent of the pion emission source and azimuthal anisotropy of the particle production.

  20. Uniform description of bulk observables in the hydrokinetic model of A+A collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider

    Science.gov (United States)

    Karpenko, Iu. A.; Sinyukov, Yu. M.; Werner, K.

    2013-02-01

    A simultaneous description of hadronic yields; pion, kaon, and proton spectra; elliptic flows; and femtoscopy scales in the hydrokinetic model of A+A collisions is presented at different centralities for the top BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) 2.76-TeV energies. The initial conditions are based on the Monte Carlo Glauber simulations. When going from RHIC to LHC energy in the model, the only parameters changed are the normalization of the initial entropy defined by the number of all charged particles in most central collisions, contribution to entropy from binary collisions, and barionic chemical potential. The hydrokinetic model is used in its hybrid version, which provides the correct match (at the isochronic hypersurface) of the decaying hadron matter evolution with hadronic ultrarelativistic quantum molecular dynamics cascade. The results are compared with the standard hybrid models where hydrodynamics and hadronic cascade are matching just at the non-space-like hypersurface of chemical freeze-out or on the isochronic hypersurface. The modification of the particle-number ratios at LHC caused, in particular, by the particle annihilations at the afterburn stage is also analyzed.

  1. Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter

    International Nuclear Information System (INIS)

    This volume contains the proceedings of the RBRC/CATHIE workshop on 'P- and CP-odd Effects in Hot and Dense Matter' held at the RIKEN-BNL Research Center on April 26-30, 2010. The workshop was triggered by the experimental observation of charge correlations in heavy ion collisions at RHIC, which were predicted to occur due to local parity violation (P- and CP-odd fluctuations) in hot and dense QCD matter. This experimental result excited a significant interest in the broad physics community, inspired a few alternative interpretations, and emphasized the need for a deeper understanding of the role of topology in QCD vacuum and in hot and dense quark-gluon matter. Topological effects in QCD are also closely related to a number of intriguing problems in condensed matter physics, cosmology and astrophysics. We therefore felt that a broad cross-disciplinary discussion of topological P- and CP-odd effects in various kinds of matter was urgently needed. Such a discussion became the subject of the workshop. Specific topics discussed at the workshop include the following: (1) The current experimental results on charge asymmetries at RHIC and the physical interpretations of the data; (2) Quantitative characterization of topological effects in QCD matter including both analytical (perturbative and non-perturbative using gauge/gravity duality) and numerical (lattice-QCD) calculations; (3) Topological effects in cosmology of the Early Universe (including baryogenesis and dark energy); (4) Topological effects in condensed matter physics (including graphene and superfiuids); and (5) Directions for the future experimental studies of P- and CP-odd effects at RHIC and elsewhere. We feel that the talks and intense discussions during the workshop were extremely useful, and resulted in new ideas in both theory and experiment. We hope that the workshop has contributed to the progress in understanding the role of topology in QCD and related fields. We thank all the speakers and

  2. Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, A.; Fukushima, K.; Kharzeev, D.; Warringa, H.; Voloshin, S.

    2010-04-26

    This volume contains the proceedings of the RBRC/CATHIE workshop on 'P- and CP-odd Effects in Hot and Dense Matter' held at the RIKEN-BNL Research Center on April 26-30, 2010. The workshop was triggered by the experimental observation of charge correlations in heavy ion collisions at RHIC, which were predicted to occur due to local parity violation (P- and CP-odd fluctuations) in hot and dense QCD matter. This experimental result excited a significant interest in the broad physics community, inspired a few alternative interpretations, and emphasized the need for a deeper understanding of the role of topology in QCD vacuum and in hot and dense quark-gluon matter. Topological effects in QCD are also closely related to a number of intriguing problems in condensed matter physics, cosmology and astrophysics. We therefore felt that a broad cross-disciplinary discussion of topological P- and CP-odd effects in various kinds of matter was urgently needed. Such a discussion became the subject of the workshop. Specific topics discussed at the workshop include the following: (1) The current experimental results on charge asymmetries at RHIC and the physical interpretations of the data; (2) Quantitative characterization of topological effects in QCD matter including both analytical (perturbative and non-perturbative using gauge/gravity duality) and numerical (lattice-QCD) calculations; (3) Topological effects in cosmology of the Early Universe (including baryogenesis and dark energy); (4) Topological effects in condensed matter physics (including graphene and superfiuids); and (5) Directions for the future experimental studies of P- and CP-odd effects at RHIC and elsewhere. We feel that the talks and intense discussions during the workshop were extremely useful, and resulted in new ideas in both theory and experiment. We hope that the workshop has contributed to the progress in understanding the role of topology in QCD and related fields. We thank all the speakers and

  3. Calibration of the Heavy Flavor Tracker (HFT) detector in star experiment at RHIC

    Science.gov (United States)

    Alanazi, Norah

    This project is in the area of Relativistic Nuclear collisions and the commissioning of a new silicon vertex detector, the Heavy Flavor Tracker (HFT) in the STAR experiment at Brookhaven National Laboratory (BNL). BNL hosts RHIC, the Relativistic Heavy Ion Collider, the world's most advanced dedicated heavy ion and polarized proton accelerator facility. Heavy Ion collisions at RHIC provide a unique probe into the understanding of several aspects of the behavior of nuclear, i.e. strongly inter- acting, matter. Among the many insights that can be provided is the description of parton interaction inside the hot and dense medium produced in the early stages of a collision. It also allows us to search for evidence for a phase transition in nuclear matter, a phase where partons [quarks and gluons] can move freely over an extended volume. Production of heavy quarks in high-energy nuclear collisions at RHIC occurs mainly during the initial collisions where energetic gluon and quark interactions can create heavy quarks. Thus, heavy flavor provides an ideal probe in studying the hot and dense medium created in the early phases of high-energy nuclear collisions. A detailed study of heavy flavor is essential to better understand the parton dynamics and select among competing theoretical approaches, however, precise measurements of heavy flavor are difficult to obtain due to relatively low production rates and short lifetimes of heavy flavor hadrons. The combinatorial background in nuclear collisions makes the measurement of heavy flavor a challenging task. One approach to dramatically reduce the combinatorial background by several orders of magnitude is to separate the heavy-flavor hadron's decay vertex from the background. This is done with the help of high resolution vertex detectors. The Heavy Flavor Tracker upgrade for the STAR experiment, which made its debut during the year 2014 RHIC run (Run14), greatly improved the experiment's track pointing capabilities making STAR

  4. Status and prospects of Di-jet production in high-energy polarized proton-proton collisions at RHIC at s**(1/2) = 200-GeV

    CERN Document Server

    ,

    2015-01-01

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transversely or longitudinally polarized proton beams at = 200-500 GeV to gain deeper insigh t into the spin structure and dynamics of the proton. These studies provide fundamental insight into Quantum Chromodynamics (QCD). One of the main objectives is the determination of the polarized gluon distribution function, g, through the measurement of the longitudinal double-spin asymmetry, ALL, for various processes. Inclusive hadron and jet production from polarized pp collision data collected so far at = 200 GeV using the STAR detector at RHIC have placed important constraints on g. Di-jet producti on provides direct access to the initial parton kinematics at leading order (LO) QCD and thus provides sensitivity to the Bjorken-x dependence of g. The status of the mid-rapidity di-jet cross section analysis from the 2005 RHIC run and the longitudinal d ouble-spin...

  5. ANALYSIS OF AVAILABILITY AND RELIABILITY IN RHIC OPERATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    PILAT, F.; INGRASSIA, P.; MICHNOFF, R.

    2006-06-26

    RHIC has been successfully operated for 5 years as a collider for different species, ranging from heavy ions including gold and copper, to polarized protons. We present a critical analysis of reliability data for RHIC that not only identifies the principal factors limiting availability but also evaluates critical choices at design times and assess their impact on present machine performance. RHIC availability data are typical when compared to similar high-energy colliders. The critical analysis of operations data is the basis for studies and plans to improve RHIC machine availability beyond the 50-60% typical of high-energy colliders.

  6. Conceptual design of a quadrupole magnet for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Witte, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    eRHIC is a proposed upgrade to the existing Relativistic Heavy Ion Collider (RHIC) hadron facility at Brookhaven National Laboratory, which would allow collisions of up to 21 GeV polarized electrons with a variety of species from the existing RHIC accelerator. eRHIC employs an Energy Recovery Linac (ERL) and an FFAG lattice for the arcs. The arcs require open-midplane quadrupole magnets of up to 30 T/m gradient of good field quality. In this paper we explore initial quadrupole magnet design concepts based on permanent magnetic material which allow to modify the gradient during operation.

  7. Near integer tune for polarization preservation in the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Tsoupas N.; Ahrens, L.; Bai, M.; Brown, K.; Glenn, J.W.; Huang, H.; MacKay, W.W.; Roser, T.; Schoefer, V.; Zeno, K.

    2012-05-20

    The high energy (T = 250 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the beam. In order to preserve the polarization of the proton beam, during the acceleration in the AGS, which is the pre-injector to RHIC, we have installed in AGS two partial helical magnets which minimize the loss of the beam polarization caused by the various intrinsic spin resonances occurring during the proton acceleration. The minimization of the polarization loss during the acceleration cycle, requires that the vertical tune of the AGS is between the values of 8.97 and 8.985 during the acceleration. With the AGS constrained to run at near integer tune {approx}8.980, the perturbations to the beam caused by the partial helical magnets are large and also result in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have installed in specified straight sections of the AGS compensation quads and we have also generated a beam bump at the location of the cold partial helix. In this paper we present the beam optics of the AGS which ameliorates the adverse effect of the two partial helices on the beam optics.

  8. Ferrite HOM Absorber for the RHIC ERL

    Energy Technology Data Exchange (ETDEWEB)

    Hahn,H.; Choi, E.M.; Hammons, L.

    2008-10-01

    A superconducting Energy Recovery Linac is under construction at Brookhaven National Laboratory to serve as test bed for RHIC upgrades. The damping of higher-order modes in the superconducting five-cell cavity for the Energy-Recovery linac at RHIC is performed exclusively by two ferrite absorbers. The ferrite properties have been measured in ferrite-loaded pill box cavities resulting in the permeability values given by a first-order Debye model for the tiled absorber structure and an equivalent permeability value for computer simulations with solid ring dampers. Measured and simulated results for the higher-order modes in the prototype copper cavity are discussed. First room-temperature measurements of the finished niobium cavity are presented which confirm the effective damping of higher-order modes in the ERL. by the ferrite absorbers.

  9. Charm and beauty production at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Kabana, Sonia [Laboratoire de Physique Subatomique et des Technologies Associees (SUBATECH), Ecole des Mines, 4 rue Alfred Kastler, 44307 Nantes (France)

    2011-01-15

    We review selected highlights on charm and beauty production at RHIC from p+p, d+Au and A+A collisions at {radical}(s{sub NN})=200GeV, and compare them to model calculations. We focus on two particular issues, jet quenching and quarkonia. Anomalous energy loss (jet quenching) of quarks passing through the dense and hot matter built in heavy ion collisions is one of the outstanding discoveries made at RHIC. This phenomenon allows for an estimate of the initial gluon density. Furthermore, color screening of hidden charm and beauty states is a key signature of the QCD phase transition, allowing an estimate of the initial temperature. We present results on the flavour dependence of jet quenching. Heavy flavour production in A+A as compared to p+p collisions will be discussed for open and hidden charm.

  10. THE TWO STAGE CRYSTAL COLLIMATOR FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    FLILLER, R.P. III; DREES, A.; GASSNER, D.; HAMMONS, L.; MCINTYRE, G.; TRBOJEVIC, D.; BIRYUKOV, V.; CHESNOKOV, Y.; TEREKHOV, V.

    2001-06-18

    The use of a two stage crystal collimation system in the RHIC yellow ring is examined. The system includes a copper beam scraper and a bent silicon crystal. While scrapers were installed in both of the RHIC rings before the year 2000 run, the crystal is installed for the 2001 run in one ring only, forming a two stage collimation system there. We present simulations of the expected channeling through the bent silicon crystal for both protons and gold ions with various beam parameters. This gives a picture of the particle losses around the ring, and the expected channeling efficiency. These results are then used to optimize the beam parameters in the area of the crystal to obtain maximum channeling efficiency, minimize out-scattering in the secondary collimator, and reduce beam halo.

  11. Azimuthal jet tomography at RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Betz, Barbara; Gyulassy, Miklos [Institute for Theoretical Physics, Johann Wolfgang Goethe-University, 60438 Frankfurt am Main (Germany); Department of Physics, Columbia University, New York 10027 (United States)

    2014-12-15

    A generic jet-energy loss model that is coupled to state-of-the-art hydrodynamic fields and interpolates between a wide class of running coupling pQCD-based and AdS/CFT-inspired models is compared to recent data on the azimuthal and transverse momentum dependence of high-pT pion nuclear modification factors and high-pT elliptic flow measured at RHIC and LHC. We find that RHIC data are surprisingly consistent with various scenarios considered. However, extrapolations to LHC energies favor running coupling pQCD-based models of jet-energy loss. While conformal holographic models are shown to be inconsistent with data, recent non-conformal generalizations of AdS holography may provide an alternative description.

  12. Accelerator physics issues in eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, I.; Kewisch, J.; Murphy, J.; Peggs, S. E-mail: peggs@bnl.gov

    2001-05-01

    The accelerator physics issues associated with adding electron-gold and polarized electron-proton collisions to the RHIC repertoire are discussed. Two scenarios are considered: ring-ring and linac-ring collisions. In the first scenario a third electron ring, possibly made from permanent magnets, is added to the RHIC tunnel. In the second scenario the considerable beam power is recuperated by recycling the beam through the full energy linac injector. Straw man ring optics are presented, including an integrated spin rotator which provides longitudinally polarized electrons at the interaction points. Electron and ion intensity limitations are investigated, for operations with as many as 2520 bunches. Synchrotron radiation, beam-beam, electron cloud, and cryogenic heat load limits are examined. The implications for new and upgraded ion ring systems are discussed, including electron cooling, RF systems, the ion abort dumps, and injection and extraction kickers.

  13. SUCCESSFUL BUNCHED BEAM STOCHASTIC COOLING IN RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BRENNAN, J.M.; BLASKIEWICZ, M.; SEVERINO, F.

    2006-06-23

    We report on a successful test of bunch-beam stochastic cooling in RHIC at 100 GeV. The cooling system is designed for heavy ions but was tested in the recent RHIC run which operated only with polarized protons. To make an analog of the ion beam a special bunch was prepared with very low intensity. This bunch had {approx}1.5 x 10{sup 9} protons, while the other 100 bunches contained {approx}1.2 x 10{sup 11} protons each. With this bunch a cooling time on the order 1 hour was observed through shortening of the bunch length and increase in the peak bunch current, together with a narrowing of the spectral line width of the Scottky power at 4 GHz. The low level signal processing electronics and the isolated-frequency kicker cavities are described.

  14. Adjusting the IP $\\beta$ Functions in RHIC

    CERN Document Server

    Wittmer, W; Pilat, F; Ptitsyn, V; Van Zeijts, J

    2004-01-01

    The beta functions at the IP can be adjusted without perturbation of other optics functions via several approaches. In this paper we describe a scheme based on a vector knob, which assigns fixed values to the different tuning quadrupoles and scales them by a common multiplier. The values for the knob vector were calculated for a lattice without any errors using MADX. Previous studies for the LHC [1] have shown that this approach can meet the design goals. A specific feature of the RHIC lattice is the nested power supply system. To cope with the resulting problems a detailed response matrix analysis has been carried out and different sets of knobs were calculated and compared. The knobs were tested at RHIC during the 2004 run and preliminary results are discussed. Simultaneously a new approach to measure the beam sizes of both colliding beams at the IP, based on the tunability provided by the knobs, was developed and tested.

  15. New Results from Spin Physics at RHIC

    Science.gov (United States)

    Fatemi, Renee

    2009-05-01

    The sign and magnitude of the gluon spin contribution (δG) to the spin of the proton has been a topic of intense interest and speculation since inclusive deep inelastic scattering experiments found the total quark spin contribution to be surprisingly small. Starting in 2002, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab has provided access to longitudinally and transversely polarized proton collisions. Both PHENIX and STAR, the two largest collaborations at RHIC, have used this data to complete a series of inclusive hadron and jet double spin asymmetry (ALL) measurements. The mid-rapidity 0̂ and jet results, now included in a global analysis of existing world data, are shown to provide significant constraints on δG within their range of kinematic sensitivity. Recent inclusive pion and jet ALL measurements will be presented. Plans to measure ALL in correlation channels, for example di-jets and photon-jets, and parity violating asymmetries for identified W^+/- in future longitudinal proton runs will be discussed. In addition to a successful δG program, the RHIC-Spin community is actively contributing to the new and rapidly expanding frontier within nucleon structure studies of transverse spin measurements. Quantum Chromodynamics predicts an extremely small (mq√s) spin asymmetry for leading hadron production in the reaction p^p->h+X. Contrary to expectations, transverse single-spin asymmetries (SSA) of up to 30% were discovered in forward particle production more than three decades ago, and surprisingly, asymmetries of the same magnitude have been found to persist at current RHIC center-of-mass energies. The most recent forward 0̂ and η SSA from STAR and PHENIX, as well as charged hadron measurements from the BRAHMS collaboration, will be discussed and compared with theoretical predictions.

  16. Photoproduction at RHIC and the LHC

    OpenAIRE

    Klein, Spencer

    2008-01-01

    The strong electromagnetic fields carried by relativistic highly charged ions make heavy-ion colliders attractive places to study photonuclear interactions and two-photon interactions. At RHIC, three experiments have studied coherent photoproduction of $\\rho^0$, 4$\\pi$, $J/\\psi$, $e^+e^-$ pairs, and $e^+e^-$ pairs where the electron is bound to one of the incident nuclei. These results show that photoproduction studies are possible, and demonstrate some of the unique possibilities due to the ...

  17. Parton Collectivity from RHIC to the LHC

    CERN Document Server

    Snellings, Raimond

    2009-01-01

    Anisotropic flow is recognized as one of the main observables providing information on the early dynamics in heavy-ion collisions. The large elliptic flow observed at RHIC is considered to be evidence for almost perfect liquid behavior of the strongly coupled Quark Gluon Plasma produced in the collisions. In this report we review our current understanding of this new state of matter and investigate the predictions for anisotropic flow at the LHC.

  18. RHIC polarized proton performance in run-8.

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.; Abreu, N.; Ahrens, L.; Bai, M.; Barton, D.; et al.

    2008-06-23

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.

  19. Towards Improved Proton Polarimetry at RHIC

    International Nuclear Information System (INIS)

    The RHIC polarized proton collider polarimeters employ the analyzing power in p-Carbon elastic scattering in the Coulomb Nuclear Interference region to measure the proton beam polarization. These are calibrated by the polarized hydrogen jet target that measures the absolute beam polarization utilizing the pp elastic scattering process in the CNI region. This paper describes the status of these polarimeters and the efforts employed to improve the performance in terms of better resolution, rate handling capability, and reduced systematic uncertainties.

  20. QCD and Heavy Ions RHIC Overview

    CERN Document Server

    Granier de Cassagnac, Raphael

    2010-01-01

    Nowadays, the most violent heavy ion collisions available to experimental study occur at the Relativistic Heavy Ion Collider (RHIC) of the Brookhaven National Laboratory. There, gold ions collide at psNN = 200 GeV. The early and most striking RHIC results were summarised in 2005 by its four experiments, BRAHMS, PHENIX, PHOBOS and STAR, in their so-called white papers [1, 2, 3, 4] that will be largely referenced thereafter. Beyond and after this, a wealth of data has been collected and analysed, providing additional information about the properties of the matter created at RHIC. It is categorically impossible to give a comprehensive review of these results in a 20 minutes talk or a 7 pages report. Here, I have made a selection of some of the most striking or intriguing signatures: jet quenching in Section 2, quarkonia suppressions in Section 3 and thermal photons in Section 4. A slightly longer and older version of this review can be found in [5]. Some updates are given here, as well as emphasis on new probes ...

  1. Strongly interacting matter at RHIC: experimental highlights

    CERN Document Server

    Okorokov, V A

    2014-01-01

    Recent experimental results obtained at the Relativistic Heavy-Ion Collider (RHIC) will be discussed. Investigations of different nucleus-nucleus collisions in recent years focus on two main tasks, namely, the detailed study of sQGP properties and the exploration of the QCD phase diagram. Results at top RHIC energy provide important information about event shapes as well as transport and thermodynamic properties of the hot medium for various flavors. Heavy-ion collisions are a unique tool for the study of topological properties of theory. Experimental results obtained for discrete QCD symmetries at finite temperatures are discussed. These results confirm indirectly the topologically non-trivial structure of the QCD vacuum. Most results obtained during phase-I of the RHIC beam energy scan (BES) program show smooth behavior vs initial energy. However, certain results suggest the transition in the domain of dominance of hadronic degrees of freedom at center-of-mass energies between 10-20 GeV. Future developments...

  2. Heavy flavor in heavy-ion collisions at RHIC and RHIC II

    Energy Technology Data Exchange (ETDEWEB)

    Frawley, A D; Ullrich, T; Vogt, R

    2008-03-30

    In the initial years of operation, experiments at the Relativistic Heavy Ion Collider (RHIC) have identified a new form of matter formed in nuclei-nuclei collisions at energy densities more than 100 times that of a cold atomic nucleus. Measurements and comparison with relativistic hydrodynamic models indicate that the matter thermalizes in an unexpectedly short time, has an energy density at least 15 times larger than needed for color deconfinement, has a temperature about twice the critical temperature predicted by lattice QCD, and appears to exhibit collective motion with ideal hydrodynamic properties--a 'perfect liquid' that appears to flow with a near-zero viscosity to entropy ratio--lower than any previously observed fluid and perhaps close to a universal lower bound. However, a fundamental understanding of the medium seen in heavy-ion collisions at RHIC does not yet exist. The most important scientific challenge for the field in the next decade is the quantitative exploration of the new state of nuclear matter. That will require new data that will, in turn, require enhanced capabilities of the RHIC detectors and accelerator. In this report we discuss the scientific opportunities for an upgraded RHIC facility --RHIC II--in conjunction with improved capabilities of the two large RHIC detectors, PHENIX and STAR. We focus solely on heavy flavor probes. Their production rates are calculable using the well-established techniques of perturbative QCD and their sizable interactions with the hot QCD medium provide unique and sensitive measurements of its crucial properties making them one of the key diagnostic tools available to us.

  3. Measurements of phi meson production in relativistic heavy-ion collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    STAR Coll

    2009-06-16

    We present results for the measurement of {phi} meson production via its charged kaon decay channel {phi} {yields} K{sup +}K{sup -} in Au + Au collisions at {radical}s{sub NN} = 62.4, 130, and 200 GeV, and in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (|y| < 0.5) {phi} meson transverse momentum (p{sub T}) spectra in central Au + Au collisions are found to be well described by a single exponential distribution. On the other hand, the p{sub T} spectra from p + p, d + Au and peripheral Au + Au collisions show power-law tails at intermediate and high p{sub T} and are described better by Levy distributions. The constant {phi}/K{sup -} yield ratio vs beam species, collision centrality and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for {phi} production at RHIC. The {Omega}/{phi} yield ratio as a function of p{sub T} is consistent with a model based on the recombination of thermal s quarks up to p{sub T} {approx} 4 GeV/c, but disagrees at higher transverse momenta. The measured nuclear modification factor, R{sub dAu}, for the {phi} meson increases above unity at intermediate p{sub T}, similar to that for pions and protons, while R{sub AA} is suppressed due to the energy loss effect in central Au + Au collisions. Number of constituent quark scaling of both R{sub cp} and v{sub 2} for the {phi} meson with respect to other hadrons in Au + Au collisions at {radical}s{sub NN} = 200 GeV at intermediate p{sub T} is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate p{sub T} region at RHIC.

  4. Development of a Polarized Helium-3 Source for RHIC and eRHIC

    Science.gov (United States)

    Maxwell, J.; Epstein, C.; Milner, R.; Alessi, J.; Beebe, E.; Pikin, A.; Ritter, J.; Zelenski, A.

    2016-02-01

    The addition of a polarized 3He ion source for use at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory would enable a host of new measurements, particularly in the context of a planned eRHIC. We are developing such a source using metastability exchange optical pumping to polarize helium-3, which will be then transferred into RHIC’s Electron Beam Ion Source for ionization. We aim to deliver nuclear polarization of near 70%, and roughly 1011 doubly-ionized 3He++ ions will be created in each 20 μsec pulse. We discuss the design of the source, and the status of its development.

  5. EVENT DRIVEN AUTOMATIC STATE MODIFICATION OF BNL'S BOOSTER FOR NASA SPACE RADIATION LABORATORY SOLAR PARTICLE SIMULATOR.

    Energy Technology Data Exchange (ETDEWEB)

    BROWN, D.; BINELLO, S.; HARVEY, M.; MORRIS, J.; RUSEK, A.; TSOUPAS, N.

    2005-05-16

    The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The NSRL makes use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. NASA is interested in reproducing the energy spectrum from a solar flare in the space environment for a single ion species. To do this we have built and tested a set of software tools which allow the state of the Booster and the NSRL beam line to be changed automatically. In this report we will describe the system and present results of beam tests.

  6. Measurements of strangeness production in the STAR experiment at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, W.K. [Wayne State Univ., Detroit, MI (United States)

    1995-07-15

    Simulations of the ability of the STAR (Solenoidal Tracker at RHIC) detector to measure strangeness production in central Au+Au collisions at RHIC are presented. Emphasis is placed on the reconstruction of short lived particles using a high resolution inner tracker. The prospects for performing neutral kaon interferometry are discussed. Simulation results for measurements of strange and multi-strange baryons are presented.

  7. Ring imaging Cherenkov detector of PHENIX experiment at RHIC

    International Nuclear Information System (INIS)

    The RICH detector of the PHENIX experiment at RHIC is currently under construction. Its main function is to identity electron tracks in a very high particle density, about 1000 charged particles per unit rapidity, expected in the most violent collisions at RHIC. The design and construction status of the detector and its expected performance are described

  8. Ring imaging Cherenkov detector of PHENIX experiment at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Akiba, Y. E-mail: akiba@bnl.gov; Begay, R.; Burward-Hoy, J.; Chappell, R.; Crook, D.; Ebisu, K.; Emery, M.S.; Ferriera, J.; Frawley, A.D.; Hamagaki, H.; Hara, H.; Hayano, R.S.; Hemmick, T.K.; Hibino, M.; Hutter, R.; Kennedy, M.; Kikuchi, J.; Matsumoto, T.; Moscone, C.G.; Nagasaka, Y.; Nishimura, S.; Oyama, K.; Sakaguchi, T.; Salomone, S.; Shigaki, K.; Tanaka, Y.; Walker, J.W.; Wintenberg, A.L.; Young, G.R

    1999-08-21

    The RICH detector of the PHENIX experiment at RHIC is currently under construction. Its main function is to identity electron tracks in a very high particle density, about 1000 charged particles per unit rapidity, expected in the most violent collisions at RHIC. The design and construction status of the detector and its expected performance are described.

  9. Ring imaging Cherenkov detector of PHENIX experiment at RHIC

    CERN Document Server

    Akiba, Y; Burward-Hoy, J; Chappell, R; Crook, D; Ebisu, K; Emery, M S; Ferriera, J; Frawley, A D; Hamagaki, H; Hara, H; Hayano, R S; Hemmick, T K; Hibino, M; Hutter, R; Kennedy, M; Kikuchi, J; Matsumoto, T; Moscone, C G; Nagasaka, Y; Nishimura, S; Oyama, K; Sakaguchi, T; Salomone, S; Shigaki, K; Tanaka, Y; Walker, J W; Wintenberg, A L; Young, G R

    1999-01-01

    The RICH detector of the PHENIX experiment at RHIC is currently under construction. Its main function is to identity electron tracks in a very high particle density, about 1000 charged particles per unit rapidity, expected in the most violent collisions at RHIC. The design and construction status of the detector and its expected performance are described.

  10. A FIVE-WATTS G-M/J-T REFRIGERATOR FOR THE TARGET AT BNL

    International Nuclear Information System (INIS)

    A five-watts G-M/J-T refrigerator was built and installed for the high-energy physics research at Brookhaven National Laboratory in 2001. A liquid helium target of 8.25 liters was required for an experiment in the proton beam line at the Alternating Gradient Synchrotron (AGS) of BNL. The large radiation heat load towards the target requires a five-watts refrigerator at 4.2 K to support a liquid helium flask of 0.2 meter in diameter and 0.3 meter in length which is made of Mylar film of 0.35 mm in thickness. The liquid helium flask is thermally exposed to the vacuum windows that are also made of 0.35 mm thickness Mylar film at room temperature. The refrigerator uses a two-stage Gifford-McMahon cryocooler for precooling the Joule-Thomson circuit that consists of five Linde-type heat exchangers. A mass flow rate of 0.8(approx) 1.0 grams per second at 17.7 atm is applied to the refrigerator cold box. The two-phase helium flows between the liquid target and liquid/gas separator by means of thermosyphon. The paper presents the system design as well as the test results including the control of thermal oscillation

  11. The RHIC SPIN Program: Achievements and Future Opportunities

    CERN Document Server

    Aschenauer, Elke-Caroline; Diehl, Markus; Drachenberg, James; Eyser, Kjeld Oleg; Fatemi, Renee; Gagliardi, Carl; Kang, Zhongbo; Kovchegov, Yuri; Lajoie, John; Lee, Jeong-Hun; Nocera, Emanuele-R; Pitonyak, Daniel; Prokudin, Alexei; Sassot, Rodolfo; Seidl, Ralf; Sichtermann, Ernst; Sievert, Matt; Surrow, Bernd; Stratmann, Marco; Vogelsang, Werner; Vossen, Anselm; Wissink, Scott W; Yuan, Feng

    2015-01-01

    Time and again, spin has been a key element in the exploration of fundamental physics. Spin-dependent observables have often revealed deficits in the assumed theoretical framework and have led to novel developments and concepts. Spin is exploited in many parity-violating experiments searching for physics beyond the Standard Model or studying the nature of nucleon-nucleon forces. The RHIC spin program plays a special role in this grand scheme: it uses spin to study how a complex many-body system such as the proton arises from the dynamics of QCD. Many exciting results from RHIC spin have emerged to date, most of them from RHIC running after the 2007 Long Range Plan. In this document we present highlights from the RHIC program to date and lay out the roadmap for the significant advances that are possible with future RHIC running.

  12. Modelling of the AGS using Zgoubi - Status

    Energy Technology Data Exchange (ETDEWEB)

    Meot F.; Ahrens, L.; Dutheil, Y.; Glenn, J.; Huang, H.; Roser, T.; Schoefer, V.; Tsoupas, N.

    2012-05-20

    This paper summarizes the progress achieved so far, and discusses various outcomes, regarding the development of a model of the Alternating Gradient Synchrotron at the RHIC collider. The model, based on stepwise ray-tracing methods, includes beam and polarization dynamics. This is an on-going work, and a follow-on of code developments and particle and spin dynamics simulations that have been subject to earlier publications at IPAC and PAC [1, 2, 3]. A companion paper [4] gives additional informations, regarding the use of the measured magnetic field maps of the AGS main magnets.

  13. A LOW NOISE RF SOURCE FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    HAYES,T.

    2004-07-05

    The Relativistic Heavy Ion Collider (RHIC) requires a low noise rf source to ensure that beam lifetime during a store is not limited by the rf system. The beam is particularly sensitive to noise from power line harmonics. Additionally, the rf source must be flexible enough to handle the frequency jump required for rebucketing (transferring bunches from the acceleration to the storage rf systems). This paper will describe the design of a Direct Digital Synthesizer (DDS) based system that provides both the noise performance and the flexibility required.

  14. RHIC operation with asymmetric collisions in 2015

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Aschenauer, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Atoian, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brown, K. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Connolly, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ottavio, T. D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Drees, K. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gardner, C. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hayes, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Laster, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Makdisi, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Marr, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Morris, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Narayan, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Nayak, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Nemesure, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pile, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Poblaguev, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schmidke, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Severino, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Shrey, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Steski, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); White, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yip, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zeno, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhang, S. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-08-07

    To study low-x shadowing/saturation physics as well as other nuclear effects [1], [2], proton-gold (p-Au, for 5 weeks) and proton-Aluminum (p-Al, for 2 weeks) collisions were provided for experiments in 2015 at the Relativistic Heavy Ion Collider (RHIC), with polarized proton beam in the Blue ring and Au/Al beam in the Yellow ring. The special features of the asymmetric run in 2015 will be introduced. The operation experience will be reviewed as well in the report.

  15. Recent Results from PHOBOS at RHIC

    Science.gov (United States)

    Garcia, Edmundo; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; Garcia, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Halliwell, C.; Hamblen, J.; Hauer, M.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Seals, H.; Sedykh, I.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wysłouch, B.

    2006-04-01

    The PHOBOS detector is one of four heavy-ion experiments at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. In this paper we will review some of the results of PHOBOS from the data collected in p+p, d+Au and Au+Au collisions at nucleon-nucleon center-of-mass energies up to 200 GeV. In the most central Au+Au collisions at the highest energy, evidence is found for the formation of a very high energy density and highly interactive system, which can not be described in terms of hadrons, and which has a relatively low baryon density.

  16. LEPTON AND PHOTON PHYSICS AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    TANNENBAUM,M.J.

    2003-01-06

    Results on physics at RHIC using outgoing leptons and photons will be presented from Au+Au collisions at nucleon-nucleon c.m. energies {radical}(sNN) = 130 GeV and 200 GeV, and from p-p collisions at {radical}(sNN) = 200 GeV. Introduction and motivation will be presented both from the theoretical and experimental perspectives. Topics include open charm production via single e{sup {+-}}, J/{Psi} {yields} e{sup +} + e{sup -}, {mu}{sup +} + {mu}{sup -} and inclusive photon production.

  17. RHIC spin physics: Proceedings. Volume 7

    International Nuclear Information System (INIS)

    This proceedings compiles one-page summaries and five transparencies for each talk, with the intention that the speaker should include a web location for additional information in the summary. Also, email addresses are given with the participant list. The order follows the agenda: gluon, polarimetry, accelerator, W production and quark/antiquark polarization, parity violation searches, transversity, single transverse spin, small angle elastic scattering, and the final talk on ep collisions at RHIC. The authors begin the Proceedings with the full set of transparencies from Bob Jaffe's colloquium on spin, by popular request

  18. Construction progress of the RHIC electron lenses

    Energy Technology Data Exchange (ETDEWEB)

    Fischer W.; Altinbas, Z.; Anerella, M.; Beebe, E.; et al

    2012-05-20

    In polarized proton operation the RHIC performance is limited by the head-on beam-beam effect. To overcome this limitation two electron lenses are under construction. We give an overview of the construction progress. Guns, collectors and the warm electron beam transport solenoids with their power supplies have been constructed. The superconducting solenoids that guide the electron beam during the interaction with the proton beam are near completion. A test stand has been set up to verify the performance of the gun, collector and some of the instrumentation. The infrastructure is being prepared for installation, and simulations continue to optimize the performance.

  19. RHIC spin physics: Proceedings. Volume 7

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This proceedings compiles one-page summaries and five transparencies for each talk, with the intention that the speaker should include a web location for additional information in the summary. Also, email addresses are given with the participant list. The order follows the agenda: gluon, polarimetry, accelerator, W production and quark/antiquark polarization, parity violation searches, transversity, single transverse spin, small angle elastic scattering, and the final talk on ep collisions at RHIC. The authors begin the Proceedings with the full set of transparencies from Bob Jaffe`s colloquium on spin, by popular request.

  20. Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Quarkonium Production in Elementary and Heavy Ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Dumitru, A.; Lourenco, C.; Petreczky, P.; Qiu, J., Ruan, L.

    2011-08-03

    Understanding the structure of the hadron is of fundamental importance in subatomic physics. Production of heavy quarkonia is arguably one of the most fascinating subjects in strong interaction physics. It offers unique perspectives into the formation of QCD bound states. Heavy quarkonia are among the most studied particles both theoretically and experimentally. They have been, and continue to be, the focus of measurements in all high energy colliders around the world. Because of their distinct multiple mass scales, heavy quarkonia were suggested as a probe of the hot quark-gluon matter produced in heavy-ion collisions; and their production has been one of the main subjects of the experimental heavy-ion programs at the SPS and RHIC. However, since the discovery of J/psi at Brookhaven National Laboratory and SLAC National Accelerator Laboratory over 36 years ago, theorists still have not been able to fully understand the production mechanism of heavy quarkonia, although major progresses have been made in recent years. With this in mind, a two-week program on quarkonium production was organized at BNL on June 6-17, 2011. Many new experimental data from LHC and from RHIC were presented during the program, including results from the LHC heavy ion run. To analyze and correctly interpret these measurements, and in order to quantify properties of the hot matter produced in heavy-ion collisions, it is necessary to improve our theoretical understanding of quarkonium production. Therefore, a wide range of theoretical aspects on the production mechanism in the vacuum as well as in cold nuclear and hot quark-gluon medium were discussed during the program from the controlled calculations in QCD and its effective theories such as NRQCD to various models, and to the first principle lattice calculation. The scientific program was divided into three major scientific parts: basic production mechanism for heavy quarkonium in vacuum or in high energy elementary collisions; the

  1. Commissioning and performance of the BNL EBIS LLRF system

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, S.; Smith, K.S.; Hayes, T.; Severino, F.; Harvey, M.; Narayan, G.; Zaltsman, A.

    2011-03-28

    The Electron Beam Ion Source (EBIS) LLRF system utilizes the RHIC LLRF upgrade platform to achieve the required functionality and flexibility. The LLRF system provides drive to the EBIS high-level RF system, employs I-Q feedback to provide required amplitude and phase stability, and implements a cavity resonance control scheme. The embedded system provides the interface to the existing Controls System, making remote system control and diagnostics possible. The flexibility of the system allows us to reuse VHDL codes, develop new functionalities, improve current designs, and implement new features with relative ease. In this paper, we will discuss the commissioning process, issues encountered, and performance of the system.

  2. High luminosity electron-hadron collider eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Ptitsyn, V.; Aschenauer, E.; Bai, M.; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M..; Calaga, R.; Chang, X.; Fedotov, A.; Gassner, D.; Hammons, L.; Hahn, H.; Hammons, L.; He, P.; Hao, Y.; Jackson, W.; Jain, A.; Johnson, E.C.; Kayran, D.; Kewisch, J.; Litvinenko, V.N.; Luo, Y.; Mahler, G.; McIntyre, G.; Meng, W.; Minty, M.; Parker, B.; Pikin, A.; Rao, T.; Roser, T.; Skaritka, J.; Sheehy, B.; Skaritka, J.; Tepikian, S.; Than, Y.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Webb, S.; Wu, Q.; Xu, W.; Pozdeyev, E.; Tsentalovich, E.

    2011-03-28

    We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 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 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

  3. First results from RHIC-PHENIX

    Indian Academy of Sciences (India)

    Tarun Kanti Ghosh; K Adcox; S S Adler; N Ajitanand; Y Akiba; J Alexander; L Aphecetche; Y Arai; S H Aronson; R Averbeck; T C Awes; K N Barish; P D Barnes; J Barrette; B Bassalleck; S Bathe; V Baublis; A Bazilevsky; S Belikov; F G Bellaiche; S T Belyaev; M J Bennett; Y Berdnikov; S Botelho; M L Brooks; D S Brown; N Bruner; D Bucher; H Buesching; V Bumazhnov; G Bunce; J Burward-Hoy; S Butsyk; T A Carey; P Chand; J Chang; W C Chang; L L Chavez; S Chernichenko; C Y Chi; J Chiba; M Chiu; R K Choudhury; T Christ; T Chujo; M S Chung; P Chung; V Cianciolo; B A Cole; D G D’Enterria; G David; H Delagrange; A Denisov; A Deshpande; E J Desmond; O Dietzsch; B V Dinesh; A Drees; A Durum; D Dutta; K Ebisu; Y V Efremenko; K El Chenawi; H En’yo; S Esumi; L Ewell; T Ferdousi; D E Fields; S L Fokin; Z Fraenkel; A Franz; A D Frawley; S-Y Fung; S Garpman; T K Ghosh; A Glenn; A L Godoi; Y Goto; S V Greene; M Grosse Perdekamp; S K Gupta; W Guryn; H-Å Gustafsson; J S Haggerty; H Hamagaki; A G Hansen; H Hara; E P Hartouni; R Hayano; N Hayashi; X He; T K Hemmick; J Heuser; J C Hill; D S Ho; K Homma; B Hong; A Hoover; T Ichihara; K Imai; M S Ippolitov; M Ishihara; B V Jacak; W Y Jang; J Jia; B M Johnson; S C Johnson; K S Joo; S Kametani; J H Kang; M Kann; S S Kapoor; S Kelly; B Khachaturov; A Khanzadeev; J Kikuchi; D J Kim; H J Kim; S Y Kim; Y G Kim; W W Kinnison; E Kistenev; A Kiyomichi; C Klein-Boesing; S Klinksiek; L Kochenda; D Kochetkov; V Kochetkov; D Koehler; T Kohama; A Kozlov; P J Kroon; K Kurita; M J Kweon; Y Kwon; G S Kyle; R Lacey; J G Lajoie; J Lauret; A Lebedev; D M Lee; M J Leitch; X H Li; Z Li; D J Lim; M X Liu; X Liu; Z Liu; C F Maguire; J Mahon; Y I Makdisi; V I Manko; Y Mao; S K Mark; S Markacs; G Martinez; M D Marx; A Masaike; F Matathias; T Matsumoto; P L McGaughey; E Melnikov; M Merschmeier; F Messer; M Messer; Y Miake; T E Miller; A Milov; S Mioduszewski; R E Mischke; G C Mishra; J T Mitchell; A K Mohanty; D P Morrison; J M Moss; F Mühlbacher; M Muniruzzaman; J Murata; S Nagamiya; Y Nagasaka; J L Nagle; Y Nakada; B K Nandi; J Newby; L Nikkinen; P Nilsson; S Nishimura; A S Nyanin; J Nystrand; E O’Brien; C A Ogilvie; H Ohnishi; I D Ojha; M Ono; V Onuchin; A Oskarsson; L Österman; I Otterlund; K Oyama; L Paffrath; A P T Palounek; V S Pantuev; V Papavassiliou; S F Pate; T Peitzmann; A N Petridis; C Pinkenburg; R P Pisani; P Pitukhin; F Plasil; M Pollack; K Pope; M L Purschke; I Ravinovich; K F Read; K Reygers; V Riabov; Y Riabov; M Rosati; A A Rose; S S Ryu; N Saito; A Sakaguchi; T Sakaguchi; H Sako; T Sakuma; V Samsonov; T C Sangster; R Santo; H D Sato; S Sato; S Sawada; B R Schlei; Y Schutz; V Semenov; R Seto; T K Shea; I Shein; T-A Shibata; K Shigaki; T Shiina; Y H Shin; I G Sibiriak; D Silvermyr; K S Sim; J Simon-Gillo; C P Singh; V Singh; M Sivertz; A Soldatov; R A Soltz; S Sorensen; P W Stankus; N Starinsky; P Steinberg; E Stenlund; A Ster; S P Stoll; M Sugioka; T Sugitate; J P Sullivan; Y Sumi; Z Sun; M Suzuki; E M Takagui; A Taketani; M Tamai; K H Tanaka; Y Tanaka; E Taniguchi; M J Tannenbaum; J Thomas; J H Thomas; T L Thomas; W Tian; J Tojo; H Torii; R S Towell; I Tserruya; H Tsuruoka; A A Tsvetkov; S K Tuli; H Tydesjö; N Tyurin; T Ushiroda; H W van Hecke; C Velissaris; J Velkovska; M Velkovsky; A A Vinogradov; M A Volkov; A Vorobyov; E Vznuzdaev; H Wang; Y Watanabe; S N White; C Witzig; F K Wohn; C L Woody; W Xie; K Yagi; S Yokkaichi; G R Young; I E Yushmanov; W A Zajc; Z Zhang; S Zhou

    2001-08-01

    The PHENIX experiment consists of a large detector system located at the newly commissioned relativistic heavy ion collider (RHIC) at the Brookhaven National Laboratory. The primary goal of the PHENIX experiment is to look for signatures of the QCD prediction of a deconfined high-energy-density phase of nuclear matter quark gluon plasma. PHENIX started data taking for Au+Au collisions at $\\sqrt{s_{NN}} = 130$ GeV in June 2000. The signals from the beam-beam counter (BBC) and zero degree calorimeter (ZDC) are used to determine the centrality of the collision. A Glauber model reproduces the ZDC spectrum reasonably well to determine the participants in a collision. Charged particle multiplicity distribution from the first PHENIX paper is compared with the other RHIC experiment and the CERN, SPS results. Transverse momentum of photons are measured in the electro-magnetic calorimeter (EMCal) and preliminary results are presented. Particle identification is made by a time of flight (TOF) detector and the results show clear separation of the charged hadrons from each other.

  4. The PHOBOS perspective on discoveries at RHIC

    Science.gov (United States)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N. K.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C. M.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.; Zhang, J.; Phobos Collaboration

    2005-08-01

    This paper describes the conclusions that can be drawn from the data taken thus far with the PHOBOS detector at RHIC. In the most central Au + Au collisions at the highest beam energy, evidence is found for the formation of a very high energy density system whose description in terms of simple hadronic degrees of freedom is inappropriate. Furthermore, the constituents of this novel system are found to undergo a significant level of interaction. The properties of particle production at RHIC energies are shown to follow a number of simple scaling behaviors, some of which continue trends found at lower energies or in simpler systems. As a function of centrality, the total number of charged particles scales with the number of participating nucleons. When comparing Au + Au at different centralities, the dependence of the yield on the number of participants at higher p ( ˜4 GeV/c) is very similar to that at low transverse momentum. The measured values of charged particle pseudorapidity density and elliptic flow were found to be independent of energy over a broad range of pseudorapidities when effectively viewed in the rest frame of one of the colliding nuclei, a property we describe as "extended longitudinal scaling". Finally, the centrality and energy dependences of several observables were found to factorize to a surprising degree.

  5. Results from RHIC with Implications for LHC

    CERN Document Server

    Tannenbaum, M J

    2010-01-01

    Results from the PHENIX experiment at RHIC in p-p and Au+Au collisions are reviewed from the perspective of measurements in p-p collisions at the CERN-ISR which serve as a basis for many of the techniques used. Issues such as J/Psi suppression and hydrodynamical flow in A+A collisions require data from LHC-Ions for an improved understanding. Suppression of high pT particles in Au+Au collisions, first observed at RHIC, also has unresolved mysteries such as the equality of the suppression of inclusive pi0 (from light quarks and gluons) and direct-single electrons (from the decay of heavy quarks) in the transverse momentum range 4< pT < 9 GeV/c. This disfavors a radiative explanation of suppression and leads to a fundamental question of whether the Higgs boson gives mass to fermions. Observation of an exponential distribution of direct photons in central Au+Au collisions for 1< pT <2 GeV/c where hard-processes are negligible and with no similar exponential distribution in p-p collisions indicates the...

  6. Upgrade scenario for the RHIC collimation system

    Energy Technology Data Exchange (ETDEWEB)

    Robert-Demolaize, G.; Drees, A.

    2012-01-19

    The RHIC collimation system is used to reduce background levels in both STAR and PHENIX detectors. With a push for higher luminosity in the near future, it becomes critical to check if and how the level of performance of the collimators can be improved. The following reviews a proposal for additional collimators placed further downstream of the current system and designed to intercept the tertiary halo coming out of the IR8 insertion before it can reach the triplet quadrupoles in either STAR or PHENIX. Simulations have been peformed to quantify the efficiency of additional collimator jaws in RHIC. Each figure presented in this article clearly shows that the additional mask collimators provide the expected reduction in losses around the machine, and especially to the incoming triplet to the STAR experiment (IP6), for the Yellow beam as much as for the Blue beam. Looking at compiled statistics for all three working point cases studied, proton losses around the machine are reduced by roughly one order of magnitude: at most a factor 30 for magnet losses, and at most a factor 40 for losses in spaces between magnets.

  7. DOE/NORA/BNL oil heat research agenda development

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.J. [Brookhaven National Lab., Upton, NY (United States); Batey, J. [Energy Research Center, Easton, CT (United States)

    1996-07-01

    The National Oilheat Research Alliance (NORA) has been formed and is currently working to establish a Congressionally approved oilheat check-off program to provide funding for research, education, training, safety, and marketing to benefit the US oilheat industry. NORA will be presenting this program to the Congress for its consideration and approval in the coming year. It will follow the same path as the National Propane Gas Association which is currently working on obtaining Congressional approval of a propane check off program that has already attracted over 120 cosponsors in the House of representatives. An effort to define the basis of a joint US Department of Energy (DOE) and Oilheat industry (marketers) program for future oilheat equipment research and development will be conducted during FY-1996. At the request of NORA representatives BNL will coordinate the development of a research agenda addressing three categories of activities, research appropriate for DOE support only, research appropriate for NORA support only, and research appropriate for co-funding by both organizations. This will also serve to update a prior oil-fueled research plan developed for DOE ten years ago which has been the road map for DOE`s very successful Oil Heat R&D program at BNL.

  8. Studies and proposed changes to the RHIC p-Carbon polarimeters for the upcoming RUN-11

    Energy Technology Data Exchange (ETDEWEB)

    Makdisi, Y.; Alekseev, I.; Aschenauer, E.; Atoian, G.; Bazilevsky, A.; Gill, R.; Huang, H.; Morozov, B.; Svirida, D.; Yip, K.; Zelenski, A.

    2010-09-27

    The RHIC polarized proton complex utilizes polarimeters in each of the Blue and Yellow beams that measure the beam polarization through the p-Carbon elastic scattering process in the Coulomb Nuclear Interference kinematic region. This along with a Polarized Hydrogen Jet Target that utilizes the proton-proton elastic scattering process to first measure the analyzing power of the reaction and using the reverse process to measure the beam polarization. The latter is used to calibrate the p-Carbon polarimeters at the desired beam energy. In Run 9 RHIC ran with beams at center-of-mass energies of 200 and 500 GeV respectively. The higher beam intensities as well as the fact that the 250 GeV beam size is much smaller than that at 100 GeV resulted in significantly higher rates seen by the polarimeters and led to observed instability. In this paper, we will discuss the problems encountered and the tests that were carried out using the AGS as a proxy in an attempt to solve the problems and the path forward we took towards the upcoming polarized proton Run11.

  9. Studies and proposed changes to the RHIC p-Carbon polarimeters for the upcoming RUN-11

    International Nuclear Information System (INIS)

    The RHIC polarized proton complex utilizes polarimeters in each of the Blue and Yellow beams that measure the beam polarization through the p-Carbon elastic scattering process in the Coulomb Nuclear Interference kinematic region. This along with a Polarized Hydrogen Jet Target that utilizes the proton-proton elastic scattering process to first measure the analyzing power of the reaction and using the reverse process to measure the beam polarization. The latter is used to calibrate the p-Carbon polarimeters at the desired beam energy. In Run 9 RHIC ran with beams at center-of-mass energies of 200 and 500 GeV respectively. The higher beam intensities as well as the fact that the 250 GeV beam size is much smaller than that at 100 GeV resulted in significantly higher rates seen by the polarimeters and led to observed instability. In this paper, we will discuss the problems encountered and the tests that were carried out using the AGS as a proxy in an attempt to solve the problems and the path forward we took towards the upcoming polarized proton Run11.

  10. A number of upgrades on RHIC power supply system

    Energy Technology Data Exchange (ETDEWEB)

    Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drozd, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Nolan, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Orsatti, F. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Heppener, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Di Lieto, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schultheiss, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Zapasek, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Sandberg, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    This year marks the 15th run for the Relativistic Heavy Ion Collider (RHIC). Operation of a reliable superconducting magnet power supply system is a key factor of an accelerator’s performance. Over the past 15 years, the RHIC power supply group has made many improvements to increase the machine availability and reduce failures. During these past 15 years of operating RHIC a lot of problems have been solved or addressed. In this paper some of the essential upgrades/improvements are discussed.

  11. Search for quark compositeness with polarized beams at RHIC

    CERN Document Server

    Virey, J M

    1996-01-01

    Around 1999, thanks to the RHIC Spin Collaboration (RSC), the Relativistic Heavy Ion Collider (RHIC) will be used as a polarized proton-proton collider. A new handed interaction between quark subconstituents, which could explain the excess of large E_T jet found by the CDF collaboration, could be at the origin of some small parity violating effects in one-jet inclusive production. Using spin asymmetries it is possible, at RHIC, to disentangle this new effect from the Standard Model prediction due to QCD-ElectroWeak interferences.

  12. AC dipole based optics measurement and correction at RHIC

    CERN Document Server

    Shen, X; Bai, M; White, S; Robert-Domolaize, G; Luo, Y; Marusic, A; Tomas, R

    2013-01-01

    Independent component analysis (ICA) was applied to the AC dipole based optics measurement at RHIC to extract beta functions as well as phase advances at each BPM. Existence of excessive beta-beat was observed in both rings of RHIC at polarized proton store energy. A unique global optics correction scheme was then developed and tested successfully during the RHIC polarized proton run in 2013. The feasibility of using horizontal closed orbit bump at sextupole for arc beta-beat correction was also demonstrated.

  13. RHIC POWER SUPPLIES - LESSONS LEARNED FROM THE 1999 - 2001 RHIC RUNS.

    Energy Technology Data Exchange (ETDEWEB)

    BRUNO,D.ENG,W.GANETIS,G.LAMBIASE,R.F.LOUIE,W.SANDBERG,J.SCHULTHEISS,C.

    2003-05-12

    The Relativistic Heavy Ion Collider (RHIC) was commissioned in 1999 and 2000. The two RHIC rings require a total of 933 power supplies (PSs) to supply currents to highly inductive superconducting magnets. These units function as 4 main PSs, 237 insertion region (02) PSs, 24 sextupole PSs, 24 Gamma-T PSs, 8 snake PSs, 16 spin rotator PSs, and 620 correction PSs. PS reliability in this type of machine is of utmost importance because the IR PSs are nested within other IR PSs, and these are all nested within the main PSs. This means if any main or IR PS trips off due to a PS fault or quench indication, then all the IR and main PSs in that ring must follow. When this happens, the Quench Protection Assemblies (QPA's) for each unit disconnects the PSs from the circuit and absorb the stored energy in the magnets. Commissioning these power supplies and QPA's was and still is a learning experience. A summary of the major problems encountered during these first three RHIC runs will be presented along with solutions.

  14. The electromagnetic calorimeter for the solenoidal tracker at RHIC

    International Nuclear Information System (INIS)

    This report discusses the following on the electromagnetic calorimeter for the solenoidal tracker at RHIC: conceptual design; the physics of electromagnetic calorimetry in STAR; trigger capability; integration into STAR; and cost, schedule, manpower, and funding

  15. ERL Based Electron-Ion Collider eRHIC

    CERN Document Server

    Litvinenko, Vladimir N; Bai, Mei; Beebe-Wang, Joanne; Ben-Zvi, Ilan; Blaskiewicz, Michael; Brennan, Joseph M; Calaga, Rama; Chang, Xiangyun; Deshpande, Abhay A; Farkhondeh, Manouchehr; Fedotov, Alexei V; Fischer, Wolfram; Kayran, Dmitry; Kewisch, Jorg; MacKay, William W; Montag, Christoph; Parker, Brett; Peggs, Steve; Ptitsyn, Vadim; Roser, Thomas; Ruggiero, Alessandro; Satogata, Todd; Surrow, Bernd; Tepikian, Steven; Trbojevic, Dejan; Yakimenko, Vitaly; Zhang, S Y

    2005-01-01

    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.

  16. Code generation of RHIC accelerator device objects

    International Nuclear Information System (INIS)

    A RHIC Accelerator Device Object is an abstraction which provides a software view of a collection of collider control points known as parameters. A grammar has been defined which allows these parameters, along with code describing methods for acquiring and modifying them, to be specified efficiently in compact definition files. These definition files are processed to produce C++ source code. This source code is compiled to produce an object file which can be loaded into a front end computer. Each loaded object serves as an Accelerator Device Object class definition. The collider will be controlled by applications which set and get the parameters in instances of these classes using a suite of interface routines. Significant features of the grammar are described with details about the generated C++ code

  17. RHIC 10 Hz global orbit feedback system

    Energy Technology Data Exchange (ETDEWEB)

    Michnoff, R.; Arnold, L.; Carboni, L.; Cerniglia, P; Curcio, A.; DeSanto, L.; Folz, C.; Ho, C.; Hoff, L.; Hulsart, R.; Karl, R.; Luo, Y.; Liu, C.; MacKay, W.; Mahler, G.; Meng, W.; Mernick, K.; Minty, M.; Montag, C.; Olsen, R.; Piacentino, J.; Popken, P.; Przybylinski, R.; Ptitsyn, V.; Ritter, J.; Schoenfeld, R.; Thieberger, P.; Tuozzolo, J.; Weston, A.; White, J.; Ziminski, P.; Zimmerman, P.

    2011-03-28

    Vibrations of the cryogenic triplet magnets at the Relativistic Heavy Ion Collider (RHIC) are suspected to be causing the horizontal beam perturbations observed at frequencies around 10 Hz. Several solutions to counteract the effect have been considered in the past, including a local beam feedback system at each of the two experimental areas, reinforcing the magnet base support assembly, and a mechanical servo feedback system. However, the local feedback system was insufficient because perturbation amplitudes outside the experimental areas were still problematic, and the mechanical solutions are very expensive. A global 10 Hz orbit feedback system consisting of 36 beam position monitors (BPMs) and 12 small dedicated dipole corrector magnets in each of the two 3.8 km circumference counter-rotating rings has been developed and commissioned in February 2011. A description of the system architecture and results with beam will be discussed.

  18. Recent results from PHOBOS at RHIC

    International Nuclear Information System (INIS)

    PHOBOS is one of the four heavy ion experiments currently running at the Relativistic Heavy Ion Collider (RHIC). In this paper we will present some of the current results from PHOBOS: the study of charged multiplicity distribution as function of pseudorapidity and centrality at √SNN 19.6, 130 and 200 GeV, a discussion of multiplicity scaling, and a measurement of transverse momentum spectra (pT ) of charged hadrons produced in d+Au and Au+Au interactions at √SNN = 200 GeV. The dependence of the Au+Au yields as function of centrality is found to be independent of pT . A strong suppression in the Au+Au hadron spectra relative pp-bar at high pT is observed. The spectral shape for d+Au collisions is significantly different from the observations in Au+Au, the yield suppression is not observed in d+Au. (author)

  19. A Helical Magnet Design for RHIC^*.

    Science.gov (United States)

    Willen, E.; Gupta, R.; Kelly, E.; Muratore, J.

    1997-05-01

    Helical dipole magnets are required in a project for the Relativistic Heavy Ion Collider (RHIC) to control and preserve the beam polarization in order to allow the collision of polarized proton beams. The project requires superconducting magnets with a 100 mm coil aperture and a 4 Tesla field in which the field rotates 360 degrees over a distance of 2.4 meters. A design restraint is that the magnets operate at relatively low current (less than 500 amperes) in order to minimize the heat load from the current leads. A magnet has been developed that uses a small diameter superconducting cable wound into helical grooves machined into a thick-walled aluminum cylinder. The design and test results of this prototype magnet will be described. ^*Work supported by the U.S. Department of Energy.

  20. Systematics of heavy quark production at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R.

    2002-01-30

    We discuss a program for systematic studies of heavy quark production in pp, pA and AA interactions. The Q{ovr Q} production cross sections themselves cannot be accurately predicted to better than 50% at RHIC. For studies of deviations in Q{ovr Q} production such as those by nuclear shadowing and heavy quark energy loss, the pp cross-section thus needs to be measured. We then show that the ratio of pA to pp dilepton mass distributions can provide a measurement of the nuclear gluon distribution. With total rates and nuclear shadowing under control it is easier to study energy loss and to use c{ovr c} as a normalization of J/{Psi} production.

  1. Polarization simulations in the RHIC run 15 lattice

    Energy Technology Data Exchange (ETDEWEB)

    Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    RHIC polarized proton Run 15 uses a new acceleration ramp optics, compared to RHIC Run 13 and earlier runs, in relation with electron-lens beam-beam compensation developments. The new optics induces different strengths in the depolarizing snake resonance sequence, from injection to top energy. As a consequence, polarization transport along the new ramp has been investigated, based on spin tracking simulations. Sample results are reported and discussed.

  2. Tracking studies in eRHIC energy-recovery recirculator

    Energy Technology Data Exchange (ETDEWEB)

    Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brooks, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-07-13

    Beam and polarization tracking studies in eRHIC energy recovery electron recirculator are presented, based on a very preliminary design of the FFAG lattice. These simulations provide examples of some of the beam and spin optics aspects of the linear FFAG lattice concept and its application in eRHIC, they provide code benchmarking for synchrotron radiation and spin diffusion in addition, and pave the way towards end-to-end 6-D(phasespace)+3D(spin) tracking simulations.

  3. Field testing the prototype BNL fan-atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    BNL has developed a new oil burner design referred to as the Fan Atomized burner System. The primary objective of the field study was to evaluate and demonstrate the reliable operation of the Fan Atomized Burner. The secondary objective was to establish and validate the ability of a low firing rate burner (0.3-0.4 gph) to fully satisfy the heating and domestic hot water load demands of an average household in a climate zone with over 5,000 heating-degree-days. The field activity was also used to evaluate the practicality of side-wall venting with the Fan Atomized Burner with a low stack temperature (300F) and illustrate the potential for very high efficiency with an integrated heating system approach based on the Fan Atomized Burner.

  4. Proceedings of the symposium on RHIC detector R&D

    Energy Technology Data Exchange (ETDEWEB)

    Makdisi, Y.; Stevens, A.J. [eds.

    1991-12-31

    This report contains papers on the following topics: Development of Analog Memories for RHIC Detector Front-end Electronic Systems; Monolithic Circuit Development for RHIC at Oak Ridge National Laboratory; Highly Integrated Electronics for the STAR TPC; Monolithic Readout Circuits for RHIC; New Methods for Trigger Electronics Development; Neurocomputing methods for Pattern Recognition in Nuclear Physics; The Development of a Silicon Multiplicity Detector System; The Vertex Detector for the Lepton/Photon Collaboration; Simulations of Silicon Vertex Tracker for STAR Experiment at RHIC; Calorimeter/Absorber Optimization for a RHIC Dimuon Experiment (RD-10 Project); Applications of the LAHET simulation Code to Relativistic Heavy Ion Detectors; Highly Segmented, High Resolution Time-of-Flight System; Research and Development on a Sub 100 Picosecond Time-of-Flight System Based on Silicon Avalance Diodes; Behavior of TPC`s in a High Particle Flux Environment; Generic R&D on Undoped Cesium Iodide and Lead Fluoride; and A Transition Radiation Detector for RHIC Featuring Accurate Tracking and dE/dx Particle Identification. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  5. PHYSICS OF THE 1 TERAFLOP RIKEN-BNL-COLUMBIA QCD PROJECT.

    Energy Technology Data Exchange (ETDEWEB)

    MAWHINNEY,R.

    1998-10-16

    A workshop was held at the RIKEN-BNL Research Center on the afternoon of October 16, i 998, as part of the first anniversary ceremony for the center. Titled ''Workshop on Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD Project'', this meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. In addition, Akira Ukawa, a leader of the CP-PACS project at the University of Tsukuba in Japan, attended and gave a talk on the Aoki phase. There were also others in attendance who were interested in more general properties of the QCDSP computer. The QCDSP computer and lattice QCD had been presented during the morning ceremony by Shigemi Ohta of KEK and the RIKEN-BNL Research Center. This was followed by a tour of the QCDSP machine room and a formal unveiling of the computer to the attendees of the anniversary ceremony and the press. The rapid completion of construction of the QCDSP computer was made possible through many factors: (1) the existence of a complete design and working hardware at Columbia when the RIKEN-BNL center was being set up, (2) strong support for the project from RIKEN and the center and (3) aggressive involvement of members of the Computing and Communications Division at BNL. With this powerful new resource, the members of the RIKEN-BNL-Columbia, QCD project are looking forward to advances in our understanding of QCD.

  6. PHYSICS OF THE 1 TERAFLOP RIKEN-BNL-COLUMBIA QCD PROJECT.

    Energy Technology Data Exchange (ETDEWEB)

    MAWHINNEY,R.

    1998-10-16

    A workshop was held at the RIKEN-BNL Research Center on the afternoon of October 16, 1998, as part of the first anniversary ceremony for the center. Titled ''Workshop on Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD Project'', this meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. In addition, Akira Ukawa, a leader of the CP-PACS project at the University of Tsukuba in Japan, attended and gave a talk on the Aoki phase. There were also others in attendance who were interested in more general properties of the QCDSP computer. The QCDSP computer and lattice QCD had been presented during the morning ceremony by Shigemi Ohta of KEK and the RIKEN-BNL Research Center. This was followed by a tour of the QCDSP machine room and a formal unveiling of the computer to the attendees of the anniversary ceremony and the press. The rapid completion of construction of the QCDSP computer was made possible through many factors: (1) the existence of a complete design and working hardware at Columbia when the RIKEN-BNL center was being set up, (2) strong support for the project from RIKEN and the center and (3) aggressive involvement of members of the Computing and Communications Division at BNL. With this powerful new resource, the members of the RIKEN-BNL-Columbia, QCD project are looking forward to advances in our understanding of QCD.

  7. BNL workshop on rare K decays and CP violation, August 25-27, 1988

    International Nuclear Information System (INIS)

    This report contains viewgraphs on the following topics: rare and forbidden K decays; CP violation in the K system; the status of current experiments at BNL, CERN, FNAL, and KEK; and future experiments and facilities

  8. BNL workshop on rare K decays and CP violation, August 25-27, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1988-10-01

    This report contains viewgraphs on the following topics: rare and forbidden K decays; CP violation in the K system; the status of current experiments at BNL, CERN, FNAL, and KEK; and future experiments and facilities.

  9. Heavy ion acceleration at the AGS

    International Nuclear Information System (INIS)

    The Brookhaven AGS is alternating gradient synchrotron, 807 meters in circumference, which was originally designed for only protons. Using the 15 MV Brookhaven Tandem Van de Graaff as an injector, the AGS started to accelerate heavy ions of mass lighter than sulfur. Because of the relatively poor vacuum (∼10-8 Torr), the AGS is not able to accelerate heavier ions which could not be fully stripped of electrons at the Tandem energy. When the AGS Booster, which is under construction, is completed the operation will be extended to all species of heavy ions including gold and uranium. Because ultra-high vacuum (∼10-11 Torr) is planned, the Booster can accelerate partially stripped elements. The operational experience, the parameters, and scheme of heavy ion acceleration will be presented in detail from injection to extraction, as well as future injection into the new Relativistic Heavy Ion Collider (RHIC). A future plan to improve intensity of the accelerator will also be presented. 5 figs., 4 tabs

  10. Transverse and longitudinal dynamics at RHIC

    Science.gov (United States)

    Staszel, P.; BRAHMS Collaboration

    2008-04-01

    We review results obtained by the BRAHMS experiment at the Relativistic Heavy Ion Collider (RHIC) for the systems of Au+Au and p+p colliding at \\rootsnn{200} and at \\rootsnn{62.4} . Rapidity-dependent \\barp/\\pi^- and K±/π± ratios within 0 < y < 3 for Au+Au at \\rootsnn{200} are found to be enhanced in nucleus-nucleus collisions as compared to p+p collisions. The particle ratios are discussed in terms of their system size and rapidity dependence. From comparison of RAA for different systems and energies it is found that RAA increases with decreasing collision energy, decreasing system size and when going toward more peripheral collisions. However, RAA shows only a very weak dependence on rapidity (for 0 < y < 3.2), both for pions and protons. The \\barp/p ratio for p+p collisions at \\roots{200} is below 0.1 at high pT (≈4 GeV/c) and y ≈ 3. Such a strong asymmetry in p and \\barp production cannot be described within next-to-leading order perturbative QCD utilizing any known sets of FFs. At the same rapidity but lower energy (\\roots{62.4}) the charge asymmetry is stronger by an order of magnitude for both protons and kaons.

  11. Possibilities for stochastic cooling at RHIC

    CERN Document Server

    Brennan, J M; Wei, J

    2004-01-01

    Intra-Beam Scattering (IBS) is the fundamental performance limitation for RHIC. The emittance growth from IBS determines the ultimate luminosity lifetime and the only cure is cooling. Full-energy electron cooling will be installed to not only control emittance growth but also reduce emittances during a store. Before that, stochastic cooling could increase integrated luminosity by momentum cooling. Two significant benefits would follow; the average luminosity in a 10 h store would double, and the problem of coasting beam in the abort gap would be solved. Of course high-frequency bunched beam stochastic cooling is required and previous attempts at this at the Tevatron and SPS were not successful. It appears that the conditions in the heavy ion collider are more favorable. First, the high charge state of ions gives better signal to noise ratio in the Schottky signal. Second, the anomalous coherent components in the pick up signals that caused saturation in the electronics in previous attempts are greatly reduced...

  12. PHOBOS at RHIC: Some global observations

    Indian Academy of Sciences (India)

    Alan S Carroll; B B Back; M D Baker; D S Barton; R R Betts; M Ballintijn; A A Bickley; R Bindel; A Budzanowski; W Busza; A Carroll; M P Decowski; E García; N George; K Gulbrandsen; S Gushue; C Halliwell; J Hamblen; G A Heintzelman; C Henderson; D J Hofman; R S Hollis; R Hoyłyński; B Holzman; A Iordanova; E Johnson; J L Kane; J Katzy; N Khan; W Kucewicz; P Kulinich; C M Kuo; W T Lin; S Manly; D McLeod; J Michałowski; A C Mignerey; R Nouicer; A Olszewski; R Pak; I C Park; H Pernegger; C Reed; L P Remsberg; M Reuter; C Roland; G Roland; L Rosenberg; J Sagerer; P Sarin; P Sawicki; W Skulski; S G Steadman; P Steinberg; G S F Stephans; M Stodulski; A Sukhanov; J-L Tang; R Teng; A Trzupek; C Vale; G J van Nieuwenhuizen; R Verdier; B Wadsworth; F L H Wolfs; B Wosiek; K Woźniak; A H Wuosmaa; B Wysłouch; For the PHOBOS Collaboration

    2003-11-01

    Particle production in Au+Au collisions has been measured in the PHOBOS experiment at RHIC for a range of collision energies for a large span of pseudorapidities, || < 5.4. Three empirical observations have emerged from this data set which require theoretical examination. First, there is clear evidence of limiting fragmentation. Namely, particle production in central Au+Au collisions, when expressed as d/d' (' ≡ -beam), becomes energy independent at high energy for a broad region of ' around '=0. This energy-independent region grows with energy, allowing only a limited region (if any) of longitudinal boost-invariance. Second, there is a striking similarity between particle production in +- and Au + Au collisions (scaled by the number of participating nucleon pairs). Both the total number of produced particles and the longitudinal distribution of produced particles are approximately the same in +- and in scaled Au + Au. This observation was not predicted and has not been explained. Finally, particle production has been found to scale approximately with the number of participating nucleon pairs for $\\langle N_{\\text{part}}\\rangle > 65$. This scaling occurs both for the total multiplicity and for high T particles (3 < T < 4.5 GeV/c).

  13. Particle Production at RHIC and LHC Energies

    CERN Document Server

    Tawfik, A; Shalaby, A G

    2012-01-01

    The production of different particle species is recently measured in $Pb-Pb$ collisions by the ALICE experiment at $\\sqrt{s}=7 $TeV. This motivates the use of various bosons and baryons measured at lower center-of-mass energies in comparing their ratios to the hadron resonance (HRG) gas model and PYTHIA event generator. It is found that the particle-to-antiparticle ratios are perfectly reproduce by means of HRG and PYTHIA at RHIC and LHC energies. The kaon-to-pion and proton-to-pion ratios are entirely overestimated by the HRG model. The PYTHIA event generator obviously underestimates the kaon-to-pion ratio and simultaneously reproduces the proton-to-pion ratio, almost perfectly, especially at LHC energy. While matter-to-antimatter and non-strange abundances are partly in line with predictions from the HRG model, it is found in the ALICE experiment that the measured baryon ratios are suppressed by a factor of $\\sim1.5$. The strange abundances are overestimated in the HRG model.

  14. Azimuthal jet tomography at RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Betz, Barbara [Institute for Theoretical Physics, Johann Wolfgang Goethe-University, 60438 Frankfurt am Main (Germany); Gyulassy, Miklos [Department of Physics, Columbia University, New York 10027 (United States)

    2014-11-15

    Results based on a generic jet-energy loss model that interpolates between running coupling pQCD-based and AdS/CFT-inspired holographic prescriptions are compared to recent data on the high-p{sub T} pion nuclear modification factor and the high-p{sub T} elliptic flow in nuclear collisions at RHIC and LHC. The jet-energy loss model is coupled to various (2+1)d (viscous hydrodynamic) fields. The impact of energy-loss fluctuations is discussed. While a previously proposed AdS/CFT jet-energy loss model with a temperature-independent jet-medium coupling is shown to be inconsistent with the LHC data, we find a rather broad class of jet-energy independent energy-loss models dE/dx=κ(T)x{sup z}T{sup 2+z} that can account for the current data with different temperature-dependent jet-medium couplings κ(T) and path-length dependence exponents of 0≤z≤2.

  15. Beam energy dependence of two-proton correlations at the AGS

    CERN Document Server

    Panitkin, S Y; Alexander, J; Anderson, M; Best, D; Brady, F P; Case, T; Caskey, W; Cebra, D; Chance, J; Chung, J; Cole, B; Crowe, K M; Das, A; Draper, J E; Gilkes, M L; Gushue, S; Heffner, M; Hirsch, A; Hjort, E; Huo, L; Justice, M; Kaplan, M; Keane, D; Kintner, J C; Klay, J L; Krofcheck, D; Lacey, R A; Lisa, M A; Liu, H; Liu, Y; McGrath, R; Milosevich, Z; Odyniec, Grazyna Janina; Olson, D; Pinkenburg, C H; Porile, N T; Rai, G; Ritter, H G; Romero, J; Scharenberg, R P; Schröder, L; Srivastava, B; Stone, N; Symons, T J M; Wang, S; Whitfield, J; Wienold, T; Witt, R; Wood, L; Yang, X; Zhang, W; Zhang, Y

    1999-01-01

    First measurements of the beam energy dependence of the two proton correlation function in central Au+Au collisions are performed by the E895 Collaboration at the BNL AGS. No significant changes with beam energy were observed. The imaging technique of Brown-Danielewicz is used in order to extract information about the space-time content of the proton source at freeze-out. Extracted source functions show peculiar enhancement at low relative separation.

  16. The BNL Accelerator Test Facility and experimental program

    International Nuclear Information System (INIS)

    The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high power laser pulses synchronized to the electron beam, suitable for studies of new methods of high gradient acceleration and state of the art free electron lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 to 100 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps Nd:YAG laser and a 100 mJ, 10 ps CO2 laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various acceleration schemes, Free-Electron Laser experiments and a program on the development of high brightness electron beams. The AFT's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the High power laser will begin operation this year. 28 refs., 4 figs

  17. First Results from the DUV-FEL Upgrade at BNL

    CERN Document Server

    Wang, Xijie; Murphy, James; Pinayev, Igor; Rakowsky, George; Rose, James; Shaftan, Timur; Sheehy, Brian; Skaritka, John; Wu, Zilu; Yu Li Hua

    2005-01-01

    The DUV-FEL at BNL is the world’s only facility dedicated to laser-seeded FEL R&D and its applications. Tremendous progress was made in both HGHG FEL and its applications in the last couple years.*,** In response to the requests of many users to study chemical science at the facility, the DUV-FEL linac was upgraded from 200 to 300 MeV to enable the HGHG FEL to produce 100 uJ pulses of 100 nm light. This will establish the DUV FEL as a premier user facility for ultraviolet radiation and enable state-of-the-art gas phase photochemistry research. The upgraded facility will also make possible key R&D experiments such as higher harmonic HGHG (n>5) that would lay the groundwork for future X-ray FEL based on HGHG. The upgraded HGHG FEL will operate at the 4th harmonic with the seed laser at either 800 nm or 400nm. The increase of the electron beam energy will be accomplished by installing a 5th linac cavity and two 45 MW klystrons. New HGHG modulator and dispersion sections vacuum chambers w...

  18. The BNL fan-atomized burner system prototype

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T.A.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    Brookhaven National Laboratory (BNL) has a continuing interest in the development of advanced oil burners which can provide new capabilities not currently available with pressure atomized, retention head burners. Specifically program goals include: the ability to operate at firing rates as low as 0.25 gph; the ability to operate with very low excess air levels for high steady state efficiency and to minimize formation of sulfuric acid and iron sulfate fouling; low emissions of smoke, CO, and NO{sub x} even at very low excess air levels; and the potential for modulation - either staged firing or continuous modulation. In addition any such advanced burner must have production costs which would be sufficiently attractive to allow commercialization. The primary motivation for all work sponsored by the US DOE is, of course, improved efficiency. With existing boiler and furnace models this can be achieved through down-firing and low excess air operation. Also, with low excess air operation fouling and efficiency degradation due to iron-sulfate scale formation are reduced.

  19. BWR stability analysis with the BNL Engineering Plant Analyzer

    International Nuclear Information System (INIS)

    March 9, 1989 instability at the LaSalle-2 Power Plant and more than ninety related BWR transients have been simulated on the BNL Engineering Plant Analyzer (EPA). Power peaks were found to be potentially seventeen times greater than the rated power, flow reversal occurs momentarily during large power oscillations, the fuel centerline temperature oscillates between 1,030 and 2,090 K, while the cladding temperature oscillates between 560 and 570 K. The Suppression Pool reaches its specified temperature limit either never or in as little as 4.3 minutes, depending on operator actions and transient scenario. Thermohydraulic oscillations occur at low core coolant flow (both Recirculation Pumps tripped), with sharp axial or redial fission power peaking and with partial loss of feedwater preheating while the feedwater is flow kept high to maintain coolant inventory in the vessel. Effects from BOP system were shown to influence reactor stability strongly through dosed-loop resonance feedback. High feedwater flow and low temperature destabilize the reactor. Low feedwater flow restabilizes the reactor, because of steam condensation and feedwater preheating in the downcomer, which reduces effectively the destabilizing core inlet subcooling. The EPA has been found to be capable of analyzing BWR stability '' shown to be effective for scoping calculations and for supporting accident management

  20. Analyzing power in CNI-region at AGS (experiment E950)

    International Nuclear Information System (INIS)

    Acceleration of polarized protons is one of the exciting features of the new Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. Measurements of beam polarization are required both for experiments and the accelerator tuning. Elastic scattering in the Coulomb nuclear interference (CNI) region of polarized proton beams on a carbon target demonstrates asymmetry which can be used to build a polarimeter. The methods proposed for a RHIC CNI polarimeter were tested with the AGS polarized beam in the E950 experiment. A 21.7 GeV/c polarized proton beam was scattered on an extremely thin carbon ribbon target located in the AGS ring. Two symmetrical arms consisting of silicon strip detectors (SSD) and a micro channel plate (MCP) were used to identify recoil carbon. Data obtained demonstrates a good identification of the reaction by the apparatus and a significant analyzing power. A RHIC polarimeter setup with 4 SSDs but without MCPs will be used to commission RHIC with polarized protons and for the first spin physics running in 2001

  1. Electromagnetic calorimeters for the BNL muon (g-2) experiment

    NARCIS (Netherlands)

    Sedykh, SA; Blackburn, Adrian G.; Bunker, BD; Debevec, PT; Gray, FE; Hertzog, DW; Jones, TD; Onderwater, CJG; Polly, CC; Urner, DC; Carey, RM; Coulsey, C; de Santi, G; Hare, M; Miller, JP; Ouyang, J; Rind, O; Trofimov, A; Cushman, P; Giron, S; Kindem, J; Timmermans, C; Zimmerman, D; Winn, D; Druzhinin, V.P.

    2000-01-01

    A set of 24 lead/scintillating fiber electromagnetic calorimeters has been constructed for the new muon (g - 2) experiment at the Brookhaven AGS. These calorimeters were designed to provide very good energy resolution for electrons up to 3 GeV while also yielding excellent timing information. Specia

  2. Feasibility of Electron Cooling for Low-Energy RHIC Operation

    Energy Technology Data Exchange (ETDEWEB)

    Fedotov,A.; Ben-Zvi, I.; Chang, X.; Kayran, D.; Litvinenko, V.; Pozdeyev, E.; Satogata, T.

    2008-04-01

    A concrete interest in running RHIC at low energies in a range of 2.5-25 GeV/nucleon total energy of a single beam has recently emerged. Providing collisions in this energy range, which in the RHIC case is termed 'low-energy' operation, will help to answer one of the key questions in the field of QCD about existence and location of a critical point on the QCD phase diagram. However, luminosity projections are relatively low for the lowest energy points of interest. Luminosity improvement can be provided with electron cooling applied directly in RHIC at low energies. This report summarizes the expected luminosity improvement with electron cooling, possible technical approaches and various limitations.

  3. Conceptual design of the Relativistic Heavy Ion Collider [RHIC

    International Nuclear Information System (INIS)

    In August 1984 Brookhaven National Laboratory submitted a proposal for the construction of a Relativistic Heavy Ion Collider (RHIC) to the US Department of Energy. A Conceptual Design Report for the RHIC facility was completed in May 1986 after detailed reviews of the machine design, and of the requirements of the physics research program. Since that time an extensive R ampersand D program has been initiated and considerable work has been carried out to refine the design and specification of the major accelerator components, as well as the needs for research detectors, and to prepare the project for construction. This document is an update of the Conceptual Design Report, incorporating the results of work carried out since the beginning of Fiscal Year 1987 when a formal R ampersand D program for the RHIC project funded by DOE was initiated

  4. Opportunities for Drell-Yan Physics at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer, E.; Bland, L.; Crawford, H.; Goto, Y.; Eyser, O.; Kang, Z.; Vossen, A.

    2011-05-24

    Drell-Yan (DY) physics gives the unique opportunity to study the parton structure of nucleons in an experimentally and theoretically clean way. With the availability of polarized proton-proton collisions and asymmetric d+Au collisions at the Relativistic Heavy Ion Collider (RHIC), we have the basic (and unique in the world) tools to address several fundamental questions in QCD, including the expected gluon saturation at low partonic momenta and the universality of transverse momentum dependent parton distribution functions. A Drell-Yan program at RHIC is tied closely to the core physics questions of a possible future electron-ion collider, eRHIC. The more than 80 participants of this workshop focused on recent progress in these areas by both theory and experiment, trying to address imminent questions for the near and mid-term future.

  5. Ion optics of RHIC electron beam ion source

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Okamura, M.; Raparia, D.; Ritter, J.; Tan, Y. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Kuznetsov, G. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

    2012-02-15

    RHIC electron beam ion source has been commissioned to operate as a versatile ion source on RHIC injection facility supplying ion species from He to Au for Booster. Except for light gaseous elements RHIC EBIS employs ion injection from several external primary ion sources. With electrostatic optics fast switching from one ion species to another can be done on a pulse to pulse mode. The design of an ion optical structure and the results of simulations for different ion species are presented. In the choice of optical elements special attention was paid to spherical aberrations for high-current space charge dominated ion beams. The combination of a gridded lens and a magnet lens in LEBT provides flexibility of optical control for a wide range of ion species to satisfy acceptance parameters of RFQ. The results of ion transmission measurements are presented.

  6. The eRHIC Ring-Ring Collider Design

    CERN Document Server

    Wang, Fuhua; Beebe-Wang, Joanne; Deshpande, Abhay A; Farkhondeh, Manouchehr; Franklin, Wilbur; Graves, William; Litvinenko, Vladimir N; MacKay, William W; Milner, Richard; Montag, Christoph; Ozaki, Satoshi; Parker, Brett; Peggs, Steve; Ptitsyn, Vadim; Roser, Thomas; Tepikian, Steven; Trbojevic, Dejan; Tschalär, C; Wang, Dong; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan

    2005-01-01

    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.

  7. First results from RHIC What are they telling us?

    CERN Document Server

    Nagle, J L

    2001-01-01

    The Relativistic Heavy Ion Collider (RHIC) facility at Brookhaven National Laboratory is the first accelerator specifically constructed for the study of very hot and dense nuclear matter. At sufficiently high temperature, nuclear matter is expected to undergo a phase transition to a quark-gluon plasma. It is the specific goal of the field to study the nature of this plasma and understand the phase transitions between different states. The RHIC accelerator along with four experiments BRAHMS, PHENIX, PHOBOS, and STAR were commissioned last year with first collisions occurring in June 2000. Presented here are the first results from low luminosity beam in Run I. They are a glimpse of the wealth of physics to be extracted from the RHIC program over the next several years.

  8. Detectors for relativistic heavy-ion experiments

    International Nuclear Information System (INIS)

    We present in some detail an overview of the detectors currently used in relativistic heavy-ion research at the BNL AGS and the CERN SPS. Following that, a detailed list of RandD projects is given, including specific areas of work which need to be addressed in preparation for further experiments at the AGS and SPS for the upcoming experiments at RHIC

  9. Flow in Au+Au collisions at RHIC

    Science.gov (United States)

    Belt Tonjes, Marguerite; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wyslouch, B.

    2004-08-01

    The study of flow can provide information on the initial state dynamics and the degree of equilibration attained in heavy-ion collisions. This contribution presents results for both elliptic and directed flow as determined from data recorded by the PHOBOS experiment in Au+Au runs at RHIC at \\sqrt{s_{{\\rm NN}}} = 19.6, 130 and 200 GeV. The PHOBOS detector provides a unique coverage in pseudorapidity for measuring flow at RHIC. The systematic dependence of flow on pseudorapidity, transverse momentum, centrality and energy is discussed.

  10. Simulations of silicon vertex tracker for star experiment at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W. [Lawrence Berkeley Lab., CA (United States); Liko, D. [Institut fur Hochenenergiephysik, Vienna, (Austria); Cramer, J.; Prindle, D.; Trainor, T. [Univ. of Washington, Seattle (United States); Braithwaite, W. [Univ. of Arkansas, Little Rock (United States)

    1991-12-31

    The first computer simulations to optimize the Silicon Vertex Tracker (SVT) designed for the STAR experiment at RHIC are presented. The physics goals and the expected complexity of the events at RHIC dictate the design of a tracking system for the STAR experiment. The proposed tracking system will consist of a silicon vertex tracker (SVT) to locate the primary interaction and secondary decay vertices and to improve the momentum resolution, and a time projection chamber (TPC), positioned inside a solenoidal magnet, for continuous tracking.

  11. Study of orbit correction for eRHIC FFAG design

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hao, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The unique feature of the orbits in the eRHIC Fixed Field Alternating Gradient (FFAG) design is that multiple accelerating and decelerating bunches pass through the same magnets with different horizontal offsets. Therefore, it is critical for the eRHIC FFAG to correct multiple orbits in the same vacuum pipe for better spin transmission and alignment of colliding beams. In this report, the effects on orbits from multiple error sources will be studied. The orbit correction method will be described and results will be presented.

  12. Lessons from RHIC for the LHC and vice versa

    CERN Document Server

    Tannenbaum, Michael J

    2012-01-01

    For the past decade, measurements of semi-inclusive single identified particle spectra and two particle correlations in p-p and A+A collisions at RHIC have produced a treasure trove of results which indicate that the medium produced in Au+Au collisions is a strongly interacting quark gluon liquid in which both light and heavy quarks are suppressed, presumably by energy loss in the hot, dense medium. These results have been confirmed in Pb+Pb collisions at the LHC along with the addition of measurements of jets and di-jets. Results and methods at RHIC and LHC are compared which leads to some interesting conclusions.

  13. Experimental Evidence for Partonic Orbital Angular Momentum at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Douglas E. [University of New Mexico, Department of Physics and Astronomy, Albuquerque, NM 871331 (United States)

    2011-12-14

    Although one might naively anticipate that the proton, being the lowest baryonic energy state, would be in a L = 0 state, the current theoretical understanding is that it must carry orbital angular momentum in order, for example, to have a non-zero anomalous magnetic moment. I will review the experimental evidence linked theoretically to orbital angular momentum of the proton's constituents from the RHIC experiments and summarize by presenting a challenge to the theory community--to develop a consistent framework which can explain the spin polarization asymmetries seen at RHIC and elsewhere, and give insight to the partonic wave-functions including orbital angular momentum.

  14. Surface Emission of Quark Gluon Plasma at RHIC and LHC

    Institute of Scientific and Technical Information of China (English)

    XIANG Wen-Chang; WAN Ren-Zhuo; ZHOU Dai-Cui

    2008-01-01

    Within the framework of a factorization model, we study the behaviour of nuclear modification factor in Au-Au collisions at RHIC and Pb-Pb collisions at LHC. We find that the nuclear modification factor is inversely proportional to the radius of the quark-gluon plasma and is dominated by the surface emission of hard jets. We predict the nuclear modification factor RLHCAA~0.15 in central Pb-Pb collisions at LHC. The study shows that the factorization model can be used to describe the centrality dependence of nuclear modification factor of the high transverse momentum particles produced in heavy ion collisions at both RHIC and LHC.

  15. HIGH PT PHYSICS WITH THE STAR EXPERIMENT AT RHIC

    International Nuclear Information System (INIS)

    The STAR experiment at RHIC is a TPC-based, general purpose detector designed to obtain charged particle spectra, with an emphasis on hadrons over a large phase space. An electromagnetic calorimeter provides measurement of e's, γ's, π0's and jets. Data-taking with Au + Au collisions at √5 = 200 GeV/c2 begins in Fall 1999. The STAR experiment's investigation of techniques and signals using hard probes to study the high energy-density matter at RHIC and to search for quark-gluon plasma formation will be described

  16. Selected Experimental Highlights from Nucleus-Nucleus Collisions at RHIC

    CERN Document Server

    Huang, H Z

    2006-01-01

    Nucleus-nucleus collisions at RHIC produce high temperature and high energy density matter which exhibits partonic degrees of freedom. We will discuss measurements of nuclear modification factors for light hadrons and non-photonic electrons from heavy quark decays, which reflect the flavor dependence of energy loss of high momentum partons traversing the dense QCD medium. The hadronization of bulk partonic matter exhibits collectivity in effective partonic degrees of freedom. Nuclear collisions at RHIC provide an intriguing environment, where many constituent quark ingredients are readily available for possible formation of exotic particles through quark coalescences or recombinations.

  17. RHIC Workshop: experiments for a relativistic heavy ion collider

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for individual papers in this workshop proceedings, covering such topics as: calorimeter-based experiments, dimuon detection, large magnetic spectrometers, experiments in the fragmentation region, two-photon physics, and theoretical questions relevant to experimental work at the RHIC

  18. Measurement of HOMs in the RHIC RF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Abreu,N.P.; Choi, E. M.

    2009-01-07

    The authors present results of Higher Order Modes (HOMs) measurements in the RHIC accelerating (28 MHz system) and storage (197 MHz system) cavities. The power of the excited HOMs deposited into the HOM damper is measured and compared with an analytical calculation of the HOMs power. The quality factors (Q) are also measured and compared to previous measurements.

  19. A hardware overview of the RHIC LLRF platform

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, T.; Smith, K.S.

    2011-03-28

    The RHIC Low Level RF (LLRF) platform is a flexible, modular system designed around a carrier board with six XMC daughter sites. The carrier board features a Xilinx FPGA with an embedded, hard core Power PC that is remotely reconfigurable. It serves as a front end computer (FEC) that interfaces with the RHIC control system. The carrier provides high speed serial data paths to each daughter site and between daughter sites as well as four generic external fiber optic links. It also distributes low noise clocks and serial data links to all daughter sites and monitors temperature, voltage and current. To date, two XMC cards have been designed: a four channel high speed ADC and a four channel high speed DAC. The new LLRF hardware was used to replace the old RHIC LLRF system for the 2009 run. For the 2010 run, the RHIC RF system operation was dramatically changed with the introduction of accelerating both beams in a new, common cavity instead of each ring having independent cavities. The flexibility of the new system was beneficial in allowing the low level system to be adapted to support this new configuration. This hardware was also used in 2009 to provide LLRF for the newly commissioned Electron Beam Ion Source.

  20. Elliptic flow at RHIC with NeXSPheRIO

    International Nuclear Information System (INIS)

    Elliptic flow at RHIC is computed event-by-event with NeXSPheRIO. Reasonable agreement with experimental results on ν2(η) is obtained. Various effects are studied as well: reconstruction of impact parameter direction, freeze-out temperature, equation of state (with or without crossover), emission mechanism. (author)

  1. Feasibility Studies of Exclusive Diffractive Bremsstrahlung Measurement at RHIC Energies

    OpenAIRE

    Chwastowski, Janusz; Cyz, Antoni; Fulek, Łukasz; Kycia, Radosław; Pawlik, Bogdan; Sikora, Rafał; Turnau, Jacek

    2015-01-01

    Feasibility studies of an observation of the exclusive diffractive bremsstrahlung at RHIC at $\\sqrt{s} = 200$~GeV and at $\\sqrt{s} = 500$~GeV are reported. A simplified approach to the photon and the scattered proton energy reconstruction is used. Influence of possible backgrounds is discussed.

  2. STAR results from the first year at RHIC

    Indian Academy of Sciences (India)

    Helen Caines

    2003-04-01

    An overview of the latest results from the STAR experiment at RHIC is presented. Preliminary measurements of , , , and Ξ, plus their respective anti-particles at t < 2 GeV/c, where the majority of particle production occurs, allow us to probe the soft processes whilst the harder perturbative regime can be accessed by studying particle spectra and yields at higher momenta.

  3. Measurements of the radioactive inventory of the old effluent pipe line on the BNL site

    International Nuclear Information System (INIS)

    When Berkeley Nuclear Laboratory (BNL) was built, a 3 inch cast iron pipe was laid to carry the radioactive effluent from the BNL effluent treatment plant to the power station for further treatment and/or discharge. In 1980/81 a new pipe line was installed and since then the old line has remained unused. As part of the refurbishment of certain parts of the BNL site currently in progress, the majority of the pipe is to be dug up in two stages, although a small length of the pipe which runs under existing foundations will be left in the ground. This report gives the radioactive inventory of the pipe based on measurements made during the first state of removal. Samples from the trench dug to expose the pipe were taken before and after the removal of the pipe and analysed to determine whether the pipe had leaked and the level of contamination caused by the pipe's removal. (author)

  4. RHIC-spin program for the next several years

    Science.gov (United States)

    Okada, Kensuke

    2009-10-01

    It has been almost a decade since RHIC provided the first polarized proton proton collision. The performance is improving towards the design luminosity and polarization. With the applicability of the factorized perturbative QCD (pQCD) and gluons in a leading order process, RHIC is a unique place to access to the gluon spin in the proton. In the first stage, PHENIX and STAR measured the double helicity asymmetries of inclusive channels. The data excluded the large gluon polarization scenario and prefers rather small polarization in the range of Bjorken-x presently measured. The next step is to study the x dependence. One way is to fix the kinematics, and the other is to change the collision energy to enlarge the x-coverage. The inclusion of data with lower collision energy than the nominal RHIC energy (√s=200GeV) might be an option if the range where the factorized pQCD can be applied is extended. The field of transverse spin physics is rapidly growing. PHENIX and STAR spent a half of their beam time taking data with transverse beam polarization. BRAHMS used its great capability of particle ID and its broad rapidity coverage to measure single spin asymmetries. At this stage, it is important to collect many experimental evidences in wide range of kinematics and channels. For this purpose, STAR recently extended their forward acceptance. With the full energy (√s=500GeV), W boson has a reasonable production rate. Thanks to its parity violating process, it provides a unique way to separate the flavor spin components with the high scale of Q^2 (˜6400GeV^2) and no fragmentation involved. In 2009, RHIC provided the first 500GeV polarized collisions successfully. Experiments demonstrated the feasibility of this program. In this talk, I will give a short summary of what we have learned from the past RHIC runs and prospects for the near future measurements.

  5. Red Hat Enterprise Virtualization - KVM-based infrastructure services at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Cortijo, D.

    2011-06-14

    Over the past 18 months, BNL has moved a large percentage of its Linux-based servers and services into a Red Hat Enterprise Virtualization (RHEV) environment. This presentation will address our approach to virtualization, critical decision points, and a discussion of our implementation. Specific topics will include an overview of hardware and software requirements, networking, and storage; discussion of the decision of Red Hat solution over competing products (VMWare, Xen, etc); details on some of the features of RHEV - both current and on their roadmap; Review of performance and reliability gains since deployment completion; path forward for RHEV at BNL and caveats and potential problems.

  6. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP (VOL. 71)

    Energy Technology Data Exchange (ETDEWEB)

    KHARZEEV, D.; STASTO, A.; TUCHIN, K.; VOGELSANG, W.

    2005-03-07

    The high energy limit of Quantum Chromodynamics is one of the most fascinating areas in the theory of strong interactions. Over a decade ago the HERA experiment at DESY in Hamburg provided strong evidence for the rise of the proton structure function at small values of the Bjorken variable x. This behavior can be explained as an increase of the gluon density of the proton with energy or correspondingly with smaller values of x. This increase can be attributed on the other hand to the large probability of gluon splitting in QCD. The natural framework for describing the gluon dynamics at small x is the Balitskii-Fadin-Kuraev-Lipatov formalism developed some 30 years ago. It predicts that the gluon density grows very fast with increasing energy, as a power with a large intercept. This increase has to be tamed in order to satisfy the unitarily bound. Over two decades ago, Gribov, Levin and Ryskin proposed the mechanism called the parton saturation, which slows down the fast rise of the gluon density. This formalism accounts for an additional gluon recombination apart from the pure gluon splitting. It leads to the very interesting non-linear modification of the evolution equations for the gluon distributions. Since then, much progress has been made in the theoretical formulation of the parton saturation. Currently the most complete theory for parton saturation is the Color Glass Condensate (CGC) with the corresponding renormalization group functional evolution equation, the JIMWLK equation, which describes the nonlinear evolution of the gluon density at small values of x and in the regime where gluon fields are strong. The simpler form of the JIMWLK equation, the Balitskii-Kovchegov (BK) equation has been successfully used to explain the experimental data on proton structure function. The models, which include the parton saturation, have been applied to explain the experimental data at Tevatron and RHIC. In the latter case the Color Glass Condensate can be thought of as

  7. Modeling and Analysis of AGS (1998) Thermal Shock Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Haines, J.R.; Kim, S.H.; Taleyarkhan, R.P.

    1999-11-14

    An overview is provided on modeling and analysis of thermal shock experiments conducted during 1998 with high-energy, short-pulse energy deposition in a mercury filled container in the Alternating Gradient Synchrotron (AGS) facility at Brookhaven National Laboratory (BNL). The simulation framework utilized along with the results of simulations for pressure and strain profiles are presented. While the magnitude of penk strain predictions versus data are in reasonable agreement, the temporal variations were found to differ significantly in selected cases, indicating lack of modeling of certain physical phenomena or due to uncertainties in the experimental data gathering techniques. Key thermal-shock related issues and uncertainties are highlighted. Specific experiments conducted at BNL's AGS facility during 1998 (the subject of this paper) involved high-energy (24 GeV) proton energy deposition in the mercury target over a time frame of - 0.1s. The target consisted of an - 1 m. long cylindrical stainless steel shell with a hemispherical dome at the leading edge. It was filled with mercury at room temperature and pressure. Several optical strain gages were attached to the surface of the steel target. Figure 1 shows a schematic representation of the test vessel along with the main dimensions and positions of three optical strain gages at which meaningful data were obtained. As

  8. OVERVIEW OF THE RHIC INSERTION REGION, SEXTUPOLE, AND SNAKE POWER SUPPLY SYSTEMS

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider (RHIC) was commissioned in 1999 and 2000. RHIC requires power supplies to supply currents to highly inductive superconducting magnets. The RHIC Insertion Region (IR) contains many shunt power supplies to trim the current of different magnet elements in a large superconducting magnet circuit. There are a total of 237 Insertion Region power supplies in both RHIC rings. RHIC also requires sextupole power supplies. One sextupole power supply is connected across 12 sextupole magnets. There are a total of 24 sextupole power supplies in both rings. Snake magnets are also a part of the RHIC ring, and these snake magnets also require power supplies. There shall be a total of 24 snake power supplies in both rings. Power supply technology, connections, control systems and interfacing with the Quench Protection System will be presented

  9. Implications of BNL measurement of dam on a class of scalar leptoquark interactions

    CERN Document Server

    Mahanta, U

    2001-01-01

    Recently BNL have measured the muon magnetic moment anomaly with increased precision [1]. The world average experimental value shows a discrepancy of 43(16)x 10^{-10} from the current Standard Model value. In this paper we investigate the implications of this difference on a class of scalar leptoquark interactions to SM quark lepton pair.

  10. New result on K+ → π+ ν νbar from BNL E787

    International Nuclear Information System (INIS)

    E787 at BNL has reported evidence for the rare decay K+ → π+νbar ν, based on the observation of one candidate event. In this paper, we present the result of analyzing a new dataset of comparable sensitivity to the published result

  11. QUARKONIUM PRODUCTION IN RELATIVISTIC NUCLEAR COLLISIONS. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 12

    Energy Technology Data Exchange (ETDEWEB)

    KHARZEEV,D.

    1999-04-20

    The RIKEN-BNL Workshop on Quarkonium Production in Relativistic Nuclear Collisions was held September 28--October 2, 1998, at Brookhaven National Laboratory. The Workshop brought together about 50 invited participants from around the world and a number of Brookhaven physicists from both particle and nuclear physics communities.

  12. Electromagnetic radiation from nuclear collisions at RHIC energies

    CERN Document Server

    Turbide, Simon; Frodermann, Evan; Heinz, Ulrich

    2008-01-01

    The hot and dense strongly interacting matter created in collisions of heavy nuclei at RHIC energies is modeled with relativistic hydrodynamics, and the spectra of real and virtual photons produced at mid-rapidity in these events are calculated. Several different sources are considered, and their relative importance is compared. Specifically, we include jet fragmentation, jet-plasma interactions, the emission of radiation from the thermal medium and from primordial hard collisions. Our calculations consistently take into account jet energy loss, as evaluated in the AMY formalism. We obtain results for the spectra, the nuclear modification factor (R_AA), and the azimuthal anisotropy (v_2) that agree with the photon measurements performed by the PHENIX collaboration at RHIC.

  13. z-scaling in heavy ion collisions at the RHIC

    Science.gov (United States)

    Tokarev, M. V.

    2007-09-01

    Experimental data on transverse particle spectra obtained by the STAR, PHENIX, PHOBOS, and BRAHMS collaborations at the RHIC are analyzed in the framework of the generalized concept of z-scaling. It was developed for analysis of inclusive particle production in proton-(anti)proton collisions at high p T and high multiplicities. The general scheme of the approach based on the physical principles of self-similarity, locality, and fractality is reviewed. Independence of the scaling function ψ( z) from energy, multiplicity, and atomic weight for h ±, π ±,0, K {/S 0}, and Λ hadrons produced in Au-Au and Cu-Cu collisions at √ s = 130 and 200 GeV is discussed. Based on z-scaling, the multiplicity dependence of pion transverse spectra up to p T = 25 GeV/ c in Au-Au collisions at √ s = 200 GeV for experiments at the RHIC is predicted.

  14. Overview of results from PHOBOS experiment at RHIC

    Science.gov (United States)

    Olszewski, Andrzej; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Corbo, J.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hicks, D.; Hofman, D. J.; Holzman, B.; Hollis, R. S.; Hoyński, R.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michaowski, J.; Mignerey, A. C.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Rafelski, M.; Rbeiz, M.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J. L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysouch, B.

    2002-07-01

    An overview of results for interactions of Au+Au ions at centre-of-mass energies of √sNN = 56, 130 and 200 GeV obtained by the PHOBOS collaboration at RHIC is given. Measurements of primary charged particle density near mid-rapidity indicate that particle production grows logarithmically with collision energy and faster than linearly with the number of interacting nucleons. Elliptic flow is found to be much stronger at RHIC than at SPS energy. The effect is strongest in peripheral events and decreases for more central collisions and emission angles |η| > 1. The measured anti-particle to particle ratios of production rates for pions, kaons and protons in central Au+Au interactions at √sNN = 130 GeV are compatible with the statistical model of particle production, showing an increasingly baryon-free region in mid-rapidity with the increase of collision energy.

  15. Cronin effect at different energies: from RHIC to LHC

    Directory of Open Access Journals (Sweden)

    Krelina Michal

    2014-03-01

    Full Text Available Using the QCD improved parton model we study production of hadrons with large transverse momenta pT in proton-proton and proton-nucleus collisions at different energies corresponding to experiments at RHIC and LHC. For investigation of large-pT hadrons produced on nuclear targets we include additionally the nuclear modification of parton distribution functions and the nuclear broadening calculated within the color dipole formalism. We demonstrate that complementary effect of initial state interactions causes a significant suppression at large pT and at forward rapidities. We provide a good description of the Cronin effect at medium-high pT and the nuclear suppression at large pT in agreement with available data from experiments at RHIC and LHC. In the LHC energy range this large-pT suppression expected at forward rapidities can be verified by the future measurements.

  16. Absolute beam emittance measurements at RHIC using ionization profile monitors

    Energy Technology Data Exchange (ETDEWEB)

    Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Connolly, R [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Summers, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-08-15

    In the past, comparisons between emittance measurements obtained using ionization profile monitors, Vernier scans (using as input the measured rates from the zero degree counters, or ZDCs), the polarimeters and the Schottky detectors evidenced significant variations of up to 100%. In this report we present studies of the RHIC ionization profile monitors (IPMs). After identifying and correcting for two systematic instrumental errors in the beam size measurements, we present experimental results showing that the remaining dominant error in beam emittance measurements at RHIC using the IPMs was imprecise knowledge of the local beta functions. After removal of the systematic errors and implementation of measured beta functions, precise emittance measurements result. Also, consistency between the emittances measured by the IPMs and those derived from the ZDCs was demonstrated.

  17. HEAVY QUARKS AT RHIC FROM PARTON TRANSPORT THEORY.

    Energy Technology Data Exchange (ETDEWEB)

    MOLNAR, D.

    2006-05-15

    There are several indications that an opaque partonic medium is created in energetic Au+Au collisions ({radical}s{sub NN} {approx} GeV/nucleon) at the Relativistic Heavy Ion Collider (RHIC). At the extreme densities of {approx} 10-100 times normal nuclear density reached even heavy-flavor hadrons are affected significantly. Heavy-quark observables are presented from the parton transport model MPC, focusing on the nuclear suppression pattern, azimuthal anisotropy (''elliptic flow''), and azimuthal correlations. Comparison with Au + Au data at top RHIC energy {radical}s{sub NN} = 200 GeV indicates significant heavy quark rescattering, corresponding roughly five times higher opacities than estimates based on leading-order perturbative QCD. We propose measurements of charm-anticharm, e.g., D-meson azimuthal correlations as a sensitive, independent probe to corroborate these findings.

  18. Polarized proton collisions at 205 GeV at RHIC.

    Science.gov (United States)

    Bai, M; Roser, T; Ahrens, L; Alekseev, I G; Alessi, J; Beebe-Wang, J; Blaskiewicz, M; Bravar, A; Brennan, J M; Bruno, D; Bunce, G; Courant, E; Drees, A; Fischer, W; Gardner, C; Gill, R; Glenn, J; Haeberli, W; Huang, H; Jinnouchi, O; Kewisch, J; Luccio, A; Luo, Y; Nakagawa, I; Okada, H; Pilat, F; Mackay, W W; Makdisi, Y; Montag, C; Ptitsyn, V; Satogata, T; Stephenson, E; Svirida, D; Tepikian, S; Trbojevic, D; Tsoupas, N; Wise, T; Zelenski, A; Zeno, K; Zhang, S Y

    2006-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 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 first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions. PMID:16712305

  19. Matter in extremis: Ultrarelativistic nuclear collisions at RHIC

    International Nuclear Information System (INIS)

    We review the physics of nuclear matter at high energy density and the experimental search for the Quark-Gluon Plasma at the Relativistic Heavy Ion Collider (RHIC). The data obtained in the first three years of the RHIC physics program provide several lines of evidence that a novel state of matter has been created in the most violent, head-on collisions of Au nuclei at √s = 200 GeV. Jet quenching and global measurements show that the initial energy density of the strongly interacting medium generated in the collision is about two orders of magnitude larger than that of cold nuclear matter, well above the critical density for the deconfinement phase transition predicted by lattice QCD. The observed collective flow patterns imply that the system thermalizes early in its evolution, with the dynamics of its expansion consistent with ideal hydrodynamic flow based on a Quark-Gluon Plasma equation of state

  20. An approximately 4π tracking magnetic spectrometer for RHIC

    International Nuclear Information System (INIS)

    A tracking magnetic spectrometer based on large Time Projection Chambers (TPC) is proposed to measure the momentum of charged particles emerging from the RHIC beam pipe at angles larger than four degrees and to identify the particle type for those beyond fifteen degrees with momenta up to 700 MeV/c, which is a large fraction of the final charged particles emitted by a low rapidity quark-gluon plasma

  1. Simulations of Gaussian electron guns for RHIC electron lens

    International Nuclear Information System (INIS)

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  2. Benchmarking of collimation tracking using RHIC beam loss data.

    Energy Technology Data Exchange (ETDEWEB)

    Robert-Demolaize,G.; Drees, A.

    2008-06-23

    State-of-the-art tracking tools were recently developed at CERN to study the cleaning efficiency of the Large Hadron Collider (LHC) collimation system. In order to estimate the prediction accuracy of these tools, benchmarking studies can be performed using actual beam loss measurements from a machine that already uses a similar multistage collimation system. This paper reviews the main results from benchmarking studies performed with specific data collected from operations at the Relativistic Heavy Ion Collider (RHIC).

  3. Monolithic circuit development for RHIC at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Alley, G.T.; Britton, C.L. Jr.; Kennedy, E.J.; Newport, D.F.; Wintenberg, A.L.; Young, G.R. [Oak Ridge National Laboratory, TN (United States)

    1991-12-31

    The work performed for RHIC at Oak Ridge National Laboratory during FY 91 is presented in this paper. The work includes preamplifier, analog memory, and analog-digital converter development for Dimuon Pad Readout, and evaluation and development of preamplifier-shapers for silicon strip readout. The approaches for implementation are considered as well as measured data for the various circuits that have been developed.

  4. Proposal; Precise measurements of very forward particle production at RHIC

    CERN Document Server

    Itow, Y; Sako, T; Sakurai, N; Kasahara, K; Suzuki, T; Torii, S; Adriani, O; Bonechi, L; D'Alessandro, R; Mitsuka, G; Tricomi, A; Goto, Y; Tanida, K

    2014-01-01

    We propose a new experiment Relativistic Heavy Ion Collider forward (RHICf) for the precise measurements of very forward particle production at RHIC. The proposal is to install the LHCf Arm2 detector in the North side of the ZDC installation slot at the PHENIX interaction point. By installing high-resolution electromagnetic calorimeters at this location we can measure the spectra of photons, neutrons and pi0 at pseudorapidity eta>6.

  5. Has the QCD critical point been observed at RHIC?

    CERN Document Server

    Antoniou, N G; Diakonos, F K

    2016-01-01

    The experimental search for the location of the QCD critical point in the phase diagram is of primary importance. In a recent publication it is claimed that measurements at RHIC lead not only to the location of the critical point ($\\mu_{cep}=95$ MeV, $T_{cep}=165$ MeV) but also to the verification of its universality class ($3d$ Ising system) by extracting the values of the critical exponents ($\\gamma=1.2$, $\

  6. Simulations of Gaussian electron guns for RHIC electron lens

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-02-28

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  7. PHENIX Experiment Results from the RHIC Beam Energy Scan Program

    CERN Document Server

    ,

    2013-01-01

    The PHENIX Experiment at RHIC has conducted a beam energy scan at several collision energies in order to search for signatures of the QCD critical point and the onset of deconfinement. PHENIX has conducted measurements of transverse energy production, muliplicity fluctuations, the skewness and kurtosis of net charge distributions, Hanbury-Brown Twiss correlations, charged hadron flow, and energy loss. The data analyzed to date show no significant indications of the presence of the critical point.

  8. THE ANALYSIS OF DEPOLARIZATION FACTORS IN THE LAST RHIC RUN

    International Nuclear Information System (INIS)

    Polarized proton beams were accelerated successfully at RHIC up to 100 Gev with the use of Siberian Snakes. Although the snakes were designed to preserve polarization, the successful acceleration and storage of polarized beams was dependent also on beam characteristics, like closed orbit, betatron tunes and even betatron coupling. The high-order spin resonances were observed and evaluated. The paper summarizes depolarizing effects observed during the run

  9. OVERVIEW ON BNL ASSESSMENT OF SEISMIC ANALYSIS METHODS FOR DEEPLY EMBEDDED NPP STRUCTURES.

    Energy Technology Data Exchange (ETDEWEB)

    XU,J.; COSTANTINO, C.; HOFMAYER, C.; GRAVES, H.

    2007-04-01

    A study was performed by Brookhaven National Laboratory (BNL) under the sponsorship of the U. S. Nuclear Regulatory Commission (USNRC), to determine the applicability of established soil-structure interaction analysis methods and computer programs to deeply embedded and/or buried (DEB) nuclear power plant (NPP) structures. This paper provides an overview of the BNL study including a description and discussions of analyses performed to assess relative performance of various SSI analysis methods typically applied to NPP structures, as well as the importance of interface modeling for DEB structures. There are four main elements contained in the BNL study: (1) Review and evaluation of existing seismic design practice, (2) Assessment of simplified vs. detailed methods for SSI in-structure response spectrum analysis of DEB structures, (3) Assessment of methods for computing seismic induced earth pressures on DEB structures, and (4) Development of the criteria for benchmark problems which could be used for validating computer programs for computing seismic responses of DEB NPP structures. The BNL study concluded that the equivalent linear SSI methods, including both simplified and detailed approaches, can be extended to DEB structures and produce acceptable SSI response calculations, provided that the SSI response induced by the ground motion is very much within the linear regime or the non-linear effect is not anticipated to control the SSI response parameters. The BNL study also revealed that the response calculation is sensitive to the modeling assumptions made for the soil/structure interface and application of a particular material model for the soil.

  10. Photon-jet ridge at RHIC and the LHC

    Science.gov (United States)

    Rezaeian, Amir H.

    2016-05-01

    We investigate long-range rapidity correlations of pairs of prompt photons and jets in the color glass condensate framework in proton-proton and proton-nucleus collisions at RHIC and the LHC. We show that photon-jet correlations exhibit long-range azimuthal collimation at the near side for low transverse momenta of the produced photon and jet in high-multiplicity events. These ridge-like features are strikingly similar to the observed ridge effect for dihadron correlations at RHIC and the LHC. We show that correlations in the relative rapidity and the relative azimuthal angle between pairs of prompt photons and jets strongly depend on the gluon saturation dynamics at small-x kinematics and such measurements can help to understand the true origin of the observed dihadron ridge in p +A collisions, and address whether the ridge is a universal phenomenon for all two-particle correlations at high-energy and high-multiplicity events. We also investigate whether there is a ridge-like structure for photon-hadron pair correlations at RHIC and the LHC. We find that the hadronization of jets has nontrivial effects on the photon-jet correlations.

  11. Recent RHIC in-situ coating technology developments

    CERN Document Server

    Hershcovitch, A; Brennan, J M; Chawla, A; Fischer, W; Liaw, C-J; Meng, W; Todd, R; Custer, A; Erickson, M; Jamshidi, N; Kobrin, P; Laping, R; Poole, H J; Jimenez, J M; Neupert, H; Taborelli, M; Yin-Vallgren, C; Sochugov, N

    2013-01-01

    To rectify the problems of electron clouds observed in RHIC and unacceptable ohmic heating for superconducting magnets that can limit future machine upgrades, we started developing a robotic plasma deposition technique for $in-situ$ coating of the RHIC 316LN stainless steel cold bore tubes based on staged magnetrons mounted on a mobile mole for deposition of Cu followed by amorphous carbon (a-C) coating. The Cu coating reduces wall resistivity, while a-C has low SEY that suppresses electron cloud formation. Recent RF resistivity computations indicate that 10 {\\mu}m of Cu coating thickness is needed. But, Cu coatings thicker than 2 {\\mu}m can have grain structures that might have lower SEY like gold black. A 15-cm Cu cathode magnetron was designed and fabricated, after which, 30 cm long samples of RHIC cold bore tubes were coated with various OFHC copper thicknesses; room temperature RF resistivity measured. Rectangular stainless steel and SS discs were Cu coated. SEY of rectangular samples were measured at ro...

  12. Elliptic Flow in Heavy-Ion Collisions from AGS to RHIC

    CERN Document Server

    Ivanov, Yu B

    2014-01-01

    The integrated elliptic flow of charged particles, $v_2$(charged), and that of identified hadrons from Au+Au collisions are computed in a wide range of incident energies 2.7 GeV $\\le \\sqrt{s_{NN}}\\le$ 39 GeV. The simulations are performed within a three-fluid model employing three different equations of state (EoS's): a purely hadronic EoS and two versions of EoS involving the deconfinement transition--the first-order phase transition and a smooth crossover one. The present simulations demonstrate that $v_2$(charged) is insensitive to the EoS. All considered scenarios equally well reproduce recent STAR data on $v_2$(charged) for mid-central Au+Au collisions and properly describe its change of sign at the incident energy decrease below $\\sqrt{s_{NN}}\\approx$ 3.5 GeV. This good reproduction of $v_2$(charged) indicates that the viscosity is small even at low incident energies. The predicted integrated elliptic flow of various species exhibits a stronger dependence on the EoS. A noticeable sensitivity to the EoS ...

  13. Preparation, characterization, and photocatalytic activity of porous AgBr@Ag and AgBrI@Ag plasmonic photocatalysts

    Science.gov (United States)

    Yang, Fan; Tian, Baozhu; Zhang, Jinlong; Xiong, Tianqing; Wang, Tingting

    2014-02-01

    Porous AgBr@Ag and AgBrI@Ag plasmonic photocatalysts were synthesized by a multistep route, including a dealloying method to prepare porous Ag, a transformation from Ag to AgBr and AgBrI, and a photo-reduction process to form Ag nanoparticles on the surface of AgBr and AgBrI. It was found that the porous structure kept unchanged during Ag was transferred into AgBr, AgBrI, AgBr@Ag, and AgBrI@Ag. Both porous AgBr@Ag and porous AgBrI@Ag showed much higher visible-light photocatalytic activity than cubic AgBr@Ag for the degradation of methyl orange, which is because the interconnected pore channels not only provide more reactive sites but also favor the transportation of photo-generated electrons and holes. For AgBrI@Ag, AgBrI solid solution formed at the interface of AgBr and AgI, and the phase junction can effectively separate the photo-generated electrons and holes, favorable to the improvement of photocatalytic activity. The optimal I content for obtaining the highest activity is ∼10 at.%.

  14. Initial-state bremsstrahlung versus final-state hydrodynamic sources of azimuthal harmonics in p+A at RHIC and LHC

    International Nuclear Information System (INIS)

    Recent pT<2 GeV azimuthal correlation data from the Beam Energy Scan (BES) and d+Au runs at RHIC/BNL and, especially, the surprising similarity of 2ℓ=2,4,⋯-particle cummulant azimuthal n=2,3,4,5 harmonics, vn{2ℓ}(pT), in p+Pb and Pb+Pb at LHC have challenged the uniqueness of local equilibrium “perfect fluid” interpretations of those data. We report results derived in [1] on azimuthal harmonics arising from non-equilibrium initial-state non-abelian “wave interference” effects predicted by perturbative QCD gluon bremsstrahlung and sourced by Color Scintillation Arrays (CSA) of color antennas. CSA are naturally identified with multiple projectile and target beam jets produced in inelastic p+A reactions. We find a remarkable similarity between azimuthal harmonics sourced by initial state CSA and those predicted with final state perfect fluid models of high energy p+A reactions. The question of which mechanism dominates in p+A and A+A remains open at this time

  15. Initial-State Bremsstrahlung versus Final-State Hydrodynamic Sources of Azimuthal Harmonics in p+A at RHIC and LHC

    CERN Document Server

    Gyulassy, Miklos; Vitev, Ivan; Biro, Tamas S

    2014-01-01

    Recent pT<2~GeV azimuthal correlation data from the Beam Energy Scan (BES) and D+Au runs at RHIC/BNL and, especially, the surprising similarity of azimuthal $v_n\\{2m\\}(p_T)$ ``transeverse flow'' harmonics in $p+Pb$ and $Pb+Pb$ at LHC have challenged the uniqueness of local equilibrium ``perfect fluid'' interpretations of those data. We report results at QM14 on azimuthal harmonics associated with initial-state non-abelian ``wave interference'' effects predicted by perturbative QCD gluon bremsstrahlung and sourced by Color Scintillation Arrays (CSA) of color antennas. CSA are naturally identified with multiple projectile and target beam jets produced in inelastic p+A reactions. We find a remarkable similarity between azimuthal harmonics sourced by initial state CSA and those predicted with final state perfect fluid models of high energy p+A reactions. The question of which mechanism dominates in $p+A$ and $A+A$ remains open at this time.

  16. Initial-state bremsstrahlung versus final-state hydrodynamic sources of azimuthal harmonics in p+A at RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Gyulassy, M. [MTA WIGNER Research Centre for Physics, RMI, Budapest (Hungary); Department of Physics, Columbia University, New York, NY 10027 (United States); Levai, P. [MTA WIGNER Research Centre for Physics, RMI, Budapest (Hungary); Vitev, I. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Biró, T.S. [MTA WIGNER Research Centre for Physics, RMI, Budapest (Hungary)

    2014-11-15

    Recent p{sub T}<2 GeV azimuthal correlation data from the Beam Energy Scan (BES) and d+Au runs at RHIC/BNL and, especially, the surprising similarity of 2ℓ=2,4,⋯-particle cummulant azimuthal n=2,3,4,5 harmonics, v{sub n}{2ℓ}(p{sub T}), in p+Pb and Pb+Pb at LHC have challenged the uniqueness of local equilibrium “perfect fluid” interpretations of those data. We report results derived in [1] on azimuthal harmonics arising from non-equilibrium initial-state non-abelian “wave interference” effects predicted by perturbative QCD gluon bremsstrahlung and sourced by Color Scintillation Arrays (CSA) of color antennas. CSA are naturally identified with multiple projectile and target beam jets produced in inelastic p+A reactions. We find a remarkable similarity between azimuthal harmonics sourced by initial state CSA and those predicted with final state perfect fluid models of high energy p+A reactions. The question of which mechanism dominates in p+A and A+A remains open at this time.

  17. An Inclusive Cross Section for the Nucleus - Nucleus Interaction at RHIC Energies

    OpenAIRE

    Bondarenko, S.; Gotsman, E.; Levin, E.; Maor, U.

    2001-01-01

    We discuss the saturation of the parton density in heavy ion collisions at RHIC energiesusing a Pomeron approach. Our predictions for the particle density in ion-ion collisions at RHIC energies can be utilized as the background for the observation of possible quark-gluon plasma production.

  18. POLARIZED HYDROGEN JET TARGET FOR MEASUREMENT OF RHIC PROTON BEAM POLARIZATION.

    Energy Technology Data Exchange (ETDEWEB)

    MAKDISI,Y.; WISE,T.; CHAPMAN,M.; GRAHAM,D.; KPONOU,A.; MAHLER,G.; MENG,W.; NASS,A.; RITTER,J.

    2005-01-28

    The performance and unique features of the RHIC polarized jet target and our solutions to the important design constraints imposed on the jet by the RHIC environment are described. The target polarization and thickness were measured to be 0.924 {+-} 2% and 1.3 {+-} 0.2 x 10{sup 12} atoms/cm{sup 2} respectively.

  19. Beyond the standard model physics at RHIC in polarized pp collision

    OpenAIRE

    Murata, Jiro

    2001-01-01

    A polarized hadron collider experiment must have a great discovery potential for a search of physics beyond the standard model. Experimental data of various symmetry tests at RHIC are going to be obtained within a few years. The author developed a simulation tool, studying a sensitivity of hunting contact interaction at RHIC by measuring parity violating spin asymmetries.

  20. Elliptic flow at SPS and RHIC from kinetic transport to hydrodynamics

    CERN Document Server

    Kolb, P F; Heinz, Ulrich W; Heiselberg, H

    2001-01-01

    Anisotropic transverse flow is studied in Pb+Pb and Au+Au collisions at SPS and RHIC energies. The centrality and transverse momentum dependence at midrapidity of the elliptic flow coefficient v_2 is calculated in the hydrodynamic and low density limits. Hydrodynamics is found to agree well with the RHIC data for semicentral collisions up to transverse momenta of 1-1.5 GeV/c, but it considerably overestimates the measured elliptic flow at SPS energies. The low density limit LDL is inconsistent with the measured magnitude of v_2 at RHIC energies and with the shape of its p_t-dependence at both RHIC and SPS energies. The success of the hydrodynamic model points to very rapid thermalization in Au+Au collisions at RHIC and provides a serious challenge for kinetic approaches based on classical scattering of on-shell particles.

  1. Comparison of the Window-Frame RHIC-abort kicker with C-type Kicker

    Energy Technology Data Exchange (ETDEWEB)

    Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hahn, H. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Meng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Severance, Michael [Stony Brook Univ., NY (United States); McMahan, Brandon [Westhampton High School, NY (United States)

    2014-08-26

    The high intensity proton bunches (~2.5x1011 p/bunch ) circulating in RHIC increase the temperature of the ferrite-made RHIC-abort-kickers above the Curie point; as a result, the kickers cannot provide the required field to abort the beam at the beam dump. A team of experts in the CAD department worked on modifying the design of the window-frame RHIC-abort kicker to minimize the hysteresis losses responsible for the increase of the ferrite’s temperature. In this technical note we report some results from the study of two possible modifications of the window-frame RHIC-abort kicker, and we compare these results with those of a propose C-type RHIC-abort kicker. We also include an Appendix where we describe a method which may further reduce the hysteresis losses of the window-frame kicker.

  2. PRODEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP : HIGH PERFORMANCE COMPUTING WITH QCDOC AND BLUEGENE.

    Energy Technology Data Exchange (ETDEWEB)

    CHRIST,N.; DAVENPORT,J.; DENG,Y.; GARA,A.; GLIMM,J.; MAWHINNEY,R.; MCFADDEN,E.; PESKIN,A.; PULLEYBLANK,W.

    2003-03-11

    Staff of Brookhaven National Laboratory, Columbia University, IBM and the RIKEN BNL Research Center organized a one-day workshop held on February 28, 2003 at Brookhaven to promote the following goals: (1) To explore areas other than QCD applications where the QCDOC and BlueGene/L machines can be applied to good advantage, (2) To identify areas where collaboration among the sponsoring institutions can be fruitful, and (3) To expose scientists to the emerging software architecture. This workshop grew out of an informal visit last fall by BNL staff to the IBM Thomas J. Watson Research Center that resulted in a continuing dialog among participants on issues common to these two related supercomputers. The workshop was divided into three sessions, addressing the hardware and software status of each system, prospective applications, and future directions.

  3. STATUS OF HIGH TEMPERATURE SUPERCONDUCTOR MAGNET R AND D AT BNL.

    Energy Technology Data Exchange (ETDEWEB)

    GUPTA,R.; ANERELLA,M.; COZZOLINO,J.; ESCALLIER,J.; GANETIS,G.; GHOSH,A.; ET AL.

    2004-01-22

    We report the status and test results of the High Temperature Superconductor (HTS) cable and magnet R&D at Brookhaven National Laboratory (BNL). If successful, this will enhance the performance and reduce the cost of operation of magnets that must absorb a large amount of energy. The need for developing this technology has been seen in a number of high field magnet applications for high energy colliders, and a medium field application in the proposed Rare Isotope Accelerator (RIA). The likelihood of the future use of HTS is improving because of the availability of longer and more uniform length tapes and cables and because of the ongoing construction and test experience at BNL and elsewhere. The design of a super-ferric quadrupole, that must survive the very high radiation environment of RIA, and operate at 20-40 K, is also presented.

  4. A wire scanner system for characterizing the BNL energy recovery LINAC beam position monitor system

    Energy Technology Data Exchange (ETDEWEB)

    Michnoff R.; Biscardi, C.; Cerniglia, P.; Degen, C.; Gassner, D.; Hoff, L.; Hulsart, R.

    2012-04-15

    A stepper motor controlled wire scanner system has recently been modified to support testing of the Brookhaven National Laboratory (BNL) Collider-Accelerator department's Energy Recovery Linac (ERL) beam position monitor (BPM) system. The ERL BPM consists of four 9.33 mm diameter buttons mounted at 90 degree spacing in a cube with 1.875 inch inside diameter. The buttons were designed by BNL and fabricated by Times Microwave Systems. Libera brilliance single pass BPM electronic modules with 700 MHz bandpass filter, manufactured by Instrumentation Technologies, will be used to measure the transverse beam positions at 14 locations around the ERL. The wire scanner assembly provides the ability to measure the BPM button response to a pulsed wire, and evaluate and calibrate the Libera position measurement electronics. A description of the wire scanner system and test result data will be presented.

  5. Radar Wind Profiler for Cloud Forecasting at Brookhaven National Laboratory (BNL) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Michael P [Brookhaven National Lab. (BNL), Upton, NY (United States); Giangrande, Scott E [Brookhaven National Lab. (BNL), Upton, NY (United States); Bartholomew, Mary Jane [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-04-01

    The Radar Wind Profiler for Cloud Forecasting at Brookhaven National Laboratory (BNL) [http://www.arm.gov/campaigns/osc2013rwpcf] campaign was scheduled to take place from 15 July 2013 through 15 July 2015 (or until shipped for the next U.S. Department of Energy Atmospheric Radiation Measurement [ARM] Climate Research Facility first Mobile Facility [AMF1] deployment). The campaign involved the deployment of the AMF1 Scintec 915 MHz Radar Wind Profiler (RWP) at BNL, in conjunction with several other ARM, BNL and National Weather Service (NWS) instruments. The two main scientific foci of the campaign were: 1) To provide profiles of the horizontal wind to be used to test and validate short-term cloud advection forecasts for solar-energy applications and 2) to provide vertical profiling capabilities for the study of dynamics (i.e., vertical velocity) and hydrometeors in winter storms. This campaign was a serendipitous opportunity that arose following the deployment of the RWP at the Two-Column Aerosol Project (TCAP) campaign in Cape Cod, Massachusetts and restriction from participation in the Green Ocean Amazon 2014/15 (GoAmazon 2014/15) campaign due to radio-frequency allocation restriction for international deployments. The RWP arrived at BNL in the fall of 2013, but deployment was delayed until fall of 2014 as work/safety planning and site preparation were completed. The RWP further encountered multiple electrical failures, which eventually required several shipments of instrument power supplies and the final amplifier to the vendor to complete repairs. Data collection began in late January 2015. The operational modes of the RWP were changed such that in addition to collecting traditional profiles of the horizontal wind, a vertically pointing mode was also included for the purpose of precipitation sensing and estimation of vertical velocities. The RWP operated well until the end of the campaign in July 2015 and collected observations for more than 20 precipitation

  6. BNL program in support of LWR degraded-core accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ginsberg, T.; Greene, G.A.

    1982-01-01

    Two major sources of loading on dry watr reactor containments are steam generatin from core debris water thermal interactions and molten core-concrete interactions. Experiments are in progress at BNL in support of analytical model development related to aspects of the above containment loading mechanisms. The work supports development and evaluation of the CORCON (Muir, 1981) and MARCH (Wooton, 1980) computer codes. Progress in the two programs is described in this paper. 8 figures.

  7. Analysis of failed ramps during the RHIC FY09 run

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider (RHIC) is a versatile accelerator that supports operation with polarized protons of up to 250 GeV and ions with up to 100 GeV/nucleon. During any running period, various operating scenarios with different particle species, beam energies or accelerator optics are commissioned. In this report the beam commissioning periods for establishing full energy beams (ramp development periods) from the FY09 run are summarized and, for the purpose of motivating further developments, we analyze the reasons for all failed ramps.

  8. Elliptic flow in Au+Au collisions at RHIC

    Science.gov (United States)

    Vale, Carla M.; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Ngyuen, M.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wyslouch, B.

    2005-04-01

    Elliptic flow is an interesting probe of the dynamical evolution of the dense system formed in the ultrarelativistic heavy ion collisions at the relativistic heavy ion collider (RHIC). The elliptic flow dependences on transverse momentum, centrality and pseudorapidity were measured using data collected by the PHOBOS detector, which offers a unique opportunity to study the azimuthal anisotropies of charged particles over a wide range of pseudorapidity. These measurements are presented, together with an overview of the analysis methods and a discussion of the results.

  9. Design and test of the RHIC CMD10 abort kicker

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pai, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sandberg, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tuozzolo, J. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhang, W. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    In recent RHIC operational runs, planned and unplanned pre-fire triggered beam aborts have been observed that resulted in quenches of SC main ring magnets, indicating a weakened magnet kick strength due to beam-induced ferrite heating. An improvement program was initiated to reduce the longitudinal coupling impedance with changes to the ferrite material and the eddy-current strip geometry. Results of the impedance measurements and of magnet heating tests with CMD10 ferrite up to 190°C are reported. All 10 abort kickers in the tunnel have been modified and were provided with a cooling system for the RUN 15.

  10. Photon multiplicity measurements: From SPS to RHIC and LHC

    Indian Academy of Sciences (India)

    Bedangadas Mohanty

    2003-04-01

    Results from the photon multiplicity measurements using a fine granularity pre-shower photon multiplicity detector (PMD) at CERN SPS are discussed. These include study of pseudorapidity distributions of photons, scaling of photon multiplicity with number of participating nucleons, centrality dependence of $\\langle p_{T}\\rangle$ of photons, event-by-event fluctuations in photon multiplicity and localised charged-neutral fluctuations. Basic features of the PMD to be used in STAR experiment at RHIC and in ALICE experiment at LHC are also discussed.

  11. Strangeness enhancement from strong color fields at RHIC

    OpenAIRE

    Bleicher, Marcus; Greiner, Walter; Stöcker, Horst; Xu, Nu

    2000-01-01

    In ultra-relativistic heavy ion collisions, early stage multiple scatterings may lead to an increase of the color electric field strength. Consequently, particle production - especially heavy quark (and di-quark) production - is greatly enhanced according to the Schwinger mechanism. We test this idea via the Ultra-relativistic Quantum Molecular Dynamics model (UrQMD) for Au+Au collisions at the full RHIC energy ($\\sqrt{s} = 200$ AGeV). Relative to p+p collisions, a factor of 60, 20 and 7 enha...

  12. Lessons from RHIC for the LHC and vice versa

    OpenAIRE

    Tannenbaum, Michael J.

    2012-01-01

    For the past decade, measurements of semi-inclusive single identified particle spectra and two particle correlations in p-p and A+A collisions at RHIC have produced a treasure trove of results which indicate that the medium produced in Au+Au collisions is a strongly interacting quark gluon liquid in which both light and heavy quarks are suppressed, presumably by energy loss in the hot, dense medium. These results have been confirmed in Pb+Pb collisions at the LHC along with the addition of me...

  13. Simultaneous global coupling and vertical dispersion correction in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Liu C.; Luo, Y.; Marusic, A.; Minty, M.

    2012-05-20

    Residual vertical dispersion on the order of +/-0.2 m (peak to peak) has been measured at store energies for both polarized protons and heavy ion beams in RHIC. The hypothesis is that this may have impact on the polarization transmission efficiency during the energy ramp, the polarization lifetime at store and, for heavy ions, the dynamic aperture. An algorithm to correct global coupling and dispersion simultaneously using existing skew quadrupoles was developed. Measured coupling and dispersion functions acquired before and after correction are presented.

  14. Universal QGP Hadronization Conditions at RHIC and LHC

    CERN Document Server

    Rafelski, Johann

    2014-01-01

    We address the principles governing QGP hadronization and particle production in relativistic heavy-ion collisions. We argue that chemical non-equilibrium is required and show that once this condition is assumed a very good description of hadron production in collider RHIC and at LHC heavy ion experiments follows. We present results of our analysis as a function of centrality. Comparing most extreme experimental conditions we show that only the reaction volume and degree of strangeness phase space saturation change. We determine the universal QGP fireball hadronization conditions.

  15. Hydrodynamic analysis of heavy ion collisions at RHIC

    CERN Document Server

    Hirano, Tetsufumi

    2008-01-01

    Current status of dynamical modeling of relativistic heavy ion collisions and hydrodynamic description of the quark gluon plasma is reported. We find the hadronic rescattering effect plays an important role in interpretation of mass splitting pattern in the differential elliptic flow data observed at RHIC. To demonstrate this, we predict the elliptic flow parameter for phi mesons to directly observe the flow just after hadronisation. We also discuss recent applications of outputs from hydrodynamic calculations to J/psi suppression, thermal photon radiation and heavy quark diffusion.

  16. Small gap magnet prototype measurements for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Y.; He, P.; Jain, A.; Mahler, G.; Meng, W.; Tuozzolo, J.; Litvinenko, V.

    2010-05-23

    In this paper we present the design and prototype measurement of small gap (5mm to 10 mm aperture) dipole and quadrupole for the future high energy ERL (Energy Recovery Linac). The small gap magnets have the potential of largely reducing the cost of the future electron-ion collider project, eRHIC, which requires a 10GeV to 30 GeV ERL with up to 6 energy recovery passes (3.8 km each pass). We also studied the sensitivity of the energy recovery pass and the alignment error in this small magnets structure and countermeasure methods.

  17. Open and hidden charm production at RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R.

    2005-10-12

    We discuss aspects of open and hidden charm production in hadron-nucleus collisions at RHIC and LHC energies. We first discuss the extraction of the total charm cross section in lower energy collisions and how it compares to next-to-leading order quantum chromodynamics calculations. We then describe calculations of the transverse momentum distributions and their agreement with the shape of the measured STAR transverse momentum distributions. We next explain how shadowing and moderate nuclear absorption can explain the PHENIX J/{psi} dAu/pp ratios.

  18. Overview and analysis of the 2016 Gold Run in the Booster and AGS

    Energy Technology Data Exchange (ETDEWEB)

    Zeno, K. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Alternating Gradient Synchrotron

    2016-09-16

    Run 16 differed from preceding Au runs in that during most of it a 12:6:2 merge was employed in the AGS instead of an 8:4:2 merge. This was done to provide higher bunch intensities for RHIC. Since the approach to providing higher bunch intensities is, and has been, to merge more Booster bunches of the same intensity into one final bunch, detailing the longitudinal aspects of this setup seems quite relevant. So, aside from providing an overview of the Au portion of Run 16, this note also contains a series of emittance measurements in the Booster and AGS. Comparisons of these to similar measurements in previous runs are also made in hopes of gaining a better understanding of what factors contribute to the emittance of a bunch at AGS extraction. The note also tries to provide some context in which to understand the various merge schemes and describes a potential 8 to 1 type merge.

  19. AGS-2000: Experiments for the 21. Century. Proceedings of the workshop held at Brookhaven National Laboratory, May 13--17, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Littenberg, L. [ed.] [Brookhaven National Lab., Upton, NY (United States); Sandweiss, J. [ed.] [Yale Univ., New Haven, CT (United States)

    1996-10-01

    The AGS has a vital and interesting potential for new research. The reasons for this are a fortunate concomitance of the energy chosen for the AGS and the steady stream of technological advances which have both increased the intensity and flexibility of the AGS beams, and the capability of detectors to use these new beam parameters. The physics potentials of the future AGS program can be roughly divided into three broad areas. (1) fundamental elementary particle studies (based on rare kaon decays, rare muon processes and searches for new particles); (2) non-perturbative QCD; and (3) heavy ion physics. The overriding considerations for the operation of the AGS in the next decade must, of course, be the interest and potential of the scientific program. However, once that has been established, there are other aspects of the AGS program which deserve mention. Although experiments at the AGS are of increasing sophistication, they are smaller, less expensive, and more quickly executed than experiments at newer, larger facilities. Finally, the authors note that since the AGS must be maintained as a viable accelerator to serve as an injector to RHIC, the cost of an AGS fixed target experiment need be only the incremental cost of the experiment itself along with some modest additional operating costs. This means that AGS fixed target experiments are substantially cheaper than they would have been before the RHIC era. The remainder of this document contains brief summaries of the experiments considered by the working groups in the AGS-2000 Workshop. These summaries expand on points discussed here.

  20. AGS-2000: Experiments for the 21. Century. Proceedings of the workshop held at Brookhaven National Laboratory, May 13--17, 1996

    International Nuclear Information System (INIS)

    The AGS has a vital and interesting potential for new research. The reasons for this are a fortunate concomitance of the energy chosen for the AGS and the steady stream of technological advances which have both increased the intensity and flexibility of the AGS beams, and the capability of detectors to use these new beam parameters. The physics potentials of the future AGS program can be roughly divided into three broad areas. (1) fundamental elementary particle studies (based on rare kaon decays, rare muon processes and searches for new particles); (2) non-perturbative QCD; and (3) heavy ion physics. The overriding considerations for the operation of the AGS in the next decade must, of course, be the interest and potential of the scientific program. However, once that has been established, there are other aspects of the AGS program which deserve mention. Although experiments at the AGS are of increasing sophistication, they are smaller, less expensive, and more quickly executed than experiments at newer, larger facilities. Finally, the authors note that since the AGS must be maintained as a viable accelerator to serve as an injector to RHIC, the cost of an AGS fixed target experiment need be only the incremental cost of the experiment itself along with some modest additional operating costs. This means that AGS fixed target experiments are substantially cheaper than they would have been before the RHIC era. The remainder of this document contains brief summaries of the experiments considered by the working groups in the AGS-2000 Workshop. These summaries expand on points discussed here

  1. Asymmetry in inclusive π±, p production at 22 GeV, BNL E925

    International Nuclear Information System (INIS)

    Preliminary results from Experiment E925 on inclusive pion asymmetries from a 22 GeV/c polarized proton beam on a carbon target show significant asymmetries for π± production similar to those observed earlier at the ZGS and Fermilab with beams of 12 and 200 GeV respectively. This experiment demonstrates the viability of using the analyzing power in inclusive pion production for high energy beam polarimetry at RHIC. Inclusive proton asymmetries are consistent with zero

  2. Can Doubly Strange Dibaryon Resonances be Discovered at RHIC?

    CERN Document Server

    Paganis, S D; Ray, R L; Tang, J L; Udagawa, T; Longacre, R S

    2000-01-01

    The baryon-baryon continuum invariant mass spectrum generated from ultrarelativistic nucleus + nucleus collision data may reveal the existence of doubly-strange dibaryons not stable against strong decay if they lie within a few MeV of threshold. Furthermore, since the dominant component of these states is a superposition of two color-octet clusters which can be produced intermediately in a color-deconfined quark-gluon plasma (QGP), an enhanced production of dibaryon resonances could be a signal of QGP formation. A total of eight, doubly-strange dibaryon states are considered for experimental search using the STAR detector (Solenoidal Tracker at RHIC) at the new Relativistic Heavy Ion Collider (RHIC). These states may decay to Lambda-Lambda and/or proton-Cascade-minus, depending on the resonance energy. STAR's large acceptance, precision tracking and vertex reconstruction capabilities, and large data volume capacity, make it an ideal instrument to use for such a search. Detector performance and analysis sensit...

  3. Saturation physics at HERA and RHIC: An unified description

    CERN Document Server

    Gonçalves, V P; Machado, M V T; Navarra, F S

    2006-01-01

    One of the frontiers of QCD which are intensely investigated in high energy experiments is the high energy (small $x$) regime, where we expect to observe the non-linear behavior of the theory. In this regime, the growth of the parton distribution should saturate, forming a Color Glass Condensate (CGC). In fact, signals of parton saturation have already been observed both in $ep$ deep inelastic scattering at HERA and in deuteron-gold collisions at RHIC. Currently, the description of the experimental data of these experiments is possible considering different phenomenological saturation models for the two processes within the CGC formalism. In this letter we analyze the universality of these dipole cross section parameterizations and verify that they are not able to describe the HERA and RHIC data simultaneously. We analyze possible improvements in the parameterizations and propose a new parametrization for the forward dipole amplitude which allows us to describe quite well the small-$x$ $ep$ HERA data on $F_2$...

  4. The gold flashlight: Coherent photons (and Pomerons) at RHIC

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider (RHIC) will be the first heavy ion accelerator energetic enough to produce hadronic final states via coherent γγ, γP, and PP interactions. Because the photon flux scales as Z2, up to an energy of about γℎc/R ∼ 3 GeV/c, the γγ interaction rates are large. RHIC γP interactions test how Pomerons couple to nuclei and measure how different vector mesons, including the J/ψ, interact with nuclear matter. PP collisions can probe Pomeron couplings. Because these collisions can involve identical initial states, for identical final states, the γγ, γP, and PP channels may interfere, producing new effects. The authors review the physics of these interactions and discuss how these signals can be detected experimentally, in the context of the STAR detector. Signals can be separated from backgrounds by using isolation cuts (rapidity gaps) and p perpendicular. The authors present Monte Carlo studies of different backgrounds, showing that representative signals can be extracted with good rates and signal to noise ratios

  5. Evidence for a quark-gluon plasma at RHIC

    International Nuclear Information System (INIS)

    This presentation is given in honor of Walter Greiner's 70th birthday, in recognition of the pioneering work of his “Frankfurt School” and their contributions to the field of heavy ion physics. Ultra-relativistic collisions of heavy nuclei at the Relativistic Heavy Ion Collider (RHIC) form an extremely hot system at energy densities greater than 5 GeV/fm3, where normal hadrons cannot exist. Upon rapid cooling of the system to a temperature T ~ 175 MeV and vanishingly small baryo-chemical potential, hadrons coalesce from quarks at the quark-hadron phase boundary predicted by lattice QCD. A large amount of collective (elliptic) flow at the quark level provides evidence for strong pressure gradients in the initial partonic stage of the collision when the system is dense and highly interacting prior to coalescence into hadrons. The suppression of both light (u,d,s) and heavy (c,b) hadrons at large transverse momenta, that form from fragmentation of hard-scattered partons, and the quenching of di-jets provide evidence for extremely large energy loss of partons as they attempt to propagate through the dense, strongly-coupled, colored medium created at RHIC. (author)

  6. Localized control of the orbit in the RHIC insertions

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuma, S.

    1992-08-01

    It is proposed here that, for RHIC92 insertions, we remove the corrector from Ql and the beam position monitor (BPM) from Q2 in order to alleviate difficulties associated with the physical layout of the quadrupole triplet (Ql-Q2-Q3). Furthermore, it is suggested that there should be both (horizontal and vertical) types of BPMs at each end of the free space between Q3 and Q4 and between Q7 and Q8 so that one can measure the direction of the closed orbit. With this model, a localized control of the beam position and angle at the interaction point (IP) with either four or six correctors has been investigated. Similarly, a control of the orbit within an insertion for minimizing the orbit displacements at seven (or eight) BPM locations with nine (or ten) correctors in each transverse direction has been studied. Examples are given for the beta at IP = 2m, 10m, 20m, and 200m. It is shown that the design value of the integrated field strength of 0.3 T-m for each corrector should be sufficient for the tasks considered here except for some cases with extreme parameter values. At the same time, it is emphasized that the overall correction of the closed orbit for the entire ring (arcs and insertions) should be re-examined for RHIC92 lattice with the proposed arrangement of correctors and BPMS.

  7. Photon-jet ridge at RHIC and the LHC

    CERN Document Server

    Rezaeian, Amir H

    2016-01-01

    We investigate long range rapidity correlations of pairs of prompt photon and jet in the Color Glass Condensate (CGC) framework in proton-proton and proton-nucleus collisions at RHIC and the LHC. We show that photon-jet correlations exhibit long-range azimuthal collimation at near-side for low transverse momenta of the produced photon and jet in high-multiplicity events. These ridge-like features are strikingly similar to the observed ridge effect for di-hadron correlations at RHIC and the LHC. We show that correlations in the relative rapidity and the relative azimuthal angle between pairs of prompt photon and jet strongly depend on the gluon saturation dynamics at small-x kinematics and such measurements can help to understand the true origin of the observed di-hadron ridge in p+A collisions, and address whether the ridge is a universal phenomenon for all two particle correlations at high energy and high multiplicity events. We also investigate if there is a ridge-like structure for photon-hadron pair corre...

  8. Results from PHENIX at RHIC with Implications for LHC

    CERN Document Server

    Tannenbaum, M J

    2014-01-01

    This article is based on my Proceedings for the 47th Course of the International School of Subnuclear Physics on the Most Unexpected at LHC and the Status of High Energy Frontier, Erice, Sicily, Italy, 2009. Results from the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) in nucleus-nucleus and proton-proton collisions at c.m. energy $\\sqrt{s_{NN}}=200$ GeV are presented in the context of the methods of single and two-particle inclusive reactions which were used in the discovery of hard-scattering in p-p collisions at the CERN ISR in the 1970's. These techniques are used at RHIC in A+A collisions because of the huge combinatoric background from the large particle multiplicity. Topics include $J/\\Psi$ suppression, jet quenching in the dense medium (sQGP) as observed with $\\pi^0$ at large transverse momentum, thermal photons, collective flow, two-particle correlations, suppression of heavy quarks at large $p_T$ and its possible relation to Higgs searches at the LHC. The differences and similarit...

  9. RHIC PC CNI POLARIMETER: EXPERIMENTAL SETUP AND PHYSICS RESULTS

    International Nuclear Information System (INIS)

    Acceleration of polarized proton beams and experiments with them at RHIC require fast and reliable measurements of the polarization. The polarimeter presented here uses very high figure of merit of the elastic pC scattering at very low momenta transfer since the cross section is large. Small (a few percent) analyzing power of the reaction makes it necessary to collect about 107 events per measurement. A deadtimeless DAQ system for the polarimeter is discussed in this paper. It is based on the waveform digitizer modules with ''on-board''' event analysis, resulting in typical polarization measurement times of several tens of seconds. During winter 2001/2002 RHIC polarized run several dedicated data runs were taken by the polarimeter to extract the form of the analyzing power dependence as a function of the momentum transferred at beam energies 24 and 100 GeV. This dependence is extremely important for the theoretical understanding of the CNI process including the contribution of the spin-flip hadronic amplitude. The new data may become an input to some theoretical models predicting the energy dependence of the analyzing power

  10. Evidence for a Quark-Gluon Plasma at Rhic

    Science.gov (United States)

    Harris, John W.

    This presentation is given in honor of Walter Greiner's 70th birthday, in recognition of the pioneering work of his "Frankfurt School" and their contributions to the field of heavy ion physics. Ultra-relativistic collisions of heavy nuclei at the Relativistic Heavy Ion Collider (RHIC) form an extremely hot system at energy densities greater than 5 GeV/fm3, where normal hadrons cannot exist. Upon rapid cooling of the system to a temperature T ~ 175 MeV and vanishingly small baryo-chemical potential, hadrons coalesce from quarks at the quark-hadron phase boundary predicted by lattice QCD. A large amount of collective (elliptic) flow at the quark level provides evidence for strong pressure gradients in the initial partonic stage of the collision when the system is dense and highly interacting prior to coalescence into hadrons. The suppression of both light (u,d,s) and heavy (c,b) hadrons at large transverse momenta, that form from fragmentation of hard-scattered partons, and the quenching of di-jets provide evidence for extremely large energy loss of partons as they attempt to propagate through the dense, strongly-coupled, colored medium created at RHIC.

  11. Beam Energy Scan at RHIC and z-Scaling

    International Nuclear Information System (INIS)

    Beam Energy Scan (BES) data obtained at RHIC are briefly reviewed. Method of data analysis (z-scaling approach) based on self-similarity and locality of constituent interactions in hadron and nucleus collisions at high energy is described. The method is applied for analysis of BES data to search for signatures of phase transition and Critical Point (CP). Some results of analysis of hadron spectra measured in heavy ion collisions (HIC) at RHIC over a wide range of the energy √(sNN)=7.7–200 GeV are presented. Microscopic scenario of constituent interactions in the framework of this approach is discussed. Dependence of the energy loss on the momentum of the produced hadron, energy and centrality of the collision is studied. Self-similarity of the constituent interactions in terms of momentum fractions is used to characterize the nuclear medium by a “specific heat” and the colliding nuclei by fractal dimensions. Kinematic regions which are assumed to be most preferable for search for signatures of phase transition of nuclear matter produced in HIC in BES are discussed

  12. Spin Dependence in Polarized pp->pp and pC->pC Elastic Scattering at Very Low Momentum Transfer t at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Bravar, A. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Alekseev, I. [ITEP, Moscow, 117259 (Russian Federation); Bunce, G. [Brookhaven National Laboratory, Upton, NY 11973 (United States); RIKEN BNL Research Center, Upton, NY 11973 (United States); Dhawan, S. [Yale University, New Haven, CT 06511 (United States); Gill, R. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Huang, H. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Haeberli, W. [University of Wisconsin, Madison, WI 53706 (United States); Igo, G. [UCLA, Los Angeles, CA 90095 (United States); Jinnouchi, O. [RIKEN BNL Research Center, Upton, NY 11973 (United States); Khodinov, A. [SUNY at Stony Brook, Stony Brook, NY 11794 USA (United States); Kponou, A. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Kurita, K. [Rikkyo University, Toshima-ku, Tokyo 171-8501 (Japan); Makdisi, Y. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Meng, W. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Nass, A. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Okada, H. [Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Saito, N. [Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); RIKEN BNL Research Center, Upton, NY 11973 (United States); Spinka, H. [Argonne National Laboratory, Argonne, IL 60439 (United States); Stephenson, E. [Indiana University, Bloomington, IN 47405 (United States); Svirida, D. [ITEP, Moscow, 117259 (Russian Federation); Underwood, D. [Argonne National Laboratory, Argonne, IL 60439 (United States); Whitten, C. [UCLA, Los Angeles, CA 90095 (United States); Wise, T. [University of Wisconsin, Madison, WI 53706 (United States); Wood, J. [UCLA, Los Angeles, CA 90095 (United States); Zelenski, A. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2005-09-15

    Interference phenomena in (polarized) hadron collisions have often led to spectacular spin effects in the final state. These effects are expressed in terms of the spin observables, like the analyzing power A{sub N}. The interference of the electromagnetic spin-flip amplitude with a hadronic spin-nonflip amplitude in the elastic scattering of hadrons generates a significant A{sub N} at very low t (0.001< vertical bar t vertical bar <0.01(GeV/c){sup 2}). This kinematical region is referred to as the Coulomb Nuclear Interference (CNI) region. A possible hadronic spin-flip amplitude can substantially modify the magnitude and shape of A{sub N}, which otherwise is exactly calculable. First results on A{sub N} in polarized proton-proton elastic scattering in the CNI region at 100 GeV from the 2004 polarized proton run at RHIC are presented. New results on A{sub N} in the elastic scattering of polarized protons off a carbon target over a wide energy range from 4 GeV to 100 GeV from AGS and RHIC are presented, as well. These results allow us to further study the spin dependence in elastic scattering and the mechanisms that generate these effects.

  13. Spin Dependence in Polarized pp->pp and pC->pC Elastic Scattering at Very Low Momentum Transfer t at RHIC

    International Nuclear Information System (INIS)

    Interference phenomena in (polarized) hadron collisions have often led to spectacular spin effects in the final state. These effects are expressed in terms of the spin observables, like the analyzing power AN. The interference of the electromagnetic spin-flip amplitude with a hadronic spin-nonflip amplitude in the elastic scattering of hadrons generates a significant AN at very low t (0.0012). This kinematical region is referred to as the Coulomb Nuclear Interference (CNI) region. A possible hadronic spin-flip amplitude can substantially modify the magnitude and shape of AN, which otherwise is exactly calculable. First results on AN in polarized proton-proton elastic scattering in the CNI region at 100 GeV from the 2004 polarized proton run at RHIC are presented. New results on AN in the elastic scattering of polarized protons off a carbon target over a wide energy range from 4 GeV to 100 GeV from AGS and RHIC are presented, as well. These results allow us to further study the spin dependence in elastic scattering and the mechanisms that generate these effects

  14. THE BNL ASTD FIELD LAB - NEAR - REAL - TIME CHARACTERIZATION OF BNL STOCKPILED SOILS TO ACCELERATE COMPLETION OF THE EM CHEMICAL HOLES PROJECT

    International Nuclear Information System (INIS)

    As of October 2001, approximately 7,000 yd3 of stockpiled soil remained at Brookhaven National Laboratory (BNL) after the remediation of the BNL Chemical/Animal/Glass Pits disposal area. The soils were originally contaminated with radioactive materials and heavy metals, depending on what materials had been interred in the pits, and how the pits were excavated. During the 1997 removal action, the more hazardous/radioactive materials were segregated, along with, chemical liquids and solids, animal carcasses, intact gas cylinders, and a large quantity of metal and glass debris. Nearly all of these materials have been disposed of. In order to ensure that all debris was removed and to characterize the large quantity of heterogeneous soil, BNL initiated an extended sorting, segregation, and characterization project directed at the remaining soil stockpiles. The project was co-funded by the Department of Energy Environmental Management Office (DOE EM) through the BNL Environmental Restoration program and through the DOE EM Office of Science and Technology Accelerated Site Technology Deployment (ASTD) program. The focus was to remove any non-conforming items, and to assure that mercury and radioactive contaminant levels were within acceptable limits for disposal as low-level radioactive waste. Soils with mercury concentrations above allowable levels would be separated for disposal as mixed waste. Sorting and segregation were conducted simultaneously. Large stockpiles (ranging from 150 to 1,200 yd3) were subdivided into manageable 20 yd3 units after powered vibratory screening. The 1/2-inch screen removed almost all non-conforming items (plus some gravel). Non-conforming items were separated for further characterization. Soil that passed through the screen was also visually inspected before being moved to a 20 yd3 ''subpile.'' Eight samples from each subpile were collected after establishing a grid of four quadrants: north, east, south and west, and two layers: top and

  15. AGS experiments -- 1991, 1992, 1993

    International Nuclear Information System (INIS)

    This report contains: (1) FY 1993 AGS schedule as run; (2) FY 1994--95 AGS schedule; (3) AGS experiments ≥ FY 1993 (as of 30 March 1994); (4) AGS beams 1993; (5) AGS experimental area FY 1991 physics program; (6) AGS experimental area FY 1992 physics program; (7) AGS experimental area FY 1993 physics program; (8) AGS experimental area FY 1994 physics program (planned); (9) a listing of experiments by number; (10) two-page summaries of each experiment; (11) listing of publications of AGS experiments; and (12) listing of AGS experiments

  16. AGS experiments - 1994, 1995, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Depken, J.C.

    1997-01-01

    This report contains the following information on the Brookhaven AGS Accelerator complex: FY 1996 AGS schedule as run; FY 1997 AGS schedule (working copy); AGS beams 1997; AGS experimental area FY 1994 physics program; AGS experimental area FY 1995 physics program; AGS experimental area FY 1996 physics program; AGS experimental area FY 1997 physics program (in progress); a listing of experiments by number; two-phage summaries of each experiment begin here, also ordered by number; listing of publications of AGS experiments begins here; and listing of AGS experimenters begins here.

  17. AGS experiments - 1994, 1995, 1996

    International Nuclear Information System (INIS)

    This report contains the following information on the Brookhaven AGS Accelerator complex: FY 1996 AGS schedule as run; FY 1997 AGS schedule (working copy); AGS beams 1997; AGS experimental area FY 1994 physics program; AGS experimental area FY 1995 physics program; AGS experimental area FY 1996 physics program; AGS experimental area FY 1997 physics program (in progress); a listing of experiments by number; two-phage summaries of each experiment begin here, also ordered by number; listing of publications of AGS experiments begins here; and listing of AGS experimenters begins here

  18. Design and construction status of the AGS Booster accelerator

    International Nuclear Information System (INIS)

    To meet the requirements of new experiments in high energy physics and nuclear physics, a fast cycling Booster accelerator was proposed to fulfill the following three technical objectives: The AGS Booster has three objectives. They are to increase the space charge limit of the AGS, to incrase the intensity of the polarized proton beam by accumulating many linac pulses (since the intensity is limited by the polarized ion source), and to re-accelerate heavy ions from the BNL Tandem Van de Graaff before injection iinto the AGS. The machine is capable of accelerating protons at 7.5 Hertz from 200 MeV to 1.5 GeV or to lower final energies at faster repetition rates. The machine will also be able to accelerate heavy ions from as low as 1 MeV/nucleon to a magnetic rigidity as high as 17.6 Tesla-meters with a one second repetition rate. As an accumulator for polarized protons, the Booster should be able to store the protons at 200 MeV for several seconds. We will report primarily those design and construction issues related to high intensity proton acceleration of the Booster. 4 refs., 6 figs., 4 tabs

  19. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP CIRCUM-PAN-PACIFIC RIKEN SYMPOSIUM ON HIGH ENERGY SPIN PHYSICS, VOLUME 25

    International Nuclear Information System (INIS)

    The Circum-Pan-Pacific Riken Symposium on High Energy Spin Physics was held at Oukouchi Memorial Hall in Riken from November 3 through 6, 1999. It was held as a joint meeting of the 2nd Circum-Pan-Pacific Symposium on High Energy Spin Physics and the 3rd of the series of Riken Symposia related to the RHIC-SPIN. The 1st Circum-Pan-Pacific Symposium on High Energy Spin Physics was held at Kobe in 1996 and the RHIC-SPIN Riken Symposia had been held every two years since 1995. As Prof. Ozaki mentioned in his talk at the beginning of this meeting, the RHIC was ready for the first beam, physics experiments scheduled in 2000, and the RHIC-SPIN would start in 2001. It was therefore considered to be very timely for the researchers in the field of high energy spin physics to get together, clarifying the present status of the field and discussing interesting and important topics as well as experimental subjects to be pursued. It is especially important for the success of the RHIC-SPIN project that the researchers in the neighboring countries surrounding the Pacific are actively involved in it. This is why the above two series were joined in this. symposium. The subjects discussed in the symposium include: Hard processes probing spin-structure functions, polarization mechanisms in high energy reactions, lattice studies of polarized structure functions, theoretical models for the nucleon and its spin structure, RHIC and RHIC-SPIN projects, results and future projects of existing experimental facilities. Totally 73 scientists participated in the symposium, 27 from abroad and 46 from Japan. it consisted of 13 main sessions, with 33 invited and contributed talks, and 4 discussion sessions covering recent experimental and theoretical developments and important topics in high energy spin physics and closely related fields

  20. Weakness or Strength in the Golden Years of RHIC and LHC?

    CERN Document Server

    Horowitz, W A

    2012-01-01

    Recent LHC data suggest that perturbative QCD provides a qualitatively consistent picture of jet quenching. Constrained to RHIC pi0 suppression, zero parameter WHDG energy loss predictions agree quantitatively with the charged hadron v2 and D meson RAA measured at LHC and qualitatively with the charged hadron RAA. On the other hand, RHIC-constrained LHC predictions from fully strongly-coupled AdS/CFT qualitatively oversuppress D mesons compared to data; light meson predictions are on less firm theoretical ground but also suggest oversuppression. More detailed data from heavy, especially B, mesons will continue to help clarify our picture of the physics of the quark-gluon plasma. Since the approach of pQCD predictions to LHC data occurs at momenta >~ 15 GeV/c, a robust consistency check between pQCD and both RHIC and LHC data requires RHIC jet measurements.

  1. Simulations to study the static polarization limit for RHIC lattice with the Polymorphic Tracking Code

    CERN Document Server

    Duan, Zhe

    2015-01-01

    We report a study of spin dynamics based on simulations with the Polymorphic Tracking Code (PTC), exploring the dependence of the static polarization limit on various beam parameters and lattice settings for a practical RHIC lattice.

  2. US-Japan collaboration in the construction of the BNL superconducting muon storage ring and inflector

    Energy Technology Data Exchange (ETDEWEB)

    Hirabayashi, Hiromi; Yamamoto, Akira [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    2003-03-01

    The US-Japan collaboration in the contraction of a BNL muon storage ring for the g-2 experiment (E821) is described from the viewpoint of Japanese collaborators. Japan has contributed in the production of the pole pieces made of a vacuum-melted Ultra-Low Carbon Steel, Al-stabilized Nb/Ti superconductors for the superferric storage ring dipole coils, including technology transfer, and the development of a sophisticated superconducting inflector for muon injection. All of above items seem to be essential techniques to pursue accurate and detailed muon g-2 experiments. Recent experimental results are also mentioned in the latter part of this report. (author)

  3. Design and Data Model of the BNL Archive and Dissemination System

    Energy Technology Data Exchange (ETDEWEB)

    Heller, J.; Osterer, L.

    1977-03-01

    The BNL Archive and Dissemination (BNLAD) System was designed to operate on a homogeneous distributed data base in a computer network. Its primary function is to present a uniform logical and physical view of already existing sequential files of data, so that these files can be accessed at any node of a computer network where the BNLAD System is operable. The architecture of the system, based on a subset of PL/I (the host language), is presented. The Data Model, i.e. the information content of the data base as it is viewed by the users, of the BNLAD System is discussed by means of examples. 7 figs.

  4. Simulations of the recent Lasalle-2 incident with the BNL plant analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H.S.; Mallen, A.N.; Wulff, W.

    1989-01-01

    This paper presents the results of simulations of the recent power oscillation incident at the LaSalle-2 Nuclear Power Plant using the BNL Plant Analyzer. The causes of the oscillation were investigated and the sensitivity of the oscillation to key parameters was studied. It is concluded that the observed power oscillation was caused by boiling instability (i.e., density wave oscillation) reinforced by the reactivity feedback in neutron kinetics, and that the density wave oscillation resulted from flow reduction due to recirculation pump trip and feedwater temperature reduction due to partial loss of feedwater heating capability as well as power peaking. 7 refs., 9 figs., 1 tab.

  5. Notes on dumping gold beam in the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, C.J.; Ahrens, L.; Thieberger, P.

    2010-08-01

    Localized losses of gold beam in the AGS during RHIC Run 8 produced vacuum leaks which required the replacement of several vacuum chambers. A review of what happened and why was given by Leif Ahrens at the Run 8 Retreat. The following notes trace the subsequent development of clean dumping of gold beam on the beam dump in the J10 straight. The novel idea of stripping Au77+ ions in order to put them directly into the upstream face of the dump was introduced by Leif Ahrens and developed by all three of us. George Mahler made the actual stripping device and Dave Gassner developed its control. Leif Ahrens successfully commissioned the device with gold beam during Run 10. The reader may find it helpful to first view the figures herein and then refer to the text for details.

  6. Parton Rescatterings in Large-x Nuclear Suppression at RHIC

    CERN Document Server

    Nemchik, J

    2008-01-01

    We demonstrate that strong suppression of the relative production rate (d+Au)/(p+p) of inclusive high-pT hadrons at forward rapidities observed at RHIC is due to parton multiple rescatterings in nuclear matter. The light-cone dipole approach-based calculations are in a good agreement with BRAHMS and STAR data. They also indicate a significant nuclear suppression at midrapidities with a weak onset of the coherence effects. This prediction is supported by the preliminary d+Au data from the PHENIX Collaboration. Moreover, since similar suppression pattern is also expected to show up at lower energies where effects of parton saturation are not expected, we are able to exclude from the interpretation of observed phenomena models based on the Color Glass Condensate.

  7. Constraining the polarized gluon PDF in pp collisions at RHIC

    CERN Document Server

    Ellinghaus, Frank

    2008-01-01

    The main focus of the physics program at PHENIX and STAR that makes use of RHIC's polarized proton beams is to figure out how and if at all the gluons inside protons are polarized, or to put it another way, do the spin 1 gluons prefer to have their spins aligned or anti-aligned with the spin of the proton, or do they just not care? This question is an important part of the more general question of how the constituents of protons, gluons and quarks, conspire to make up the overall spin 1/2 of the proton. Measurements of, e.g, jet and hadron, production cross-section differences between the two cases where the two polarized protons colliding have their spins aligned and anti-aligned are sensitive to the gluon polarization, which is encoded in the spin--dependent parton distribution function (PDF) for gluons, Delta-g(x).

  8. Proton to pion ratio at RHIC from dynamical quark recombination

    CERN Document Server

    Ayala, Alejandro; Paic, Guy; Toledo-Sanchez, Genaro

    2008-01-01

    We propose an scenario to study, from a dynamical point of view, the thermal recombination of quarks in the midsts of a relativistic heavy-ion collision. We coin the term dynamical quark recombination to refer to the process of quark-antiquark and three-quark clustering, to form mesons and baryons, respectively, as a function of energy density. Using the string-flip model we show that the probabilities to form such clusters differ. We apply these ideas to the calculation of the proton and pion spectra in a Bjorken-like scenario that incorporates the evolution of these probabilities with proper time and compute the proton to pion ratio, comparing to recent RHIC data at the highest energy. We show that for a standard choice of parameters, this ratio reaches one, though the maximum is very sensitive to the initial evolution proper time.

  9. The first operation of 56 MHz SRF cavity in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); DeSanto, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Goldberg, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hayes, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); McIntyre, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Orfin, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Seberg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Severino, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    A 56 MHz superconducting RF cavity has been designed, fabricated and installed in the Relativistic Heavy Ion Collider (RHIC). The cavity operates at 4.4 K with a “quiet helium source” to isolate the cavity from environmental acoustic noise. The cavity is a beam driven quarter wave resonator. It is detuned and damped during injection and acceleration cycles and is brought to operation only at store energy. For a first test operation, the cavity voltage was stabilized at 300 kV with full beam current. Within both Au + Au and asymmetrical Au + He3 collisions, luminosity improvement was detected from direct measurement, and the hourglass effect was reduced. One higher order mode (HOM) coupler was installed on the cavity. We report in this paper on our measurement of a broadband HOM spectrum excited by the Au beam.

  10. Operation experience of p-Carbon polarimeter in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Alekseev, I. G. [Inst. of Theoretical and Experimental Physics (ITEP), Moscow (Russian Federation); Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Atoian, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bazilevsky, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Eyser, O. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kalinkin, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kewisch, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Makdisi, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Nemesure, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Poblaguev, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schmidke, W. B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Svirida, D. [Inst. of Theoretical and Experimental Physics (ITEP), Moscow (Russian Federation); Steski, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Webb, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zelenski, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tip, K. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The spin physics program in Relativistic Heavy Ion Collider (RHIC) requires fast polarimeter to monitor the polarization evolution on the ramp and during stores. Over past decade, the polarimeter has evolved greatly to improve its performance. These include dual chamber design, monitoring camera, Si detector selection (and orientation), target quality control, and target frame modification. The preamp boards have been modified to deal with the high rate problem, too. The ultra thin carbon target lifetime is a concern. Simulations have been carried out on the target interaction with beam. Modification has also been done on the frame design. Extra caution has been put on RF shielding to deal with the pickup noises from the nearby stochastic cooling kickers. This paper summarizes the recent operation performance of this delicate device.

  11. First results from the PHOBOS experiment at RHIC

    Science.gov (United States)

    Wuosmaa, A. H.; Back, B. B.; Baker, M. D.; Barton, D. S.; Basilev, S.; Bates, B. D.; Baum, R.; Betts, R. R.; Białas, A.; Bindel, R.; Bogucki, W.; Budzanowski, A.; Busza, W.; Carroll, A.; Ceglia, M.; Chang, Y.-H.; Chen, A. E.; Coghen, T.; Conner, C.; Czyz, W.; Dabrowski, B.; Decowski, M. P.; Despet, M.; Fita, P.; Fitch, J.; Friedl, M.; Galuska, K.; Ganz, R.; Garcia, E.; George, N.; Godlewski, J.; Gomes, C.; Griesmayer, E.; Gulbrandsen, K.; Gushue, S.; Halik, J.; Halliwell, C.; Haridas, P.; Hayes, A.; Heintzelman, G. A.; Henderson, C.; Hollis, R.; Hołynski, R.; Holzman, B.; Johnson, E.; Kane, J.; Katzy, J.; Kita, W.; Kotuła, J.; Kraner, H.; Kucewicz, W.; Kulinich, P.; Law, C.; Lemler, M.; Ligocki, J.; Lin, W. T.; Manly, S.; McCleod, D.; Michałowski, J.; Mignerey, A.; Mülmenstädt, J.; Neal, M.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Patel, M.; Pernegger, H.; Plesko, M.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Ross, D.; Rosenberg, L.; Ryan, J.; Sanzgiri, A.; Sarin, P.; Sawicki, P.; Scaduto, J.; Shea, J.; Sinacore, J.; Skulski, W.; Steadman, S. G.; Stephans, G. S. F.; Steinberg, P.; Straczek, A.; Stodulski, M.; Strek, M.; Stopa, Z.; Sukhanov, A.; Surowiecka, K.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wysłouch, B.; Zalewski, K.; Zychowski, P.

    2001-07-01

    The PHOBOS experiment at RHIC has measured the charged-particle density dN/dη at mid-rapidity for central Au+Au collisions at center of mass energies of √sNN =56, and 130 GeV. We deduce that dN/dη=408±12(stat)±30(syst) and 555±12(stat)±35(syst) for collision energies of 56 GeV and 130 GeV, respectively. These numbers suggest energy densities that are some 70% higher than have been achieved in any heavy-ion collisions previously studied, and also 25-40% higher than nucleon-nucleon collisions at comparable center of mass energies.

  12. Physics with the collider detectors at RHIC and the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.; Hallman, T. [eds.

    1995-07-15

    On January 8, 1995, over 180 participants gathered to hear the QM95 preconference workshop on `Physics with the Collider Detectors at RHIC and the LHC`. The goal was to bring together the experimentalists from a wide community of hadron and heavy ion collider detector collaborations. The speakers were encouraged to present the current status of their detectors, with all the blemishes, and the audience was encouraged to share their successes and failures in approaching similar detector design issues. The presentations were excellent and the discussions were lively and stimulating. The editors hope that the reader will find these proceedings to be equally stimulating. Separate abstracts have been submitted to the energy database from articles in this report.

  13. Operation experience of p-Carbon polarimeter in RHIC

    International Nuclear Information System (INIS)

    The spin physics program in Relativistic Heavy Ion Collider (RHIC) requires fast polarimeter to monitor the polarization evolution on the ramp and during stores. Over past decade, the polarimeter has evolved greatly to improve its performance. These include dual chamber design, monitoring camera, Si detector selection (and orientation), target quality control, and target frame modification. The preamp boards have been modified to deal with the high rate problem, too. The ultra thin carbon target lifetime is a concern. Simulations have been carried out on the target interaction with beam. Modification has also been done on the frame design. Extra caution has been put on RF shielding to deal with the pickup noises from the nearby stochastic cooling kickers. This paper summarizes the recent operation performance of this delicate device.

  14. Jet quenching effects on the anisotropic flow at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, R.P.G. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP, 09210-170 (Brazil); Noronha, J. [Instituto de Física, Universidade de São Paulo, C.P. 66318, 05315-970 São Paulo, SP (Brazil); Denicol, Gabriel S. [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (Canada)

    2014-12-15

    In this article we investigate how the energy and momentum deposited by partonic dijets in the quark–gluon plasma may perturb the geometry-induced hydrodynamic expansion of the bulk nuclear matter created in heavy ion collisions at the RHIC. The coupling between the jets and the medium is done through a source term in the energy–momentum conservation equations for ideal hydrodynamics. We concentrate our attention at mid-rapidity and solve the equations event-by-event imposing boost-invariance. For p{sub T}≳1 GeV the anisotropic flow is found to be considerably enhanced, if the dijets deposit on average more than 12 GeV in the medium (or equivalently 6 GeV for each jet of the pair), which corresponds, in our model, to an average suppression greater than 65% of the initial jet transverse energy.

  15. Jet quenching effects on the anisotropic flow at RHIC

    International Nuclear Information System (INIS)

    In this article we investigate how the energy and momentum deposited by partonic dijets in the quark–gluon plasma may perturb the geometry-induced hydrodynamic expansion of the bulk nuclear matter created in heavy ion collisions at the RHIC. The coupling between the jets and the medium is done through a source term in the energy–momentum conservation equations for ideal hydrodynamics. We concentrate our attention at mid-rapidity and solve the equations event-by-event imposing boost-invariance. For pT≳1 GeV the anisotropic flow is found to be considerably enhanced, if the dijets deposit on average more than 12 GeV in the medium (or equivalently 6 GeV for each jet of the pair), which corresponds, in our model, to an average suppression greater than 65% of the initial jet transverse energy

  16. Timelike Compton Scattering from JLAB to RHIC and LHC energies

    CERN Document Server

    Pire, B; Wagner, J

    2012-01-01

    Timelike Compton scattering (TCS) i.e. the exclusive photoproduction of a lepton pair with large invariant mass nicely complements the already successful experimental study of deeply virtual Compton scattering (DVCS). The same Generalized Parton Distributions enter both amplitudes, which offer a promissing way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the fact that analyticity and factorization properties dictate the relation of the NLO corrections to TCS to those of DVCS. We also stress that data on TCS at high energy should be available soon thanks to the proposed experimental program at JLab at 12 GeV, and that, before the future high energy electron ion colliders become reality, the study of ultraperipheral collisions at the RHIC and LHC may open a window on quark and gluon GPDs at very small skewness. .

  17. Physics with the collider detectors at RHIC and the LHC

    International Nuclear Information System (INIS)

    On January 8, 1995, over 180 participants gathered to hear the QM95 preconference workshop on 'Physics with the Collider Detectors at RHIC and the LHC'. The goal was to bring together the experimentalists from a wide community of hadron and heavy ion collider detector collaborations. The speakers were encouraged to present the current status of their detectors, with all the blemishes, and the audience was encouraged to share their successes and failures in approaching similar detector design issues. The presentations were excellent and the discussions were lively and stimulating. The editors hope that the reader will find these proceedings to be equally stimulating. Separate abstracts have been submitted to the energy database from articles in this report

  18. A Study of Parton Energy Loss in Au+Au Collisions at RHIC using Transport Theory

    OpenAIRE

    Nara, Y.; Vance, S. E.; Csizmadia, P.

    2001-01-01

    Parton energy loss in Au+Au collisions at RHIC energies is studied by numerically solving the relativistic Boltzmann equation for the partons including $2 \\leftrightarrow 2$ and $2 \\to 2 + final state radiation$ collision processes. Final particle spectra are obtained using two hadronization models; the Lund string fragmentation and independent fragmentation models. Recent, preliminary $\\pi^0$ transverse momentum distributions from central Au+Au collisions at RHIC are reproduced using gluon-g...

  19. Charged multiplicities and $J/\\psi$ suppression at SPS and RHIC energies

    CERN Document Server

    Capella, A

    2001-01-01

    Charged multiplicities in nucleus--nucleus collisions are calculated in the Dual Parton Model taking into account shadowing corrections. Its dependence on the number of collisions and participants is analyzed and found in agreement with experiment at SPS and RHIC energies. Using these results, we compute the $J/\\psi$ suppression at SPS as a function of the transverse energy and of the energy of the zero degree calorimeter. Predictions for RHIC are presented.

  20. Optics correction for the multi-pass FFAG ERL machine eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brooks, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    Gradient errors in the multi-pass Fixed Field Alternating Gradient (FFAG) Energy Recovery Linac (ERL) machine, eRHIC, distort the beam orbit and therefore cause emittance increase. The localization and correction of gradient errors are essential for an effective orbit correction and emittance preservation. In this report, the methodology and simulation of optics correction for the multi-pass FFAG ERL machine eRHIC will be presented.

  1. Highlights from Heavy Ion Collisions at RHIC and the Acoustics of the Little Bangs

    CERN Document Server

    Sorensen, Paul

    2012-01-01

    At the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, heavy nuclei are collided at high energies to create matter that is hot enough and dense enough to dissolve hadrons into a quark-gluon-plasma (QGP). In this lecture, dedicated to the memory of Aditya Sambamurti, I present an introduction to heavy-ion collisions and highlights from the first decade of RHIC results.

  2. High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, James; /UCLA; Travish, Gil; /UCLA; Hogan, Mark; /SLAC; Muggli, Patric; /Southern California U.

    2012-07-05

    Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal of demonstrating >GeV acceleration in {approx}33 cm DWA tubes. In the nearer term before FACET's commissioning, we are planning measurements at the BNL ATF, in which we drive {approx}50-200 MV/m fields with single pulses or pulse trains. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for efficient operation with pulse trains.

  3. AGS experiments: 1993 - 1994 - 1995

    International Nuclear Information System (INIS)

    This report contains: FY 1995 AGS Schedule as Run; FY 1996-97 AGE Schedule (working copy); AGS Beams 1995; AGS Experimental Area FY 1993 Physics Program; AGS Experimental Area FY 1994 Physics Program; AGS Experimental Area FY 1995 Physics Program; AGS Experimental Area FY 1996 Physics Program (In progress); A listing of experiments by number; Two-page summaries of each experiment begin here, also ordered by number; Listing of publications of AGS experiments begins here; and Listing of AGS experimenters begins here. This is the twelfth edition

  4. AGS experiments: 1993 - 1994 - 1995

    Energy Technology Data Exchange (ETDEWEB)

    Depken, J.C.

    1996-04-01

    This report contains: FY 1995 AGS Schedule as Run; FY 1996-97 AGE Schedule (working copy); AGS Beams 1995; AGS Experimental Area FY 1993 Physics Program; AGS Experimental Area FY 1994 Physics Program; AGS Experimental Area FY 1995 Physics Program; AGS Experimental Area FY 1996 Physics Program (In progress); A listing of experiments by number; Two-page summaries of each experiment begin here, also ordered by number; Listing of publications of AGS experiments begins here; and Listing of AGS experimenters begins here. This is the twelfth edition.

  5. Silicon Vertex Tracker for PHENIX Upgrade at RHIC: Capabilities and Detector Technology

    CERN Document Server

    Nouicer, Rachid

    2008-01-01

    From the wealth of data obtained from the first three years of RHIC operation, the four RHIC experiments, BRAHMS, PHENIX, PHOBOS and STAR, have concluded that a high density partonic matter is formed at central Au+Au collisions at \\sqrt{s_{NN}} = 200 GeV. The research focus now shifts from initial discovery to a detailed exploration of partonic matter. Particles carrying heavy flavor, i.e. charm or beauty quarks, are powerful tool for study the properties of the hot and dense medium created in high-energy nuclear collisions at RHIC. They also allow to probe the spin structure of the proton in a new and precise way. An upgrade of RHIC (RHIC-II) is intended for the second half of the decade, with a luminosity increase to about 20-40 times the design value of 8 x 10^26 cm^-2 s^-1 for Au+Au, and 2 x 10^32 cm^-2 s^-1 for polarized proton beams. The PHENIX collaboration plans to upgrade its experiment to exploit with an enhanced detector new physics then in reach. For this purpose, we are constructing the Silicon V...

  6. ERL with non-scaling fixed field alternating gradient lattice for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brooks, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hao, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. N. [Brookhaven National Lab. (BNL), Upton, NY (United States); Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The proposed eRHIC electron-hadron collider uses a "non-scaling FFAG" (NS-FFAG) lattice to recirculate 16 turns of different energy through just two beam lines located in the RHIC tunnel. This paper presents lattices for these two FFAGs that are optimized for low magnet field and to minimize total synchrotron radiation across the energy range. The higher number of recirculations in the FFAG allows a shorter linac (1.322GeV) to be used, drastically reducing cost, while still achieving a 21.2 GeV maximum energy to collide with one of the existing RHIC hadron rings at up to 250GeV. eRHIC uses many cost-saving measures in addition to the FFAG: the linac operates in energy recovery mode, so the beams also decelerate via the same FFAG loops and energy is recovered from the interacted beam. All magnets will be constructed from NdFeB permanent magnet material, meaning chillers and large magnet power supplies are not needed. This paper also describes a small prototype ERL-FFAG accelerator that will test all of these technologies in combination to reduce technical risk for eRHIC.

  7. Chemical aspects of the commissioning and early operation of the BNL pond water treatment plant

    International Nuclear Information System (INIS)

    An account is given of the chemical aspects of the work done in commissioning and setting-to-work the pond water treatment plant at BNL. The plant is designed to maintain the fuel pond within the specified chemical conditions for Magnox fuel storage. In normal operation the treatment requirements are met by anion exchange, i.e. the carbonate and other impurity anions in the pond water are replaced by hydroxide held on an anion exchange resin. This method is referred to as ''anion only''. In the commissioning tests the performance of the plant was substantiated by passing simulated pond water of the correct chemical composition through the plant and monitoring the water quality at the plant outlet. During the first phase of operation on the pond itself the plant was operated in non-standard fashion to convert the chemistry from the previous ''carbonate'' regime to the required conditions. (author)

  8. Parameters Optimization for a Novel Vacuum Laser Acceleration Test at BNL-ATF

    CERN Document Server

    Shao, Lei; Zhou, Feng

    2005-01-01

    This paper presents a new VLA theory model which has revealed that the injection electrons with low energy and small incident angle relative to the laser beam are captured and significantly accelerated in a strong laser field. For the further step for verifying the novel-VLA mechanics, we propose to use the BNL-ATF Terawatt CO2 laser and a high-brightness electron beam to carry out a proof-of-principle beam experiment. Experiment setup including the laser injection optics and electron extraction system and beam diagnostics is presented. Extensive optimized simulation results with ATF practical parameters are also presented, which shows that even when the laser intensity is not very high, the net energy gain still can be seen obviously. This could be prospect for a new revolution of vacuum laser acceleration.

  9. Studies of material properties under irradiation at BNL Linear Isotope Producer (BLIP)

    CERN Document Server

    Simos, N; Ludewig, H; Mokhov, N; Hurh, P; Misek, J

    2012-01-01

    Effects of proton beams irradiating materials considered for targets in high-power accelerator experiments have been under study using the Brookhaven National Laboratory's (BNL) 200 MeV Linac. The primary objectives of the study that includes a wide array of materials and alloys ranging between low and high-Z are to (a) observe changes in physio-mechanical properties which are important in maintaining high-power target functionality, (b) identify possible limits of proton flux or fluence above which certain material seize to maintain integrity, (c) study the role of material operating temperature in inducing or maintaining radiation damage reversal, and (d) correlate radiation damage effects of different species such as energetic protons and neutrons on materials by utilizing reactor and particle accelerator experience data. These objectives are specifically being addressed in the latest material irradiation study linked to the Long Baseline Neutrino Experiment (LBNE). Observations on irradiation effects on m...

  10. Progress on the high-current 704 MHz superconducting RF cavity at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Xu W.; Astefanous, C.; Belomestnykh, S.; Ben-Zvi, I.; et al

    2012-05-20

    The 704 MHz high current superconducting cavity has been designed with consideration of both performance of fundamental mode and damping of higher order modes. A copper prototype cavity was fabricated by AES and delivered to BNL. RF measurements were carried out on this prototype cavity, including fundamental pass-band and HOM spectrum measurements, HOM studies using bead-pull setup, prototyping of antenna-type HOM couplers. The measurements show that the cavity has very good damping for the higher-order modes, which was one of the main goals for the high current cavity design. 3D cavity models were simulated with Omega3P code developed by SLAC to compare with the measurements. The paper describes the cavity design, RF measurement setups and results for the copper prototype. The progress with the niobium cavity fabrication will also be described.

  11. Centrality Dependent Studies of Identified Particle Spectra at RHIC

    Science.gov (United States)

    Bekele, Selemon

    2008-10-01

    We present preliminary results from the BRAHMS experiment on identified particle spectra and ratios at y ˜0 and y ˜3 as a function of centrality for 200 GeV/NN Cu+Cu collisions. By comparing the Cu+Cu data with earlier results for the Au+Au and d+Au systems, it is possible to study how the heavy-ion reaction dynamics for a given number of participants depends on the overall system size. Particle yields, , and particle ratios are studied as a function of the number of participants. Transverse momentum distributions provide information on the final stages of the collision evolution at kinetic freeze-out. The kinetic freeze-out parameters of the Cu+Cu system are studied as a function of centrality by a simultaneous blast-wave model fit to the pion, kaon and (anti)proton spectra. The Cu+Cu results will be compared to other collision systems at RHIC to unravel the dependence on system size.

  12. RHIC Performance with Polarized Protons in Run-6

    Science.gov (United States)

    Ptitsyn, V.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Bravar, S.; Brown, K. A.; Brennan, J. M.; Bruno, D.; Bunce, G.; Calaga, R.; Cameron, P.; Connolly, R.; DeLong, J.; D'Ottavio, T.; Drees, A.; Fedotov, A.; Fischer, W.; Ganetis, G.; Hahn, H.; Hayes, T.; Hseuh, H.-C.; Huang, H.; Ingrassia, P.; Kayran, D.; Kewisch, J.; Lee, R.; Litvinenko, V. N.; Luo, Y.; MacKay, W. W.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Michnoff, R.; Montag, C.; Morris, J.; Pilat, F.; Pile, P.; Roser, T.; Russo, T.; Sandberg, J.; Satogata, T.; Schultheiss, C.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zeno, K.; Zelenski, A.; Zhang, S. Y.

    2007-06-01

    The RHIC polarized proton run (Run-6) in 2006 started on February 1 and continued for 21 weeks. The Run-6 included the machine operation at different beam energies and with different orientation of beam polarization at the collision points. The machine operation at 100GeV and 31.2 GeV provided physics data of polarized proton collisions to the STAR, PHENIX and BRAHMS experiments. Record levels of the luminosity (up to 3.5ṡ1031 cm-2 s-1 peak) and proton beam polarization (up to 65%) were achieved during the 100GeV operation. The beam polarization was preserved during the acceleration by using Siberian Snakes, based on helical magnets. The polarization orientation at STAR and PHENIX experiments was controlled with helical spin rotators. During different stages of the run the physics data were provided with longitudinal, vertical and horizontal orientations of the beam polarization at the collision points. Total luminosity integrals of 45 pb-1 at 100 GeV and 0.35 pb-1 at 31.2 GeV were delivered to the experiments.

  13. Beam optics and the pp2pp experiment at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Pile P. H.; Guryn, W.; Lee, J.H.; Tepikian, S.; Yip, K.

    2012-05-20

    The newly installed forward detector system at the STAR experiment at RHIC measures small angle elastic and inelastic scattering of polarized protons on polarized protons. The detector system makes use of a pair of Roman Pot (RP) detectors, instrumented with silicon detectors, and located on either side of the STAR intersection region downstream of the DX and D0 dipoles and quadrupole triplets. The parallel to point optics is designed so that scattering angles are determined from position measurements at the RP's with small error. The RP setup allows measurement of position and angle for a subset of the scattered protons. With this position/angle correlations at the RP's can be compared with optics model predictions to get a measure of the accuracy of the quadrupole triplet current settings. The current in each quadrupole in the triplets is comprised of sums and differences of up to six power supplies and an overall 1% error in the triplet field strengths results in a 4% error in four-momentum transfer squared. This technique is also useful to check the polarity of the skew elements located in each quadrupole triplet. Results of the analysis will be presented.

  14. Multiple scattering and $p_t$-broadening at RHIC energies

    CERN Document Server

    Papp, G; Fái, G; Lévai, Peter; Zhang, Y

    2002-01-01

    In ultrarelativistic heavy-ion collisions, in the 2 GeV$RHIC energies ($\\sqrt{s}=$130 AGeV), the slope of the calculated spectra is reminiscent of that of fluid-dynamical descriptions, but lacks any thermal ori...

  15. Survey of Recent Results from the PHOBOS Experiment at RHIC

    Science.gov (United States)

    Roland, Christof; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2002-10-01

    We present an overview of the latest results for interactions of Au+Au ions at center-of-mass energies of √SNN of 56, 130 and 200 GeV obtained by the PHOBOS collaboration at the Relativistic Heavy Ion Collider (RHIC). These data have allowed us to perform an extensive study of the pseudorapidity density of primary charged particles as a function of incident energy, centrality and pseudorapidity. Our results show a non-trivial evolution of particle densities with both centrality and collision energy, reaching significantly higher values per participating nucleon than at lower energies or in nucleon-nucleon collisions. Further we present results on the azimuthal asymmetry of particle production observed in the √SNN of 130 GeV data set. The observed strong event anisotropy of v2max > 0.06, reaching beyond the value predicted in hadronic cascade models, indicates a closer approach to local thermal equilibration than at lower collision energies. The measured antiparticle-particle ratios of production rates for pions kaons and protons in central Au+Au interactions at √SNN of 130 GeV are compatible with predictions from statistical models, showing an approach to a baryon free region in mid-rapidity with the increase in collision energy.

  16. Future of the Beam Energy Scan program at RHIC

    International Nuclear Information System (INIS)

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of the QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation

  17. First results froim the PHOBOS experiment at RHIC

    CERN Document Server

    Roland, G; Baker, M D; Barton, D S; Betts, R R; Bindel, R; Budzanowski, A; Busza, W; Carroll, A; Decowski, M P; García, E; George, N; Gulbrandsen, K H; Gushue, S; Halliwell, C; Hamblen, J; Heintzelman, G A; Henderson, C; Holynski, R; Hofman, D J; Holzman, B; Johnson, E; Kane, J L; Katzy, J M; Khan, N; Kucewicz, W; Kulinich, P A; Lin, W T; Manly, S L; McLeod, D; Michalowski, J; Mignerey, A C; Mülmenstädt, J; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Pernegger, H; Reed, C; Remsberg, L P; Reuter, M; Roland, C; Roland, G; Rosenberg, L J; Sarin, P; Sawicki, P; Skulski, W; Steadman, S G; Stephans, G S F; Steinberg, P; Stodulski, M; Sukhanov, A; Tang, J L; Teng, R; Trzupek, A; Vale, C; van Nieuwenhuizen, G J; Verdier, R; Wadsworth, B; Wolfs, F L H; Wosiek, B; Wozniak, K; Wuosmaa, A H; Byslouch, B

    2002-01-01

    During the first run of RHIC, the PHOBOS experiment recorded Au+Au collisions at square root (S/sub NN/) of 56 GeV and 130 GeV. These data have allowed us-to study. the, energy and centrality dependence of particle production, the anisotropy of the final state azimuthal distribution and particle-ratios at mid-rapidity. Our results show a non-trivial evolution of particle densities with both centrality and collision energy reaching significantly higher values per participating nucleon than at lower energies or in nucleon-nucleon collisions. At square root (S/sub NN/)=130 GeV we observe 4100+or-100 (stat.)+or-400(stat.) charged particles with \\eta 0.06, beyond the value predicted in hadronic cascade models, indicates a closer approach to local thermal equilibration than at lower collision energies. The data on particle ratios show that at square root (S/sub NN/)=130 GeV a significant fraction of the incoming baryon number is still shifted towards mid-rapidity. Nevertheless, the resulting baryochemical potential...

  18. Conceptual design report for the Solenoidal Tracker at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    The STAR Collaboration

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it`s experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  19. COMMISSIONING AND FUTURE PLANS FOR POLARIZED PROTONS IN RHIC

    International Nuclear Information System (INIS)

    Polarized protons were injected and accelerated in the clockwise ring of RHIC to commission the first full helical Siberian snake ever used in an accelerator. With the snake turned on, the stable spin direction is in the horizontal plane. Vertically polarized protons were injected with the snake off. The snake was adiabatically ramped to give a spin rotation of 180degree around a horizontal rotation axis about 13degree from the longitudinal. When the beam was accelerated from injection Gγ = 46.5 to Gγ = 48 the spin flipped sign as expected and polarization was preserved. At Gγ = 48 without the snake, no polarization was observed since several spin resonances were crossed. Eventually polarized beam was accelerated to Gγ = 55.7 (29.1 GeV). In the next proton running period we plan to run with two full helical snakes in each ring and collide both transversely and longitudinally polarized protons at an energy around 100 GeV per beam

  20. Quantifying the sQGP - Heavy Ion Collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Seto, Richard [Univ. of California, Riverside, CA (United States)

    2014-12-01

    This is the closeout for DE-FG02-86ER40271 entitled Quantifying the sQGP - Heavy Ion Collisions at the RHIC. Two major things were accomplished. The first, is the physics planning, design, approval, construction, and commissioning of the MPC-EX. The MPC-EX is an electromagnetic calorimeter covering a rapidity of 3<|eta|<4, which was added to the PHENIX detector. Its primary aim is to measure low-x gluons, in order to understand the suppression seen in a variety of signatures, such as the J/Psi. A candidate to explain this phenomena is the Color Glass Condensate (CGC) A second task was to look at collisions of asymmetric species, in particularly Cu+Au. The signature was the suppression of J/Psi mesons at forward and backward rapidity, where a stronger suppression was seen in the copper going direction. While the blue of the suppression is due to hot nuclear matter effects (e.g. screening) the increase in suppression on the Au side was consistent with cold nuclear matter effects seen in d+Au collisions. A major candidate for the explanation of this phenomena is the aforementioned CGC. Finally the work on sPHENIX, particularly an extension to the forward region, called fsPHENIX is described.

  1. STAR Results from the RHIC Beam Energy Scan-I

    CERN Document Server

    ,

    2012-01-01

    The Beam Energy Scan (BES) program is being pursued at RHIC to study the QCD phase diagram, and search for the possible QCD phase boundary and possible QCD critical point. The data for Phase-I of the BES program have been collected for Au+Au collisions at center-of-mass energies ($\\sqrt{s_{NN}}$) of 7.7, 11.5, 19.6, 27, and 39 GeV. These collision energies allowed the STAR experiment to cover a wide range of baryon chemical potential $\\mu_{B}$ (100--400 MeV) in the QCD phase diagram. We report on several interesting results from the BES Phase-I covering the high net-baryon density region. These results shed light on particle production mechanism and freeze-out conditions, first-order phase transition and "turn-off" of QGP signatures, and existence of a critical point in the phase diagram. Finally, we give an outlook for the future BES Phase-II program and a possible fixed target program at STAR.

  2. Review of Recent Results from the RHIC Beam Energy Scan

    CERN Document Server

    Kumar, Lokesh

    2013-01-01

    We review recent results from the RHIC beam energy scan (BES) program, aimed to study the Quantum Chromodynamics (QCD) phase diagram. The main goals are to search for the possible phase boundary, softening of equation of state or first order phase transition, and possible critical point. Phase-I of the BES program has recently concluded with data collection for Au+Au collisions at center-of-mass energies ($\\sqrt{s_{NN}}$) of 7.7, 11.5, 19.6, 27, and 39 GeV. Several interesting results are observed for these lower energies where the net-baryon density is high at the mid-rapidity. These results indicate that the matter formed at lower energies (7.7 and 11.5 GeV) is hadron dominated and might not have undergone a phase transition. In addition, the centrality dependence of freeze-out parameters is observed for the first time at lower energies, slope of directed flow for (net)-protons measured versus rapidity shows an interesting behavior at lower energies, and higher moments of net-proton show deviation from Skel...

  3. Future of the beam energy scan program at RHIC

    Directory of Open Access Journals (Sweden)

    Odyniec Grazyna

    2015-01-01

    Full Text Available The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy, suggest that the highest potential for discovery of the QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation.

  4. RIKEN BNL RESEARCH CENTER WORKSHOP ON HIGH ENERGY POLARIMETRY, VOLUME 23

    Energy Technology Data Exchange (ETDEWEB)

    LEADER,E.

    2000-06-15

    The RHIC collider, in its pp mode, will be a unique machine. It will open up a new frontier in the use of spin in the study of hadronic physics. Using its polarized beams, a whole new range of tests of the Standard Model will become feasible, and much new information about the detailed partonic structure of-the nucleon will emerge. It will also be possible to answer intriguing questions concerning the relationship between pp and pp total cross-sections and real parts of forward amplitudes, questions which are relevant to attempts to understand certain aspects of non-perturbative QCD. This entire, rich program relies upon an accurate determination of the polarization of the proton beams, a matter which is far from trivial. In the summer of 1997 Larry Trueman and the author ran a six-week Working Group, the aim of which was to try to understand theoretically the accuracy with which one could predict the analyzing power of various reactions which were under consideration as high energy proton polarimeters. The results of the study were somewhat negative in the sense that they concluded that analyzing powers could only be predicted to within an accuracy of {+-}10%, whereas RHIC was aiming for {+-}5%. On the other hand some very positive consequences followed. The working group stimulated the study of a polarimeter based on CNI in proton-carbon scattering and this is the polarimeter that will be used in the early stages of RHIC operation. It will be regarded as a relative polarimeter and will have to be calibrated absolutely at some later stage, probably via use of a polarized jet hydrogen target. In addition the surprising discovery was made that proton-proton elastic scattering, at high energy and very small momentum transfer, is self-spin analyzing, in the sense that the measurement of a sufficient number of spin-dependent observables will yield not only the values of the helicity amplitudes, but also the value of the beam and target polarizations.

  5. Thermal Analysis of Particle Ratios and p(perpendicular) Spectra at RHIC

    International Nuclear Information System (INIS)

    The thermal model of particle production is used to analyze the particle ratios and the p(perpendicular) spectra measured recently at RHIC. Our fit of the particle ratios yields the temperature at the chemical freeze-out Tchem = 165±7 MeV with the corresponding baryon chemical potential μchem = 41 ± 5 MeV. The quality of the fit shows that the model works well for RHIC. The p(perpendicular) spectra are evaluated in an approach which takes into account the modifications of the initial thermal distributions by the secondary decays of resonances. All two- and three-body decays are included. This leads to an effective ''cooling'' of the spectra in the data region by about 30-40 MeV. We find that the pion spectrum is characterized by the inverse slope which agrees well with the value inferred from the RHIC data. (author)

  6. Optimization of dynamic aperture for hadron lattices in eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Yichao [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, Vladimir [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, Dejan [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The potential upgrade of the Relativistic Heavy Ion Collider (RHIC) to an electron ion collider (eRHIC) involves numerous extensive changes to the existing collider complex. The expected very high luminosity is planned to be achieved at eRHIC with the help of squeezing the beta function of the hadron ring at the IP to a few cm, causing a large rise of the natural chromaticities and thus bringing with it challenges for the beam long term stability (Dynamic aperture). We present our effort to expand the DA by carefully tuning the nonlinear magnets thus controlling the size of the footprints in tune space and all lower order resonance driving terms. We show a reasonably large DA through particle tracking over millions of turns of beam revolution.

  7. ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC

    Energy Technology Data Exchange (ETDEWEB)

    MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

    2007-06-25

    The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

  8. Initial temperature of the strongly interacting Quark Gluon Plasma created at RHIC

    CERN Document Server

    Csanad, Mate

    2011-01-01

    A 1+3 dimensional solution of relativistic hydrodynamics is analyzed in this paper. Momentum distribution and other observables are calculated from the solution and compared to hadronic measurements from the Relativistic Heavy Ion Collider (RHIC). The solution is compatible with the data, but only the freeze-out point of the evolution is determined. Many equation of states and initial states (initial temperatures) are valid with the same freeze-out distribution, thus the same hadronic observables. The observable that would distinguish between these initial temperatures is momentum distribution of photons, as photons are created throughout the evolution of the fireball created in RHIC collisions. The PHENIX experiment at RHIC measures such data via low invariant mass e+e- pairs. Average temperature from this data is T=221+-23+-18 MeV, while a model calculation with initial temperature 370 MeV agree with the data.

  9. THE AGS-BASED SUPER NEUTRINO BEAM FACILITY CONCEPTUAL DESIGN REPORT

    Energy Technology Data Exchange (ETDEWEB)

    WENG,W.T.; DIWAN,M.; RAPARIA,D.

    2004-10-08

    After more than 40 years of operation, the AGS is still at the heart of the Brookhaven hadron accelerator complex. This system of accelerators presently comprises a 200 MeV linac for the pre-acceleration of high intensity and polarized protons, two Tandem Van der Graaffs for the pre-acceleration of heavy ion beams, a versatile Booster that allows for efficient injection of all three types of beams into the AGS and, most recently, the two RHIC collider rings that produce high luminosity heavy ion and polarized proton collisions. For several years now, the AGS has held the world intensity record with more than 7 x 10{sup 13} protons accelerated in a single pulse. The requirements for the proton beam for the super neutrino beam are summarized and a schematic of the upgraded AGS is shown. Since the present number of protons per fill is already close to the required number, the upgrade is based on increasing the repetition rate and reducing beam losses (to avoid excessive shielding requirements and to maintain activation of the machine components at workable level). It is also important to preserve all the present capabilities of the AGS, in particular its role as injector to RHIC. The AGS Booster was built not only to allow the injection of any species of heavy ion into the AGS but to allow a fourfold increase of the AGS intensity. It is one-quarter the circumference of the AGS with the same aperture. However, the accumulation of four Booster loads in the AGS takes about 0.6 s, and is therefore not well suited for high average beam power operation. To minimize the injection time to about 1 ms, a 1.2 GeV linac will be used instead. This linac consists of the existing warm linac of 200 MeV and a new superconducting linac of 1.0 GeV. The multi-turn H{sup -} injection from a source of 30 mA and 720 {micro}s pulse width is sufficient to accumulate 9 x 10{sup 13} particle per pulse in the AGS[10]. The minimum ramp time of the AGS to full energy is presently 0.5 s; this must

  10. Silicon Vertex Tracker for PHENIX Upgrade at RHIC: Capabilities and Detector Technology

    OpenAIRE

    Nouicer, Rachid; Collaboration, for the PHENIX

    2008-01-01

    From the wealth of data obtained from the first three years of RHIC operation, the four RHIC experiments, BRAHMS, PHENIX, PHOBOS and STAR, have concluded that a high density partonic matter is formed at central Au+Au collisions at 200 GeV. The research focus now shifts from initial discovery to a detailed exploration of partonic matter. Particles carrying heavy flavor, i.e. charm or beauty quarks, are powerful tool for study the properties of the hot and dense medium created in high-energy nu...

  11. PARTON STRUCTURE THROUGH TWO PARTICLE CORRELATIONS IN AU-AU AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    LONGACRE,R.S.

    1999-10-23

    A method for determining the presence of partonic scattering through two-particle correlations is developed and applied to models which have jets and mini-jets in them. We only consider the correlation of mid-rapidity particles because they will be easily measured in large numbers at RHIC. The level of two-particle correlations will be a direct measure of how dense a system is made in Au-Au collisions at RHIC. The STAR TPC will be ideal for making these measurements in the first year of running.

  12. Chemical equilibration of quarks and gluons at RHIC and LHC energies

    CERN Document Server

    Elliott, D M; Elliott, Duncan M.; Rischke, Dirk H.

    2000-01-01

    We study chemical equilibration of quarks and gluons in central nuclear collisions at RHIC and LHC energies. The initial quark and gluon densities are taken from earlier studies as well as from recent perturbative QCD estimates and are then evolved via rate equations coupled to longitudinally boost-invariant fluid dynamics. We find that, for RHIC initial conditions, the lifetime of quark-gluon matter is not sufficiently long enough to chemically equilibrate the quark and gluon number densities prior to hadronization. In contrast, at LHC energies equilibration is complete before the system hadronizes. Entropy production due to chemical equilibration can be as large as 30 %.

  13. Optics measurement and correction during acceleration with beta-squeeze in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    In the past, beam optics correction at RHIC has only taken place at injection and at final energy, with interpolation of corrections partially into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats that, if corrected, could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoiding the high-order multipole fields sampled by particles within the bunch. We recently demonstrated successful beam optics corrections during acceleration at RHIC. We verified conclusively the superior control of the beam realized via these corrections

  14. Research and development of RHIC injection kicker upgrade with nano second FID pulse generator

    Energy Technology Data Exchange (ETDEWEB)

    Zhang W.; Sandberg, J.; Hahn, H.; Fischer, W.; Liaw, C.J.; Pai, C.; Tuozzolo, J.

    2012-05-20

    Our recent effort to test a 50 kV, 1 kA, 50 ns pulse width, 10 ns pulse rise time FID pulse generator with a 250 ft transmission cable, resistive load, and existing RHIC injection kicker magnet has produced unparalleled results. This is the very first attempt to drive a high strength fast kicker magnet with a nano second high pulsed power (50 MVA) generator for large accelerator and colliders. The technology is impressive. We report here the result and future plan of RHIC Injection kicker upgrade.

  15. Measuring two-particle Bose-Einstein correlations with PHOBOS@RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Betts, R.; Barton, D.; Carroll, A. [and others

    1995-07-15

    The authors present results of a simulation of the measurement of two-particle Bose-Einstein correlations in central Au-Au collisions with the PHOBOS detector at RHIC. This measurement is expected to yield information on the relevant time and distance scales in these collisions. As the space-time scale is directly connected with the equation of state governing the evolution of the particle source, this information will be essential in understanding the physics of nucleus-nucleus collisions at RHIC energies. The authors demonstrate that the PHOBOS detector has sufficient resolution and acceptance to distinguish a variety of physics scenarios.

  16. Strangeness production in heavy ion collisions at SPS and RHIC within two-source statistical model

    OpenAIRE

    Lu, Zhong-Dao; Faessler, Amand; Fuchs, C.; Zabrodin, E.

    2002-01-01

    The experimental data on hadron yields and ratios in central Pb+Pb and Au+Au collisions at SPS and RHIC energies, respectively, are analysed within a two-source statistical model of an ideal hadron gas. These two sources represent the expanding system of colliding heavy ions, where the hot central fireball is embedded in a larger but cooler fireball. The volume of the central source increases with rising bombarding energy. Results of the two-source model fit to RHIC experimental data at midra...

  17. Conceptual design report for the Solenoidal Tracker at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it's experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  18. Performance of microstrip gas chambers in BNL-E885: a search for LAMBDA LAMBDA-hypernuclei

    CERN Document Server

    Landry, M; Davis, C A; Faszer, W; Gan, L; Lee, L; Page, S A; Ramsay, W D; Salomon, M; Oers, W T H

    1999-01-01

    The performance of MicroStrip Gas Chambers (MSGC) in BNL Experiment 885, a search for LAMBDA LAMBDA-hypernuclei, is detailed. Chambers with an active area of 80x50 mm sup 2 were instrumented and operated as a vertex detector in the experiment. Furthermore, two distinct types of microstrip prints were utilized in these chambers. Prints manufactured with Integrated Circuit (IC) photolithographic technology have fine tolerances and thin minimum trace widths, but can suffer from a high rate of defects per print and are more costly. Prints constructed with Printed Circuit (PC) photolithographic technology have coarser tolerances but relatively few defects per print, and are extremely cost-effective. Results of bench and beam tests of both IC and PC based MSGCs are presented and their performance in BNL-E885 is discussed. E885 marks the first use of PC based MSGCs in an experiment.

  19. Status of 4-cm-aperture, 17-m-long SSC dipole magnet R ampersand D program at BNL

    International Nuclear Information System (INIS)

    Over the last year-and-a-half, several 4-cm-aperture, 17-m-long dipole magnet prototypes were built by Brookhaven National Laboratory (BNL) under contract with the Superconducting Super Collider (SSC) Laboratory. These prototypes are the last phase of a half-decade-long R ampersand D program, carried out in collaboration with Fermi National Accelerator Laboratory and Lawrence Berkeley Laboratory, and aimed at demonstrating the feasibility of the SSC main ring dipole magnets. They also prepare the way of the 5-cm-aperture dipole magnet program to be started soon. In this paper, we analyze the mechanical behavior of the BNL prototypes during cool-down and excitation, and we attempt to relate this behavior to the magnet features. The data reveal that the mechanical behavior is sensitive to the vertical collar-yoke interference, and that the magnets exhibited somewhat erratic changes in coil end-loading during cool-down. 9 refs., 6 figs

  20. Sulfur polymer stabilization/solidification (SPSS) treatment of mixed waste mercury recovered from environmental restoration activities at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Kalb, P.; Adams, J.; Milian, L.

    2001-01-29

    Over 1,140 yd{sup 3} of radioactively contaminated soil containing toxic mercury (Hg) and several liters of mixed-waste elemental mercury were generated during a Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) removal action at Brookhaven National Laboratory (BNL). The US Department of Energy's (DOE) Office of Science and Technology Mixed Waste Focus Area (DOE MWFA) is sponsoring a comparison of several technologies that may be used to treat these wastes and similar wastes at BNL and other sites across the DOE complex. This report describes work conducted at BNL on the application and pilot-scale demonstration of the newly developed Sulfur Polymer Stabilization/Solidification (SPSS) process for treatment of contaminated mixed-waste soils containing high concentrations ({approximately} 5,000 mg/L) of mercury and liquid elemental mercury. BNL's SPSS (patent pending) process chemically stabilizes the mercury to reduce vapor pressure and leachability and physically encapsulates the waste in a solid matrix to eliminate dispersion and provide long-term durability. Two 55-gallon drums of mixed-waste soil containing high concentrations of mercury and about 62 kg of radioactive contaminated elemental mercury were successfully treated. Waste loadings of 60 wt% soil were achieved without resulting in any increase in waste volume, while elemental mercury was solidified at a waste loading of 33 wt% mercury. Toxicity Characteristic Leaching Procedure (TCLP) analyses indicate the final waste form products pass current Environmental Protection Agency (EPA) allowable TCLP concentrations as well as the more stringent proposed Universal Treatment Standards. Mass balance measurements show that 99.7% of the mercury treated was successfully retained within the waste form, while only 0.3% was captured in the off gas system.