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1

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

indicate that collisions of small particles with large gold nuclei at the Relativistic Heavy Ion Collider may be serving up miniscule servings of hot quark-gluon plasma. RHIC...

2

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites

Brookhaven National Laboratory Brookhaven National Laboratory search U.S. Department of Energy logo Home RHIC Science News Images Videos For Scientists Björn Schenke 490th Brookhaven Lecture, 12/18 Join Björn Schenke of Brookhaven Lab's Physics Department for the 490th Brookhaven Lecture, titled 'The Shape and Flow of Heavy Ion Collisions,' on Wednesday, Dec. 18, at 4 p.m. in Berkner Hall. droplets Tiny Drops of Hot Quark Soup-How Small Can They Be? New analyses indicate that collisions of small particles with large gold nuclei at the Relativistic Heavy Ion Collider may be serving up miniscule servings of hot quark-gluon plasma. RHIC Physics RHIC is the first machine in the world capable of colliding ions as heavy as gold. The Spin Puzzle RHIC is the world's only machine capable of colliding beams of polarized

3

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider Relativistic Heavy Ion Collider Photo of LINAC The Relativistic Heavy Ion Collider (RHIC) is a world-class particle accelerator at Brookhaven National Laboratory where physicists are exploring the most fundamental forces and properties of matter and the early universe. RHIC accelerates beams of particles (e.g., the nuclei of heavy atoms such as gold) to nearly the speed of light, and smashes them together to recreate a state of matter thought to have existed immediately after the Big Bang some 13.8 billion years ago. STAR and PHENIX, two large detectors located around the 2.4-mile-circumference accelerator, take "snapshots" of these collisions to reveal a glimpse of the basic constituents of visible matter, quarks and gluons. Understanding matter at

4

RHIC | Electron-Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron-Ion Collider A breakthrough particle accelerator could collide electrons with heavy ions or protons at nearly the speed of light to create rapid-fire, high-resolution...

5

Relativistic Heavy Ion Collider, RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

The Relativistic Heavy Ion Collider website has moved to www.bnl.govrhicdefault.asp Sponsored by the U.S. Department of Energy Office of Science, Office of Nuclear Physics. Last...

6

RHIC | Physics of the Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

The Physics of RHIC Physicists from around the world are using the Relativistic Heavy Ion Collider to explore some of Nature's most basic -- and intriguing -- ingredients and...

7

Brookhaven National Laboratory The Relativistic Heavy Ion Collider (RHIC)  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider (RHIC) Relativistic Heavy Ion Collider (RHIC) An Exciting Beginning and a Compelling Future At the Relativistic Heavy Ion Collider (RHIC), a world-class particle accelerator at Brookhaven National Laboratory, physicists are exploring the most fundamental forces and properties of matter and the early universe, with important implications for our understanding of the world around us. Operated with funding from the U.S. Department of Energy's Office of Science, the Relativistic Heavy Ion Collider (RHIC), was designed to recreate a state of matter thought to have existed immediately after the Big Bang some 13 billion years ago, and to investigate how the proton gets its spin and intrinsic magnetism from its quark and gluon constituents. Large detectors located

8

Relativistic Heavy Ion Collider (RHIC) Animation and Multimedia Collection  

DOE Data Explorer (OSTI)

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is a world-class scientific research facility that began operation in 2000, following 10 years of development and onstruction. Hundreds of physicists from around the world use RHIC to study what the universe may have looked like in the first few moments after its creation. RHIC drives two intersecting beams of gold ions head-on, in a subatomic collision. This library of animations and multimedia includes virtual video tours of the RHIC complex, of the spin configuration, and of experiments; documentaries of the science involved; animations of the various kinds of collisions and reactions; event displays; and even interactive Java games about RHIC and RHIC physics.

9

The Relativistic Heavy Ion Collider (RHIC) - the nation's only remaining  

NLE Websites -- All DOE Office Websites (Extended Search)

Collider (RHIC) - the nation's only remaining Collider (RHIC) - the nation's only remaining particle collider, located at Brookhaven National Laboratory - has made a series of landmark discoveries and continuing breakthroughs in science and technology. One major accomplishment has been RHIC's ability to recreate and study in detail a type of matter that last existed at the beginning of the universe to better understand the strongest force in nature - the force that holds together the fundamental particles that make up 99 percent of visible matter in the universe today, everything from stars to planets to people. In addition to giving us a new way to explore and understand the nature of the early universe and the force that holds together ordinary matter, research at RHIC has revealed stunning

10

Home of eRHIC: the Electron-Ion-Collider at BNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Ion Collider (EIC) Project Web Page Electron Ion Collider (EIC) Project Web Page This webpage is perpetually under construction October 26, 2007 (Maintained by Abhay Deshpande) A high luminosity polarized e-p/He and unpolarized e-A collider to study the hyperfine structure of the nucleon including (spin and flavor) and to explore nuclear matter at high parton densities. EIC Collaboration WebPage EIC Meeting at SBU, December 7-8, 2007 The most recent meeting: EICC meeting at MIT, May 2007 A Joint EIC2006 (Third Electron Ion Collider) and Hot-QCD Workshop hosted by BNL, July 17-22, 2006 eRHIC Related Papers and other Material White Papers & other information and documents for NSAC Long Range Planning 2007 Study of fundamental structure of matter with an electron-ion collider, A.

11

e-RHIC: Future electron-ion collider at BNL (405th Brookhaven Lecture)  

SciTech Connect

While RHIC scientists continue their quest to look deep into nuclear phenomena resulting from collisions of ion beams and beams of polarized protons, new design work is under way for a possible extension of RHIC to include e-RHIC, a 10-billion electron volt, high-intensity polarized proton beam.

Ptitsyn, Vadim (Ph.D., Collider-Accelerator Department)

2005-06-22T23:59:59.000Z

12

THE RELATIVISTIC HEAVY ION COLLIDER (RHIC) REFRIGERATOR SYSTEM AT BROOKHAVEN NATIONAL LABORATORY: PHASE III OF THE SYSTEM PERFORMANCE AND OPERATIONS UPGRADES FOR 2003  

SciTech Connect

An ongoing program at Brookhaven National Laboratory (BNL) consists of improving the efficiency of the Relativistic Heavy Ion Collider (RHIC) cryogenic system and reducing its power consumption. Phase I and I1 of the program addressed plant operational improvements and modifications that resulted in substantial operational cost reduction and improved system reliability and stability, and a compressor input power reduction of 2 MW has been demonstrated. Phase 111, now under way, consists of plans for further increasing the efficiency of the plant by adding a load ''wet'' turbo-expander and its associated heat exchangers at the low temperature end of the plant. This additional stage of cooling at the coldest level will further reduce the required compressor flow and therefore compressor power input. This paper presents the results of the plant characterization, as it is operating presently, as well as the results of the plant simulations of the various planned upgrades for, the plant. The immediate upgrade includes the changes associated with the load expander. The subsequent upgrade will involve the resizing of expander 5 and 6 to increase their efficiencies. The paper summarizes the expected improvement in the plant efficiency and the overall reduction in the compressor power.

SIDI-YEKHLEF,A.; TUOZZOLO,J.; THAN, R.; KNUDSEN, P.; ARENIUS, D.

2005-08-29T23:59:59.000Z

13

Microsoft Word - 2003-0820 RHIC collider projections.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Collider Projections (FY2004 - FY2008) RHIC Collider Projections (FY2004 - FY2008) Thomas Roser, Wolfram Fischer Last update: August 20, 2003 This note discusses in Part I possible operating modes for the RHIC Run-4 (FY2004) running period including constraints from cryogenic cool-down, machine set-up and beam commissioning. In Part II a 5-year projection is given for gold-gold and polarized proton collisions. Part I - Run-4 Projections Cryogenic operation - After the summer shutdown the two RHIC rings will be at room temperature. They will be first brought to liquid nitrogen temperature, in about 10 days. Then, two weeks will be required to cool down to 4 Kelvin. At the end of the run, one week of refrigerator operation is required for the warm-up to 80 Kelvin. Running modes - A number of running modes are considered in RHIC, such as Au-Au

14

ON THE FEASIBILITY OF POLARIZED HEAVY IONS IN RHIC.  

Science Conference Proceedings (OSTI)

Heavy nonspherical ions such as uranium have been proposed for collisions in RHIC[1]. When two such ions collide with their long axes aligned parallel to the beams (large helicities), then the plasma density might be as much as 60% higher. Since the collisions might have any orientation of the two nuclei, the alignment of the nuclei must be inferred from a complicated unfolding of multiplicity distributions. Instead, if it would be possible to polarize the ions and control the orientation in RHIC, then a much better sensitivity might be obtained. This paper investigates the manipulation of such polarized ions with highly distorted shapes in RHIC. A number of ion species are considered as possibilities with either full or partial Siberian snakes in RHIC.

MACKAY, W.W.

2006-06-23T23:59:59.000Z

15

PROCEEDINGS OF THE SECOND WORKSHOP ON EXPERIMENTS AND DETECTORS FOR A RELATIVISTIC HEAVY ION COLLIDER (RHIC), LAWRENCE BERKELEY LABORATORY, MAY 25-29, 1987  

E-Print Network (OSTI)

Heavy-Ion Collider. Brookhaven National Lab.. Upton N.Y. (Zingman Lawrence Berkeley Laboratory Brookhaven NationalLaboratory Brookhaven National Laboratory Johns Hopkins

Ritter, Hans Georg

2010-01-01T23:59:59.000Z

16

Heavy Ion Collisions at RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

at Heavy Ion Colliders at Heavy Ion Colliders Theory Drivers & View from LHC Urs Achim Wiedemann CERN PH-TH NSAC Implementation Subcommittee Hearings 7 September 2012 Heavy Ion Physics - Main Tools of Theorists Understanding properties of hot and dense matter from the elementary interactions in QCD High Energy Physics String Theory Computational Physics Fluid Dynamics Dissipative fluid dynamic description * Based on: E-p conservation: 2 nd law of thermodynamics: * Sensitive to properties of matter that are calculated from first principles in quantum field theory - EOS: and sound velocity - transport coefficients: shear , bulk viscosity, conductivities ...

17

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

E-Print Network (OSTI)

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.

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

2008-06-05T23:59:59.000Z

18

Relativistic Heavy Ion Collider | The Case for Continuing Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

The Case for Continuing RHIC Operations The Case for Continuing RHIC Operations The Relativistic Heavy Ion Collider (RHIC) - the nation's only remaining particle collider, located at Brookhaven National Laboratory - has made a series of landmark discoveries and continuing breakthroughs in science and technology. One major accomplishment has been RHIC's ability to recreate and study in detail a type of matter that last existed at the beginning of the universe to better understand the strongest force in nature - the force that holds together the fundamental particles that make up 99 percent of visible matter in the universe today, everything from stars to planets to people. In addition to giving us a new way to explore and understand the nature of the early universe and the force that holds together ordinary matter, research at RHIC has revealed stunning

19

Medium energy heavy ion operations at RHIC  

Science Conference Proceedings (OSTI)

As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

2011-03-28T23:59:59.000Z

20

PROCEEDINGS OF THE SECOND WORKSHOP ON EXPERIMENTS AND DETECTORS FOR A RELATIVISTIC HEAVY ION COLLIDER (RHIC), LAWRENCE BERKELEY LABORATORY, MAY 25-29, 1987  

E-Print Network (OSTI)

at RHIC. Designing the "event trigger" is important for thecollisions, the event trigger for "high multiplicity" or "can be used as an event trigger in their experiment. We have

Ritter, Hans Georg

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider Relativistic Heavy Ion Collider managed for the U.S. Department of Energy by Brookhaven Science Associates, founded by Stony Brook University and Battelle. managed for the U.S. Department of Energy by Brookhaven Science Associates, a company founded by Stony Brook University and Battelle 07/07 Brookhaven National Laboratory Funded by the U.S. Department of Energy, Brookhaven National Laboratory is a multipurpose research institution located on a 5,300-acre site on Long Island, New York. Six Nobel Prize-winning discoveries have been made at Brookhaven Lab. The Laboratory operates large-scale scientific facilities and performs research in physics, chemistry, biology, medicine, applied science, and

22

Observation of snake resonances at Relativistic Heavy Ion Collider  

SciTech Connect

The Siberian snakes are powerful tools in preserving polarization in high energy accelerators has been demonstrated at the Brookhaven Relativistic Heavy Ion Collider (RHIC). Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the Siberian snakes also introduce a new set of depolarization resonances, i.e. snake resonances as first discovered by Lee and Tepikian. The intrinsic spin resonances above 100 GeV are about a factor of two stronger than those below 100 GeV which raises the challenge to preserve the polarization up to 250 GeV. In 2009, polarized protons collided for the first time at the RHIC design store energy of 250 GeV. This paper presents the experimental measurements of snake resonances at RHIC. The plan for avoiding these resonances is also presented.

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

2010-09-27T23:59:59.000Z

23

ESTIMATION OF INTRABEAM SCATTERING EFFECTS FOR RHIC  

E-Print Network (OSTI)

Heavy Ion Collider RHIC, Brookhaven National Laboratoryon the RHlC Performance Brookhaven National Laboratory Marchfor construction at Brookhaven National Laboratory, is

Zisman, M.S.

2010-01-01T23:59:59.000Z

24

Vector meson production in coherent hadronic interactions: Update on predictions for energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider  

SciTech Connect

In this Rapid Communication we update our predictions for the photoproduction of vector mesons in coherent pp and AA collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies using the color dipole approach and the Color Glass Condensate formalism. In particular, we present our predictions for the first run of the LHC at half energy and for the rapidity dependence of the ratio between the J/{Psi} and {rho} cross sections at RHIC energies.

Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Machado, M. V. T. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2011-07-15T23:59:59.000Z

25

RHIC | Accelerator Complex  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Accelerators RHIC Accelerators The Relativistic Heavy Ion Collider complex is actually composed of a long "chain" of particle accelerators Heavy ions begin their travels in the Electron Beam Ion Source accelerator (1). The ions then travel to the small, circular Booster (3) where, with each pass, they are accelerated to higher energy. From the Booster, ions travel to the Alternating Gradient Synchrotron (4), which then injects the beams via a beamline (5) into the two rings of RHIC (6). In RHIC, the beams get a final accelerator "kick up" in energy from radio waves. Once accelerated, the ions can "orbit" inside the rings for hours. RHIC can also conduct colliding-beam experiments with polarized protons. These are first accelerated in the Linac (2), and further in the Booster (3), AGS (4), and

26

POLARIZED PROTON OPERATIONS IN THE AGS AND RHIC.  

Science Conference Proceedings (OSTI)

Polarized proton beam has been accelerated and stored at 100 GeV in Relativistic Heavy Ion Collider (RHIC) to study spin effects in the hadronic reactions. The essential equipment includes four Siberian snakes and eight spin rotators in two RHIC rings, a partial snake in the AGS, fast relative polarimeters, and ac dipoles in the AGS and RHIC. This paper summarizes the performance of RHIC as a polarized proton collider and of AGS as the injector to RHIC.

HUANG,H.; AHRENS,L.; BAI,M.; BEEBE-WANG,J.; ALESSI,J.; ALEKSEEV,I.; BRARVAR,S.; BRENNAN,M.; BROWN,K.; BUNCE,G.; DREES,A.; FISCHER,W.; GARDNER,C.; GLENN,W.; IGO,G.; JINNOCHI,O.; LUCCIO,A.; MACKAY,W.; MONTAG,C.; PILAT,F.; PTITSYN,V.; ROSER,T.; SATOGATA,T.; SPINKA,H.; SVIRIDA,D.; TEPIKIAN,S.; TRBOJEVIC,D.; TSOUPAS,N.; UNDERWOOD,D.; VANZEIJTS,J.; WOOD,J.; ZELENSKI,A.; ZENO,K.; ZHANG,S.Y.

2003-05-12T23:59:59.000Z

27

Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

at the same time. Capable of accelerating 70 trillion protons with every pulse, and heavy ions such as gold and iron, the AGS receives protons and other ions from the AGS...

28

Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider  

E-Print Network (OSTI)

We have studied the time evolution of the heavy ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC), at BNL, and in the Large Hadron Collider (LHC), at CERN. First, we present measurements from a large number of RHIC stores (from Run 7), colliding 100 GeV/nucleon Au beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the RF bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future Pb beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

R. Bruce; M. Blaskiewicz; W. Fischer; J. M. Jowett

2010-09-08T23:59:59.000Z

29

OPERATIONS AND PERFORMANCE OF RHIC AS A CU-CU COLLIDER.  

Science Conference Proceedings (OSTI)

The 5th year of RHIC operations, started in November 2004 and expected to last till June 2005, consists of a physics run with Cu-Cu collisions at 100 GeV/u followed by one with polarized protons (pp) at 100 GeV [l]. We will address here the overall performance of the RHIC complex used for the first time as a Cu-Cu collider, and compare it with previous operational experience with Au, PP and asymmetric d-Au collisions. We will also discuss operational improvements, such as a {beta}* squeeze to 85cm in the high luminosity interaction regions from the design value of 1m, system improvements, machine performance and limitations, and address reliability and uptime issues.

PILAT, R.; AHRENS, L.; BAI, M.; BARTON, D.S.; ET AL.

2005-05-16T23:59:59.000Z

30

RHIC Sextant Test -- Physics and performance  

Science Conference Proceedings (OSTI)

This paper presents beam physics and machine performance results of the Relativistic Heavy Ion Collider (RHIC) Sextant and AGS-to-RHIC (AtR) transfer line during the Sextant Test in early 1997. Techniques used to measure both machine properties (difference orbits, dispersion, and beamline optics) and beam parameters (energy, intensity, transverse and longitudinal emittances) are described. Good agreement was achieved between measured and design lattice optics. The gold ion beam quality was shown to approach RHIC design requirements.

Wei, J.; Fischer, W.; Ahrens, L. [and others

1997-07-01T23:59:59.000Z

31

Spin tracking in RHIC (Code Spink)  

SciTech Connect

The evolution of the spin during acceleration in the Relativistic Heavy Ion Collider (RHIC) has been studied with a new numerical code, Spink. Results of spin tracking through resonances are shown.

Luccio, A.U.

1995-12-31T23:59:59.000Z

32

RHIC OPERATION WITH LONGITUDINALLY POLARIZED PROTONS.  

Science Conference Proceedings (OSTI)

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.

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

2004-07-05T23:59:59.000Z

33

ANALYSIS OF AVAILABILITY AND RELIABILITY IN RHIC OPERATIONS.  

SciTech Connect

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.

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

2006-06-26T23:59:59.000Z

34

Ion polarization in the MEIC figure-8 ion collider ring  

SciTech Connect

The nuclear physics program envisaged at the Medium-energy Electron-Ion Collider (MEIC) currently being developed at the Jefferson Lab calls for collisions of 3-11 GeV/c longitudinally polarized electrons and 20-100 GeV/c, in equivalent proton momentum, longitudinally/ transversely polarized protons/ deuterons/ light ions. We present a scheme that provides the required ion polarization arrangement in the MEIC's ion collider ring.

V.S. Morozov, Ya.S. Derbenev, Y. Zhang, P. Chevtsov, A.M. Kondratenko, M.A. Kondratenko, Yu.N. Filatov

2012-07-01T23:59:59.000Z

35

AGS to RHIC transfer line: Design and commissioning  

SciTech Connect

In the fall of 1995, we successfully completed a major milestone in the RHIC (Relativistic Heavy Ion Collider) project: the first beam test of the AGS (Alternating Gradient Synchrotron) to RHIC (ATR) transfer line. The ATR serves as a test bed for the new RHIC control system. This transfer line is highly instrumented, with several types of instrumentation for characterizing the extracted beam from AGS and for matching the beam into RHIC. We describe the design and performance of ATR with gold ions with an eye to reaching the design criteria for RHIC operation, both in beam quality and controls.

MacKay, W.W; Ahrens, L.; Bennan, M.; Brown, K. [and others

1996-09-01T23:59:59.000Z

36

RHIC | New Areas of Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

A New Area of Physics A New Area of Physics RHIC has created a new state of hot, dense matter out of the quarks and gluons that are the basic particles of atomic nuclei, but it is a state quite different and even more remarkable than had been predicted. Instead of behaving like a gas of free quarks and gluons, as was expected, the matter created in RHIC's heavy ion collisions is more like a liquid. Quarks Gluons and quarks Ions Ions about to collide Impact Just after collision Perfect Liquid The "perfect" liquid hot matter Hot Nuclear Matter A review article in the journal Science describes groundbreaking discoveries that have emerged from RHIC, synergies with the heavy-ion program at the Large Hadron Collider, and the compelling questions that will drive this research forward on both sides of the Atlantic.

37

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

Science Conference Proceedings (OSTI)

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| 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.

STAR Coll

2009-06-16T23:59:59.000Z

38

Sorting chromatic sextupoles for easily and effectively correcting second order chromaticity in the Relativistic Heavy Ion Collider  

Science Conference Proceedings (OSTI)

Based on the contributions of the chromatic sextupole families to the half-integer resonance driving terms, we discuss how to sort the chromatic sextupoles in the arcs of the Relativistic Heavy Ion Collider (RHIC) to easily and effectively correct the second order chromaticities. We propose a method with 4 knobs corresponding to 4 pairs of chromatic sextupole families to online correct the second order chromaticities. Numerical simulation justifies this method, showing that this method reduces the unbalance in the correction strengths of sextupole families and avoids the reversal of sextupole polarities. Therefore, this method yields larger dynamic apertures for the proposed RHIC 2009 100GeV polarized proton run lattices.

Luo,Y.; Tepikian, S.; Fischer, W.; Robert-Demolaize, G.; Trbojevic, D.

2009-01-02T23:59:59.000Z

39

RHIC | Spin Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

Spin Physics Spin Physics RHIC is the world's only machine capable of colliding high-energy beams of polarized protons, and is a unique tool for exploring the puzzle of the proton's 'missing' spin. In addition to colliding heavy ions, RHIC is able to collide single protons. While these collisions don't produce quark-gluon plasma, they're interesting to physicists for other reasons. Scientists want to know more about a property of particles called 'spin'. Spin is the direction a particle is spinning around an axis as it travels -- just like the Earth spins on its axis as it travels around the sun. Each proton has a specific spin, which helps give it a characteristic magnetic property. spin In this picture of a proton-proton collision, the spin of the particles is shown as arrows circling the spherical particles. The red and green

40

Electron Ion Collider: The Next QCD Frontier  

NLE Websites -- All DOE Office Websites (Extended Search)

Ion Collider: Ion Collider: The Next QCD Frontier Understanding the glue that binds us all Electron Ion Collider: The Next QCD Frontier Understanding the glue that binds us all BNL-98815-2012-JA JLAB-PHY-12-1652 arXiv:1212.1701 Authors A. Accardi 14,28 , J. L. Albacete 16 , M. Anselmino 29 , N. Armesto 36 , E. C. Aschenauer 3,† , A. Bacchetta 35 , D. Boer 33 , W. Brooks 37,† , T. Burton 3 , N.-B. Chang 23 , W.-T. Deng 13,23 , A. Deshpande 25,∗,† , M. Diehl 11,† , A. Dumitru 2 , R. Dupr´ e 7 , R. Ent 28,‡ , S. Fazio 3 , H. Gao 12,† , V. Guzey 28 , H. Hakobyan 37 , Y. Hao 3 , D. Hasch 15 , R. Holt 1,† , T. Horn 5,† , M. Huang 23 , A. Hutton 28,† , C. Hyde 20 , J. Jalilian-Marian 2 , S. Klein 17 , B. Kopeliovich 37 , Y. Kovchegov 19,† , K. Kumar 24,† , K. Kumeriˇ cki 40 , M. A. C. Lamont 3 , T. Lappi 34 , J.-H. Lee 3 , Y. Lee 3 , E. M. Levin 26,37 , F.-L. Lin 28 , V. Litvinenko 3 , T. W. Ludlam 3,‡ , C. Marquet

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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41

RHIC Newsroom  

NLE Websites -- All DOE Office Websites (Extended Search)

Feature Stories Feature Stories Björn Schenke 490th Brookhaven Lecture, 12/18 December 13, 2013 Join Björn Schenke of Brookhaven Lab's Physics Department for the 490th Brookhaven Lecture, titled 'The Shape and Flow of Heavy Ion Collisions,' on Wednesday, Dec. 18, at 4 p.m. in Berkner Hall. droplets Tiny Drops of Hot Quark Soup-How Small Can They Be? December 06, 2013 New analyses indicate that collisions of small particles with large gold nuclei at the Relativistic Heavy Ion Collider may be serving up miniscule servings of hot quark-gluon plasma. Lokesh Kumar RHIC Physics Feeds Future High-Tech Workforce: Lokesh Kumar November 06, 2013 Search for "critical point" in early universe matter continues...from India. LHC magnets Backup Magnets Ready to Ship to LHC September 30, 2013

42

RHIC physics overview  

E-Print Network (OSTI)

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.

Lijuan Ruan

2010-07-16T23:59:59.000Z

43

The Science Case for An Electron-Ion Collider: The Next QCD Frontier  

NLE Websites -- All DOE Office Websites (Extended Search)

Case for Case for An Electron-Ion Collider: The Next QCD Frontier Jianwei Qiu Brookhaven National Laboratory NSAC Subcommittee Meeting on Scientific Facilities February 15-16, 2013 for both BNL and JLab EIC efforts, ... 1 White Paper for the Electron-Ion Collider ELIC (JLab) eRHIC (BNL) 2 arXiv:1212.1701 Community effort and commitment Ten-week program (9/13-11/19, 2010) at Institute for Nuclear Theory (INT Report: arXiv:1108.1713v2, 500+ pages)  Many workshops on EIC physics: 3  Commitment from BNL and JLab:  EICAC - jointly by BNL and JLab  BNL EIC Task force (https://wiki.bnl.gov/eic/index.php/Main_Page)  EIC@JLab (https://eic.jlab.org/wiki/index.php/Main_Page)  Detector R&D (https://wiki.bnl.gov/conferences/index.php/EIC_R%25D)

44

Science for the Future of RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

77334-2006-IR 77334-2006-IR Future Science at the Relativistic Heavy Ion Collider December 30, 2006 Summary of the 2004 - 2005 RHIC II Science Working Groups 1 2 Table of contents 1. Overview 4 2. Summary of the first 5 years at RHIC 9 2..1. Heavy ion physics 9 2..2. Spin physics 18 3. The RHIC facility - evolution and future 22 4. Fundamental questions for the next ten years at RHIC 25 4.1. What are the phases of QCD matter? 25 4.2. What is the wave function of a heavy nucleus. 26 4.3. What is the wave function of the proton? 26 4.4. What is the nature of non-equilibrium processes in a fundamental theory? 27 5. The future physics program at RHIC 28 5.1. Equation of state and the QCD phase diagram 29 5.1.1. Dynamical considerations 29

45

BEAM DIFFUSION MEASUREMENTS AT RHIC.  

Science Conference Proceedings (OSTI)

During a store, particles from the beam core continually diffuse outwards into the halo through a variety of mechanisms. Understanding the diffusion rate as a function of particle amplitude can help discover which processes are important to halo growth. A collimator can be used to measure the amplitude growth rate as a function of the particle amplitude. In this paper we present results of diffusion measurements performed at the Relativistic Heavy Ion Collider (RHIC) with fully stripped gold ions, deuterons, and protons. We compare these results with measurements from previous years, and simulations, and discuss any factors that relate to beam growth in RHIC.

FLILLER,R.P.,IIIDREES,A.GASSNER,D.MCINTYRE,G.PEGGS,S.TRBOJEVIC,D.

2003-05-12T23:59:59.000Z

46

RHIC Polarized proton performance in run-8  

SciTech Connect

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.

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.

2008-10-06T23:59:59.000Z

47

FEL potential of eRHIC  

Science Conference Proceedings (OSTI)

Brookhaven National Laboratory plans to build a 5-to-30 GeV energy-recovery linac (ERL) for its future electron-ion collider, eRHIC. In past few months, the Laboratory turned its attention to the potential of this unique machine for free electron lasers (FELS), which we initially assessed earlier. In this paper, we present our current vision of a possible FEL farm, and of narrow-band FEL-oscillators driven by this accelerator. eRHIC, the proposed electron-ion collider at BNL, takes advantage of the existing Relativistic Heavy Ion Collider (RHIC) complex. Plans call for adding a six-pass super-conducting (SRF) ERL to this complex to collide polarized- and unpolarized- electron beams with heavy ions (with energies up to 130 GeV per nucleon) and with polarized protons (with energies up to 325 GeV). RHIC, with a circumference of 3.834 km, has three-fold symmetry and six straight sections each {approx} 250 m long. Two of these straight sections will accommodate 703-MHz SRF linacs. The maximum energy of the electron beam in eRHIC will be reached in stages, from 5 GeV to 30 GeV, by increasing the lengths of its SRF linacs. We plan to install at the start the six-pass magnetic system with small gap magnets. The structure of the eRHIC's electron beam will be identical with that of its hadron beam, viz., 166 bunches will be filled, reserving about a one-microsecond gap for the abort kicker. With modest modifications, we can assure that eRHIC's ERL will become an excellent driver for continuous wave (CW) FELs (see Fig.1). The eRHIC's beam structure will support the operation of several such FELs in parasitic mode.

Litvinenko, V.N.; Ben-Zvi, I.; Hao, Y.; Kao, C-C.; Kayran, D.; Murphy, J.B.; Ptitsyn, V.; Trbojevic, D.; Tsoupas, N.

2010-08-23T23:59:59.000Z

48

Hydrodynamics at RHIC -- how well does it work, where and how does it break down?  

E-Print Network (OSTI)

I review the successes and limitations of the ideal fluid dynamic model in describing hadron emission spectra from Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC).

Ulrich W. Heinz

2004-12-24T23:59:59.000Z

49

AdS/CFT Correspondence and Hydrodynamics of Relativistic Heavy Ion Collisions.  

E-Print Network (OSTI)

??The experiments performed at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab have discovered a state of matter called the strongly coupled quark-gluon (more)

Alsup, James Ethan

2010-01-01T23:59:59.000Z

50

The online system of the PHENIX experiment in the RHIC run 5  

Science Conference Proceedings (OSTI)

PHENIX [1] is one of two large experiments at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC). At the time of this conference, the Run 5 of RHIC is in progress and has been very successful so far. Compared to the previous run, ...

Martin L. Purschke

2005-06-01T23:59:59.000Z

51

PREVENTING POLLUTION USING ISO 14001 AT A PARTICLE ACCELERATOR THE RELATIVISTIC HEAVY ION COLLIDER PROJECT.  

SciTech Connect

In early 1997 Brookhaven National Laboratory (BNL) discovered that the spent fuel pool of their High Flux Beam Reactor was leaking tritium into the groundwater. Community members, activist groups, politicians and regulators were outraged with the poor environmental management practices at BNL. The reactor was shut down and the Department of Energy (DOE) terminated the contract with the existing Management Company. At this same time, a major new scientific facility, the Relativistic Heavy Ion Collider (RHIC), was nearing the end of construction and readying for commissioning. Although environmental considerations had been incorporated into the design of the facility; some interested parties were skeptical that this new facility would not cause significant environmental impacts. RHIC management recognized that the future of its operation was dependent on preventing pollution and allaying concerns of its stakeholders. Although never done at a DOE National Laboratory before Brookhaven Science Associates, the new management firm, committed to implementing an Environmental Management System (EMS) and RHIC managers volunteered to deploy it within their facility on an extremely aggressive schedule. Several of these IS0 requirements contribute directly to preventing pollution, an area where particular emphasis was placed. This paper describes how Brookhaven used the following key IS0 14001 elements to institutionalize Pollution Prevention concepts: Environmental Policy, Aspects, Objectives and Targets, Environmental Management Program, Structure and Responsibility, Operational Controls, Training, and Management Review. In addition, examples of implementation at the RHIC Project illustrate how BNL's premiere facility was able to demonstrate to interested parties that care had been taken to implement technological and administrative controls to minimize environmental impacts, while at the same time reduce the applicability of regulatory requirements to their operations.

BRIGGS,S.L.K.; MUSOLINO,S.V.

2001-06-01T23:59:59.000Z

52

Strange quark suppression and strange hadron production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider  

Science Conference Proceedings (OSTI)

The parton and hadron cascade model PACIAE based on PYTHIA is utilized to systematically investigate strange particle production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). Globally speaking, the PACIAE results of the strange particle rapidity density at midrapidity and the transverse momentum distribution are better than those of PYTHIA (default) in comparison with STAR and ALICE experimental data. This may represent the importance of the parton and hadron rescatterings, as well as the reduction mechanism of strange quark suppression, added in the PACIAE model. The K/{pi} ratios as a function of reaction energy in pp collisions from CERN Super Proton Synchrotron (SPS) to LHC energies are also analyzed in this paper.

Long Haiyan; Feng Shengqin; Zhou Daimei; Yan Yuliang; Ma Hailiang; Sa Benhao [Department of Physics, College of Science, China Three Gorges University, Yichang 443002 (China); Institute of Particle Physics, Huazhong Normal University, Wuhan 430082 (China); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); Institute of Particle Physics, Huazhong Normal University, Wuhan 430082 (China); CCAST (World Laboratory), P.O. Box 8730, Beijing 100080 (China)

2011-09-15T23:59:59.000Z

53

Coherent beam-beam effects observation and mitigation at the RHIC collider  

SciTech Connect

In polarized proton operation in RHIC coherent beam-beam modes are routinely observed with beam transfer function measurements in the vertical plane. With the existence of coherent modes a larger space is required in the tune diagram than without them and stable conditions can be compromised for operation with high intensity beams as foreseen for future luminosity upgrades. We report on experiments and simulations carried out to understand the existence of coherent modes in the vertical plane and their absence in the horizontal plane, and investigate possible mitigation strategies.

White S.; Fischer, W.; Luo, Y.

2012-05-20T23:59:59.000Z

54

RHIC low energy tests and initial operations  

SciTech Connect

Future Relativistic Heavy Ion Collider (RHIC) runs, including a portion of FY10 heavy ion operations, will explore collisions at center of mass energies of 5-50 GeV/n (GeV/nucleon). Operations at these energies is motivated by a search for the QCD phase transition critical point. The lowest end of this energy range is nearly a factor of four below the nominal RHIC injection center of mass energy of {radical} s = 20.8 GeV/n. There are several operational challenges in the RHIC low-energy regime, including harmonic number changes, small longitudinal acceptance, lowered magnet field quality, nonlinear orbit control, and luminosity monitoring. We report on the experience with some of these challenges during beam tests with gold in March 2008, including first RHIC operations at {radical}s = 9.18 GeV/n and first beam experience at {radical}s = 5 GeV/n.

Satogata,T.; Ahrens, L.; Bai, M.; Brennan, J.M.; Bruno, D.; Butler, J.; Drees, A.; Fedotov, A.; Fischer, W.; Harvey, M.; Hayes, T.; Jappe, W.; Lee, R.C.; Mackay, W.W.; Malitsky, N.; Marr, G.; Michnoff, R.; Oerter, B.; Pozdeyev, E.; Roser, T.; Severino, F.; Smith, K.; Tepikian, S.; Tsoupas, N.

2009-05-04T23:59:59.000Z

55

RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN  

SciTech Connect

Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; DOttavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

2010-05-23T23:59:59.000Z

56

RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN  

Science Conference Proceedings (OSTI)

Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; DOttavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

2010-05-23T23:59:59.000Z

57

RHIC | NSAC Recommendations  

NLE Websites -- All DOE Office Websites (Extended Search)

Excerpts from the "Report to NSAC on Implementing the 2007 Long Range Excerpts from the "Report to NSAC on Implementing the 2007 Long Range Plan" The full report of a Nuclear Science Advisory Committee (NSAC) subcommittee charged with making recommendations for the field of nuclear physics under constrained budget scenarios and the "transmittal letter" delivering this report from NSAC to the Department of Energy and the National Science Foundation are now available online. Background on the task facing the subcommittee and documents presenting the scientific and economic impact of the research program at the Relativistic Heavy Ion Collider (RHIC) at DOE's Brookhaven National Laboratory, one of three facilities described in detail in the report, can be found on the RHIC website here. What follows are direct quotes taken from the report that help to describe the

58

Direct Photons at RHIC  

E-Print Network (OSTI)

A brief overview of direct-photon measurements in p+p and Au+Au collisions at sqrt(s_NN) = 200 GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) is given. Direct-photon yields for pT > 4 GeV/c and photon-hadron azimuthal correlations were determined with the aid of an electromagnetic calorimeter. By detecting e+e- pairs from the internal conversion of virtual photons direct-photon yields were measured between 1 direct-photon yield in this range.

Klaus Reygers; for the PHENIX Collaboration

2009-08-17T23:59:59.000Z

59

Recent Heavy Flavor Results at RHIC  

E-Print Network (OSTI)

We summarize the recent experimental results of heavy favor physics from the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Lab (BNL) at Long Island, New York, USA.We will discuss the directly reconstructed open charm mesons as well as electrons from heavy favor hadron decays. The charm and bottom quark production cross-sections have also been measured. We will also discuss JPsi and Upsilon states in p+p and heavy ion collisions. The studies described here were carried out and reported by the STAR and PHENIX collaborations at RHIC.

Wenqin Xu

2011-10-13T23:59:59.000Z

60

Heavy Nuclei from RHIC to the Cosmos  

E-Print Network (OSTI)

Ultra-relativistic heavy ion collisions produce a high-temperature, thermalized system that may mimic the conditions present shortly after the big bang. This writeup will given an overview of early results from the Relativistic Heavy Ion Collider (RHIC), and discuss what we have learned about hot, strongly interacting nuclear systems. The thermal and chemical composition of the system will be discussed, along with observables that are sensitive to the early evolution of the system. I will also discuss the implications of the RHIC results for cosmic ray air showers.

Spencer R. Klein

2002-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Collider-Accelerator Department  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Tunnel and Magnets RHIC Tunnel and Magnets RHIC Tunnel and Magnets AGS Tunnel and Magnets NSRL Beamline RF Kicker Snake 200-MeV LINAC AGS Cold Snake Magnet About the Collider-Accelerator Department The mission of the Collider-Accelerator Department is to develop, improve and operate the suite of particle / heavy ion accelerators used to carry out the program of accelerator-based experiments at BNL; to support the experimental program including design, construction and operation of the beam transports to the experiments plus support of detector and research needs of the experiments; to design and construct new accelerator facilities in support of the BNL and national missions. The C-A Department supports an international user community of over 1500 scientists. The department performs all these functions in an environmentally responsible and safe manner under a rigorous conduct of operations approach.

62

Nuclear physics with a medium-energy Electron-Ion Collider  

E-Print Network (OSTI)

A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy sqrt(s) ~ 20-70 GeV and a luminosity ~ 10^{34} cm^{-2} s^{-1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.

A. Accardi; V. Guzey; A. Prokudin; C. Weiss

2011-10-05T23:59:59.000Z

63

Nuclear physics with a medium-energy Electron-Ion Collider  

Science Conference Proceedings (OSTI)

A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy {radical}s {approx} 20-70 GeV and a luminosity {approx}10{sup 34} cm{sup -2} s{sup -1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.

A. Accardi, V. Guzey, A. Prokudin, C. Weiss

2012-06-01T23:59:59.000Z

64

The Strongly Interacting Quark Gluon Plasma at RHIC and LHC  

E-Print Network (OSTI)

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.

Itzhak Tserruya

2012-12-30T23:59:59.000Z

65

RHIC | Booster Synchrotron  

NLE Websites -- All DOE Office Websites (Extended Search)

Booster Synchrotron Booster Synchrotron Construction of the Alternating Gradient Synchrotron (AGS) Booster was begun in 1986 and completed in 1991. The Booster is less than one quarter the size of the AGS. It is used to preaccelerate particles entering the AGS ring, increasing the intensity of the proton beams generated by the AGS. The Booster also plays an important role in the operation of the Relatavistic Heavy Ion Collider by accepting heavy ions from EBIS or protons from the 200-million electron volt (MeV) Linac. It then feeds them to the AGS for further acceleration and delivery to RHIC. After the installation of the heavy-ion transfer line in 1986, the AGS was capable of accelerating ions up to silicon with its atomic mass of 28. However, due to its superior vacuum, the Booster makes it possible for the AGS to

66

Relativistic Heavy Ion Collider Funding Agencies  

NLE Websites -- All DOE Office Websites (Extended Search)

Funding Agencies Funding Agencies In addition to the operations funding received from the Office of Nuclear Physics within the U.S. Department of Energy's Office of Science, RHIC experiments receive funding from a variety of sources PHENIX U.S. National Science Foundation Ministry of Education, Culture, Sports, Science and Technology of Japan Japan Society for the Promotion of Science National Council for Scientific and Technological Development, Brazil Research Supporting Foundation of the State of Sao Paulo, Brazil National Natural Science Foundation of China National Institute of Nuclear Physics and Particle Physics of the National Center for Scientific Research of France Atomic Energy Commission of France ARMINES (France) Federal Ministry of Education and Research of Germany

67

Proton Polarimetry at the Relativistic Heavy Ion Collider  

DOE Green Energy (OSTI)

The RHIC polarized proton collider employs polarimeters in each of the Blue and Yellow rings that utilize the analyzing power in p-Carbon elastic scattering in the Coulomb Nuclear Interference region to measure the absolute beam polarization. These are calibrated by the polarized Hydrogen Jet Target that measures the absolute beam polarization in pp elastic scattering in the CNI region. This paper describes the status and performance of these polarimeters in the FY09 run which included both a 250 GeV/c and 100 GeV/c physics data taking periods. We will describe some of the difficulties encountered and the efforts underway to improve the performance in better energy resolution, rate handling capability, and reduced systematic uncertainties.

Makdisi, Y.; Aschenauer, E.; Atoian, G.; Bazilevsky, A.; Bunce, G.; Gill, R.; Huang, H.; Morozov, B.; Rescia, S.; Sivertz, M.; Yip, K.; Zelenski, A.; Lee, S.K.; Li, X.; Alekseev, I.; Svirida, D.

2009-09-07T23:59:59.000Z

68

HYDROGEN AND ITS DESORPTION IN RHIC.  

DOE Green Energy (OSTI)

Hydrogen is the dominating gas specie in room temperature, ultrahigh vacuum systems of particle accelerators and storage rings, such as the Relativistic Heavy Ion Collider (RHIC) at Brookhaven. Rapid pressure increase of a few decades in hydrogen and other residual gases was observed during RHIC's recent high intensity gold and proton runs. The type and magnitude of the pressure increase were analyzed and compared with vacuum conditioning, beam intensity, number of bunches and bunch spacing. Most of these pressure increases were found to be consistent with those induced by beam loss and/or electron stimulated desorption from electron multipacting.

HSEUH,H.C.

2002-11-11T23:59:59.000Z

69

Highlights from BNL-RHIC-2012  

E-Print Network (OSTI)

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 means of direct measurements of charm and beauty particles at both RHIC and LHC are discussed.

M. J. Tannenbaum

2013-02-07T23:59:59.000Z

70

A critical review of RHIC experimental results  

E-Print Network (OSTI)

The relativistic heavy ion collider (RHIC) was constructed to achieve an asymptotic state of nuclear matter in heavy ion collisions, a near-ideal gas of deconfined quarks and gluons denoted quark-gluon plasma or QGP. RHIC collisions are indeed very different from the hadronic processes observed at the Bevalac and AGS, but high-energy elementary-collision mechanisms are also non-hadronic. The two-component model (TCM) combines measured properties of elementary collisions with the Glauber eikonal model to provide an alternative asymptotic limit for A-A collisions. RHIC data have been interpreted to indicate formation of a {\\em strongly-coupled} QGP or "perfect liquid". In this review I consider the experimental evidence that seems to support such conclusions and alternative evidence that may conflict with those conclusions and suggest different interpretations.

Thomas A. Trainor

2013-03-19T23:59:59.000Z

71

Electron Ion Collider: The Next QCD Frontier - Understanding the glue that binds us all  

E-Print Network (OSTI)

This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics and, in particular, the focused ten-week program on "Gluons and quark sea at high energies" at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them, and it benefited from inputs from the users' communities of BNL and JLab. This White Paper offers the promise to propel the QCD science program in the U.S., established with the CEBAF accelerator at JLab and the RHIC collider at BNL, to the next QCD frontier.

A. Accardi; J. L. Albacete; M. Anselmino; N. Armesto; E. C. Aschenauer; A. Bacchetta; D. Boer; W. Brooks; T. Burton; N. -B. Chang; W. -T. Deng; A. Deshpande; M. Diehl; A. Dumitru; R. Dupr; R. Ent; S. Fazio; H. Gao; V. Guzey; H. Hakobyan; Y. Hao; D. Hasch; R. Holt; T. Horn; M. Huang; A. Hutton; C. Hyde; J. Jalilian-Marian; S. Klein; B. Kopeliovich; Y. Kovchegov; K. Kumar; K. Kumeri?ki; M. A. C. Lamont; T. Lappi; J. -H. Lee; Y. Lee; E. M. Levin; F. -L. Lin; V. Litvinenko; T. W. Ludlam; C. Marquet; Z. -E. Meziani; R. McKeown; A. Metz; R. Milner; V. S. Morozov; A. H. Mueller; B. Mller; D. Mller; P. Nadel-Turonski; A. Prokudin; V. Ptitsyn; X. Qian; J. -W. Qiu; M. Ramsey-Musolf; T. Roser; F. Sabati; R. Sassot; G. Schnell; P. Schweitzer; E. Sichtermann; M. Stratmann; M. Strikman; M. Sullivan; S. Taneja; T. Toll; D. Trbojevic; T. Ullrich; R. Venugopalan; S. Vigdor; W. Vogelsang; C. Weiss; B. -W. Xiao; F. Yuan; Y. -H. Zhang; L. Zheng

2012-12-07T23:59:59.000Z

72

Modified Fragmentation Function in Heavy Ion Collisions at RHIC via Direct photon-Jet Measurements  

E-Print Network (OSTI)

The presented results are the first measurements at RHIC for direct $\\gamma$-charged hadron azimuthal correlations in heavy ion collisions. We use these correlations to study the color charge density of the medium through the medium-induced modification of high-p$_T$ parton fragmentation. Azimuthal correlations of direct photons at high transverse energy (8 $direct photons and photons from the decays of high p$_T$ $\\pi^{0}$. The per-trigger away-side yield of direct $\\gamma$ is smaller than from $\\pi^{0}$ trigger at the same centrality class. Within the current uncertainty the I$_{CP}$ of direct $\\gamma$ and $\\pi^{0}$ are similar.

Ahmed M. Hamed

2008-09-08T23:59:59.000Z

73

Preparing accelerator systems for the RHIC sextant commissioning  

Science Conference Proceedings (OSTI)

The Relativistic Heavy Ion Collider (RHIC) construction is progressing steadily towards completion in 1999 when beams will circulate in both collider rings. One of the major tests of the RHIC project was the commissioning of the first sextant with gold ion beams in early 1997. This is a report on preparation of the RHIC accelerator systems for the first sextant test. It includes beam position monitors, timing, injection correction through the magnetic septum and kickers, current transformers, flags and the ionization beam profile monitors, beam loss monitors, beam and quench permit link system, power supply controls, and the configuration database system. The software and hardware development and coordination of the different systems before commissioning were regularly checked during bi-weekly, and (later) weekly, progress report meetings.

Trbojevic, D.; Pilat, F.; Ahrens, L. [and others

1997-07-01T23:59:59.000Z

74

Opportunities for Drell-Yan Physics at RHIC  

SciTech Connect

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.

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

2011-05-24T23:59:59.000Z

75

RHIC Videos  

NLE Websites -- All DOE Office Websites (Extended Search)

Brookhaven National Laboratory Brookhaven National Laboratory search U.S. Department of Energy logo Home RHIC Science News Images Videos For Scientists RHIC Videos Other Videos 401 LHC magnets Backup Magnets Ready to Ship to LHC Physicists and engineers in Brookhaven National Laboratory's Superconducting Magnet Division are in the final stages of assembling "replacement" magnets for the Large Hadron Collider (LHC) at Europe's CERN laboratory. 398 Photo of Milind Diwan Why Particle Physics Matters: Milind Diwan Particle physicists dedicate their lives to understanding the fundamental nature of energy, matter, space and time. Why do they do it? Symmetry magazine asked some of them to explain: Why does particle physics matter? 399 Photo of Elizabeth Worcester Why Particle Physics Matters: Elizabeth Worcester

76

RHIC II Science Working Groups  

NLE Websites -- All DOE Office Websites (Extended Search)

Workshops Workshops The series of RHIC II Science Workshops began in November 2004, at which time seven Working Groups were initiated. These groups met in workshops through 2005, with the purpose of providing an organized forum for the community to address and describe quantitatively the most important science issues for the proposed RHIC II luminosity upgrade, and corresponding detector upgrades. Each Working Group was led by three convenors representing theory and experiment, and each has produced a detailed report (except for the "New Directions" group, which provided a sounding board and input to the other groups). The Working Group reports are linked below. The summary "white paper" document, "Future Science at the Relativistic Heavy Ion Collider" (PDF), is based on these reports, and was prepared by a Writing Committee that included at least one convenor from each of the Working Groups.

77

Workshop on the RHIC performance  

SciTech Connect

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.

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

1988-07-01T23:59:59.000Z

78

Off-momentum dynamic aperture for lattices in the RHIC heavy ion runs  

Science Conference Proceedings (OSTI)

To reduce transverse emittance growth rates from intrabeam scattering in the RHIC heavy ion runs, a lattice with an increased phase advance in the arc FODO cells was adopted in 2008-2011. During these runs, a large beam loss due to limited off-momentum dynamic aperture was observed during longitudinal RF re-bucketing and with transverse cooling. Based on the beam loss observations in the previous ion runs and the calculated off-momentum apertures, we decided to adopt the lattice used before 2008 for the 2012 U-U and Cu-Au runs. The observed beam decay and the measured momentum aperture in the 2012 U-U run are presented.

Luo Y.; Bai, M.; Blaskiewicz, M.; Gu, X.; Fischer, W.; Marusic, A.; Roser, T.; Tepikian, S.; Zhang, S.

2012-05-20T23:59:59.000Z

79

MACHINE PROTECTION SYSTEM FOR CONCURRENT OPERATION OF RHIC AND BLIP.  

SciTech Connect

The Brookhaven 200MeV linac is a multipurpose machine used to inject low intensity polarized protons for RHIC (Relativistic Heavy Ion Collider), as well as to inject high intensity protons to BLIP (Brookhaven Linac Isotope Producer), a medical isotope production facility. If high intensity protons were injected to RHIC by mistake, administrative radiation limits could be exceeded or sensitive electronics could be damaged. In the past, the changeover from polarized proton to high intensity proton operation has been a lengthy process, thereby never allowing the two programs to run simultaneously. To remedy this situation and allow concurrent operation of RHIC and BLIP, an active interlock system has been designed to monitor current levels in the AGS using two current transformers with fail safe circuitry and associated electronics to inhibit beam to RHIC if high intensity currents are detected.

WILINSKI, M.; BELLAVIA, S.; GLENN, J.W.; MAUSNER, L.F.; UNGER, K.L.

2005-05-16T23:59:59.000Z

80

Transfer of polarized 3He ions in the AtR beam transfer line  

SciTech Connect

In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will facilitate the collisions of electrons with polarized {sup 3}He ions. The AGS is the last acceleration stage, before injection into one of the RHIC's collider ring for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized {sup 3}He ions from AGS into one of the RHIC's collider rings. Some of the peculiarities of the AtR line's layout (simultaneous horizontal and vertical bends) may degrade the matching of the stable spin direction of the AtR line with that of RHIC's. In this paper we discuss possible simple modifications of the AtR line to accomplish a perfect matching of the stable spin direction of the injected {sup 3}He beam with the stable spin direction at the injection point of RHIC.

Tsoupas N.; MacKay, W.W.; Meot, F.; Roser, T.; Trbojevic, D.

2012-05-20T23:59:59.000Z

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81

Ion desorption stability in superconducting high energy physics proton colliders  

DOE Green Energy (OSTI)

In this article we extend our previous analysis of a cold beam tube vacuum in a superconducting proton collider to include ion desorption in addition to thermal desorption and synchrotron radiation induced photodesorption. The ion desorption terms introduce the possibility of vacuum instability. This is similar to the classical room temperature case but is now modified by the inclusion of ion desorption coefficients for cryosorbed (physisorbed) molecules which can greatly exceed the coefficients for tightly bound molecules. The sojourn time concept for physisorbed H{sub 2} is generalized to include photodesorption and ion desorption as well as the usually considered thermal desorption. The ion desorption rate is density dependent and divergent so at the onset of instability the sojourn time goes to zero. Experimental data are used to evaluate the H{sub 2} sojourn time for the conditions of the Large Hadron Collider (LHC) and the situation is found to be stable. The sojourn time is dominated by photodesorption for surface density {ital s}(H{sub 2}) less than a monolayer and by thermal desorption for {ital s}(H{sub 2}) greater than a monolayer. For a few percent of a monolayer, characteristic of a beam screen, the photodesorption rate exceeds the ion desorption rate by more than two orders of magnitude. The photodesorption rate corresponds to a sojourn time of approximately 100 s. The article then turns to the evaluation of stability margins and the inclusion of gases heavier than H{sub 2} (CO, CO{sub 2}, and CH{sub 4}), where ion desorption introduces coupling between molecular species. Stability conditions are worked out for a simple cold beam tube, a cold beam tube pumped from the ends, and a cold beam tube with a coaxial perforated beam screen. In each case a simple inequality for stability of a single component is replaced by a determinant that must be greater than zero for a gas mixture. (Abstract Truncated)

Turner, W.C. [E. O. Lawrence Berkeley National Laboratory, University of California--Berkeley, Berkeley, California 94720 (United States)] [E. O. Lawrence Berkeley National Laboratory, University of California--Berkeley, Berkeley, California 94720 (United States)

1996-07-01T23:59:59.000Z

82

Crab Crossing Schemes and Studies for Electron Ion Collider  

Science Conference Proceedings (OSTI)

This report shows our progress in crab crossing consideration for future electron-ion collider envisioned at JLab. In this design phase, we are evaluating two crabbing schemes viz., the deflecting and dispersive. The mathematical formulations and lattice design for these schemes are discussed in this paper. Numerical simulations involving particle tracking through a realistic deflecting RF cavity and optics illustrate the desired crab tilt of 25 mrad for 1.35 MV. Evolution of beam propagation are shown which provides the physical insight of the crabbing phenomenon.

S. Ahmed, Y. Derbenev, V. Morozov, A. Castilla, G.A. Krafft, B. Yunn, Y. Zhang, J.R. Delayen

2011-09-01T23:59:59.000Z

83

Improvement plans for the RHIC/AGS on-line model environments  

SciTech Connect

The on-line models for Relativistic Ion Collider (RHIC) and the RHIC pre-injectors (the AGS and the AGS Booster) can be thought of as containing our best collective knowledge of these accelerators. As we improve these on-line models we are building the framework to have a sophisticated model-based controls system. Currently the RHIC on-line model is an integral part of the controls system, providing the interface for tune control, chromaticity control, and non-linear chromaticity control. What we discuss in this paper is our vision of the future of the on-line model environment for RHIC and the RHIC preinjectors. Although these on-line models are primarily used as Courant-Snyder parameter calculators using live machine settings, we envision expanding these environments to encompass many other problem domains.

Brown,K.A.; Ahrens, L.; Beebe-Wang, J.; Morris, J.; Nemesure, S.; Robert-Demolaize, G.; Satogata, T.; Schoefer, V.; Tepikian, S.

2009-08-31T23:59:59.000Z

84

Stochastic cooling in RHIC  

SciTech Connect

After the success of longitudinal stochastic cooling of bunched heavy ion beam in RHIC, transverse stochastic cooling in the vertical plane of Yellow ring was installed and is being commissioned with proton beam. This report presents the status of the effort and gives an estimate, based on simulation, of the RHIC luminosity with stochastic cooling in all planes.

Brennan,J.M.; Blaskiewicz, M. M.; Severino, F.

2009-05-04T23:59:59.000Z

85

Heavy-quark probes of the quark-gluon plasma and interpretation of recent data taken at the BNL Relativistic Heavy Ion Collider  

E-Print Network (OSTI)

Thermalization and collective flow of charm (c) and bottom (b) quarks in ultrarelativistic heavy-ion collisions are evaluated based on elastic parton rescattering in an expanding quark-gluon plasma (QGP). We show that resonant interactions in a strongly interacting QGP (sQGP), as well as parton coalescence, can play an essential role in the interpretation of recent data from the BNL Relativistic Heavy-Ion Collider (RHIC), and thus illuminate the nature of the sQGP and its hadronization. Our main assumption, motivated by recent findings in lattice quantum chromodynamics, is the existence of D- and B-meson states in the sQGP, providing resonant cross sections for heavy quarks. Pertinent drag and diffusion coefficients are implemented into a relativistic Langevin simulation to compute transverse-momentum spectra and azimuthal asymmetries (v(2)) of b- and c-quarks in Au-Au collisions at RHIC. After hadronization into D- and B-mesons using quark coalescence and fragmentation, associated electron-decay spectra and v(2) are compared to recent RHIC data. Our results suggest a reevaluation of radiative and elastic quark energy-loss mechanisms in the sQGP.

van Hees, H.; Greco, V.; Rapp, Ralf.

2006-01-01T23:59:59.000Z

86

RHIC Polarized proton operation  

DOE Green Energy (OSTI)

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 injection, the polarized hydrogen jet target runs for every fill with both beams. Based on the known analyzing power, there is very little polarization loss between injection and 100 GeV. An alternative way is to measure the asymmetry at 100 GeV followed by ramping up to 250 GeV and back down to 100 GeV and then to measure the asymmetry again at 100 GeV. If the asymmetry after the down ramp is similar to the measurement before the up ramp, polarization was also preserved during the ramp to 250 GeV. The analyzing power at storage energy can then be extracted from the asymmetries measured at 100 GeV and 250 GeV. The tune and orbit feedbacks are essential for the down ramp to be possible. The polarized proton operation is still going on. We will push bunch intensity higher until reaching the beam-beam limit. The even higher intensity will have to wait for the electron lenses to compensate the beam-beam effect. To understand the details of spin dynamics in RHIC with two snakes, spin simulation with the real magnet fields have been developed recently. The study will provide guidance for possible polarization loss schemes. Further polarization gain will requires a polarized source upgrade; more careful setup jump quads in the AGS to get full benefit; and control emittance in the whole accelerator chain.

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.

2011-03-28T23:59:59.000Z

87

Overview of magnetic nonlinear beam dynamics in the RHIC  

SciTech Connect

In this article we review our studies of nonlinear beam dynamics due to the nonlinear magnetic field errors in the Relativistic Heavy Ion Collider (RHIC). Nonlinear magnetic field errors, including magnetic field errors in interaction regions (IRs), chromatic sextupoles, and sextupole components from arc main dipoles are discussed. Their effects on beam dynamics and beam dynamic aperture are evaluated. The online methods to measure and correct the IR nonlinear field errors, second order chromaticities, and horizontal third order resonance are presented. The overall strategy for nonlinear corrections in RHIC is discussed.

Luo,Y.; Bai, M.; Beebe-Wang, J.; Bengtsson, J.; Calaga, R.; Fischer, W.; Jain, A.; Pilat, f.; Ptitsyn, V.; Malitsky, N.; Robert-Demolaize, g.; Satogata, T.; Tepikian, S.; Tomas, R.; Trbojevic, D.

2009-05-04T23:59:59.000Z

88

SUMMARY OF BEAM BEAM OBSERVATIONS DURING STORES IN RHIC.  

Science Conference Proceedings (OSTI)

During stores, the beam-beam interaction has a significant impact on the beam and luminosity lifetimes in RHIC. This was observed in heavy ion, and even more pronounced in proton collisions. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. In addition, RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. Coherent beam-beam modes were observed, and suppressed by tune changes. In this article we summarize the most important beam-beam observations made during stores so far.

FISCHER,W.

2003-05-19T23:59:59.000Z

89

Fourth workshop on experiments and detectors for a relativistic heavy ion collider  

Science Conference Proceedings (OSTI)

This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4{pi} tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/{psi} detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector.

Fatyga, M.; Moskowitz, B. (eds.)

1990-01-01T23:59:59.000Z

90

RHIC | STAR Detector  

NLE Websites -- All DOE Office Websites (Extended Search)

The STAR Detector The STAR detector specializes in tracking the thousands of particles produced by each ion collision at RHIC. Weighing 1,200 tons and as large as a house, STAR is...

91

Electron Ion Collider: The Next QCD Frontier Understanding  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Electron Ion Collider: The Next QCD Frontier Understanding the glue that binds us all White Paper Writing Committee Elke C. Aschenauer Brookhaven National Laboratory William Brooks Universidad T´ ecnica Federico Santa Maria Abhay Deshpande 1 Stony Brook University Markus Diehl Deutsches Elektronen-Synchrotron DESY Haiyan Gao Duke University Roy Holt Argonne National Laboratory Tanja Horn The Catholic University of America Andrew Hutton Thomas Jefferson National Accelerator Facility Yuri Kovchegov The Ohio State University Krishna Kumar University of Massachusetts, Amherst Zein-Eddine Meziani 1 Temple University Alfred Mueller Columbia University Jianwei Qiu 1 Brookhaven National Laboratory Michael Ramsey-Musolf University of Wisconsin Thomas Roser Brookhaven National Laboratory 1 Co-Editor 1 Franck Sabati´ e Commissariat ` a l' ´ Energie Atomique-Saclay

92

Physics implications of correlation data from the RHIC and LHC heavy-ion programs  

E-Print Network (OSTI)

Two-dimensional angular correlation data from the STAR experiment at RHIC and from the LHC experiments provide critical information about dynamical processes in relativistic heavy-ion collisions. The principal correlation structures of interest are a broad jet-related peak at small relative azimuth ($\\phi$) extending to large relative pseudorapidity ($\\eta$), the dijet ridge at large relative azimuth, and an independent double ridge on $\\phi$ represented by a quadrupole function. The broad peak at small relative azimuth has been attributed, in large part, to initial-state fluctuations and hydrodynamic flow which produce higher-order harmonics on $\\phi$. That conjecture is challenged in this paper. It is shown that the net effect of additional higher harmonic model elements is to describe small, non-Gaussian (NG) shapes in the broad jet-related peak. The quadrupole correlation, which is also conventionally attributed to hydrodynamic flow, is considered within the Balitsky - Fadin - Kuraev - Lipatov (BFKL) Pomeron framework. Preliminary results using this model for the quadrupole correlation for particle production from 200 GeV $p+p$ collisions are shown to be consistent with recent data from STAR.

R. L. Ray

2013-11-04T23:59:59.000Z

93

Polarized neutrons in RHIC  

Science Conference Proceedings (OSTI)

There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the neutrons in the analysis of the reactions produced by the heavy ion beams. The best neutron carriers for this purpose are probably {sup 3}He nuclei and deuterons. A polarized deuteron is primarily a combination of a proton and a neutron with their spins pointing in the same direction; in the {sup 3}He nucleus the spins of the two protons are opposite and the net spin (and magnetic moment) is almost the same as that of a free neutron. Polarized ions other than protons may be accelerated, stored and collided in a ring such as RHIC provided the techniques proposed for polarized proton operation can be adapted (or replaced by other strategies) for these ions. This paper discusses techniques for accelerating polarized {sup 3}He nuclei and deuterons.

Courant, E.D.

1998-04-20T23:59:59.000Z

94

RHIC Mid-Term Strategic Plan: 2006-2011  

NLE Websites -- All DOE Office Websites (Extended Search)

Mid-Term Strategic Plan: 2006-2011 Mid-Term Strategic Plan: 2006-2011 For the Relativistic Heavy Ion Collider At Brookhaven National Laboratory Prepared by Brookhaven National Laboratory With the RHIC Scientific Community For the U.S. Department of Energy February 14, 2006 1 Table of Contents 1. Introduction............................................................... 3 1.1 BNL's vision for RHIC 1.2 Mid-Term strategy - motivation and overview 2. The science case for the future ....................................... 9 2.1 Discoveries in the first five years 2.2 Implications for the future program at RHIC 2.3 Exploring QCD matter 2.4 Gluon saturation 2.5 The spin structure of the nucleon 2.6 Physics goals for the mid-term 3. The mid-term run plan: 2006 - 2011................................ 24

95

Beam lifetime and limitations during low-energy RHIC operation  

SciTech Connect

The low-energy physics program at the Relativistic Heavy Ion Collider (RHIC), motivated by a search for the QCD phase transition critical point, requires operation at low energies. At these energies, large nonlinear magnetic field errors and large beam sizes produce low beam lifetimes. A variety of beam dynamics effects such as Intrabeam Scattering (IBS), space charge and beam-beam forces also contribute. All these effects are important to understand beam lifetime limitations in RHIC at low energies. During the low-energy RHIC physics run in May-June 2010 at beam {gamma} = 6.1 and {gamma} = 4.1, gold beam lifetimes were measured for various values of space-charge tune shifts, transverse acceptance limitation by collimators, synchrotron tunes and RF voltage. This paper summarizes our observations and initial findings.

Fedotov, A.V.; Bai, M.; Blaskiewicz, M.; Fischer, W.; Kayran, D.; Montag, C.; Satogata, T.; Tepikian, S.; Wang, G.

2011-03-28T23:59:59.000Z

96

Opportunities for Polarized He-3 in RHIC and EIC  

Science Conference Proceedings (OSTI)

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.

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

2011-10-01T23:59:59.000Z

97

RHIC SPIN FLIPPER  

Science Conference Proceedings (OSTI)

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.

BAI,M.; ROSER, T.

2007-06-25T23:59:59.000Z

98

Inside RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

Inside RHIC is a web publication that -- in some small measure -- reflects the excitement of the RHIC and AGS program at Brookhaven, as explained by some of the people who are...

99

Design of Electron and Ion Crabbing Cavities for an Electron-Ion Collider  

SciTech Connect

Beyond the 12 GeV upgrade at the Jefferson Lab a Medium Energy Electron-Ion Collider (MEIC) has been considered. In order to achieve the desired high luminosities at the Interaction Points (IP), the use of crabbing cavities is under study. In this work, we will present to-date designs of superconducting cavities, considered for crabbing both ion and electron bunches. A discussion of properties such as peak surface fields and higher-order mode separation will be presented. Keywords: super conducting, deflecting cavity, crab cavity.

Alejandro Castilla Loeza, Geoffrey Krafft, Jean Delayen

2012-07-01T23:59:59.000Z

100

RHIC low-energy challenges and plans  

SciTech Connect

Future Relativistic Heavy Ion Collider (RHIC) runs, including a portion of FY10 heavy ion operations, will explore collisions at center of mass energies of 5-50 GeV/n (GeV/nucleon). Operations at these energies is motivated by the search for a possible QCD phase transition critical point. The lowest end of this energy range is nearly a factor of four below the nominal RHIC injection center of mass energy {radical}s = 19.6 GeV/n. There are several operational challenges in the RHIC low-energy regime, including harmonic number changes, small longitudinal acceptance, lowered magnet field quality, nonlinear orbit control, and luminosity monitoring. We report on the experience with these challenges during beam tests with gold beams in March 2008. This includes first operations at {radical}s = 9.18 GeV/n, first beam experience at {radical}s = 5 GeV/n, and luminosity projections for near-term operations.

Satogata,T.; Ahrens, L.; Bai, M.; Brennan, J.M.; Bruno, D.; Butler, J.; Drees, A.; Fedotov, A.; Fischer, W.; Harvey, M.; Hayes, T.; Jappe, W.; Lee, R.C.; MacKay, W.W.; Malitsky, N.; Marr, G.; Michnoff, R.; Oerter, B.; Pozdeyev, E.; Roser, T.; Schoefer, V.; Severino, F.; Smith, K.; Tepikian, S.; Tsoupas, N.

2009-06-08T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Elliptic flow of thermal photons in heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider  

E-Print Network (OSTI)

We calculate the thermal photon transverse momentum spectra and elliptic flow in $\\sqrt{s_{NN}} = 200$ GeV Au+Au collisions at RHIC and in $\\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb collisions at the LHC, using an ideal-hydrodynamical framework which is constrained by the measured hadron spectra at RHIC and LHC. The sensitivity of the results to the QCD-matter equation of state and to the photon emission rates is studied, and the photon $v_2$ is discussed in the light of the photonic $p_T$ spectrum measured by the PHENIX Collaboration. In particular, we make a prediction for the thermal photon $p_T$ spectra and elliptic flow for the current LHC Pb+Pb collisions.

Hannu Holopainen; Sami Rsnen; Kari J. Eskola

2011-04-28T23:59:59.000Z

102

Stochastic cooling in RHIC  

SciTech Connect

The full 6-dimensional [x,x'; y,y'; z,z'] stochastic cooling system for RHIC was completed and operational for the FY12 Uranium-Uranium collider run. Cooling enhances the integrated luminosity of the Uranium collisions by a factor of 5, primarily by reducing the transverse emittances but also by cooling in the longitudinal plane to preserve the bunch length. The components have been deployed incrementally over the past several runs, beginning with longitudinal cooling, then cooling in the vertical planes but multiplexed between the Yellow and Blue rings, next cooling both rings simultaneously in vertical (the horizontal plane was cooled by betatron coupling), and now simultaneous horizontal cooling has been commissioned. The system operated between 5 and 9 GHz and with 3 x 10{sup 8} Uranium ions per bunch and produces a cooling half-time of approximately 20 minutes. The ultimate emittance is determined by the balance between cooling and emittance growth from Intra-Beam Scattering. Specific details of the apparatus and mathematical techniques for calculating its performance have been published elsewhere. Here we report on: the method of operation, results with beam, and comparison of results to simulations.

Brennan J. M.; Blaskiewicz, M.; Mernick, K.

2012-05-20T23:59:59.000Z

103

RHIC sextant test: Accelerator systems and performance  

SciTech Connect

One sextant of the RHIC Collider was commissioned in early 1997 with beam. We describe here the performance of the accelerator systems, instrumentation subsystems and application software. We also describe a ramping test without beam that took place after the commissioning with beam. Finally, we analyze the implications of accelerator systems performance and their impact on the planning for RHIC installation and commissioning.

Pilat, F.; Trbojevic, D.; Ahrens, L. [and others

1997-08-01T23:59:59.000Z

104

Polarization transmission at RHIC, numerical simulations  

SciTech Connect

Typical tracking simulations regarding the transmission of the polarization in the proton-proton collider RHIC are discussed. They participate in general studies aimed at understanding and improving polarization performances during polarized proton-proton runs.

Meot F.; Bai, M.; Liu, C.; Minty, M.; Ranjbar, V.

2012-05-20T23:59:59.000Z

105

POLARIZED NEUTRONS IN RHIC  

SciTech Connect

There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the neutrons in the analysis of the reactions produced by the heavy ion beams. The best neutron carriers for this purpose are probably {sup 3}He nuclei and deuterons. A polarized deuteron is primarily a combination of a proton and a neutron with their spins pointing in the same direction; in the {sup 3}He nucleus the spins of the two protons are opposite and the net spin (and magnetic moment) is almost the same as that of a free neutron. Polarized ions other than protons may be accelerated, stored and collided in a ring such as RHIC provided the techniques proposed for polarized proton operation can be adapted (or replaced by other strategies) for these ions. To accelerate polarized particles in a ring, one must make provisions for overcoming the depolarizing resonances that occur at certain energies. These resonances arise when the spin tune (ratio of spin precession frequency to orbit frequency) resonates with a component present in the horizontal field. The horizontal field oscillates with the vertical motion of the particles (due to vertical focusing); its frequency spectrum is dominated by the vertical oscillation frequency and its modulation by the periodic structure of the accelerator ring. In addition, the magnet imperfections that distort the closed orbit vertically contain all integral Fourier harmonics of the orbit frequency.

COURANT,E.D.

1998-04-27T23:59:59.000Z

106

Superconducting RF systems for eRHIC  

Science Conference Proceedings (OSTI)

The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

Belomestnykh S.; Ben-Zvi, I.; Brutus, J.C.; Hahn, H. et al

2012-05-20T23:59:59.000Z

107

Formation of Dense Partonic Matter in High Energy Heavy-Ion Collisions: Highlights of RHIC Results  

E-Print Network (OSTI)

I review some important results from RHIC experiments. They were obtained in a unique environment for studying QCD bulk matter at temperatures and densities that surpass the limits where hadrons can exist as individual entities, raising the quark-gluon degrees of freedom to prominence. These findings support the major experimental observations from measuring the bulk properties of particle production, particle ratios and chemical freeze-out conditions, elliptic flow followed by hard probes measurements: di-jet fragment azimuthal correlations, high-pt hadron suppression, and heavy-flavors probes. I present the measurements as a function of collision centrality, energy, system size and for different particle species. These results reveal that a dense strongly interacting medium was created in central Au+Au collisions at 200 GeV: the RHIC discovery. Further, they suggest that this medium is partonic. However, the discoveries so far observed at RHIC are far from being understood fully. Accordingly, the focus of the experiments has shifted from the discovery phase to the detailed exploration phase of the properties of this medium.

Rachid Nouicer

2009-01-07T23:59:59.000Z

108

The RHIC and RHIC pre-injectors controls systems: status and plans  

SciTech Connect

For the past twelve years experiments at the Relativistic Heavy Ion Collider (RHIC) have recorded data from collisions of heavy ions and polarized protons, leading to important discoveries in nuclear physics and the spin dynamics of quarks and gluons. BNL is the site of one of the first and still operating alternating gradient synchrotrons, the AGS, which first operated in 1960. The accelerator controls systems for these instruments span multiple generations of technologies. In this report we will describe the current status of the Collider-Accelerator Department controls systems, which are used to control seven different accelerator facilities and multiple science programs (high energy nuclear physics, high energy polarized proton physics, NASA programs, isotope production, and multiple accelerator research and development projects). We will describe the status of current projects, such as the just completed Electron Beam Ion Source (EBIS), our R&D programs in superconducting RF and an Energy Recovery LINAC (ERL), innovations in feedback systems and bunched beam stochastic cooling at RHIC, and plans for future controls system developments.

Brown, K.A.; Altinbas, Z.; Aronson, J.; Binello, S.; Campbell, I.; Costanzo, M.; D

2011-10-10T23:59:59.000Z

109

Calculation of synchrotron radiation from high intensity electron beam at eRHIC  

Science Conference Proceedings (OSTI)

The Electron-Relativistic Heavy Ion Collider (eRHIC) at Brookhaven National Lab is an upgrade project for the existing RHIC. A 30 GeV energy recovery linac (ERL) will provide a high charge and high quality electron beam to collide with proton and ion beams. This will improve the luminosity by at least 2 orders of magnitude. The synchrotron radiation (SR) from the bending magnets and strong quadrupoles for such an intense beam could be penetrating the vacuum chamber and producing hazards to electronic devices and undesired background for detectors. In this paper, we calculate the SR spectral intensity, power density distributions and heat load on the chamber wall. We suggest the wall thickness required to stop the SR and estimate spectral characteristics of the residual and scattered background radiation outside the chamber.

Jing Y.; Chubar, O.; Litvinenko, V.

2012-05-20T23:59:59.000Z

110

DVCS and GPDs at eRHIC: Towards a high resolution partonic imaging  

Science Conference Proceedings (OSTI)

The feasibility for a measurement of the exclusive production of a real photon, a process although known as Deeply Virtual Compton Scattering (DVCS) at an eRHIC has been explored. An electron-proton/ion collider facility (eRHIC) is under consideration at BrookhavenNational Laboratory (BNL). Such a new facility will require the design and construction of a new optimized detector profiting from the experience gained from electron-proton colliders like at the experiments H1 and ZEUS at DESY-HERA. In particular, eRHIC is a machine designed to collide an electron beam with energies ranging from 5 GeV up to 20 GeV with the RHIC hadron beams (protons (100-250 GeV) and nuclei ({large rapidity acceptance of a newly designed dedicated detector, will open the opportunity for measuring DVCS with an unprecedented precision, providing an important tool toward a 2+1 dimensional picture of the internal structure of the proton. The huge impact such measurements would have on the determination of GPDs will be discussed.

Fazio, Salvatore [Brookhaven National Laboratory, PO Box 5000, 11973 Upton NY (United States)

2013-03-25T23:59:59.000Z

111

Design of the Proposed Low Energy Ion Collider Ring at Jefferson Lab  

SciTech Connect

The polarized Medium energy Electron-Ion Collider (MEIC) envisioned at Jefferson Lab will cover a range of center-of-mass energies up to 65 GeV. The present MEIC design could also allow the accommodation of low energy electron-ion collisions (LEIC) for additional science reach. This paper presents the first design of the low energy ion collider ring which is converted from the large ion booster of MEIC. It can reach up to 25 GeV energy for protons and equivalent ion energies of the same magnetic rigidity. An interaction region and an electron cooler designed for MEIC are integrated into the low energy collider ring, in addition to other required new elements including crab cavities and ion spin rotators, for later reuse in MEIC itself. A pair of vertical chicanes which brings the low energy ion beams to the plane of the electron ring and back to the low energy ion ring are also part of the design.

Nissen, Edward W. [JLAB; Lin, Fanglei [JLAB; Morozov, Vasiliy [JLAB; Zhang, Yuhong [JLAB

2013-06-01T23:59:59.000Z

112

RHIC STATUS AND PLANS.  

Science Conference Proceedings (OSTI)

RHIC ended successfully its second year of operation in January 2002 after a six month run with gold ions and two months of polarized proton collisions. I will review the machine performance and accomplishments, that include reaching design energy (100 GeV/u) and design luminosity during the gold run, and the first high energy (100 GeV) polarized proton collisions. I will also discuss the machine development strategy and the main performance milestones. The goals and plans for the shutdown and the nest run, scheduled to start in November 2002 have been the focus of a RHIC Retreat in March 2002. I will summarize findings and plans for the upcoming run and outline a vision for the nest few years of RHIC operation and upgrades.

PILAT,R.

2002-06-02T23:59:59.000Z

113

Measurements of phi meson production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC)  

E-Print Network (OSTI)

We present results for the measurement of ? meson production via its charged kaon decay channel ??K[superscript +]K[superscript -] in Au+Au collisions at ?(s[subscript NN])=62.4,130, and 200 GeV, and in p+p and d+Au ...

Sakuma, Tai

114

Matter in extremis: Ultrarelativistic nuclear collisions at RHIC  

Science Conference Proceedings (OSTI)

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 {radical}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.

Jacobs, Peter; Wang, Xin-Nian

2004-08-20T23:59:59.000Z

115

Polarized Proton Collisions at 205 GeV at RHIC  

Science Conference Proceedings (OSTI)

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.

Bai, M.; Roser, T.; Ahrens, L.; Alessi, J.; Beebe-Wang, J.; Blaskiewicz, M.; Bravar, A.; Brennan, J.M.; Bruno, D.; Courant, E.; Drees, A.; Fischer, W.; Gardner, C.; Gill, R.; Glenn, J.; Huang, H.; Kewisch, J.; Luccio, A.; Luo, Y.; Pilat, F. [Brookhaven National Laboratory, Upton, New York 11973 (United States)] (and others)

2006-05-05T23:59:59.000Z

116

OPTIMIZATION OF THE PHASE ADVANCE BETWEEN RHIC INTERACTION POINTS.  

SciTech Connect

The authors consider a scenario of having two identical Interaction Points (IPs) in the Relativistic Heavy Ion Collider (RHIC). The strengths of beam-beam resonances strongly depend on the phase advance between these two IPs and therefore certain phase advances could improve beam life-time and luminosity. The authors compute the dynamic aperture (DA) as function of the phase advance between these IPs to find the optimum settings.The beam-beam interaction is treated in the weak-strong approximation and a non-linear model of the lattice is used. For the current RHIC proton working point (0.69.0.685) [1] the design lattice is found to have the optimum phase advance. However this is not the case for other working points.

TOMAS, R.; FISCHER, W.

2005-05-16T23:59:59.000Z

117

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab  

Science Conference Proceedings (OSTI)

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF linac will serve as a full-energy injector, and, if needed, provide top

Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B

2012-08-01T23:59:59.000Z

118

LEIC - A Polarized Low Energy Electron-ion Collider at Jefferson Lab  

Science Conference Proceedings (OSTI)

A polarized electron-ion collider is envisioned as the future nuclear science program at JLab beyond the 12 GeV CEBAF. Presently, a medium energy collider (MEIC) is set as an immediate goal with options for a future energy upgrade. A comprehensive design report for MEIC has been released recently. The MEIC facility could also accommodate electron and proton/ion collisions in a low CM energy range, covering proton energies from 10 to 25 GeV and ion energies with a similar magnetic rigidity, for additional science reach. In this paper, we present a conceptual design of this low energy collider, LEIC, showing its luminosity can reach above 10{sup 33} cm{sup -2}s{sup -1}. The design specifies that the large booster of the MEIC is converted to a low energy ion collider ring with an interaction region and an electron cooler integrated into it. The design provides options for either sharing the detector with the MEIC or a dedicated low energy detector in a third collision point, with advantages of either a minimum cost or extra detection parallel to the MEIC operation, respectively. The LEIC could be positioned as the first and low cost phase of a multi-stage approach to realize the full MEIC.

Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Hutton, Andrew M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Krafft, Geoffrey A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Nissen, Edward W. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Yunn, Byung C. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, He [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Sullivan, Michael K. [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2013-06-01T23:59:59.000Z

119

ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC  

DOE Green Energy (OSTI)

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.

MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

2007-06-25T23:59:59.000Z

120

OBSERVATION OF STRONG - STRONG AND OTHER BEAM - BEAM EFFECTS IN RHIC.  

SciTech Connect

RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. For the first time, coherent beam-beam modes were observed in a bunched beam hadron collider. Other beam-beam effects in RHIC were observed in operation and in dedicated experiments with gold ions, deuterons and protons. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. During ramps unequal radio frequencies in the two rings cause the crossing points to move longitudinally. Thus bunches experience beam-beam interactions only in intervals and the tunes are modulated. In this article we summarize the most important beam-beam observations made so far.

Fischer, W; Brennan, J M; Cameron, P; Connolly, R; Montag, C; Peggs, S; Pilat, F; Ptitsyn, V; Tepikian, S; Trbojevic, D

2003-05-12T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

RHIC & AGS Userscenter;User Facilities  

NLE Websites -- All DOE Office Websites (Extended Search)

User Facilities User Facilities Experimenters work at one of five user facilities. The largest of these facilities is the Relativistic Heavy Ion Collider (RHIC), others include the Alternating Gradient Synchrotron facility (AGS), the Tandem Van de Graaff, the Accelerator Test Facility (ATF), and the NASA Space Radiation Laboratory (NSRL). See also: National User Facility Organization (NUFO). Accelerator Test Facility (ATF) Brookhaven's newest user facility, the ATF is a proposal driven Program Committee reviewed Users' Facility dedicated for long-term R&D in Physics of Beams. Alternating Gradient Synchrotron (AGS) Since 1960, the Alternating Gradient Synchrotron (AGS) has been one of the world's premiere particle accelerators, well known for the three Nobel Prizes won as a result of research performed there.

122

Long ion chamber systems for the SLC (Stanford Linear Collider)  

Science Conference Proceedings (OSTI)

A Panofsky Long Ion Chamber (PLIC) is essentially a gas-filled coaxial cable, and has been used to protect the Stanford Linear Accelerator from damage caused by its electron beam, and as a sensitive diagnostic tool. This old technology has been updated and has found renewed use in the SLC. PLIC systems have been installed as beam steering aids in most parts of the SLC and are a part of the system that protects the SLC from damage by errant beams in several places. 5 refs., 3 figs., 1 tab.

Rolfe, J.; Gearhart, R.; Jacobsen, R.; Jenkins, T.; McComick, D.; Nelson, R.; Reagan, D.; Ross, M.

1989-03-01T23:59:59.000Z

123

BEAM-BASED NON-LINEAR OPTICS CORRECTIONS IN COLLIDERS.  

Science Conference Proceedings (OSTI)

A method has been developed to measure and correct operationally the non-linear effects of the final focusing magnets in colliders, that gives access to the effects of multi-pole errors by applying closed orbit bumps, and analyzing the resulting tune and orbit shifts. This technique has been tested and used during 4 years of RHIC (the Relativistic Heavy Ion Collider at BNL) operations. I will discuss here the theoretical basis of the method, the experimental set-up, the correction results, the present understanding of the machine model, the potential and limitations of the method itself as compared with other non-linear correction techniques.

PILAT, R.; LUO, Y.; MALITSKY, N.; PTITSYN, V.

2005-05-16T23:59:59.000Z

124

The Multi-Purpose Detector for NICA heavy-Ion Collider at JINR  

Science Conference Proceedings (OSTI)

The Multi-Purpose Detector (MPD) is designed to study heavy-ion collisions at the Nuclotron-based heavy Ion Collider fAcility (NICA) at JINR, Dubna. Its main components located inside a superconducting solenoid are a tracking system composed of a silicon microstrip vertex detector followed by a large volume time-projection chamber, a time-of-flight system for particle identification and a barrel electromagnetic calorimeter. A zero degree hadron calorimeter is designed specifically to measure the energy of spectators. In this paper, all parts of the apparatus are described and their tracking and particle identification parameters are discussed in some detail.

Rogachevsky, O. V., E-mail: rogachevsky@jinr.ru [JINR, Veksler and Baldin Laboratory on High Energy Physics (Russian Federation)

2012-05-15T23:59:59.000Z

125

OVERVIEW AND STATUS OF THE STAR DETECTOR AT RHIC.  

SciTech Connect

Presented here is the current status of the STAR Detector. STAR is one of the four detectors being constructed at the RHIC collider facility. The STAR detector is scheduled to have its first engineering run with the RHIC beams about six months from the date of this conference. The STAR project is on schedule and expects to recomplete on time.

CHRISTIE,W.B. FOR THE STAR COLLABORATION

1999-01-09T23:59:59.000Z

126

RHIC Newsroom  

NLE Websites -- All DOE Office Websites (Extended Search)

Division are in the final stages of assembling "replacement" magnets for the Large Hadron Collider (LHC) at CERN. Brookhaven built twenty magnets already installed at the LHC....

127

Results from betatron phase measurements in RHIC during the sextant test  

Science Conference Proceedings (OSTI)

The Sextant Test of the Relativistic Heavy Ion Collider (RHIC) was an important step towards its completion. One sixth of the two RHIC accelerators was fully commissioned. gold ion beam was injected and transported through one sextant of one of the two rings. The betatron phase advance per cell was measured by recording differences in the horizontal and vertical positions of the beam at the end of the sextant due to a sequence of correction dipole kicks along the beam line. Measurement results show excellent agreement with predicted values, confirming that production measurements of the integral functions of the quadrupoles were very accurate, and that the polarity of all elements (correction dipoles, quadrupoles, dipoles etc.) was correct.

Trbojevic, D.; Connolly, R.; Fischer, W. [and others

1998-08-01T23:59:59.000Z

128

Probing the Quark Sea and Gluons: the Electron-Ion Collider Projects  

Science Conference Proceedings (OSTI)

EIC is the generic name for the nuclear science-driven Electron-Ion Collider presently considered in the US. Such an EIC would be the worlds first polarized electron-proton collider, and the worlds first e-A collider. Very little remains known about the dynamical basis of the structure of hadrons and nuclei in terms of the fundamental quarks and gluons of Quantum Chromodynamics (QCD). A large community effort to sharpen a compelling nuclear science case for an EIC occurred during a ten-week program taking place at the Institute for Nuclear Theory (INT) in Seattle from September 13 to November 19, 2010. The critical capabilities of a stage-I EIC are a range in center-of-mass energies from 20 to 70 GeV and variable, full polarization of electrons and light ions (the latter both longitudinal and transverse), ion species up to A=200 or so, multiple interaction regions, and a high luminosity of about 10{sup 34} electron-nucleons per cm{sup 2} and per second. The physics program of such a stage-I EIC encompass inclusive measurements (ep/A{yields}e'+X), which require detection of the scattered lepon and/or the full scattered hadronic debris with high precision, semi-inclusive processes (ep/A{yields}e'+h+X), which require detection in coincidence with the scattered lepton of at least one (current or target region) hadron; and exclusive processes (ep/A{yields}e'+N'/A'+{gamma}/m), which require detection of all particles in the reaction. The main science themes of an EIC are to i) map the spin and spatial structure of quarks and gluons in nucleons, ii) discover the collective effects of gluons in atomic nuclei, and (iii) understand the emergence of hadronic matter from color charge. In addition, there are opportunities at an EIC for fundamental symmetry and nucleon structure measurements using the electroweak probe. To truly make headway to image the sea quarks and gluons in nucleons and nuclei, the EIC needs high luminosity over a range of energies as more exclusive scattering probabilities are small, and any integrated detector/interaction region design needs to provide uniform coverage to detect spectator and diffractive products. This is because e-p and even more e-A colliders have a large fraction of their science related to what happens to the nucleon or ion beams. As a result, the philosophy of integration of complex detectors into an extended interaction region faces challenging constraints. Designs feature crossing angles between the protons or heavy ions during collisions with electrons, to remove potential problems for the detector induced by synchrotron radiation. Designs allocate quite some detector space before the final-focus ion quads, at the cost of luminosity, given that uniform detection coverage is a must for deep exclusive and diffractive processes. The integrated EIC detector/interaction region design at JLab focused on establishing full acceptance for such processes over a wide range of proton energies (20-100 GeV) with well achievable interaction region magnets. The detector design at BNL uses the higher ion beam energies to achieve good detection efficiency for instance for protons following a DVCS reaction, for proton beam energies starting from 100 GeV. Following a recommendation of the 2007 US Nuclear Science Long-Range Planning effort, the DOE Office of Nuclear Physics (DOE/NP) has allocated accelerator R&D funds to lay the foundation for a polarized EIC. BNL, in association with JLab and DOE/NP, has also established a generic detector R&D program to address the scientific requirements for measurements at a future EIC.

Rolf Ent

2012-04-01T23:59:59.000Z

129

The E-lens test bench for RHIC beam-beam compensation  

SciTech Connect

To compensate for the beam-beam effects from the proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are fabricating two electron lenses that we plan to install at RHIC IR10. Before installing the e-lenses, we are setting-up the e-lens test bench to test the electron gun, collector, GS1 coil, modulator, partial control system, some instrumentation, and the application software. Some e-lens power supplies, the electronics for current measurement will also be qualified on test bench. The test bench also was designed for measuring the properties of the cathode and the profile of the beam. In this paper, we introduce the layout and elements of the e-lens test bench; and we discuss its present status towards the end of this paper.

Gu X.; Altinbas, F.Z.; Aronson, J.; Beebe, E. et al

2012-05-20T23:59:59.000Z

130

The ALICE Photo Gallery: Images from A Large Ion Collider Experiment (ALICE) at CERN  

DOE Data Explorer (OSTI)

ALICE is the acronym for A Large Ion Collider Experiment, one of the largest experiments in the world devoted to research in the physics of matter at an infinitely small scale. Hosted at CERN, the European Laboratory for Nuclear Research, this project involves an international collaboration of more than 1000 physicists, engineers and technicians, including around 200 graduate students, from 105 physics institutes in 30 countries across the world. The ALICE Experiment is going in search of answers to fundamental questions, using the extraordinary tools provided by the Large Hadron Collider (LHC): 1) What happens to matter when it is heated to 100,000 times the temperature at the centre of the Sun? 2) Why do protons and neutrons weigh 100 times more than the quarks they are made of? 3) Can the quarks inside the protons and neutrons be freed? [copied from http://aliceinfo.cern.ch/Public/Welcome.html]

The Alice Photo Gallery highlights images taken by three professional photographers, Pavel Cugini, Peter Ginter, and Antonio Saba. Other pictures can be found in the Cern Document Server Database at http://cdsweb.cern.ch/.

Cugini, Pavel; Ginter, Peter; Saba, Antonio

131

Beam energy dependence of strange hadron production from STAR at RHIC  

E-Print Network (OSTI)

We present STAR measurements of K^{0}_{S}, \\phi, \\Lambda, \\Xi, and \\Omega at mid-rapidity from Au+Au collisions at \\sqrt{s_{NN}} = 7.7, 11.5, 19.6, 27, and 39 GeV from the Beam Energy Scan (BES) program at the BNL Relativistic Heavy Ion Collider (RHIC). Nuclear modification factors and baryon-to-meson ratios are measured to understand recombination and parton energy loss mechanisms. Implications on partonic versus hadronic dynamics at low beam energies are discussed.

Xiaoping Zhang

2013-05-20T23:59:59.000Z

132

Beam losses from ultra-peripheral nuclear collisions between Pb ions in the Large Hadron Collider and their alleviation  

SciTech Connect

Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of {sup 208}Pb{sup 82+} ion operation in the LHC, with focus on the alice interaction region, and show that the expected heat load during nominal {sup 208}Pb{sup 82+} operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.

Bruce, R.; /CERN; Bocian, D.; /Fermilab /CERN; Gilardoni, S.; Jowett, J.M.; /CERN

2009-08-01T23:59:59.000Z

133

The Color Glass Condensate at RHIC  

E-Print Network (OSTI)

The Color Glass Condensate formalism and its application to high energy heavy ion collisions at RHIC are discussed. We argue that the RHIC data supports the view that the Color Glass Condensate provides the initial conditions for gold-gold collisions at RHIC while final state (Quark Gluon Plasma) effects are responsible for the high $p_t$ suppression in mid rapidity. At forward rapidities in deuteron-gold collisions, however, Color Glass Condensate is the underlying physics of the observed suppression of the particle spectra and their centrality dependence.

Jamal Jalilian-Marian

2004-03-26T23:59:59.000Z

134

PROPOSAL FOR AN EBIS BASED RHIC PREINJECTOR.  

DOE Green Energy (OSTI)

A proposed new heavy ion preinjector for RHIC is described. The progress made at BNL on the development of an Electron Beam Ion Source (EBIS) has increased our confidence that one can build a preinjector meeting RHIC requirements using an EBIS producing intermediate charge state heavy ions. A new RFQ and Linac will be required to accelerate beams from this source to an energy sufficient for injection into the AGS Booster. These are both straightforward devices, very similar to ones already in operation at other laboratories. Injection into the Booster will occur at the same location as the existing heavy ion injection from the Tandem Van de Graaff.

ALESSI,J.G.; BEEBE,E.; KPONOU,A.; PIKIN,A.; PRELEC,K.; RAPARIA,D.; RITTER,J.; ZHANG,S.Y.

2000-11-06T23:59:59.000Z

135

Direct Photons at RHIC  

E-Print Network (OSTI)

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 ($p_T$) 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 $p_T$ 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 $e^+e^-$ 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.

G. David; for the PHENIX Collaboration

2008-10-06T23:59:59.000Z

136

A new luminescence beam profile monitor for intense proton and heavy ion beams  

DOE Green Energy (OSTI)

A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.

Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T.; Thieberger, P.; Trbojevic, D.; Zelenski, A.

2008-10-01T23:59:59.000Z

137

The Quest for Spinning Glue in High-Energy Polarized Proton-Proton Collisions at RHIC  

SciTech Connect

The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at {radical}(s) = 200-500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD).One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, A{sub LL}, for various processes. Recent results will be shown on the measurement of A{sub LL} for inclusive jet production, neutral pion production and charged pion production at {radical}(s) = 200 GeV.

Surrow, Bernd [Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

2007-10-26T23:59:59.000Z

138

Configuration Manual Polarized Proton Collider at RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

(BNL) G. Morgan (BNL) J. Muratore (BNL) M. Okamura (RIKEN, BNL) S. Peggs (BNL) F. Pilat (BNL) V. Ptitsin (BINP) L. Ratner (BNL) T. Roser (BNL) N. Saito (RIKEN) H. Satoh (KEK)...

139

Bound-free pair production cross section in heavy-ion colliders from the equivalent photon approach  

E-Print Network (OSTI)

Exact calculations of the electron-positron pair production by a single photon in the Coulomb field of a nucleus with simultaneous capture of the electron into the K-shell are discussed for different nuclear charges. Using the equivalent photon method of Weizsaecker and Williams, a simple expression for the bound-free production of electron-positron pairs by colliding very-high-energy fully stripped heavy ions is derived for nuclei of arbitrary charge.

Andreas Aste

2007-10-23T23:59:59.000Z

140

RHIC | A Compelling Case for RHIC's Future  

NLE Websites -- All DOE Office Websites (Extended Search)

The Future of RHIC Physics STAR data Collaboration PHENIX A Nuclear Science Advisory Committee subpanel chaired by Bob Tribble of Texas A&M University is charged with recommending...

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.  

SciTech Connect

This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linac. The highly successful development of an EBIS at BNL now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based pre-injectors are presently used at most accelerator and collider facilities with the exception of RHIC, where the required gold beam intensities could only be met with a Tandem until the recent EBIS development. EBIS produces high charge state ions directly, eliminating the need for the two stripping foils presently used with the Tandem. Unstable stripping efficiencies of these foils are a significant source of luminosity degradation in RHIC. The high reliability and flexibility of the new Linac-based pre-injector will lead to increased integrated luminosity at RHIC and is an essential component for the long-term success of the RHIC facility. This new pre-injector, based on an EBIS, also has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium beams and, as part of a future upgrade, might also be used to produce polarized {sup 3}He beams. These capabilities will be critical to the future luminosity upgrades and electron-ion collisions in RHIC. The new RFQ and Linac that are used to accelerate beams from the EBIS to an energy sufficient for injection into the Booster are both very similar to existing devices already in operation at other facilities. Injection into the Booster will occur at the same location as the existing injection from the Tandem.

ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D.; ET AL.

2005-02-28T23:59:59.000Z

142

Energy dependence of directed flow over a wide range of pseudorapidity in Au+Au collisions at RHIC  

E-Print Network (OSTI)

We report on measurements of directed flow as a function of pseudorapidity in Au+Au collisions at energies of $\\sqrt{s_{_{NN}}} =$ 19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.

B. B. Back; for the PHOBOS Collaboration

2005-11-22T23:59:59.000Z

143

TRANSVERSE ECHO MEASUREMENTS IN RHIC.  

SciTech Connect

Diffusion counteracts cooling and the knowledge of diffusion rates is important for the calculation of cooling times and equilibrium beam sizes. Echo measurements are a potentially sensitive method to determine diffusion rates, and longitudinal measurements were done in a number of machines. We report on transverse echo measurements in RHIC and the observed dependence of echo amplitudes on a number of parameters for beams of gold and copper ions, and protons. In particular they examine the echo amplitudes of gold and copper ion bunches of varying intensity, which exhibit different diffusion rates from intrabeam scattering.

FISCHER, W.

2005-09-18T23:59:59.000Z

144

THE RHIC INJECTION SYSTEM.  

SciTech Connect

The RHIC injection system has to transport beam from the AGS-to-RHIC transfer line onto the closed orbits of the RHIC Blue and Yellow rings. This task can be divided into three problems. First, the beam has to be injected into either ring. Second, once injected the beam needs to be transported around the ring for one turn. Third, the orbit must be closed and coherent beam oscillations around the closed orbit should be minimized. We describe our solutions for these problems and report on system tests conducted during the RHIC Sextant test performed in 1997. The system will be fully commissioned in 1999.

FISCHER,W.; GLENN,J.W.; MACKAY,W.W.; PTITSIN,V.; ROBINSON,T.G.; TSOUPAS,N.

1999-03-29T23:59:59.000Z

145

Perspectives of a Midrapidity Dimuon Program at RHIC: A Novel and Compact Muon Telescope Detector  

E-Print Network (OSTI)

We propose a large-area, cost-effective Muon Telescope Detector (MTD) for the Solenoidal Tracker at RHIC (STAR) at mid-rapidity and for the next generation of detectors at a possible electron-ion collider. We utilize Multi-gap Resistive Plate Chambers with large modules and long readout strips (Long-MRPC) in the detector design. The results from cosmic ray and beam tests show the intrinsic timing and spatial resolution for a Long-MRPC are 60-70 ps and $\\sim1$ cm, respectively. The prototype performance of such a novel muon telescope detector at STAR indicates that muon identification at the transverse momentum of a few GeV/$c$ can be achieved through the combined information of track matching with the MTD, ionization energy loss in the Time Projection Chamber, and time-of-flight measurements. A primary muon over secondary muon ratio of better than 1/3 can be achieved. This provides a promising device for future quarkonium programs and primordial dilepton measurements at RHIC. Simulations of the muon efficiency, the signal-to-background ratio of $J/\\psi$, the separation of $\\Upsilon$ 1S from 2S+3S states, and the electron-muon correlation from charm pair production in the RHIC environment are presented.

L. Ruan; G. Lin; Z. Xu; K. Asselta; H. F. Chen; W. Christie; H. J. Crawford; J. Engelage; G. Eppley; T. J. Hallman; C. Li; J. Liu; W. J. Llope; R. Majka; T. Nussbaum; J. Scheblein; M. Shao; R. Soja; Y. Sun; Z. Tang; X. Wang; Y. Wang

2009-04-24T23:59:59.000Z

146

Inside RHIC | Submission Guidelines  

NLE Websites -- All DOE Office Websites (Extended Search)

Submission Guidelines Submission Guidelines "Inside RHIC" is an online publication covering news and views of the RHIC and AGS program at Brookhaven National Laboratory at the level of engineers and students. The RHIC AGS Users Group is sponsoring this effort, and we have tried to cover the breadth of the efforts at RHIC, from physics results to machine and detector development. The articles are relatively short and not so technical; a few hundred words are enough. It is a web publication, so length is not critical, but it is better to be concise. If you write an article for RHIC News, here's what is needed: The text of the article (a plain ASCII text file is adequate, even preferable, although we can deal with almost any format) The first few sentences (maybe 100 words) should summarize the point

147

RHIC | Black Holes?  

NLE Websites -- All DOE Office Websites (Extended Search)

Black Holes at RHIC? Black Holes at RHIC? Before RHIC began operations in 2000, some were concerned that it would produce black holes that would threaten the earth. Here's why those concerns were unfounded. Committee Review of Speculative "Disaster Scenarios" at RHIC In July 1999, Brookhaven Lab Director John Marburger convened a committee of distinguished physicists to write a comprehensive report on the arguments that address the safety of speculative disaster scenarios at RHIC. The scenarios are: Creation of a black hole that would "eat" ordinary matter. Initiation of a transition to a new, more stable universe. Formation of a "strangelet" that would convert ordinary matter to a new form. jaffee "We conclude that there are no credible mechanisms for catastrophic

148

ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.  

SciTech Connect

This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linear accelerator (Linac). The highly successful development of an EBIS at Brookhaven National Laboratory (BNL) now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based preinjectors are presently used at most accelerator and collider facilities with the exception of RHIC, where the required gold beam intensities could only be met with a Tandem until the recent EBIS development. EBIS produces high charge state ions directly, eliminating the need for the two stripping foils presently used with the Tandem. Unstable stripping efficiencies of these foils are a significant source of luminosity degradation in RHIC. The high reliability and flexibility of the new Linac-based pre-injector will lead to increased integrated luminosity at RHIC and is an essential component for the long-term success of the RHIC facility. This new pre-injector, based on an EBIS, also has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium beams and, as part of a future upgrade, might also be used to produce polarized {sup 3}He beams. These capabilities will be critical to the future luminosity upgrades and electron-ion collisions in RHIC. The proposed pre-injector system would also provide for a major enhancement in capability for the NASA Space Radiation Laboratory (NSRL), which utilizes heavy-ion beams from the RHIC complex. EBIS would allow for the acceleration of all important ion species for the NASA radiobiology program, such as, helium, argon, and neon which are unavailable with the present Tandem injector. In addition, the new system would allow for very rapid switching of ion species for NSRL experiments, reducing delays due to the interference with RHIC injection operations, and allowing enhanced mixed field radiation studies. The new RFQ and Linac that are used to accelerate beams from the EBIS to an energy sufficient for injection into the Booster are both very similar to existing devices already in operation at other facilities. Injection into the Booster will occur at the same location as the existing injection from the Tandem.

ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D.; GRANDINETTI, R.; HSEUH, H.; JAVIDFAR, A.; KPONOU, A.; LAMBIASE, R.; LESSARD, E.; LOCKEY, R.; LODESTRO, V.; MAPES, M.; MIRABELLA, D.; NEHRING, T.; OERTER, B.; PENDZICK, A.; PIKIN, A.; RAPARIA, D.; RITTER, J.; ROSER, T.; RUSSO, T.; SNYDSTRUP, L.; WILINSKI, M.; ZALTSMAN, A.; ZHANG, S.

2005-09-01T23:59:59.000Z

149

Recent Results from RHIC&Some Lessons for Cosmic-RayPhysicists  

SciTech Connect

The Relativistic Heavy Ion Collider (RHIC) studies nuclear matter under a variety of conditions. Cold nuclear matter is probed with deuteron-gold collisions, while hot nuclear matter (possibly a quark-gluon plasma (QGP)) is created in heavy-ion collisions. The distribution of spin in polarized nucleons is measured with polarized proton collisions, and photoproduction is studied using the photons that accompany heavy nuclei. The deuteron-gold data shows less forward particle production than would be expected from a superposition of pp collisions, as expected due to saturation/shadowing. Particle production in AA collisions is well described by a model of an expanding fireball in thermal equilibrium. Strong hydrodynamic flow and jet quenching shows that the produced matter interacts very strongly. These phenomena are consistent with new non-perturbative interactions near the transition temperature to the QGP. This report discusses these results, and their implications for cosmic-ray physicists.

Klein, Spencer R.

2006-10-01T23:59:59.000Z

150

Soft Physics from RHIC to LHC  

E-Print Network (OSTI)

The RHIC program was intended to identify and study the quark-gluon plasma formed in the collision of heavy nuclei. The discovery of the "perfect liquid" is an essential step towards the understanding of the medium formed in these collisions. Much of data relevant to this was provided by the study of "soft" observables, which involve many particles of low momentum produced in nearly every event, rather than high momentum particles produced in rare events. The main results related to soft physics at RHIC are discussed, as well as their implications for the physics of the LHC heavy ion program.

Peter Steinberg

2009-03-09T23:59:59.000Z

151

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

Science Conference Proceedings (OSTI)

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 background for the search of the CEP using observables related to fluctuations and correlations. While new data are pouring in from the RHIC low energy scan program, many recent advances have also been made in the phenomenological and lattice gauge theory sides in order to have a better theoretical understanding of the wealth of new data. This workshop tried to create a synergy between the experimental, phenomenological and lattice QCD aspects of the fluctuation and correlation related studies of the RHIC low energy scan program. The workshop brought together all the leading experts from related fields under the same forum to share new ideas among themselves in order to streamline the continuing search of CEP in the RHIC low energy scan program.

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

2011-10-27T23:59:59.000Z

152

RHIC Superconducting Accelerator and Electron Cooling Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Organization Chart (PDF) Organization Chart (PDF) Accelerator R&D Division eRHIC R&D Energy Recovery Linac Photocathode R&D Superconducting RF Electron Cooling LARP Center for Accelerator Science and Education C-AD Accelerator R&D Division Superconducting RF Group Group Headed By: Sergey Belomestnykh This web site presents information on the Superconducting Accelerator and RHIC Electron Cooling Group, which is in the Accelerator R&D Division of the Collider-Accelerator Department of Brookhaven National Laboratory. Work is supported mainly by the Division of Nuclear Physics of the US Department of Energy. Upcoming Events: TBD Most recent events: 56 MHz 2nd External Review, March 8-9, 2011 External Review of the Energy Recovery Linac, February 17-18, 2010. Report of the Review Committee

153

RHIC electron lens test bench diagnostics  

SciTech Connect

An Electron Lens (E-Lens) system will be installed in RHIC to increase luminosity by counteracting the head-on beam-beam interaction. The proton beam collisions at the RHIC experimental locations will introduce a tune spread due to a difference of tune shifts between small and large amplitude particles. A low energy electron beam will be used to improve luminosity and lifetime of the colliding beams by reducing the betatron tune shift and spread. In preparation for the Electron Lens installation next year, a test bench facility will be used to gain experience with many sub-systems. This paper will discuss the diagnostics related to measuring the electron beam parameters.

Gassner, D.; Beebe, E.; Fischer, W.; Gu, X.; Hamdi, K.; Hock, J.; Liu, C.; Miller, T.; Pikin, A.; Thieberger, P.

2011-05-16T23:59:59.000Z

154

Computer & Email Information, RHIC & AGS Userscenter  

NLE Websites -- All DOE Office Websites (Extended Search)

Computer & Email Information Wireless Access RHIC RHIC link to computer accounts RHIC E-mail Services Please contact useraccts at rcf.rhic.bnl.gov, for further assistance. AGS AGS...

155

RHIC News Archives  

NLE Websites -- All DOE Office Websites (Extended Search)

Features Archive Features Archive 490th Brookhaven Lecture, 12/18 December 13, 2013 Tiny Drops of Hot Quark Soup-How Small Can They Be? December 06, 2013 RHIC Physics Feeds Future High-Tech Workforce: Lokesh Kumar November 06, 2013 Backup Magnets Ready to Ship to LHC September 30, 2013 Supercomputing the Transition from Ordinary to Extraordinary Forms of Matter September 18, 2013 Why Particle Physics Matters August 30, 2013 Hot Topics for Hot Nuclear Physics August 07, 2013 Calibrators from Deep Space Tune High-Tech Earthbound Physics Experiments July 31, 2013 Young Scientist Prize for Nuclear Physics June 17, 2013 RHIC's Perfect Liquid a Study in Perfection June 17, 2013 RHIC Physics Feeds Future High-Tech Workforce: Alan Hoffman, Mike Miller & Adam Kocoloski June 11, 2013 RHIC Physics Feeds Future High-Tech Workforce: Johan Gonzalez

156

Inside RHIC | Home Page  

NLE Websites -- All DOE Office Websites (Extended Search)

theory community as well as experimentalists from RHIC, the LHC, and Jefferson Lab's CEBAF. Steve Vigdor Report on the Tribble Panel Hearings As most of you are aware, there is...

157

RHIC & AGS Userscenter  

NLE Websites -- All DOE Office Websites (Extended Search)

Servers (pdf) Thesis Award Association of Students and Postdocs (ASAP) RHIC News National User Facility Organization How to Contact Us Other Information BNL Site Index Can't View...

158

Heavy Ion Physics and Quark-Gluon Plasma  

E-Print Network (OSTI)

These proceedings represent a brief overview of the exciting physics coming out from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The experimental results from BRAHMS, PHOBOS, PHENIX and STAR indicate a strongly-coupled state of matter that can only be described on the partonic level. Here we review some of the latest experimental results as presented at the meeting of the Division of Particles and Fields of the American Physical Society in Riverside, CA in August 2004.

J. L. Nagle

2004-11-15T23:59:59.000Z

159

NSAC_RHICII-eRHIC_2-11-03.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

II/eRHICWhite Paper II/eRHICWhite Paper Brookhaven National Laboratory Upton, NY 11973 Submitted to the NSAC Future Facilities Subcommittee February 15, 2003 Lattice Results Neutron Star 1 RHIC II/eRHIC White Paper Submitted to the NSAC Sub-Committee on Future Facilities By T. Hallman, T. Kirk, T. Roser, BNL and R.G. Milner, MIT February 15, 2003 Executive Summary We present here, two stages in the evolution of RHIC: 1) provision of a 10X luminosity upgrade to the machine and its two large detectors to exploit the new realm of QCD phenomena revealed by the present high-energy, heavy ion physics investigations (RHIC II); 2) construction of a 10 GeV electron ring and a new experimental detector to provide electron-heavy ion collisions to explore a whole new class of high-

160

Experience with IBS-suppression lattice in RHIC  

SciTech Connect

An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-stars in the IPS. In this paper we report on the development, the tests and the performance of IBS-suppression lattice in RHIC, including the resulting increases in the peak and the average luminosity. We also report on our plans for future steps with the IBS suppression.

Litvinenko,V.N.; Luo, Y.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Della Penna, A.; Drees, A.; Fedotov, A.; Ganetis, G.; Hoff, L.; Louie, W.; Malitsky, N.; Marr, G.; Marusic, A.; Montag, C.; Pilat, F.; Roser, T.; Trbojevic, D.; Tsoupas, N.

2008-06-23T23:59:59.000Z

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161

Estimation of collective instabilities in RHIC  

Science Conference Proceedings (OSTI)

The authors have estimated the broadband impedance in RHIC to be {vert_bar}Z/n{vert_bar} < 1.2 {Omega} for frequencies above 100 MHz. The Z/n threshold is set for Au{sup +79} ions at transition with an estimated 10% growth in emittance for Z/n = 1.5 {Omega}. They summarize the sources of broad and narrow band impedances in RHIC and investigate the multibunch instability limits throughout the machine cycle. The largest contribution to the broadband impedance comes from the abort and injection kickers. Since RHIC is designed to accelerate fully stripped ions from H{sup +} up to Au{sup +79} they give results for both protons and gold ions; other ions should give results somewhere between these two extremes. All ion species are expected to be stable during storage. At lower energies damping systems and chromaticity corrections will limit any growth to acceptable levels during the short time it takes to inject and accelerate the beams.

MacKay, W.W.; Blaskiewicz, M.; Deng, D.; Mane, V.; Peggs, S.; Ratti, A.; Rose, J.; Shea, T.J.; Wei, J.

1995-05-01T23:59:59.000Z

162

System-size independence of directed flow at the Relativistic Heavy-Ion Collider  

E-Print Network (OSTI)

We measure directed flow ($v_1$) for charged particles in Au+Au and Cu+Cu collisions at $\\sqrt{s_{NN}} =$ 200 GeV and 62.4 GeV, as a function of pseudorapidity ($\\eta$), transverse momentum ($p_t$) and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all existing models, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to different collision systems, and investigate possible explanations for the observed sign change in $v_1(p_t)$.

STAR Collaboration; B. I. Abelev

2008-07-09T23:59:59.000Z

163

RHIC DATA CORRELATION METHODOLOGY.  

SciTech Connect

A requirement for RHIC data plotting software and physics analysis is the correlation of data from all accelerator data gathering systems. Data correlation provides the capability for a user to request a plot of multiple data channels vs. time, and to make meaningful time-correlated data comparisons. The task of data correlation for RHIC requires careful consideration because data acquisition triggers are generated from various asynchronous sources including events from the RHIC Event Link, events from the two Beam Sync Links, and other unrelated clocks. In order to correlate data from asynchronous acquisition systems a common time reference is required. The RHIC data correlation methodology will allow all RHIC data to be converted to a common wall clock time, while still preserving native acquisition trigger information. A data correlation task force team, composed of the authors of this paper, has been formed to develop data correlation design details and provide guidelines for software developers. The overall data correlation methodology will be presented in this paper.

MICHNOFF,R.; D' OTTAVIO,T.; HOFF,L.; MACKAY,W.; SATOGATA,T.

1999-03-29T23:59:59.000Z

164

Advances in high-order interaction region nonlinear optics correction at RHIC  

Science Conference Proceedings (OSTI)

A method to indirectly measure and deterministically correct the higher order magnetic errors of the final focusing magnets in the Relativistic Heavy Ion Collider has been in place for several years at BNL. This method yields control over the effects of multi-pole errors through application of closed orbit bumps followed by analysis and correction of the resulting betatron tune shifts using multi-pole correctors. The process has recently been automated in order to provide more efficient and effective corrections. The tune resolution along with the reliability of measurements has also been improved significantly due to advances/upgrades in the betatron tune measurement system employed at RHIC (BBQ). Here we describe the foundation of the IR bump method, followed by recent improvements along with experimental data.

Zimmer, C.; Binello, S.; Minty, M.; Pilat, F.

2011-03-28T23:59:59.000Z

165

LUMINESCENCE BEAM PROFILE MONITOR FOR THE RHIC POLARIZED HYDROGEN JET POLARIMETER.  

DOE Green Energy (OSTI)

A new polarized hydrogen jet target was used to provide improved beam polarization measurements during the second polarized proton m in the Relativistic Heavy Ion Collider (RHIC). The luminescence produced by beam-hydrogen excitations was also used to test the feasibility of a new beam profile monitor for RFPIC based on the detection of the emitted light. Lenses, a view-port and a sensitive CCD camera were added to the system to record the optical signals from the interaction chamber. The first very promising results are reported here. The same system with an additional optical spectrometer or optical filter system may be used in the future to detect impurities in the jet, such as oxygen molecules, which affect the accuracy of the polarization measurements.

LUCIANO, N.; NASS, A.; MAKDISI, Y.; THIEBERGER, P.; TRBOJEVIC, D.; ZELENSKI, A.

2005-05-16T23:59:59.000Z

166

RHIC | Black Holes?  

NLE Websites -- All DOE Office Websites (Extended Search)

Black Holes at RHIC? Black Holes at RHIC? Further discussion by Physicist Dmitri Kharzeev on why RHIC cannot produce a real gravitational black hole Black holes are among the most mysterious objects in the universe. The gravitational field of a black hole is so strong that Einstein's general relativity tells us that nothing, not even light, can escape from the black hole's interior. However, in 1974 physicist Stephen Hawking demonstrated that black holes must emit radiation once the quantum effects are included. According to quantum mechanics, the physical vacuum is bubbling with short-lived virtual particle-antiparticle pairs. Creation of a particle-antiparticle pair from the vacuum conflicts with energy conservation, but energy need not be conserved at short times in quantum mechanics, according to Heisenberg's

167

Charm Production at RHIC  

E-Print Network (OSTI)

The latest results for open charm and $J/\\psi$ production in p-p, d-Au and Au-Au from the PHENIX and STAR experiments at $\\sqrt{s_{NN}}=200$ GeV at RHIC are presented. The preliminary data show open charm production follows binary scaling in d-Au and Au-Au collisions at RHIC. In d-Au collisions, a suppression in $J/\\psi$ production has been observed at the forward rapidity (d direction), at the backward rapidity (Au direction), $J/\\psi$ production seems strongly dependent on collisions centrality. The implications of heavy flavor production in cold (d-Au) and hot (Au-Au) nuclear media at RHIC are discussed.

Ming Xiong Liu

2004-05-28T23:59:59.000Z

168

Dilepton Spectroscopy of QCD Matter at Collider Energies  

E-Print Network (OSTI)

Low-mass dilepton spectra as measured in high-energy heavy-ion collisions are a unique tool to obtain spectroscopic information about the strongly interacting medium produced in these reactions. Specifically, in-medium modifications of the vector spectral function, which is well known in the vacuum, can be deduced from the thermal radiation off the expanding QCD fireball. This, in particular, allows to investigate the fate of the $\\rho$ resonance in the dense medium, and possibly infer from it signatures of the (partial) restoration of chiral symmetry, which is spontaneously broken in the QCD vacuum. After briefly reviewing calculations of thermal dilepton emission rates from hot QCD matter, utilizing effective hadronic theory, lattice QCD or resummed perturbative QCD, we focus on applications to dilepton spectra at heavy-ion collider experiments at RHIC and LHC. This includes invariant-mass spectra at full RHIC energy with transverse-momentum dependencies and azimuthal asymmetries, as well as a systematic investigation of the excitation function down to fixed-target energies, thus making contact to previous precision measurements at the SPS. Furthermore, predictions for the energy frontier at the LHC are presented in both dielectron and dimuon channels.

Ralf Rapp

2013-04-08T23:59:59.000Z

169

INTRA - BEAM SCATTERING MEASUREMENTS IN RHIC.  

DOE Green Energy (OSTI)

RHIC in gold operation shows significant intra-beam scattering due to the high charge state of the stored ions. Intra-beam scattering leads to longitudinal and transverse emittance growth. The longitudinal emittance growth causes debunching in operation; the transverse emittance growth contributes to the reduction of the beam and luminosity lifetimes. The longitudinal and transverse beam growth was measured. Beam growth measurement are compared with computations.

FISCHER,W.; CONNOLLY,R.; TEPIKIAN,S.; VAN ZEIJTS,J.; ZENO,K.

2002-06-02T23:59:59.000Z

170

Mach cone shock waves at RHIC  

E-Print Network (OSTI)

Energy and momentum lost by hard jets propagating through hot and dense nuclear matter have to be redistributed in the medium. It has been conjectured that collective sound modes are excited. Those lead to Mach cone nuclear shock waves in the nuclear medium that are shown to account for three and four particle angular correlation structures of hadrons with a (semi-)hard trigger hadron in heavy-ion collisions at RHIC.

Jorg Ruppert; Thorsten Renk

2007-10-22T23:59:59.000Z

171

Beam injection into RHIC  

SciTech Connect

During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.

Fischer, W.; Hahn, H.; MacKay, W.W.; Satogata, T.; Tsoupas, N.; Zhang, W.

1997-07-01T23:59:59.000Z

172

PROCEEDINGS OF THE SECOND WORKSHOP ON EXPERIMENTS AND DETECTORS FOR A RELATIVISTIC HEAVY ION COLLIDER (RHIC), LAWRENCE BERKELEY LABORATORY, MAY 25-29, 1987  

E-Print Network (OSTI)

BGO crystals or Pb-glass blocks could be used. to comparelayer calorimetry, BOO or v Pb-glass blocks for em showers

Ritter, Hans Georg

2010-01-01T23:59:59.000Z

173

Calculation Of Change-Changing Cross Sections Of IONS Or Atoms Colliding With Fast IONS Using The Classical Trajectory Method  

DOE Green Energy (OSTI)

Evaluation of ion-atom charge-changing cross sections is needed for many accelerator applications. A classical trajectory Monte Carlo (CTMC) simulation has been used to calculate ionization and charge exchange cross sections. For benchmarking purposes, an extensive study has been performed for the simple case of hydrogen and helium targets in collisions with various ions. Despite the fact that the simulation only accounts for classical mechanics, the calculations are comparable to experimental results for projectile velocities in the region corresponding to the vicinity of the maximum cross section. Shortcomings of the CTMC method for multielectron target atoms are discussed.

Kaganovich, I. D., Shnidman, Ariel, Mebane, Harrison, Davidson, R.C.

2008-10-10T23:59:59.000Z

174

The Case for Continuing RHIC Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

2 2 Drafted by Steve Vigdor Revised with extensive feedback from RHIC user and support community 9/2/2012 The Case for Continuing RHIC Operations 1 The Case for Continuing RHIC Operations Table of Contents 1. The Case in a Nutshell ........................................................................................................................... 2 2. Hot QCD Matter: RHIC's Intellectual Challenges and Greatest Hits To Date ....................................... 4 3. Recent Breakthroughs and RHIC's Versatility Inform the Path Forward .............................................. 5 4. Unanticipated Intellectual Connections ............................................................................................. 16 5. Cold QCD Matter Studies at RHIC ....................................................................................................... 18

175

Studies of eRHIC coherent instabilities  

Science Conference Proceedings (OSTI)

In the presence of an effective coherent electron cooling, the rms ion bunch length in eRHIC will be kept at 8.3 cm for 250 GeV protons, which is much shorter than the current RHIC 45 cm rms bunch length. Together with the increased bunch intensity and total bunch number, coherent instabilities could be a potential limitation for achieving desired machine performance. In this study, we use the tracking code TRANFT to find thresholds and growth rates for single bunch and coupled bunch instabilities with linear chromaticity and amplitude dependent tune shift taken into account. Based on the simulation results, requirements of machine parameters such as rf voltage, linear chromaticity, and tune dependence of betatron amplitude are specified to suppress these instabilities.

Wang G.; Blaskiewicz, M.

2012-05-20T23:59:59.000Z

176

Proceedings of the symposium on RHIC detector R&D  

Science Conference Proceedings (OSTI)

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.

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

1991-12-31T23:59:59.000Z

177

RHIC II Science Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Working Groups and Convenors Working Groups and Convenors The purpose of these Working Groups is to provide an organized way for the community to refine the science agenda for the RHIC II upgrades, and make a compelling case for these upgrades to the broad nuclear physics community. A document summarizing the Working Group results, with a sharp focus on the science case for RHIC II, will be produced early in 2006. Electromagnetic Probes Convenors: Ralf Rapp, Zhangbu Xu, Gabor David Email list info Website Heavy Flavor Convenors: Ramona Vogt, Thomas Ullrich, Tony Frawley Email list info Website High pT Convenors: Denes Molnar, Saskia Mioduszewski, Kirill Filimonov Internal working group web page Email list info Equation of State Convenors: Steffen Bass, Julia Velkovska, Helen Caines Email list info

178

Proton Polarimetry at RHIC  

Science Conference Proceedings (OSTI)

The techniques used to measure precisely the polarization of the proton beams at RHIC are presented and discussed. Fast polarization measurements are performed using polarimeters based on pC elastic scattering. The absolute normalization is provided by a polarized hydrogen gas jet target. During the 2004 polarized proton run a relative precision on the beam polarization ?P beam /P beam of 6.6% has been achieved.

Alessandro Bravar; RHIC Polarimetry group

2005-01-01T23:59:59.000Z

179

Strangelet search at RHIC  

E-Print Network (OSTI)

Two position sensitive Shower Maximum Detector (SMDs) for Zero-Degree Calorimeters (ZDCs) were installed by STAR before run 2004 at both upstream and downstream from the interaction point along the beam axis where particles with small rigidity are swept away by strong magnetic field. The ZDC-SMDs provides information about neutral energy deposition as a function of transverse position in ZDCs. We report the preliminary results of strangelet search from a triggered data-set sampling 100 million Au+Au collisions at top RHIC energy.

A. H. Tang; for the STAR Collaboration

2004-12-07T23:59:59.000Z

180

Feedback damper system for quadrupole oscillations after transition at RHIC.  

Science Conference Proceedings (OSTI)

The heavy ion beam at RHIC undergoes strong quadrupole oscillations just after it crosses transition, which leads to an increase in bunch length making rebucketing less effective. A feedback system was built to damp these quadrupole oscillations and in this paper the characteristics of the system and the results obtained are presented and discussed.

Abreu,N.; Blaskiewicz, M.; Brennan, J.M.; Schultheiss, C.

2008-06-23T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

3D Hydro + Cascade model at RHIC and LHC  

Science Conference Proceedings (OSTI)

Using the 3D Hydro + UrQMD model which can explain hot and bulk QCD matter created at RHIC successfully, we show a prediction of one particle distributions and flow at LHC. Besides, we discuss the QCD critical point search in heavy ion collisions from point of view of quantitative analyses.

Nonaka, Chiho [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

2010-05-12T23:59:59.000Z

182

Physics of the AGS-to-RHIC transfer line commissioning  

Science Conference Proceedings (OSTI)

This paper presents beam physics results from the fall 1995 AGS-to- RHIC (ATR) transfer line commissioning run with fully ionized gold nuclei. We first describe beam position monitors and transverse video profile monitors, instrumentation relevant to measurements performed during this commissioning. Measured and corrected beam trajectories demonstrate agreement with design optics to a few percent, including optical transfer functions and beamline dispersion. Digitized 2- dimensional video profile monitors were used to measure beam emittance, and beamline optics and AGS gold ion beam parameters are shown to be comparable to RHIC design requirements.

Satogata, T.; Ahrens, L.; Brennan, M.; Brown, K.; Clifford, T.; Connolly, R.; Dell, F.; Deng, D.P.; Hoff, L.; Kewisch, J.; MacKay, W.W.; Maldonado, G.; Martin, B.; Olsen, R.; Peggs, S.; Pilat, F.; Robinson, T.; Sathe, S.; Shea, D.; Shea, T.J.; Tanaka, M.; Thompson, P.; Tepikian, S.; Trahern, C.G.; Trbojevic, D.; Tsoupas, N.; Wei, J.; Witkover, R.; Zhou, P.

1996-07-01T23:59:59.000Z

183

ABSOLUTE POLARIMETRY AT RHIC.  

DOE Green Energy (OSTI)

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.

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

2007-09-10T23:59:59.000Z

184

RHIC spin flipper commissioning results  

Science Conference Proceedings (OSTI)

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}.

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

2012-05-20T23:59:59.000Z

185

RHIC Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Project RHIC Project The Superconducting Magnet Division supplied 1740 magnetic elements, in 888 cryostats, for the RHIC facility at BNL. Of these, 780 magnetic elements were manufactured by Northrop-Grumman (Bethpage, NY) and 360 were made by Everson Electric (Bethlehem, PA). The magnets made in industry used designs developed at BNL. The first cooldown of the magnets for the RHIC engineering run was in 1999. Since then, the magnets have operated very reliably. arc dipole coil and yoke Arc dipole coil and yoke, with magnetic flux lines The magnets provide modest field (3.45 Teslas in the arc dipoles) in a cost-effective design. Key features in the principal bending and focusing magnets include the use of NbTi Rutherford cable, a single-layer coil, and cold iron as both yoke and collar. The magnets operate in forced-flow

186

Initial condition for hydrodynamics, partonic free streaming, and the uniform description of soft observables at RHIC  

E-Print Network (OSTI)

We investigate the role of the initial condition used for the hydrodynamic evolution of the system formed in ultra-relativistic heavy-ion collisions and find that an appropriate choice motivated by the models of early-stage dynamics, specifically a simple two-dimensional Gaussian profile, leads to a uniform description of soft observables measured in the Relativistic Heavy-Ion Collider (RHIC). In particular, the transverse-momentum spectra, the elliptic-flow, and the Hanbury-Brown--Twiss correlation radii, including the ratio R_out/R_side as well as the dependence of the radii on the azimuthal angle (azHBT), are properly described. We use the perfect-fluid hydrodynamics with a realistic equation of state based on lattice calculations and the hadronic gas at high and low temperatures, respectively. We also show that the inclusion of the partonic free-streaming in the early stage allows to delay the start of the hydrodynamical description to comfortable times of the order of 1 fm/c. Free streaming broadens the initial energy-density profile, but generates the initial transverse and elliptic flow. The data may be described equally well when the hydrodynamics is started early, or with a delay due to partonic free-streaming.

Wojciech Broniowski; Mikolaj Chojnacki; Wojciech Florkowski; Adam Kisiel

2008-01-28T23:59:59.000Z

187

PHYSICS OF POLARITY AT RHIC-VOLUME 10.  

SciTech Connect

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.

IMAI,K.; FIELDS,D.

1998-08-04T23:59:59.000Z

188

IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy  

Science Conference Proceedings (OSTI)

There is a strong interest in low-energy RHIC operations in the single-beam total energy range of 2.5-25 GeV/nucleon [1-3]. Collisions in this energy range, much of which is below nominal RHIC injection energy, will help to answer one of the key questions in the field of QeD about the existence and location of a critical point on the QCD phase diagram [4]. There have been several short test runs during 2006-2008 RHIC operations to evaluate RHIC operational challenges at these low energies [5]. Beam lifetimes observed during the test runs were limited by machine nonlinearities. This performance limit can be improved with sufficient machine tuning. The next luminosity limitation comes from transverse and longitudinal Intra-beam Scattering (IBS), and ultimately from the space-charge limit. Detailed discussion of limiting beam dynamics effects and possible luminosity improvement with electron cooling can be found in Refs. [6-8]. For low-energy RHIC operation, particle losses from the RF bucket are of particular concern since the longitudinal beam size is comparable to the existing RF bucket at low energies. However, operation below transition energy allows us to exploit an Intra-beam Scattering (IBS) feature that drives the transverse and longitudinal beam temperatures towards equilibrium by minimizing the longitudinal diffusion rate using a high RF voltage. Simulation studies were performed with the goal to understand whether one can use this feature of IBS to improve luminosity of RHIC collider at low-energies. This Note presents results of simulations which show that additional luminosity improvement for low-energy RHIC project may be possible with high RF voltage from a 56 MHz superconducting RF cavity that is presently under development for RHIC.

Fedotov,A.

2009-01-02T23:59:59.000Z

189

RHIC Machine/Detector Planning Meetings  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Machine/Detector Planning Meeting RHIC Machine/Detector Planning Meeting RHIC STAR PHENIX RHIC STAR PHENIX BNL Home Page C-AD Home Page C-AD ES&F Division BNL Physics Department RHIC Run History Super Conducting Magnet Division Run 14 Scheduling Physicist Home Page NPP PAC Run 13 Recommendations CAD Power Run 11-Run 13 Off-line CNI Polarization Results APEX for Run 13 RHIC Machine/Detector Meetings for Run 12 FY02-Present C-AD Energy Use Plots Cryo Power Run 11-Run 13 H-jet Target Results APEX Nov. 19-20, 2012 Workshop for Run 13 RHIC Run 13 Run Home Page (pp) FY10-Present BNL Energy Use Plot Cryo Temperatures Latest Luminosity Plots BNL Current Energy Use (BNL Intranet only and requires password) RHIC Retreat 2012

190

ANALYSIS OF BEAM INDUCED PRESSURE INCREASES IN RHIC WARM VACUUM SECTIONS.  

SciTech Connect

With increasing intensity of gold and proton beams during recent RHIC operations, pressure rises of several decades were observed at a few RHIC warm vacuum sections. The pressure increases were analyzed and compared with the beam parameters such as ion species, bunch intensity, total intensity, number ofbunches, bunch spacing and beam loss. Most of these pressure increases were found to be consistent with those induced by either beam loss and/or electron multipacting.

HSEUH,H.C.; SMART,L.A.; ZHANG,S.Y.

2002-06-02T23:59:59.000Z

191

Charged hadron transverse momentum spectra in Au+Au and d+Au collisions at 200 GeV per nucleon pair  

E-Print Network (OSTI)

The Relativistic Heavy Ion Collider (RHIC) collides Au ions at a center of mass energy of 200 GeV per nucleon pair, which produces the most energetic collisions yet seen in the laboratory. RHIC has also collided proton ...

Kane, Jay Lawrence

2005-01-01T23:59:59.000Z

192

Bound-Free Electron-Positron Pair Production in Relativistic Heavy-Ion Collisions  

E-Print Network (OSTI)

The bound-free electron-positron pair production is considered for relativistic heavy ion collisions. In particular, cross sections are calculated for the pair production with the simultaneous capture of the electron into the 1s ground state of one of the ions and for energies that are relevant for the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Colliders (LHC). In the framework of perturbation theory, we applied Monte-Carlo integration techniques to compute the lowest-order Feynman diagrams amplitudes by using Darwin wave functions for the bound states of the elec- trons and Sommerfeld-Maue wave functions for the continuum states of the positrons. Calculations were performed especially for the collision of Au + Au at 100 GeV/nucleon and Pb + Pb at 3400 GeV/nucleon.

M. Y. Sengul; M. C. Guclu; S. Fritzsche

2009-07-30T23:59:59.000Z

193

Brookhaven and the Large Hadron Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Brookhaven & the Large Hadron Collider Brookhaven & the Large Hadron Collider Home News Brookhaven & ATLAS ATLAS ATLAS Calorimeter ATLAS Muon Spectrometer Construction Computing Upgrades RHIC & LHC Education LHC tunnel ATLAS detector ATLAS detector RACF BNL built superconducting magnets Brookhaven & the LHC The world's most powerful particle accelerator, the Large Hadron Collider (LHC) in Switzerland, powers unprecedented explorations of the deepest mysteries of the universe. In addition to serving as the U.S. host laboratory for the ATLAS experiment at the LHC, Brookhaven National Lab plays multiple roles in this international collaboration, from construction and project management to data storage and distribution. ATLAS rendering Brookhaven and ATLAS Brookhaven physicists and engineers are participating in one of the most

194

Open Charm Production at RHIC  

E-Print Network (OSTI)

Recent experimental measurements on open charm production in proton-proton, proton (deuteron)-nucleus and nucleus-nucleus collisions at RHIC are reviewed. A comparison with theoretical predictions is made. Some unsettled issues in open charm production call for precise measurements on directly reconstructed open charm hadrons.

Xin Dong

2005-09-30T23:59:59.000Z

195

Cryogenic sub-system for the 56 MHz SRF storage cavity for RHIC  

Science Conference Proceedings (OSTI)

A 56 MHz Superconducting RF Storage Cavity is being constructed for the RHIC collider. This cavity is a quarter wave resonator that will be operated in a liquid helium bath at 4.4 K. The cavity requires an extremely quiet environment to maintain its operating frequency. The cavity, besides being engineered for a mechanically quiet system, also requires a quiet cryogenic system. The helium is taken from RHIC's main helium supply header at 3.5 atm, 5.3K at a phase separator tank. The boil-off is sent back to the RHIC refrigeration system to recover the cooling. To acoustically separate the RHIC helium supply and return lines, a condenser/boiler heat exchanger condenses the helium vapor generated in the RF cavity bath. A system description and operating parameters are given about the cryogen delivery system. The 56 MHz superconducting storage RF cavity project is making progress. The cryogenic system design is in its final stage. The helium supply lines have been tapped into the RHIC helium distribution lines. The plate-and-fin heat exchanger design is near completion and specification will be sent out for bid soon. The cold helium vapor heating system design will start soon as well. A booster compressor specification is underway. The first phase separator and transfer line design work is near completion and will be sent out for bid soon.

Huang, Y.; Than, R.; Orfin, P.; Lederle, D.; Tallerico, T.; Masi L.; Talty, P.; Zhang, Y.

2011-03-28T23:59:59.000Z

196

Muon Collider Papers and Reports  

NLE Websites -- All DOE Office Websites (Extended Search)

of muon collider papers and reports. Muon Collider Feasibilty Study ... Snowmass Book BNL Muon Collider Project Publication Index Fermilab Muon Collider Notes Muon Collider...

197

Simultaneous global coupling and vertical dispersion correction in RHIC  

SciTech Connect

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.

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

2012-05-20T23:59:59.000Z

198

Spin Physics Program at RHIC-PHENIX  

E-Print Network (OSTI)

Longitudinal spin physics program at RHIC-PHENIX is introduced. Recent results of pi0 cross section and A_LL are presented and discussed.

K. Aoki; for the PHENIX Collaboration

2007-09-03T23:59:59.000Z

199

The RHIC Mid-Term Strategic Plan  

NLE Websites -- All DOE Office Websites (Extended Search)

clearly felt. The combined RHIC Computing Facility and ATLAS Computing Facility (RCFACF) has reached the limit of available floor space. During the past two years, additional...

200

High intensity protons in RHIC  

SciTech Connect

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.

Montag, C.; Ahrens& #44; L.; Blaskiewicz& #44; M.; Brennan& #44; J.M.; Drees& #44; K.A.; Fischer& #44; W.; Huang& #44; H.; Minty& #44; M.; Robert-Demolaize& #44; G.; Thieberger& #44; P.; Yip& #44; K.

2012-01-05T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

LONGITUDINAL IMPEDANCE MEASUREMENT IN RHIC.  

SciTech Connect

The very clean Schottky spectra of gold beams in RHIC allow an accurate measurement of potential well distortion. By observing the variation in the small amplitude, incoherent synchrotron tune with intensity and bunch length, the intensity dependent longitudinal force can be measured. Dynamical effects associated with coherent motion are not important though some new dynamical effects appear. Measurements were carried out both at injection energy and store, which allowed the space charge and wall contributions to be individually determined.

BLASKIEWICZ,M.; BRENNAN,J.M.; CAMERON,P.; FISCHER,W.

2002-06-02T23:59:59.000Z

202

A high performance DAC /DDS daughter module for the RHIC LLRF platform  

SciTech Connect

The RHIC LLRF upgrade is a flexible, modular system. Output signals are generated by a custom designed XMC card with 4 high speed digital to analog (DAC) converters interfaced to a high performance field programmable gate array (FPGA). This paper discusses the hardware details of the XMC DAC board as well as the implementation of a low noise rf synthesizer with digital IQ modulation. This synthesizer also provides injection phase cogging and frequency hop rebucketing capabilities. A new modular RHIC LLRF system was recently designed and commissioned based on custom designed XMC cards. As part of that effort a high speed, four channel DAC board was designed. The board uses Maxim MAX5891 16 bit DACs with a maximum update rate of 600 Msps. Since this module is intended to be used for many different systems throughout the Collider Accelerator complex, it was designed to be as generic as possible. One major application of this DAC card is to implement digital synthesizers to provide drive signals to the various cavities at RHIC. Since RHIC is a storage ring with stores that typically last many hours, extremely low RF noise is a critical requirement. Synchrotron frequencies at RHIC range from a few hertz to several hundred hertz depending on the species and point in the acceleration cycle so close in phase noise is a major concern. The RHIC LLRF system uses the Update Link, a deterministic, high speed data link that broadcasts the revolution frequency and the synchronous phase angle. The digital synthesizers use this data to generate a properly phased analog drive signal. The synthesizers must also provide smooth phase shifts for cogging and support frequency shift rebucketing. One additional feature implemented in the FPGA is a digital waveform generator (WFG) that generates I and Q data pairs based on a user selected amplitude and phase profile as a function of time.

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

2011-03-28T23:59:59.000Z

203

Elastic proton-proton scattering at RHIC  

SciTech Connect

Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.

Yip, K.

2011-09-03T23:59:59.000Z

204

About the RHIC II Working Groups  

NLE Websites -- All DOE Office Websites (Extended Search)

About the Working Groups About the Working Groups The BNL Physics Department is organizing a series of meetings among theorists and experimenters from throughout the interested scientific community to focus on the central questions that will drive the next phase of RHIC physics. The November 2004 workshop was a kick-off meeting, to collect ideas and topics for future workshops, and assemble community-wide working groups. At the November workshop we had an extensive discussion of how the RHIC community should best organize itself to refine the science agenda for the next phase of RHIC research, to fully understand the science drivers for the RHIC II upgrades, and make a compelling scientific case for these upgrades to the broader nuclear physics community and to the young generation of RHIC scientists.

205

Optics measurements and corrections at RHIC  

SciTech Connect

The further improvement of RHIC luminosity performance requires more precise understanding of the RHIC modeling. Hence, it is necessary to minimize the beta-beat, deviation of measured beta function from the calculated beta functions based on an model. The correction of betabeat also opens up the possibility of exploring operating RHIC polarized protons at a working point near integer, a prefered choice for both luminosity as well as beam polarization. The segment-by-segment technique for reducing beta-beat demonstrated in the LHC operation for reducing the beta-beat was first tested in RHIC during its polarized proton operation in 2011. It was then fully implemented during the RHIC polarized proton operation in 2012. This paper reports the commissioning results. Future plan is also presented.

Bai M.; Aronson, J.; Blaskiewicz, M.; Luo, Y.; Robert-Demolaize, G.; White, S.

2012-05-20T23:59:59.000Z

206

Hard scattering phenomena from RHIC to LHC  

Science Conference Proceedings (OSTI)

In the Relativistic Heavy Ion Collider era the high-p{sub T} particle emerging from hard scattering became an important tool of exploration of excited nuclear medium formed in ultra-relativistic heavy ion collisions. Discovery of anomalous suppression of high-p{sub T} particle yield [1] together with an observation of disappearance of back-to-back hadron correlation in central Au+Au collisions in 2002 [2] were the key results interpreted as a manifestation of the deconfined QCD medium in heavy ion collisions. Analysis of the high-p{sub T} particle and jet production is already a standard experimental technique providing a test bench for pQCD description of the point-like constituent scattering in p+p collisions and sensitive probes of the excited nuclear medium in A+A collisions.

Rak, Jan [Jyvaeskylae University, FI-40014 Jyvaeskylae (Finland)

2011-05-23T23:59:59.000Z

207

Stochastic cooling of a high energy collider  

SciTech Connect

Gold beams in RHIC revolve more than a billion times over the course of a data acquisition session or store. During operations with these heavy ions the event rates in the detectors decay as the beams diffuse. A primary cause for this beam diffusion is small angle Coloumb scattering of the particles within the bunches. This intra-beam scattering (IBS) is particularly problematic at high energy because the negative mass effect removes the possibility of even approximate thermal equilibrium. Stochastic cooling can combat IBS. A theory of bunched beam cooling was developed in the early eighties and stochastic cooling systems for the SPS and the Tevatron were explored. Cooling for heavy ions in RHIC was also considered.

Blaskiewicz, M.; Brennan, J.M.; Lee, R.C.; Mernick, K.

2011-09-04T23:59:59.000Z

208

COMMISSIONING SPIN ROTATORS IN RHIC.  

Science Conference Proceedings (OSTI)

During the summer of 2002, eight superconducting helical spin rotators were installed into RHIC in order to control the polarization directions independently at the STAR and PHENIX experiments. Without the rotators, the orientation of polarization at the interaction points would only be vertical. With four rotators around each of the two experiments, we can rotate either or both beams from vertical into the horizontal plane through the interaction region and then back to vertical on the other side. This allows independent control for each beam with vertical, longitudinal, or radial polarization at the experiment. In this paper, we present results from the first run using the new spin rotators at PHENIX.

Mackay, W W; Bai, M; Courant, E D; Fischer, W; Huang, H; Luccio, A; Montag, C; Pilat, F; Ptitsyn, V; Roser, T; Satogata, T; Trbojevic, D

2003-05-12T23:59:59.000Z

209

Muon Collider History  

NLE Websites -- All DOE Office Websites (Extended Search)

Colliders: A Brief History Below is a brief potted history of the muon collider concept. Click here for a one transparency summary. The muon collider concept is an idea dating back...

210

RHIC DETECTOR ADVISORY COMMITTEE Report  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC RHIC DETECTOR ADVISORY COMMITTEE Report of Review on Nov. 22, 2003 at BNL 1. Introduction The committee, consisting of Peter Braun-Munzinger (chair), Russell Betts, Carl Haber, Berndt Mueller, Rick Van Berg, and Jerry Va'vra 1 , met for the second time on Nov. 22, 2003 at BNL, chiefly to evaluate proposals by the STAR collaboration on their "MRPC TOF Detector" and by the PHENIX collaboration on their "Si-Tracker". Brief reports were also heard on the progress of the various R&D efforts in STAR and PHENIX but time was too short to make a detailed assessment of those. This report will hence concentrate on the main proposals. At the end we will make some remarks on the status of R&D in general and on some technical aspects we heard in the open session. 2. STAR MRPC TOF Detector The development of a detailed proposal for a TOF in STAR, based on the MRPC tech- nology, is

211

Structure and design of the electron lens for RHIC  

SciTech Connect

Two electron lenses for a head-on beam-beam compensation are being planned for RHIC; one for each circulating proton beam. The transverse profile of the electron beam will be Gaussian up to a maximum radius of r{sub e} = 3{sigma}. Simulations and design of the electron gun with Gaussian radial emission current density profile and of the electron collector are presented. Ions of the residual gas generated in the interaction region by electron and proton beams will be removed by an axial gradient of the electric field towards the electron collector. A method for the optical observation of the transverse profile of the electron beam is described.

Pikin, A.; Fischer, W.; Alessi, J.; Anerella, M.; Beebe, E. Gassner, D.; Gu, X.; Gupta, R.; Hock, J.; Jain, A.; Lambiase, R.; Luo, Y.; Montag, C.; Okamura, M.; Tan, Y.; Tuozzolo, J.; Thieberger, P.; Zhang, W.

2011-03-28T23:59:59.000Z

212

Simulations of beam-beam and beam-wire interactions in RHIC  

SciTech Connect

The beam-beam interaction is one of the dominant sources of emittance growth and luminosity lifetime deterioration. A current carrying wire has been proposed to compensate long-range beam-beam effects in the LHC and strong localized long-range beam-beam effects are experimentally investigated in the RHIC collider. Tune shift, beam transfer function, and beam loss rate are measured in dedicated experiments. In this paper, they report on simulations to study the effect of beam-wire interactions based on diffusive apertures, beam loss rates, and beam transfer function using a parallelized weak-strong beam simulation code (BBSIMC). The simulation results are compared with measurements performed in RHIC during 2007 and 2008.

Kim, Hyung J.; Sen, Tanaji; /Fermilab; Abreu, Natalia P.; Fischer, Wolfram; /Brookhaven

2009-02-01T23:59:59.000Z

213

THE RHIC HYDROGEN JET LUMINESCENCE MONITOR.  

DOE Green Energy (OSTI)

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.

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

2007-06-25T23:59:59.000Z

214

A COMPREHENSIVE NEW DETECTOR FOR DETAILED STUDY OF THE QGP, INITIAL CONDITION AND SPIN PHYSICS AT RHIC II.  

SciTech Connect

A case is presented for compelling physics at a high luminosity RHIC II collider. A comprehensive new detector system is introduced to address this physics. The experimental focus is on detailed jet tomography of the quark gluon plasma (QGP); measuring gluon saturation in the nucleus, investigating the color glass condensate, measuring effects of the QCD vacuum on particle masses, determining the structure and dynamics within the proton and possible new phenomena. The physics and detector capabilities are introduced.

HARRIS, J.W.; BELLWIED, R.; SMIRNOV, N.; STEINBERG, P.; SURROW, B.; ULLRICH, T.

2004-03-15T23:59:59.000Z

215

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

Science Conference Proceedings (OSTI)

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.

BLAND,L.; SAITO,N.

2001-10-10T23:59:59.000Z

216

Summary of the RHIC Retreat 2007  

Science Conference Proceedings (OSTI)

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.

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

2008-08-01T23:59:59.000Z

217

Hadron Production in Heavy Ion Collisions  

E-Print Network (OSTI)

2A GeV 3 Hadron Production from AGS to RHIC 3.1 SystematicsHadron Production in Heavy Ion Collisions Hans Georg RitterAC02- 05CH11231. Hadron Production in Heavy Ion Collisions

Ritter, Hans Georg

2009-01-01T23:59:59.000Z

218

The U.S. Depar  

NLE Websites -- All DOE Office Websites (Extended Search)

0) The Relativistic Heavy Ion Collider (RHIC) RHIC by the Numbers Very large, supercold machine creates tiny bits of extremely hot, dense matter * The RHIC ring is 2.4 miles in...

219

A luminosity model of RHIC gold runs  

SciTech Connect

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.

Zhang, S.Y.

2011-11-01T23:59:59.000Z

220

Constraining the nuclear gluon distribution in $eA$ processes at RHIC  

E-Print Network (OSTI)

A systematic determination of the gluon distribution is of fundamental interest in understanding the parton structure of nuclei and the QCD dynamics. Currently, the behavior of this distribution at small $x$ (high energy) is completely undefined. In this paper we analyze the possibility of constraining the nuclear effects present in $xg^A$ using the inclusive observables which would be measured in the future electron-nucleus collider at RHIC. We demonstrate that the study of nuclear longitudinal and charm structure functions allows to estimate the magnitude of shadowing and antishadowing effects in the nuclear gluon distribution.

E. R. Cazaroto; F. Carvalho; V. P. Goncalves; F. S. Navarra

2008-04-16T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

PHENIX EXPERIMENT AT RHIC: DECADAL PLAN 2004-2013  

Science Conference Proceedings (OSTI)

The PHENIX Collaboration has developed a plan for the detailed investigation of quantum chromodynamics in the next decade. The demonstrated capabilities of the PHENIX experiment to measure rare processes in hadronic, leptonic and photonic channels, in combination with RHIC's unparalleled flexibility as a hadronic collider, provides a physics program of extraordinary breadth and depth. A superlative set of measurements to elucidate the states of both hot and cold nuclear matter, and to measure the spin structure of the proton has been identified. The components of this plan include: (1) Definitive measurements that will establish the nature of the matter created in nucleus+nucleus collisions, that will determine if the description of such matter as a quark-gluon plasma is appropriate, and that will quantify both the equilibrium and non-equilibrium features of the produced medium. (2) Precision measurements of the gluon structure of the proton, and of the spin structure of the gluon and sea-quark distributions of the proton via polarized proton+proton collisions. (3) Determination of the gluon distribution in cold nuclear matter using proton+nucleus collisions. Each of these fundamental fields of investigation will be addressed through a program of correlated measurements in some or all of the following channels: (1) Particle production at high transverse momentum, studied via single particle inclusive measurements of identified charged and neutral hadrons, multi-particle correlations and jet production. (2) Direct photon, photon+jet and virtual photon production. (3) Light and heavy vector mesons. (4) Heavy flavor production. These measurements, together with the established PHENIX abilities to identify hadrons at low transverse momentum, to perform detailed centrality selections, and to monitor polarization and luminosity with high precision create a superb opportunity for performing world-class science with PHENIX for the next decade. A portion of this 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.

ZAJC,W.ET. AL.

2003-11-30T23:59:59.000Z

222

Heavy Ion Collisions at the LHC - Last Call for Predictions  

SciTech Connect

In August 2006, the CERN Theory Unit announced to restructure its visitor program and to create a 'CERN Theory Institute', where 1-3 month long specific programs can take place. The first such Institute was held from 14 May to 10 June 2007, focusing on 'Heavy Ion Collisions at the LHC - Last Call for Predictions'. It brought together close to 100 scientists working on the theory of ultra-relativistic heavy ion collisions. The aim of this workshop was to review and document the status of expectations and predictions for the heavy ion program at the Large Hadron Collider LHC before its start. LHC will explore heavy ion collisions at {approx} 30 times higher center of mass energy than explored previously at the Relativistic Heavy Ion Collider RHIC. So, on the one hand, the charge of this workshop provided a natural forum for the exchange of the most recent ideas, and allowed to monitor how the understanding of heavy ion collisions has evolved in recent years with the data from RHIC, and with the preparation of the LHC experimental program. On the other hand, the workshop aimed at a documentation which helps to distinguish pre- from post-dictions. An analogous documentation of the 'Last Call for Predictions' [1] was prepared prior to the start of the heavy-ion program at the Relativistic Heavy Ion Collider RHIC, and it proved useful in the subsequent discussion and interpretation of RHIC data. The present write-up is the documentation of predictions for the LHC heavy ion program, received or presented during the CERN TH Institute. The set-up of the CERN TH Institute allowed us to aim for the wide-most coverage of predictions. There were more than 100 presentations and discussions during the workshop. Moreover, those unable to attend could still participate by submitting predictions in written form during the workshop. This followed the spirit that everybody interested in making a prediction had the right to be heard. To arrive at a concise document, we required that each prediction should be summarized on at most two pages, and that predictions should be presented, whenever possible, in figures which display measurable quantities. Full model descriptions were not accepted--the authors were encouraged to indicate the relevant references for the interested reader. Participants had the possibility to submit multiple contributions on different topics, but it was part of the subsequent editing process to ensure that predictions on neighboring topics were merged wherever possible. The contributions summarized here are organized in several sections,--though some of them contain material related with more than one section--roughly by going from low transverse momentum to high transverse momentum and from abundant to rare measurements. In the low transverse momentum regime, we start with predictions on multiplicity distributions, azimuthal asymmetries in particle production and hadronic flavor observables, followed by correlation and fluctuation measurements. The contributions on hard probes at the LHC start with predictions for single inclusive high transverse momentum spectra, and jets, followed by heavy quark and quarkonium measurements, leptonic probes and photons. A final section 'Others' encompasses those predictions which do not fall naturally within one of the above-mentioned categories, or discuss the more speculative phenomena that may be explored at the LHC.

Armesto, N; Borghini, N; Jeon, S; Wiedemann, U A; Abreu, S; Akkelin, V; Alam, J; Albacete, J L; Andronic, A; Antonuv, D; Arleo, F; Armesto, N; Arsene, I C; Barnafoldi, G G; Barrette, J; Bauchle, B; Becattini, F; Betz, B; Bleicher, M; Bluhm, M; Boer, D; Bopp, F W; Braun-Munzinger, P; Bravina, L; Busza, W; Cacciari, M; Capella, A; Casalderrey-Solana, J; Chatterjee, R; Chen, L; Cleymans, J; Cole, B A; delValle, Z C; Csernai, L P; Cunqueiro, L; Dainese, A; de Deus, J D; Ding, H; Djordjevic, M; Drescher, H; Dremin, I M; Dumitru, A; El, A; Engel, R; d' Enterria, D; Eskola, K J; Fai, G; Ferreiro, E G; Fries, R J; Frodermann, E; Fujii, H; Gale, C; Gelis, F; Goncalves, V P; Greco, V; Gyulassy, M; van Hees, H; Heinz, U; Honkanen, H; Horowitz, W A; Iancu, E; Ingelman, G; Jalilian-Marian, J; Jeon, S; Kaidalov, A B; Kampfer, B; Kang, Z; Karpenko, I A; Kestin, G; Kharzeev, D; Ko, C M; Koch, B; Kopeliovich, B; Kozlov, M; Kraus, I; Kuznetsova, I; Lee, S H; Lednicky, R; Letessier, J; Levin, E; Li, B; Lin, Z; Liu, H; Liu, W; Loizides, C; Lokhtin, I P; Machado, M T; Malinina, L V; Managadze, A M; Mangano, M L; Mannarelli, M; Manuel, C; Martinez, G; Milhano, J G; Mocsy, A; Molnar, D; Nardi, M; Nayak, J K; Niemi, H; Oeschler, H; Ollitrault, J; Paic, G; Pajares, C; Pantuev, V S; Papp, G; Peressounko, D; Petreczky, P; Petrushanko, S V; Piccinini, F; Pierog, T; Pirner, H J; Porteboeuf, S; Potashnikova, I; Qin, G Y; Qiu, J; Rafelski, J; Rajagopal, K; Ranft, J; Rapp, R; Rasanen, S S; Rathsman, J; Rau, P; Redlich, K; Renk, T; Rezaeian, A H; Rischke, D; Roesler, S; Ruppert, J; Ruuskanen, P V; Salgado, C A; Sapeta, S; Sarcevic, I; Sarkar, S; Sarycheva, L I; Schmidt, I; Shoski, A I; Sinha, B; Sinyukov, Y M; Snigirev, A M; Srivastava, D K; Stachel, J; Stasto, A; Stocker, H; Teplov, C Y; Thews, R L; Torrieri, G; Pop, V T; Triantafyllopoulos, D N; Tuchin, K L; Turbide, S; Tywoniuk, K; Utermann, A; Venugopalan, R; Vitev, I; Vogt, R; Wang, E; Wang, X N; Werner, K; Wessels, E; Wheaton, S; Wicks, S; Wiedemann, U A; Wolschin, G; Xiao, B; Xu, Z; Yasui, S; Zabrodin, E; Zapp, K; Zhang, B

2008-02-25T23:59:59.000Z

223

Review of Forward Physics at RHIC  

E-Print Network (OSTI)

The RHIC high energy collision of species ranging from p+p, p(d)+A to A+A provide access to the {small-x} component of the hadron wave function. The RHIC program has brought renewed interest in that subject with its ability to reach values of the parton momentum fraction smaller than 0.01 with studies of particle production at high rapidity. Furthermore, the use of heavy nuclei in the p(d)+A collisions facilitates the study of saturation effects in the gluonic component of the nuclei because the appropriate scale for that regime grows as A^1/3. We review the experimental results of the RHIC program that have relevance to {small-x} emphasizing the physics extracted from d+Au collisions and their comparison to p+p collisions at the same energy.

Debbe, R

2007-01-01T23:59:59.000Z

224

Summary of the RHIC Retreat 2008  

SciTech Connect

The main goal of the RHIC Retreat is to review last run's performance and prepare for the next. As always though we also discussed the longer term goals and plans for the facility to put the work in perspective and in the right priority. A straw-man plan for the facility was prepared for the DOE that assumes 30 cryoweek and running 2 species per year. The plan outlines RHIC operations for 2008-2012 and integrates well accelerator and detector upgrades to optimize the physics output with high luminosities. The plans includes guidance from the PAC and has been reviewed by DOE.

Pilat,F.; Brennan, M.; Brown, K.; Fischer, W.; Montag, C.

2008-08-01T23:59:59.000Z

225

RHIC PRESSURE RISE AND ELECTRON CLOUD.  

SciTech Connect

In RHIC high intensity operation, two types of pressure rise are currently of concern. The first type is at the beam injection, which seems to be caused by the electron multipacting, and the second is the one at the beam transition, where the electron cloud is not the dominant cause. The first type of pressure rise is limiting the beam intensity and the second type might affect the experiments background for very high total beam intensity. In this article, the pressure rises at RHIC are described, and preliminary study results are reported. Some of the unsettled issues and questions are raised, and possible counter measures are discussed.

Zhang, S Y; Blaskiewicz, M; Cameron, P; Drees, P; Afischer, W; Gassner, D; Gullotta, J; He, P; Hseuh, H; Chuang, H; Iriso-Aziz, U; Lee, R; Mackay, W; Woerter, B; Ptitsyn, V; Ponnaiyan, V; Roser, T; Satogata, T; Smart, L; Trbojevic, D

2003-05-12T23:59:59.000Z

226

RHIC II Science Physics Questions  

NLE Websites -- All DOE Office Websites (Extended Search)

work? Is there evidence for deconfinement? How does the clearly evident thermodynamic character of a high energy heavy ion collision evolve from the zero entropy...

227

Hadron Colliders and Hadron Collider Physics Symposium  

E-Print Network (OSTI)

This article summarizes main developments of the hadron colliders and physics results obtained since their inception around forty years ago. The increase in the collision energy of over two orders of magnitude and even larger increases in luminosity provided experiments with unique data samples. Developments of full acceptance detectors, particle identification and analysis methods provided fundamental discoveries and ultra-precise measurements which culminated in the completion and in depth verification of the Standard Model. Hadron Collider Physics symposium provided opportunities for those working at hadron colliders to share results of their research since 1979 and helped greatly to develop the field of particle physics.

Denisov, Dmitri

2013-01-01T23:59:59.000Z

228

Crystal-based approach to beam collimation in RHIC and SNS  

E-Print Network (OSTI)

Bent crystal serving as a scraper of the beam collimation system can channel halo particles directly into the absorber. By means of computer simulations, we analyse the capabilities of crystal technique for the beam cleaning process. Two applications are considered: the crystal collimator now being installed into RHIC for cleaning of the fully stripped gold ions, and a similar system being developed for the Accumulator Ring of the Spallation Neutron Source.

V. M. Biryukov; N. Catalan-Lasheras; A. Drees; N. Malitsky; D. Trbojevic

2001-11-14T23:59:59.000Z

229

MEASUREMENT OF LINEAR COUPLING RESONANCE IN RHIC.  

Science Conference Proceedings (OSTI)

Linear coupling is one of the factors that determine beam lifetime in RHIC. The traditional method of measuring the minimum tune separation requires a tune scan and can't be done parasitically or during the acceleration ramp. A new technique of using ac dipoles to measure linear coupling resonance has been developed at RHIC. This method measures the degree of coupling by comparing the amplitude of the horizontal coherent excitation with the amplitude of the vertical coherent excitation if the beam is excited by the vertical AC dipole and vice versa. One advantage of this method is that it can be done without changing tunes from the normal machine working points. In principle, this method can also localize the coupling source by mapping out the coupling driving terms throughout the ring. This is very useful for local decoupling the interaction regions in RHIC. A beam experiment of measuring linear coupling has been performed in RHIC during its 2003 run, and the analysis of the experimental data is discussed in this paper.

BAI,M.PILAT,F.SATOGATA,T.TOMAS,R.

2002-05-12T23:59:59.000Z

230

3-D hydro + cascade model at RHIC  

E-Print Network (OSTI)

We present a 3-D hydro + cascade model, in which viscosity and a realistic freezeout process for the hadronic phase are taken into account. We compare our results to experimental data and discuss the final state interaction effects on physical observables. 1. FREEZEOUT PROCESS AND VISCOSITY IN HYDRODYNAMICS Hydrodynamic models have been very successful in describing the collective behavior of matter at RHIC, such as single particle spectra and elliptic flow. In particular the strong elliptic flow which, for the first time, reaches the hydrodynamic limit at RHIC, provides us with a new understanding of the nature of the quark-gluon plasma (QGP) created at RHIC as strongly interacting or correlated QGP [ 1]. However there exist a number of experimental observations that contradict ideal hydrodynamic models: transverse momentum spectra above 2 GeV, elliptic flow at large pseudo-rapdities ? and Hanbury Brown- Twiss (HBT) interferometry. These observations suggest that there exist limitations to the application of a simple ideal hydrodynamic model to RHIC physics and that an improvement on an ideal hydrodynamic model is needed in order to obtain a comprehensive and unified description of the data from the point of view of hydrodynamics. In general, hydrodynamic models require initial conditions, an equations of state (EoS)

Chiho Nonakaa A; Steffen A. Bass

2005-01-01T23:59:59.000Z

231

BEAM SCRUBBING FOR RHIC POLARIZED PROTON RUN.  

SciTech Connect

One of the intensity limiting factor of RHIC polarized proton beam is the electron cloud induced pressure rise. A beam scrubbing study shows that with a reasonable period of time of running high intensity 112-bunch proton beam, the pressure rise can be reduced, allowing higher beam intensity.

ZHANG,S.Y.FISCHER,W.HUANG,H.ROSER,T.

2004-07-05T23:59:59.000Z

232

Search for Squeezed-Pair Correlations at RHIC  

E-Print Network (OSTI)

Squeezed correlations of particle-antiparticle pairs, also called Back-to-Back Correlations, are predicted to appear if the hadron masses are modified in the hot and dense hadronic medium formed in high energy nucleus-nucleus collisions. Although well-established theoretically, the squeezed-particle correlations have not yet been searched for experimentally in high energy hadronic or heavy ion collisions, clearly requiring optimized forms to experimentally search for this effect. Within a non-relativistic treatment developed earlier we show that one promising way to search for the BBC signal is to look into the squeezed correlation function of pairs of phi-mesons at RHIC energies, plotted in terms of the average momentum of the pair, K12=(k1+k2)/2. This variable's modulus, 2|K12|, is the non-relativistic limit of the variable Q_bbc, introduced herewith. The squeezing effects on the HBT correlation function are also discussed.

Sandra S. Padula; O. Socolowski Jr.; T. Csorgo; M. I. Nagy

2008-05-02T23:59:59.000Z

233

COMMISSIONING AND FUTURE PLANS FOR POLARIZED PROTONS IN RHIC.  

Science Conference Proceedings (OSTI)

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 180{degree} around a horizontal rotation axis about 13{degree} from the longitudinal. When the beam was accelerated from injection G{sub {gamma}} = 46.5 to G{sub {gamma}} = 48 the spin flipped sign as expected and polarization was preserved. At G{sub {gamma}} = 48 without the snake, no polarization was observed since several spin resonances were crossed. Eventually polarized beam was accelerated to G{sub {gamma}} = 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.

MACKAY,W.W.; AHRENS,L.; BAI,M.; BUNCE,G.; COURANT,E.; DESHPANDE,A.; DREES,A.; FISCHER,W.; HUANG,H.; KURITA,K.; LUCCIO,A.U.; ET AL

2001-06-18T23:59:59.000Z

234

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

Science Conference Proceedings (OSTI)

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.

KRETZER,S.MORRISON,D.VENUGOPALAN,R.VOGELSANG,W.

2004-02-18T23:59:59.000Z

235

Hadron Production in Heavy Ion Collisions  

E-Print Network (OSTI)

We review hadron production in heavy ion collisions with emphasis on pion and kaon production at energies below 2 AGeV and on partonic collectivity at RHIC energies.

Helmut Oeschler; Hans Georg Ritter; Nu Xu

2009-08-12T23:59:59.000Z

236

Fermilab | Muon Collider | Graphics  

NLE Websites -- All DOE Office Websites (Extended Search)

Graphics A chain of accelerators and other devices is necessary to produce and accelerate muons before scientists can make muons collide. Click image for larger version A muon...

237

Muon Muon Collider: Feasibility Study  

SciTech Connect

A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle reactions which are open to a muon collider and the physics of such reactions - what one learns and the necessary luminosity to see interesting events - are described in detail. Most of the physics accesible to an e{sup +} - e{sup -} collider could be studied in a muon collider. In addition the production of Higgs bosons in the s-channel will allow the measurement of Higgs masses and total widths to high precision; likewise, t{bar t} and W{sup +}W{sup -} threshold studies would yield m{sub t} and m{sub w} to great accuracy. These reactions are at low center of mass energy (if the MSSM is correct) and the luminosity and {Delta}p/p of the beams required for these measurements is detailed in the Physics Chapter. On the other hand, at 2 + 2 TeV, a luminosity of L {approx} 10{sup 35} cm{sup -2}s{sup -1} is desirable for studies such as, the scattering of longitudinal W bosons or the production of heavy scalar particles. Not explored in this work, but worth noting, are the opportunities for muon-proton and muon-heavy ion collisions as well as the enormous richness of such a facility for fixed target physics provided by the intense beams of neutrinos, muons, pions, kaons, antiprotons and spallation neutrons. To see all the interesting physics described herein requires a careful study of the operation of a detector in the very large background. Three sources of background have been identified. The first is from any halo accompanying the muon beams in the collider ring. Very carefully prepared beams will have to be injected and maintained. The second is due to the fact that on average 35% of the muon energy appears in its decay electron. The energy of the electron subsequently is converted into EM showers either from the synchrotron radiation they emit in the collider magnetic field or from direct collision with the surrounding material. The decays that occur as the beams traverse the low beta insert are of particular concern for detector backgrounds. A third source of background is e{sup +} - e{sup -} pair creation from {mu}{sup +} - {mu}{sup -} interaction. Studies of

Gallardo, J.C.; Palmer, R.B.; /Brookhaven; Tollestrup, A.V.; /Fermilab; Sessler, A.M.; /LBL, Berkeley; Skrinsky, A.N.; /Novosibirsk, IYF; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley

2012-04-05T23:59:59.000Z

238

Ferrite HOM Absorber for the RHIC ERL  

Science Conference Proceedings (OSTI)

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.

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

2008-10-01T23:59:59.000Z

239

Analysis of RHIC beam dump pre-fires  

SciTech Connect

It has been speculated that the beam may cause instability of the RHIC Beam Abort Kickers. In this study, we explore the available data of past beam operations, the device history of key modulator components, and the radiation patterns to examine the correlations. The RHIC beam abort kicker system was designed and built in the 90's. Over last decade, we have made many improvements to bring the RHIC beam abort kicker system to a stable operational state. However, the challenge continues. We present the analysis of the pre-fire, an unrequested discharge of kicker, issues which relates to the RHIC machine safety and operational stability.

Zhang, W.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Sandberg, J.; Tan, Y.

2011-03-28T23:59:59.000Z

240

title Brookhaven National Laboratory Inside RHIC News Features...  

NLE Websites -- All DOE Office Websites (Extended Search)

Inside RHIC News Features title description Brookhaven National Laboratory conducts research in the physical biomedical and environmental sciences as well as in energy technologies...

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
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241

Next Linear Collider Home Page  

NLE Websites -- All DOE Office Websites (Extended Search)

Welcome to the Next Linear Collider NLC Home Page If you would like to learn about linear colliders in general and about this next-generation linear collider project's mission,...

242

Papers on Muon Colliders  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnets for Muon Collider and Neutrino Storage Ring Magnets for Muon Collider and Neutrino Storage Ring (and Open Midplane Dipole for LARP): R. Gupta, et al., "High Field HTS Solenoid for a Muon Collider – Demonstrations, Challenges and Strategies, MT23, July 2013", presented at MT23, (talk) R. Weggel et al., "Open Midplane Dipoles for Muon Collider", 2011 Particle Accelerator Conference, New York (POSTER).. R. Gupta, M. Anerella, A. Ghosh, H. Kirk, R. Palmer, S. Plate, W. Sampson, Y. Shiroyanagi, P. Wanderer, B. Brandt, D. Cline, A. Garren, J. Kolonko, R. Scanlan, R. Weggel, "High field HTS R&D solenoid for muon collider", 2010 Applied Superconductivity Conference, Washington, DC, August 2010 >> Y. Shiroyanagi, W. Sampson, A. Ghosh, R. Gupta, "The Construction and

243

Building the RHIC tracking lattice model  

SciTech Connect

In this note we outline the procedure to build a realistic lattice model for the RHIC beam-beam tracking simulation. We will install multipole field errors in the arc main dipoles, arc main quadrupols and interaction region magnets (DX, D0, and triplets) and introduce a residual closed orbit, tune ripples, and physical apertures in the tracking lattice model. Nonlinearities such as local IR multipoles, second order chromaticies and third order resonance driving terms are also corrected before tracking.

Luo, Y.; Fischer, W.; Tepikian, S.

2010-01-27T23:59:59.000Z

244

FIRST POLARIZED PROTON COLLISIONS AT RHIC.  

SciTech Connect

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{sup o} about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV.

ROSER,T.; AHRENS,L.; ALESSI,J.; BAI,M.; BEEBE-WANG,J.; BRENNAN,J.M.; BROWN,K.A.; BUNCE,G.; CAMERON,P.; COURANT,E.D.; DREES,A.; FISCHER,W.; FLILLER,R.,III: GLENN,W.; HUANG,H.; LUCCIO,A.U.; MACKAY,W.W.; MAKDISI,Y.; MONTAG,C.; PILAT,F.; PTITSYN,V.; SATOGATA,T.

2002-11-06T23:59:59.000Z

245

Multiplicity Dependence of Partially Coherent Pion Production in Relativistic Heavy Ion Collisions  

E-Print Network (OSTI)

We investigate two- and three-particle intensity correlation functions of pions in relativistic heavy ion collisions for different colliding energies. Based on three models of particle production, we analyze the degree to which the pion sources are chaotic in the SPS S+Pb, Pb+Pb and the RHIC Au+Au collisions. The ``chaoticity'', $\\lambda$, of the two-particle correlation functions is corrected for long-lived resonance decays. The effect of the partial Coulomb correction is also examined. Although the partially coherent model gives a result which is consistent with that of STAR, the chaotic fraction does not exhibit clear multiplicity dependence if we take into account both the corrected chaoticity and the weight factor of the three-pion correlation function. The result of the partially-multicoherent model indicates an increasing number of coherent sources in higher multiplicity events.

Kenji Morita; Shin Muroya; Hiroki Nakamura

2006-02-04T23:59:59.000Z

246

Experimental effects of orbit on polarization loss in RHIC  

SciTech Connect

We are performing several experiments during the RHIC ramp to better understand the impact of orbit errors on the polarization at our current working point. These will be conducted by exciting specified orbit harmonics during the final two large intrinsic resonance crossing in RHIC during the 250 GeV polarized proton ramp. The resultant polarization response will then be measured.

Ranjbar V.; Bai, M.; Huang, H.; Marusic, A.; Ptitsyn, V.; Minty, M.

2012-05-20T23:59:59.000Z

247

Linear collider: a preview  

Science Conference Proceedings (OSTI)

Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center.

Wiedemann, H.

1981-11-01T23:59:59.000Z

248

muon Collider Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

Muon Collider Notes Muon Collider Notes MC-001 D. Neuffer, "Colliding Muon Beams at 90 GeV" Fermilab Note FN-319, July 1979. MC-002 D. Neuffer, "Principles and Applications of Muon Cooling" Proc. of the 12th International Conf. on High-Energy Accelerators, p. 481, 1983. MC-003 V.V. Parkhomchuk and A.N. Skrinsky, "Ionization Cooling: Physics and Applications" Proc. of the 12th International Conf. on High-Energy Accelerators, p. 485, 1983. MC-004 E.A. Perevedentsev and A.N. Skrinsky, "On the Proton Klystron" Proc. of the 12th International Conf. on High-Energy Accelerators, p. 508, 1983. MC-005 D. Neuffer, "Principles and Applications of Muon Cooling" Particle Accelerators, Vol. 14, p. 75, 1983. MC-006 D. Neuffer, "Multi-TeV Muon Colliders" Proc. of the Advanced

249

The TESLA superconducting linear collider  

Science Conference Proceedings (OSTI)

This paper summarizes the present status of the studies for a superconducting Linear Collider (TESLA).

R. Brinkmann; the TESLA Collaboration

1997-01-01T23:59:59.000Z

250

SYSTEMATIC STUDIES OF HEAVY ION COLLISIONS TO SEARCH FOR QUARK-GLUON PLASMA  

SciTech Connect

This is the final technical report for DOE Outstanding Junior Investigator (OJI) Award, 'Systematic Studies of Heavy Ion Collisions to Search for Quark-Gluon Plasma', grant DE-FG02-02ER41219, Principal Investigator (PI) Fuqiang Wang. The research under the grant was divided into two phases. The first concentrated on systematic studies of soft hadron production at low transverse momentum (p{sub T}), in particular the production of (anti-)baryon and strangeness in heavy ion collisions at RHIC energies. The second concentrated on measurements of di-hadron and multi-hadron jet-correlations and investigations of medium response to jets. The research was conducted at the Relativistic Heavy-Ion Collider (RHIC) at BNL with the Solenoidal Tracker At RHIC (STAR) experiment. The total grant is $214,000. The grant established a PC farm solely used for this research. The PC farm consists of 8 nodes with a total of 16 CPUs and 3 disk servers of total 2 TB shared storage. The current balance of the grant is $19,985. The positive balance is because an initial purchase of $22,600 for the PC farm came out of the PI's start-up fund due to the lateness of the award. The PC farm is an integral part of the Purdue Physics Department's computer cluster. The grant supported two Ph.D. graduate students. Levente Molnar was supported from July 2002 to December 2003, and worked on soft hadron production. His thesis title is Systematics of Identified Particle Production in pp, d-Au and Au-Au Collisions at RHIC Energies. He graduated in 2006 and now is a Postdoctoral fellow at INFN Sezione di Bari, Italy working on the ALICE experiment at the LHC. Jason Ulery was supported from January 2004 to July 2007. His thesis title is Two- and Three-Particle Jet-Like Correlations. He defended his thesis in October 2007 and is moving to Frankfurt University, Germany to work on the ALICE experiment at the LHC. The research by this grant resulted in 7 journal publications (2 PRL, 1 PLB, 1 PRC, 2 submitted and 1 in preparation), and 14 invited talks and 10 contributed talks at major conferences. These are listed at end of this report.

Fuqiang Wang

2007-11-29T23:59:59.000Z

251

FEASIBILITY OF INCREASING THE ENERGY OF RHIC.  

SciTech Connect

In this paper we discuss the possibility of increasing the energy of beams in RHIC by as much as 30% with a modest trade-off in luminosity. The arc dipoles and quadrupoles were designed with considerable margin. For higher energies (>100 GeV/nucleon) the minimum {beta}* may be required to increase as the interaction region triplets saturate. The separator magnets (DX) have the least margin for increased field, so we consider three scenarios: allowing for a small crossing angle with the present DX magnets, upgrading the DX magnets to higher strength, and permitting a crossing angle of {approximately}1{degree} by removing the DX magnets altogether.

MACKAY,W.W.; JAIN,A.; LUCCIO,A.U.; PILAT,F.; ROSER,T.; TEPIKIAN,S.; TROBOJEVIC,D.

2001-06-18T23:59:59.000Z

252

TRANSVERSE OPTICS IMPROVEMENTS FOR RHIC RUN 4.  

Science Conference Proceedings (OSTI)

The magnetic settings in RHIC are driven by an on-line model, and the quality of the resulting lattice functions depend on the correctness of the settings, and knowledge of the magnet transfer-functions. Here we first present the different inputs into the model, including dipole sextupole components, used to set tunes and chromaticities along the ramp. Based on an analysis of measured tunes along the FY03 polarized proton ramp, we present predictions for quadrupole transfer-function changes which have been implemented for the FY04 Au ramp. We show the improved model agreement for tunes along the ramp, and measured transverse phase-advance at store.

VAN ZEIJTS,J.

2004-07-05T23:59:59.000Z

253

UP-GRADED RHIC INJECTION SYSTEM.  

Science Conference Proceedings (OSTI)

The design of the RHIC injection systems anticipated the possibility of filling and operating the rings with a 120 bunch pattern, corresponding to 110 bunches after allowing for the abort gap. Beam measurements during the 2002 run confirmed the possibility, although at the expense of severe transverse emittance growth and thus not on an operational basis. An improvement program was initiated with the goal of reducing the kicker rise time from 110 to {approx}95 ns and of minimizing pulse timing jitter and drift. The major components of the injection system are 4 kicker magnets and Blmlein pulsers using thyratron switches. The kicker terminating resistor and operating voltage was increased to reduce the rise time. Timing has been stabilized by using commercial trigger units and extremely stable dc supplies for the thyratron reservoir. A fiber optical connection between control room and the thyratron trigger unit has been provided, thereby allowing the operator to adjust timing individually for each kicker unit. The changes were successfully implemented for use in the RHIC operation.

HAHN,H.FISCHER,W.SEMERTZIDIS,Y.K.WARBURTON,D.S.

2003-05-12T23:59:59.000Z

254

Phi-Meson Production at RHIC, Strong Color Fields and Intrinsic Transverse Momenta  

E-Print Network (OSTI)

We investigate the effects of strong color fields and of the associated enhanced intrinsic transverse momenta on the phi-meson production in ultrarelativistic heavy ion collisions at RHIC. The observed consequences include a change of the spectral slopes, varying particle ratios, and also modified mean transverse momenta. In particular, the composition of the production processes of phi mesons, that is, direct production vs. coalescence-like production, depends strongly on the strength of the color fields and intrinsic transverse momenta and thus represents a sensitive probe for their measurement.

Sven Soff; Srikumar Kesavan; Jorgen Randrup; Horst Stocker; Nu Xu

2004-04-02T23:59:59.000Z

255

Photon collider at TESLA  

E-Print Network (OSTI)

High energy photon colliders (gamma-gamma, gamma-electron) based on backward Compton scattering of laser light is a very natural addition to e+e- linear colliders. In this report we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case the gamma-gamma luminosity luminosity in the high energy part of spectrum can reach (1/3)L_{e+e-}. Typical cross sections of interesting processes in gamma-gamma collisions are higher than those in e+e- collisions by about one order of magnitude, so the number of events in gamma-gamma collisions will be more than that in e+e- collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is ``an optical storage ring (optical trap)'' with diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based at TESLA, its possible parameters and existing problems.

Valery Telnov

2000-10-13T23:59:59.000Z

256

The LHC as a Proton-Nucleus Collider  

E-Print Network (OSTI)

Following its initial operation as a proton-proton (p-p) and heavy-ion (208Pb82+-208Pb82+) collider, the LHC is expected to operate as a p-Pb collider. Later it may collide protons with other lighter nuclei such as 40Ar18+ or 16O8+. We show how the existing proton and lead-ion injector chains may be efficiently operated in tandem to provide these hybrid collisions. The two-in-one magnet design of the LHC main rings imposes different revolution frequencies for the two beams in part of the magnetic cycle. We discuss and evaluate the consequences for beam dynamics and estimate the potential performance of the LHC as a proton-nucleus collider.

Carli, C

2006-01-01T23:59:59.000Z

257

Dark matter at colliders  

SciTech Connect

We show that colliders can impose strong constraints on dark matter. We take an effective field theory approach where dark matter couples to quarks and gluons through high dimensional operators. We discuss limits on interactions of dark matter and hadronic matter from the ATLAS experiment at the Large Hadron Collider (LHC). For spin-independent scattering, the LHC limits are stronger than those from direct detection experiments for light WIMPs. For spin-dependent scattering, the LHC sets better limits over much of parameter space.

Yu Haibo [Department of Physics, University of Michigan, Ann Arbor, MI, 48109 (United States)

2013-05-23T23:59:59.000Z

258

Feasibility of Electron Cooling for Low-Energy RHIC operation April 18, 2008 FEASIBILITY OF ELECTRON COOLING FOR LOW-ENERGY RHIC  

E-Print Network (OSTI)

for RHIC low-energy cooling. 5.1 DC cooler Electron cooling with electron beam kinetic energies Ek,e=0 for the DC and RF electron beam approach. It suggests that the cost of such a cooler for Low-Energy RHIC;Feasibility of Electron Cooling for Low-Energy RHIC operation April 18, 2008 A.2 Parameters of DC electron

259

Production and Flow of Identified Hadrons at RHIC  

E-Print Network (OSTI)

We review the production and flow of identified hadrons at RHIC with a main emphasis on the intermediate transverse momentum region ($2production and resolve the anomalously large baryon yields and elliptic flow observed in the experiments.

Julia Velkovska

2004-11-18T23:59:59.000Z

260

COUPLING MEASUREMENT AND CORRECTION AT RHIC.  

SciTech Connect

Coupling correction at RHIC has been operationally achieved through a two-step process: using local triplet skew quadrupoles to compensate coupling corn rolled low-beta triplet quadrupoles, and minimizing the tune separation and residual coupling with orthogonal global skew quadrupole families. An application has been developed for global correction that allows skew quadrupole tuning and tune display with a choice of different tune measurement techniques, including tune-meter, Schottky and phase lock loop (PLL). Coupling effects have been analysed by using 1024-turn (TBT) information from the beam position monitor (BPM) system. These data allow the reconstruction of the off-diagonal terms of the transfer matrix, a measure of global coupling. At both injection and storage energies, coordination of tune meter kicks with TBT acquisition at 322 BPM's in each ring allows the measurement of local coupling at all BPM locations.

PILAT,F.; BEEBE-WANG,J.; FISCHER,W.; PTITSYN,V.; SATOGATA,T.

2002-06-02T23:59:59.000Z

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261

MEASURING LOCAL GRADIENT AND SKEW QUADRUPOLE ERRORS IN RHIC IRS.  

SciTech Connect

The measurement of local linear errors at RHIC interaction regions using an ''action and phase'' analysis of difference orbits has already been presented. This paper evaluates the accuracy of this technique using difference orbits that were taken when known gradient errors and skew quadrupole errors were intentionally introduced. It also presents action and phase analysis of simulated orbits when controlled errors are intentionally placed in a RHIC simulation model.

CARDONA,J.; PEGGS,S.; PILAT,R.; PTITSYN,V.

2004-07-05T23:59:59.000Z

262

MEASUREMENT OF MULTIPOLE STRENGTHS FROM RHIC BPM DATA.  

Science Conference Proceedings (OSTI)

Recently resonance driving terms were successfully measured in the CERN SPS and the BNL RHIC from the Fourier spectrum of BPM data. Based on these measurements a new analysis has been derived to extract multipole strengths. In this paper we present experimental measurements of sextupolar and skew quadrupolar strengths carried out at RHIC. A non-destructive measurement using an AC dipole is also presented.

TOMAS,R.BAI,M.FISCHER,W.ET AL.

2004-07-05T23:59:59.000Z

263

Commissioning results from the recently upgraded RHIC LLRF system  

Science Conference Proceedings (OSTI)

During RHIC Run 10, the first phase of the LLRF Upgrade was successfully completed. This involved replacing the aging VME based system with a modern digital system based on the recently developed RHIC LLRF Upgrade Platform, and commissioning the system as part of the normal RHIC start up process. At the start of Run 11, the second phase of the upgrade is underway, involving a significant expansion of both hardware and functionality. This paper will review the commissioning effort and provide examples of improvements in system performance, flexibility and scalability afforded by the new platform. The RHIC LLRF upgrade is based on the recently developed RHIC LLRF Upgrade Platform. The major design goals of the platform are: (1) Design a stand alone, generic, digital, modular control architecture which can be configured to satisfy all of the application demands we currently have, and which will be supportable and upgradeable into the foreseeable future; and (2) It should integrate seamlessly into existing controls infrastructure, be easy to deploy, provide access to all relevant control parameters (eliminate knobs), provide vastly improved diagnostic data capabilities, and permit remote reconfiguration. Although the system is still in its infancy, we think the initial commissioning results from RHIC indicate that these goals have been achieved, and that we've only begun to realize the benefits the platform provides.

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

2011-03-28T23:59:59.000Z

264

Parallel Simulation of Electron Cooling Physics and Beam Transport  

NLE Websites -- All DOE Office Websites (Extended Search)

Heavy Ion Collider (RHIC) at BNL. CEBAF is the main research accelerator at JLAB. The Nuclear Physics program supports a broad range of activities aimed at research and...

265

Phases of QCD: Summary of the Rutgers Long Range Plan Town Meeting, January 12-14, 2007  

E-Print Network (OSTI)

Electron-Ion Collider at CEBAF, Editors: Ya. Derbenev, L.ion complex, and ELIC, using CEBAF as a full energy injectorthe ERL-based eRHIC, and the CEBAF-based ELIC colliders. The

Jacobs, Peter

2008-01-01T23:59:59.000Z

266

Muon Collider Progress: Accelerators  

SciTech Connect

A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 10{sup 34} cm{sup 2}s{sup 1}. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (cooling). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

Zisman, Michael S.

2011-09-10T23:59:59.000Z

267

muon_collider  

NLE Websites -- All DOE Office Websites (Extended Search)

muon_collider muon_collider muon_collider FridayMeetings MCTFmeetings MondayMeetings prstab texput.log #prstab.tex# last.kumac prstab.ps arxiv.tar.gz prstab.tar.gz referee_response_II.pdf prstab.pdf prstab.aux prstab.dvi prstab.end prstab.log prstab.tex prstab.tex~ accel-010307-f03.eps accel-010307-f28.eps old conclusions.tex higgsfact.tex introduction.tex mice.tex neufact.tex physics.tex prstab.tex r_and_d.tex authors_merged.tex buncher.tex temp.prt last.kumacold ringfig.eps MICE-fig.ps chgr_norm.ps chgr_merit.ps temp.csh temp.prt~ xupdn-a-model-view-iron5.eps site1-Layout1.eps rla2.eps phaserot.eps mole-hill.eps intoap.eps emit.eps cavity.eps allcount.eps MICE-88MHz-cooling.eps changes hh_ha_susy_rtsscan.eps letter_plots.eps scott33.eps scott32b.eps scott32a.eps MICE-200MHz-long.eps MICE-resolution.eps dipole_fields.eps

268

Electron Ion Collider: The Next QCD Frontier  

E-Print Network (OSTI)

dominated region of the nucleon at the upgraded 12 GeV CEBAF at JLab and COMPASS at CERN. Applying these new orbital motion are expected to contribute. The 12 GeV upgrade of CEBAF at JLab will start on such studies upgraded CEBAF, now under construction, to achieve similar collision parameters. 10 #12;eSTAR ePHENIX 30GeV

Homes, Christopher C.

269

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

Science Conference Proceedings (OSTI)

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 formation of quarkonium in nuclear medium as well as the strong interacting quark-gluon matter produced in heavy ion collisions; and heavy quarkonium properties from the first principle lattice calculations. The heavy quarkonium production at a future Electron-Ion Collider (EIC) was also discussed at the meeting. The highlight of the meeting was the apparent success of the NRQCD approach at next-to-leading order in the description of the quarkonium production in proton-proton, electron-proton and electron positron collisions. Still many questions remain open in lattice calculations of in-medium quarkonium properties and in the area of cold nuclear matter effects.

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

2011-08-03T23:59:59.000Z

270

Opportunities for Drell-Yan Physics at RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

Proceedings Information for Proceedings Information for Speakers Accommodations Directions to Event Local Weather Visiting Brookhaven Disclaimer Event Date May 11-13, 2011 Event Location Brookhaven National Laboratory Physics Building Bldg 510 Large Seminar Room Upton, NY 11973 USA Directions Event Coordinator Susan Foster Bus: 631-344-5864 Fax: 631-344-2562 Email: sfoster@bnl.gov Opportunities for Drell-Yan Physics at RHIC Motivation 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 collisions and d+Au collisions RHIC provides a unique opportunity world wide to address several fundamental questions in QCD, i.e. parton saturation, universality of transverse momentum distributions. A DY program at RHIC is tied closely to

271

THE RHIC/AGS ONLINE MODEL ENVIRONMENT: DESIGN AND OVERVIEW.  

SciTech Connect

An integrated online modeling environment is currently under development for use by AGS and RHIC physicists and commissioners. This environment combines the modeling efforts of both groups in a CDEV [1] client-server design, providing access to expected machine optics and physics parameters based on live and design machine settings. An abstract modeling interface has been designed as a set of adapters [2] around core computational modeling engines such as MAD and UAL/Teapot++ [3]. This approach allows us to leverage existing survey, lattice, and magnet infrastructure, as well as easily incorporate new model engine developments. This paper describes the architecture of the RHIC/AGS modeling environment, including the application interface through CDEV and general tools for graphical interaction with the model using Tcl/Tk. Separate papers at this conference address the specifics of implementation and modeling experience for AGS and RHIC.

SATOGATA,T.; BROWN,K.; PILAT,F.; TAFTI,A.A.; TEPIKIAN,S.; VAN ZEIJTS,J.

1999-03-29T23:59:59.000Z

272

Results from hadron colliders  

SciTech Connect

The present status of hadron collider physics is reviewed. The total cross section for {bar p} + p has been measured at 1.8 TeV: {sigma}{sub tot} = 72.1 {plus minus} 3.3 mb. New data confirm the UA2 observation of W/Z {yields} {bar q}q. Precision measurements of M{sub W} by UA2 and CDF give an average value M{sub W} = 80.13 {plus minus} 0.30 GeV/c{sup 2}. When combined with measurements of M{sub Z} from LEP and SLC this number gives sin{sup 2}{theta}{sub W} = 0.227 {plus minus} 0.006, or m{sub top} = 130{sub {minus}60}{sup +40} GeV/c{sup 2} from the EWK radiative correction term {Delta}r. Evidence for hadron colliders as practical sources of b quarks has been strengthened, while searches for t quarks have pushed the mass above M{sub W}: m{sub top} > 89 GeV/c{sup 2} 95% cl (CDF Preliminary). Searches beyond the standard model based on the missing E{sub T} signature have not yet produced any positive results. Future prospects for the discovery of the top quark in the range m{sub top} < 200 GeV/c{sup 2} look promising. 80 refs., 35 figs., 7 tabs.

Pondrom, L.G. (Wisconsin Univ., Madison, WI (USA))

1990-12-14T23:59:59.000Z

273

Cold matter effects and quarkonium production at RHIC and LHC  

SciTech Connect

In this work we investigate two cold matter effects in J/{Psi} and {Upsilon} production in nuclear collisions at RHIC and LHC, namely the shadowing effect and nuclear absorption. We characterize these effects by estimating the rapidity dependence of some nuclear ratios in pA and AA collisions at RHIC and LHC, R{sub pA} = d{sigma}{sub pA}(J/{Psi},{Upsilon})/Ad{sigma}{sub pp}(J/{Psi},{Upsilon}) and R{sub AA} = d{sigma}{sub AA}(J/{Psi},{Upsilon})/A{sup 2}d{sigma}{sub pp}(J/{Psi},{Upsilon}).

Dos Santos, G. S.; Mariotto, C. B. [Instituto de Matematica, Estatistica e Fisica, Universidade Federal do Rio Grande, Caixa Postal 474, CEP 96203-900, Rio Grande, RS (Brazil); Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-090, Pelotas, RS (Brazil)

2013-03-25T23:59:59.000Z

274

An alternative model of jet suppression at RHIC energies  

E-Print Network (OSTI)

We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

2003-01-16T23:59:59.000Z

275

The Thermal Model at the Large Hadron Collider  

E-Print Network (OSTI)

A discussion is presented of results with identified particles at the Large Hadron Collider. Possible deviations from the standard statistical distributions are investigated by considering in detail results obtained using the Tsallis distribution. Matter-antimatter production is discussed within the framework of chemical equilibrium in \\pp and heavy ion collisions.

J. Cleymans

2012-03-26T23:59:59.000Z

276

Colliding Crystalline Beams  

SciTech Connect

Crystalline Beams* are an ordered state of an ensemble of ions, circulating in a storage ring, with very small velocity fluctuations. They can be obtained from ordinary warm ion beams with the application of powerful cooling techniques (stochastic, electron, laser, ...). Depending on the focussing properties and dimensions of the storage ring, and on the ion beam density, several ground states are possible. All of them can be visualized as a bundle of n{sub s} symmetrically distributed, parallel strings. The longitudinal ion separation {lambda} is the same for all strings. The minimum temperature that can be achieved depends on die background noise of the cooling technique used. It is required for stability that the vibration amplitude of the ions is only a fraction of the separation {lambda}.

Haffmans, A.F.; Maletic, D.; Ruggiero, A.G.

1995-06-01T23:59:59.000Z

277

Effect of jets on $v_4/v_2^2$ ratio and constituent quark scaling in relativistic heavy-ion collisions  

E-Print Network (OSTI)

The Monte Carlo HYDJET++ model, that combines parametrized hydrodynamics with jets, is employed to study formation of second v_2 and fourth v_4 components of the anisotropic flow in ultrarelativistic heavy-ion collisions at energies of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), sqrt{s}=200 AGeV and sqrt{s}=2.76 ATeV, respectively. It is shown that the quenched jets contribute to the soft part of the v_2(p_T) and v_4(p_T) spectra. The jets increase the ratio v_4/v_2^2 thus leading to deviations of the ratio from the value of 0.5 predicted by the ideal hydrodynamics. Together with the event-by-event fluctuations, the influence of jets can explain quantitatively the ratio v_4/v_2^2 at p_T energies and qualitatively the rise of its high-p_T tail at LHC. Jets are also responsible for violation of the number-of-constituent-quark (NCQ) scaling at LHC despite the fact that the scaling is fulfilled for the hydro-part of particle spectra.

L. Bravina; B. H. Brusheim Johansson; G. Eyyubova; E. Zabrodin

2013-02-26T23:59:59.000Z

278

Effect of jets on $v_4/v_2^2$ ratio and constituent quark scaling in relativistic heavy-ion collisions  

E-Print Network (OSTI)

The Monte Carlo HYDJET++ model, that combines parametrized hydrodynamics with jets, is employed to study formation of second v_2 and fourth v_4 components of the anisotropic flow in ultrarelativistic heavy-ion collisions at energies of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), sqrt{s}=200 AGeV and sqrt{s}=2.76 ATeV, respectively. It is shown that the quenched jets contribute to the soft part of the v_2(p_T) and v_4(p_T) spectra. The jets increase the ratio v_4/v_2^2 thus leading to deviations of the ratio from the value of 0.5 predicted by the ideal hydrodynamics. Together with the event-by-event fluctuations, the influence of jets can explain quantitatively the ratio v_4/v_2^2 at p_T energies and qualitatively the rise of its high-p_T tail at LHC. Jets are also responsible for violation of the number-of-constituent-quark (NCQ) scaling at LHC despite the fact that the scaling is fulfilled for the hydro-part of particle spectra.

Bravina, L; Eyyubova, G; Zabrodin, E

2013-01-01T23:59:59.000Z

279

Photon collider at TESLA 1  

E-Print Network (OSTI)

High energy photon colliders (??, ?e) based on backward Compton scattering of laser light is a very natural addition to e + e ? linear colliders. In this report we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case the ?? luminosity in the high energy part of spectrum can reach about (1/3)L e e ?. Typical cross sections of interesting processes in ?? collisions are higher than those in e + e ? collisions by about one order of magnitude, so the number of events in ?? collisions will be more than that in e + e ? collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is an optical storage ring (optical trap) with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems. PACS: 29.17.+w, 41.75.Ht, 41.75.Lx, 13.60.Fz Key words: photon collider; linear collider; photon photon; gamma gamma; photon electron; Compton scattering; backscattering 1

Valery Telnov

2001-01-01T23:59:59.000Z

280

Neutrino Physics at a Muon Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Physics at a Muon Collider The intense muon beams needed for high luminosity muon colliders produce intense beams of neutrinos. Dedicated muon storage rings with long straight...

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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Director's colloquium March 18 large hadron collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Director's colloquium large hadron collider Director's colloquium March 18 large hadron collider Lyndon Evans of CERN will talk about the most complex scientific instrument ever...

282

Links to Muon Collider Related Web Pages  

NLE Websites -- All DOE Office Websites (Extended Search)

Muon Collider related web pages: Muon Collider Feasibility Study ... Fermilab Page MUCOOL Collaboration: Ionization Cooling R&D Snowmass 1996 Feasibility Study Book Brookhaven Muon...

283

MAPPING OUT THE FULL SPIN RESONANCE STRUCTURE OF RHIC.  

SciTech Connect

We extended the ability of DEPOL [1] to calculate coupled spin resonances and used it to determine the location and strength of both intrinsic and coupled spin resonances in RHIC. In particular we are interested in the full resonance structure with solenoidal elements turned on and with quadrupole rolls[2].

RANJBAR,V.; LEE,S.Y.; MACKAY,W.W.; BAI,M.; COURANT,E.

2001-06-18T23:59:59.000Z

284

Analysis and correction of vertical dispersion in RHIC  

SciTech Connect

In the context of preserving the polarization of proton beams, the source of vertical dispersion in RHIC is analyzed. Contributions to dispersion from non-coupling sources and coupling sources are compared. Based on the analysis of sources for dispersion, the right actuator for correcting dispersion is determined and a corresponding algorithm is developed.

Liu, C.; Minty, M.

2011-09-14T23:59:59.000Z

285

Beam experiments towards high-intensity beams in RHIC  

SciTech Connect

Proton bunch intensities in RHIC are planned to be increased from 2 {center_dot} 10{sup 11} to 3 {center_dot} 10{sup 11} protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results are presented.

Montag C.; Ahrens, L.; Brennan, J.M.; Blaskiewicz, M.; Drees, A.; Fischer, W.; Hayes, T.; Huang, H.; Mernick, K.; Robert-Demolaize, G.; Smith, K.; Than, R.; Thieberger, P.; Yip, K.; Zeno, K.; Zhang, S.Y.

2012-05-20T23:59:59.000Z

286

The electromagnetic calorimeter for the STAR experiment at RHIC  

SciTech Connect

The STAR detector at RHIC can be used both for searches for quark-gluon plasma and for high energy pp spin physics. An electromagnetic calorimeter is being planned which will be used for triggering on High pt direct gammas, e[sup [plus minus

Underwood, D.G.

1992-01-01T23:59:59.000Z

287

Hard-scattering and Jets from RHIC to LHC: a critical review  

E-Print Network (OSTI)

Jets in hadron collisions are very complicated with a long learning curve replete with errors. In relativistic heavy ion (RHI) collisions, it is likely that jets will be much more complicated with an even longer and more difficult learning curve. Hard scattering is more easily observed via single particle and few particle correlation measurements. The main advantage of jets is higher rate at large $p_T$, plus the possibility of detailed studies of soft fragmentation if the soft fragments can be separated from the background. A critical review of the possibility of using jets as a probe of hard-scattering in RHI collisions is presented along with other probes and measurements which the author considers much more likely to reveal the interesting physics in Pb+Pb collisions at the LHC. Finally, a list of unanswered questions raised by results at RHIC is presented.

M. J. Tannenbaum

2007-07-11T23:59:59.000Z

288

The Very Large Hadron Collider: The farthest energy frontier  

E-Print Network (OSTI)

THE VERY LARGE HADRON COLLIDER: THE FARTHEST ENERGY FRONTIERAbstract The Very Large Hadron Collider (or Eloisatron)

Barletta, William A.

2001-01-01T23:59:59.000Z

289

Fermilab | Muon Collider | How Does a Muon Collider Work?  

NLE Websites -- All DOE Office Websites (Extended Search)

A muon collider complex would comprise several machines and many different A muon collider complex would comprise several machines and many different components. Scientists across the world are developing and testing them. View full graphic How Does a Muon Collider Work? A muon collider complex would comprise several machines and many different components. Scientists across the world are developing and testing them. Proton accelerator To create lots of muons, scientists use a high-intensity proton accelerator that steers protons into a target. The collisions create short-lived particles called pions. Within 50 meters the pions decay into muons and neutral particles called neutrinos. The muons have an energy of about 200 MeV. Capture cavities Magnets guide the muons into and through a set of radiofrequency cavities. The electric field inside the cavities increases the energy of slow muons

290

Discover Brookhaven  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Serves as World's First & Only Collider RHIC Serves as World's First & Only Collider of Polarized Protons for 'Spin' Physics As the world's first and only collider of spin-polarized protons, the Relativistic Heavy Ion Collider is being employed to investigate a fundamental question about an important particle and a universal property: What is responsible for the "spin," or intrinsic angular momentum, of the proton? While data from this spring's run are being analyzed, unexpected results from RHIC's first spin-physics run are generating great interest. by Marsha Belford FOR THE SECOND TIME SINCE ITS COMMISSIONING IN 2000 as the world's highest energy, heavy-ion collider, the Relativistic Heavy Ion Collider (RHIC) took a break from colliding gold ions in the attempt to recreate the conditions of the early universe - to serve again as the world's first and only collider of spin-polarized protons.

291

First Linear Collider ISG Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Collider Internation Study Group Workshop Full meeting proceedings Participant Photos Banquet Dinner Photos Note that you will need to have Adobe Reader 3.0 or GhostView installed...

292

Oscillation Energies of Colliding Raindrops  

Science Conference Proceedings (OSTI)

When raindrops collide, some of the kinetic energy involved in the collision will be available to initiate or sustain oscillations in the surviving drops. This paper presents results of a simple model of drop collisions that generates an estimate ...

David B. Johnson; Kenneth V. Beard

1984-04-01T23:59:59.000Z

293

Muon muon collider: Feasibility study  

Science Conference Proceedings (OSTI)

A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup {minus}2} s{sup {minus}1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice--the authors believe--to allow them to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring which has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design.

NONE

1996-06-18T23:59:59.000Z

294

Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"  

E-Print Network (OSTI)

Experimental Physics with Relativistic Heavy Ions dates from 1992 when a beam of 197Au of energy greater than 10A GeV/c first became available at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A GeV/c at the Super Proton Synchrotron (SPS) at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac in the late 1970's and early 1980's were at much lower bombarding energies (~ 1 A GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the Relativistic Heavy Ion Collider (RHIC) at BNL has produced head-on collisions of two 100A GeV beams of fully stripped Au ions, corresponding to nucleon-nucleon center-of-mass energy, sqrt(sNN)=200 GeV, total c.m. energy 200A GeV. The objective of this research program is to produce nuclear matter with extreme density and temperature, possibly resulting in a state of matter where the quarks and gluons normally confined inside individual nucleons (r laboratories: "A new state of matter", by CERN on Feb 10, 2000 and "The perfect fluid", by BNL on April 19, 2005.

M. J. Tannenbaum

2006-03-01T23:59:59.000Z

295

Moments of net-charge multiplicity distribution in Au+Au collisions measured by the PHENIX experiment at RHIC  

E-Print Network (OSTI)

Beam Energy Scan (BES) program at RHIC is important to search for the existence of the critical point in the QCD phase diagram. Lattice QCD have shown that the predictions of the susceptibility of the medium formed in heavy-ion collisions can be sensitive to the various moments (mean ($\\mu$) =${}$, variance ($\\sigma^2$) = ${}$, skewness (S) = $\\frac{}{\\sigma^3}$ and kurtosis ($\\kappa$) =$\\frac{}{\\sigma^4} -3$) of conserved quantities like net-baryon number ($\\Delta$B), net-electric charge ($\\Delta$Q) and net-strangeness ($\\Delta$S). Any non-monotonic behavior of the higher moments would confirm the existence of the QCD critical point. The recent results of the higher moments of net-charge multiplicity distributions for Au+Au collisions at $\\sqrt{s}_{NN}$ varying from 7.7 GeV to 200 GeV from the PHENIX experiment at RHIC are presented. The energy and centrality dependence of the higher moments and their products (S$\\sigma$ and $\\kappa\\sigma^{2}$) are shown for the net-charge multiplicity distributions. Furthermore, the results are compared with the values obtained from the heavy-ion collision models, where there is no QCD phase transition and critical point.

P. Garg

2013-05-31T23:59:59.000Z

296

PERFORMANCE SUMMARY OF THE HELICAL MAGNETS FOR RHIC*  

NLE Websites -- All DOE Office Websites (Extended Search)

submitted at The Particle Accelerator Conference, Portland,OR, May 12-16, 2003 submitted at The Particle Accelerator Conference, Portland,OR, May 12-16, 2003 BNL-71398-2003-CP PERFORMANCE SUMMARY OF THE HELICAL MAGNETS FOR RHIC* E. Willen, M. Anerella, J. Escallier, G. Ganetis, A. Ghosh, R. Gupta, M. Harrison, A. Jain, W. MacKay, A. Marone, J. Muratore, S. Plate, R. Thomas, P. Wanderer and KC Wu, BNL, Upton, NY 11973, USA M. Okamura, RIKEN, Japan Abstract A series of four Snake and eight Rotator superconducting helical magnet assemblies has been built and installed in RHIC to control the polarization of protons during acceleration and storage in that machine. Each of these assemblies consists of four 2.4 m long dipole magnets in each of which the field rotates through 360 degrees along the magnet's length. The magnets were

297

Reduction of beta* and increase of luminosity at RHIC  

SciTech Connect

The reduction of {beta}* beyond the 1m design value at RHIC has been consistently achieved over the last 6 years of RHIC operations, resulting in an increase of luminosity for different running modes and species. During the recent 2007-08 deuteron-gold run the reduction to 0.70 from the design 1m achieved a 30% increase in delivered luminosity. The key ingredients allowing the reduction have been the capability of efficiently developing ramps with tune and coupling feedback, orbit corrections on the ramp, and collimation, to minimize beam losses in the final focus triplets, the main aperture limitations for the collision optics. We will describe the operational strategy used to reduce the {beta}*, at first squeezing the beam at store, to test feasibility, followed by the operationally preferred option of squeezing the beam during acceleration, and the resulting luminosity increase. We will conclude with future plans for the beta squeeze.

Pilat,F.; Bai, M.; Bruno, D.; Cameron, P.; Della Penna, A.; Drees, A.; Litvinenko, V.; Luo, Y.; Malitsky, N.; Marr, G.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Trbojevic, D.

2009-05-04T23:59:59.000Z

298

Strangeness Production at RHIC in the Perturbative Regim  

E-Print Network (OSTI)

We investigate strange quark production in Au-Au collisions at RHIC in the framework of the Parton Cascade Model(PCM). The yields of (anti-) strange quarks for three production scenarios -- primary-primary scattering, full scattering, and full production -- are compared to a proton-proton baseline. Enhancement of strange quark yields in central Au-Au collisions compared to scaled p-p collisions increases with the number of secondary interactions. The centrality dependence of strangeness production for the three production scenarios is studied as well. For all production mechanisms, the strangeness yield increases with $(N_{\\rm part})^{4/3}$. The perturbative QCD regime described by the PCM is able to account for up to 50% of the observed strangeness at RHIC.

Daphne Y. Chang; Steffen A. Bass; Dinesh K. Srivastava

2004-03-13T23:59:59.000Z

299

ACTION AND PHASE ANALYSIS TO DETERMINE SEXTUPOLE ERRORS IN RHIC AND THE SPS.  

Science Conference Proceedings (OSTI)

Success in the application of the action and phase analysis to find linear errors at RHIC Interaction Regions [1] has encouraged the creation of a technique based on the action and phase analysis to find non linear errors. In this paper we show the first attempt to measure the sextupole components at RHIC interaction regions using the action and phase method. Experiments done by intentionally activating sextupoles in RHIC and in SPS [2] will also be analyzed with this method. First results have given values for the sextupole errors that at least have the same order of magnitude as the values found by an alternate technique during the RHIC 2001 run [3].

CARDONA,J.PEGGS,S.SATOGATA,T.TOMAS,R.

2003-05-12T23:59:59.000Z

300

THE ANALYSIS OF DEPOLARIZATION FACTORS IN THE LAST RHIC RUN.  

SciTech Connect

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.

PTITSYN,V.LUCCIO,A.U.RANJBAR,V.H.

2002-09-09T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

NON-LINEAR MODELING OF THE RHIC INTERACTION REGIONS.  

Science Conference Proceedings (OSTI)

For RHIC's collision lattices the dominant sources of transverse non-linearities are located in the interaction regions. The field quality is available for most of the magnets in the interaction regions from the magnetic measurements, or from extrapolations of these measurements. We discuss the implementation of these measurements in the MADX models of the Blue and the Yellow rings and their impact on beam stability.

TOMAS,R.FISCHER,W.JAIN,A.LUO,Y.PILAT,F.

2004-07-05T23:59:59.000Z

302

RHIC tracking studies with real magnets in real places  

SciTech Connect

Results from RHIC tracking studies in which measured magnetic field errors are used in all arc magnets are reported. the dependence of betatron tunes on initial amplitudes, aspect ratio, and momentum are reported and are not significantly different from measured tune dependences when randomly generated magnetic field errors are used in all magnets. Survival plots at injection and storage are also consistent with previous determinations.

Dell, G.F.; Peggs, S.; Pilat, F.

1996-07-01T23:59:59.000Z

303

PHENIX Experiment Results from the RHIC Beam Energy Scan Program  

E-Print Network (OSTI)

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.

J. T. Mitchell for the PHENIX Collaboration

2013-08-09T23:59:59.000Z

304

PHENIX Experiment Results from the RHIC Beam Energy Scan Program  

E-Print Network (OSTI)

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.

,

2013-01-01T23:59:59.000Z

305

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

6, 27/05/99 6, 27/05/99 Tolerances of Random RF Jitters in X-Band Main Linacs May 27, 1999 Kiyoshi KUBO KEK Tsukuba, Japan Abstract: Tracking simulations have been performed for the main linacs of an X-band linear collider. We discuss the choice of phase of the accelerating field relative to the bunches. The tolerances of the phase and the amplitude errors are studied. Tolerances of Random RF Jitters in X-Band Main Linacs K. Kubo, KEK Abstract Tracking simulations have been performed for main linacs of X-band linear collider. We discuss about choice of the phase of the accelerating field relative to the bunches. The tolerances of the phase and the amplitude errors are studied. 1 INTRODUCTION In order to preserve the low emittance through the main linacs of future linear colliders, various effects

306

Fake Dark Matter at Colliders  

E-Print Network (OSTI)

If the dark matter (DM) consists of a weakly interacting massive particle (WIMP), it can be produced and studied at future collider experiments like those at the LHC. The production of collider-stable WIMPs is characterized by hard scattering events with large missing transverse energy. Here we point out that the discovery of this well-characterized DM signal may turn out to be a red herring. We explore an alternative explanation -- fake dark matter -- where the only sources of missing transverse energy are standard model neutrinos. We present examples of such models, focusing on supersymmetric models with R-parity violation. We also briefly discuss means of differentiating fake dark matter from the production of new collider-stable particles.

Chang, Spencer

2009-01-01T23:59:59.000Z

307

Fake Dark Matter at Colliders  

E-Print Network (OSTI)

If the dark matter (DM) consists of a weakly interacting massive particle (WIMP), it can be produced and studied at future collider experiments like those at the LHC. The production of collider-stable WIMPs is characterized by hard scattering events with large missing transverse energy. Here we point out that the discovery of this well-characterized DM signal may turn out to be a red herring. We explore an alternative explanation -- fake dark matter -- where the only sources of missing transverse energy are standard model neutrinos. We present examples of such models, focusing on supersymmetric models with R-parity violation. We also briefly discuss means of differentiating fake dark matter from the production of new collider-stable particles.

Spencer Chang; Andre de Gouvea

2009-01-30T23:59:59.000Z

308

Large hadron collider (LHC) project quality assurance plan  

E-Print Network (OSTI)

PUB-5478-Rev.B Large Hadron Collider (LHC) Project Qualityobjectives of the Large Hadron Collider (LHC) Project in aparticipation in the Large Hadron Collider Project. The LHC/

Gullo, Lisa; Karpenko, Victor; Robinson, Kem; Turner, William; Wong, Otis

2002-01-01T23:59:59.000Z

309

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

DOE Green Energy (OSTI)

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.

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

2005-01-28T23:59:59.000Z

310

P{bar P} collider physics  

Science Conference Proceedings (OSTI)

A brief introduction to {bar p}p collider physics is given. Selected results from the collider experiments at the CERN S{bar p}pS and the Tevatron collider are described. The emphasis is on experimental aspects of {bar p}p collisions. Minimum bias physics and the production of jets, Intermediate Vector Bosons and heavy flavors is reviewed. The outlook for physics at hadron colliders for the near future is briefly discussed.

Demarteau, M. [State Univ. of New York, Stony Brook, NY (United States)

1992-04-01T23:59:59.000Z

311

http://magnets.rhic.bnl.gov/Sta.PDF  

NLE Websites -- All DOE Office Websites (Extended Search)

(BNL) is build- ing a number of magnets for the insertion regions of the Large Hadron Collider (LHC). This paper presents the magnetic de- sign and the expected field...

312

Atomic Physics Aspects of a Relativistic Nuclear Collider  

DOE Green Energy (OSTI)

Atomic collision cross sections involving bare uranium nuclei are large at relativistic energies and will affect the design and operation of a relativistic nuclear collider (RNC). The most significant may be production of electron-positron pairs and muon pairs ({approx} 10{sup 8} per sec. and 2000 per sec. respectively for a 100 GeV/nucleon collider with a luminosity of 10{sup 27} cm{sup 2} s{sup -1}). Although the pair production is a direct measure of the luminosity it is also a large source of background and capture of an electron from the pair by one of the nuclei will result in the loss of the ion. Another important loss mechanism is Coulomb excitation of the giant nuclear dipole and giant nuclear quadrupole resonances. Storing and colliding bare and highly-stripped uranium opens up new possibilities for novel atomic physics experiments and an alternate approach for present experiments. As examples, the use of a collider for experiments to study spontaneous decay of the super-critical state (both positron production and x-ray production) of quasi-atoms of atomic number Z > 172, and a storage-ring measurement of the ground state hyperfine structure of hydrogen like thallium as a test of quantum electrodynamics (QED) are discussed.

Gould, R.

1984-11-01T23:59:59.000Z

313

RESONANT BPM FOR CONTINUOUS TUNE MEASUREMENT IN RHIC.  

Science Conference Proceedings (OSTI)

A movable Beam Position Monitor (BPM) using shorted stripline Pick-Up Electrode (NE) elements has been resonated using matching stub techniques to achieve a relatively high Q resonance at about 230MHz. This PUE has been used in a feasibility study of phase-locked-loop tune measurement [1], using a lock-in amplifier and variable frequency generator to continuously track betatron tune in RHIC, as well as to observe Schottky signals of the Gold beam. The approach to providing a high Q PUE for difference mode signals, simulation studies, and the results of initial tests will be presented.

KESSELMAN,M.; CAMERON,P.; CUPOLO,J.

2001-06-18T23:59:59.000Z

314

Systematic Study of Directed Flow at RHIC Energies  

E-Print Network (OSTI)

Directed flow, v1, of charged hardons has been measured in Au-Au collisions at RHIC for center-of-mass energies sqrt(sNN) = 19.6, 130, 62.4, and 200 GeV using the PHOBOS detector. The large acceptance of PHOBOS for charged particles allows measurements over the full range of pseudorapidity |eta| <5.4. The results for a symmetric subevent method are shown at all four energies. Comparison is made to a mixed harmonic method for the highest energy, and compared to similar results from the STAR collaboration.

Alice C. Mignerey; for the Phobos Collaboration

2005-10-10T23:59:59.000Z

315

The electromagnetic calorimeter for the STAR experiment at RHIC  

SciTech Connect

The STAR detector at RHIC can be used both for searches for quark-gluon plasma and for high energy pp spin physics. An electromagnetic calorimeter is being planned which will be used for triggering on High pt direct gammas, e{sup {plus_minus}}, and the electromagnetic component of jets. Jets will be measured for both kinds of physics by using the electro-magnetic calorimeter and central TPC tracking. We describe some features of the fiber-tile calorimeter as it is presently being designed.

Underwood, D.G.

1992-11-01T23:59:59.000Z

316

Test of Chemical freeze-out at RHIC  

E-Print Network (OSTI)

We present the results of a systematic test applying statistical thermal model fits in a consistent way for different particle ratios, and different system sizes using the various particle yields measured in the STAR experiment. Comparison between central and peripheral Au+Au and Cu+Cu collisions with data from p+p collisions provides an interesting tool to verify the dependence with the system size. We also present a study of the rapidity dependence of the thermal fit parameters using available data from RHIC in the forward rapidity regions and also using different parameterization for the rapidity distribution of different particles.

Jun Takahashi; for the STAR Collaboration

2008-12-22T23:59:59.000Z

317

Designing a beam transport system for RHIC's electron lens  

SciTech Connect

We designed two electron lenses to apply head-on beam-beam compensation for RHIC; they will be installed near IP10. The electron-beam transport system is an important subsystem of the entire electron-lens system. Electrons are transported from the electron gun to the main solenoid and further to the collector. The system must allow for changes of the electron beam size inside the superconducting magnet, and for changes of the electron position by 5 mm in the horizontal- and vertical-planes.

Gu, X.; Pikin, A.; Okamura, M.; Fischer, W.; Luo, Y.; Gupta, R.; Hock, J.; Raparia, D.

2011-03-28T23:59:59.000Z

318

Institutional Plan FY 2001-2005  

E-Print Network (OSTI)

at Brookhaven National Laboratory. Berkeley Lab's uniqueLab is at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven NationalBrookhaven National Laboratory, ion source development, and magnetron development. Berkeley Lab

Chartock editor, Michael; Hansen editor, Todd

2000-01-01T23:59:59.000Z

319

THE COUPLING CORRECTION SYSTEM AT RHIC: RESULTS FOR THE RUN 2000 AND PLANS FOR 2001.  

SciTech Connect

The RHIC coupling correction system has been commissioned during the year 2000 run, which marked the successful first year of operation of the machine. The RHIC coupling correction system is described with particular emphasis on its flexibility, which allows using both global and local coupling compensation techniques. Coupling measurements and correction data are presented for the RHIC Blue and Yellow rings, together with the procedure used to reduce the minimum tune separation to 0.001, the typical resolution for tune measurements during run 2000. They further demonstrate how local coupling compensation in the interaction regions substantially reduces the strength of the skew quadrupole families used for global coupling compensation.

PILAT,F.; FISCHER,W.; PEGGS,S.; PTITSYN,V.; TEPIKIAN,S.

2001-06-18T23:59:59.000Z

320

THE COUPLING CORRECTION SYSTEM AT RHIC: RESULTS FOR THE RUN 2000 AND PLANS FOR 2001.  

SciTech Connect

The RHIC coupling correction system has been commissioned during the Year 2000 run, which marked the successful first year of operation of the machine. The RHIC coupling correction system is described with particular emphasis on its flexibility, which allows using both global and local coupling compensation techniques. Coupling measurements and correction data are presented for the RHIC Blue and Yellow rings, together with the procedure used to reduce the minimum tune separation to 0.001, the typical resolution for tune measurements during run 2000. They further demonstrate how local coupling compensation in the interaction region substantially reduces the strength of the skew quadrupole families used for global coupling compensation.

PILAT,F.; FISCHER,W.; PEGGS,S.; PTITSYN,V.; TEPIKIAN,S.

2001-06-18T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Partonic EoS in High-Energy Nuclear Collisions at RHIC  

E-Print Network (OSTI)

Partonic EoS in High-Energy Nuclear Collisions at RHIC Nu Xuproperties. In high-energy nuclear collisions, the term ?owthe early stage of high-energy nuclear collision, both the

Xu, Nu

2006-01-01T23:59:59.000Z

322

Partonic Equations of State in High-Energy Nuclear Collisions at RHIC  

E-Print Network (OSTI)

Partonic EoS in High-Energy Nuclear Collisions at RHIC Nu Xuproperties. In high-energy nuclear collisions, the term ?owthe early stage of high-energy nuclear collision, both the

Xu, Nu

2006-01-01T23:59:59.000Z

323

LINEAR AND NONLINEAR CORRECTIONS IN THE RHIC INTERACTION REGIONS.  

SciTech Connect

A method has been developed to measure operationally the linear and non-linear effects of the interaction region triplets, that gives access to the multipole content through the action kick, by applying closed orbit bumps and analysing tune and orbit shifts. This technique has been extensively tested and used during the RHIC operations in 2001. Measurements were taken at 3 different interaction regions and for different focusing at the interaction point. Non-linear effects up to the dodecapole have been measured as well as the effects of linear, sextupolar and octupolar corrections. An analysis package for the data processing has been developed that through a precise fit of the experimental tune shift data (measured by a phase lock loop technique to better than 10{sup -5} resolution) determines the multipole content of an IR triplet.

PILAT,F.; CAMERON,P.; PTITSYN,V.; KOUTCHOUK,J.P.

2002-06-02T23:59:59.000Z

324

Links to Muon Collider Related Web Pages  

NLE Websites -- All DOE Office Websites (Extended Search)

useful nu-factory related web pages: Nu-FactoryMuon Collider Studies at Fermilab Neutrino Factory Design Study MUCOOL Collaboration: Ionization Cooling R&D Brookhaven Muon...

325

Siting the International Linear Collider at Hanford  

SciTech Connect

Review of the proposed International Linear Collider, applications in high energy physics, and evaluation of the Hanford Site as a possible location for siting the facilityl.

Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.

2012-03-15T23:59:59.000Z

326

Siting the International Linear Collider at Hanford  

SciTech Connect

Review of the proposed International Linear Collider, applications in high energy physics, and evaluation of the Hanford Site as a possible location for siting the facility.

Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.

2012-05-01T23:59:59.000Z

327

Probing Higgs Boson Interactions At Future Colliders.  

E-Print Network (OSTI)

??We present in this thesis a detailed analysis of Higgs boson interactions at future colliders. In particular we examine, in a model independent way, the (more)

Biswal, Sudhansu Sekhar

2009-01-01T23:59:59.000Z

328

Subcritical Fission Reactor Based on Linear Collider  

E-Print Network (OSTI)

The beams of Linear Collider after main collision can be utilized to build an accelerator--driven sub--critical reactor.

I. F. Ginzburg

2005-07-29T23:59:59.000Z

329

The U.S. Depar  

NLE Websites -- All DOE Office Websites (Extended Search)

4/11) 4/11) The Relativistic Heavy Ion Collider The Relativistic Heavy Ion Collider (RHIC) The Relativistic Heavy Ion Collider (RHIC) is designed to study matter as it existed fractions of a second after the birth of the universe - as a plasma of quarks and gluons, the fundamental components of matter. At RHIC, physicists accelerate and collide heavy ions (atoms of heavy elements stripped of their electrons) at high energies to mimic the hot, dense conditions of the early universe (250,000 times hotter than the center of the sun). Surprisingly, the data have revealed quark-gluon matter that behaves as a nearly-perfect liquid, rather than the predicted gas. RHIC physicists also accelerate and collide polarized protons to explore the mysterious internal

330

The Next Linear Collider Program  

NLE Websites -- All DOE Office Websites (Extended Search)

To use the left side navigation on this page, you will need to turn on To use the left side navigation on this page, you will need to turn on Javascript. You do not need JavaScript to use the text-based navigation bar at the bottom of the page. The Next Linear Collider at SLAC Navbar MISSION: Scientists expect research at this facility to answer fundamental questions about the behavior of matter and the origins of the Universe. NLC 8-Pack on the Drawing Board What's New In the Next Linear Collider: • NLC Newsletter October, 2001 • NLC Snowmass report 2001 • NLC All Hands Talk, August 2001 Upcoming Events: • Fall 2001 Working Sessions, Oct. 22-23, 2001 • Pulse Compression Workshop, Oct. 22-24, 2001 • Machine Advisory Committee Mtg., Oct. 24-26, 2001 • ISG-7 at KEK, Nov. 12-15, 2001 • LC' 02 at SLAC, Feb. 4-8, 2002 NLC Website Search: Entire SLAC Web | Help |

331

Stochastic cooling in muon colliders  

SciTech Connect

Analysis of muon production techniques for high energy colliders indicates the need for rapid and effective beam cooling in order that one achieve luminosities > 10{sup 30} cm{sup {minus}2}s{sup {minus}1} as required for high energy physics experiments. This paper considers stochastic cooling to increase the phase space density of the muons in the collider. Even at muon energies greater than 100 GeV, the number of muons per bunch must be limited to {approximately}10{sup 3} for the cooling rate to be less than the muon lifetime. With such a small number of muons per bunch, the final beam emittance implied by the luminosity requirement is well below the thermodynamic limit for beam electronics at practical temperatures. Rapid bunch stacking after the cooling process can raise the number of muons per bunch to a level consistent with both the luminosity goals and with practical temperatures for the stochastic cooling electronics. A major advantage of our stochastic cooling/stacking scheme over scenarios that employ only ionization cooling is that the power on the production target can be reduced below 1 MW.

Barletta, W.A.; Sessler, A.M.

1993-09-01T23:59:59.000Z

332

Photon decay in strong magnetic field in heavy-ion collisions  

E-Print Network (OSTI)

We calculate the photon pair production rate in strong magnetic field created in off-central heavy-ion collisions. Photon decay leads to depletion of the photon yield by a few percent at RHIC and by as much as 20% at the LHC. It also generates a substantial azimuthal asymmetry ("elliptic flow") of the final photon distribution. We estimate v_2~2% at RHIC and v_2~14% at LHC. Photon decay measurements is an important tool for studying the magnetic fields in early stages of heavy-ion collisions.

Tuchin, Kirill

2010-01-01T23:59:59.000Z

333

Perturbative probes of QCD matter at the Large Hadron Collider  

E-Print Network (OSTI)

The main results on electroweak probes, jets, high-pT hadrons, heavy-flavour and quarkonia production from the first two years of heavy-ion operation at the Large Hadron Collider (LHC) are briefly reviewed. Data measured at center-of-mass energies sqrt(s_NN) = 2.76 TeV in lead-lead (Pb-Pb) collisions are compared to proton-proton (p-p) measurements in order to extract information on the properties of hot and dense strongly-interacting matter.

David d'Enterria

2012-07-18T23:59:59.000Z

334

Perturbative probes of QCD matter at the Large Hadron Collider  

E-Print Network (OSTI)

The main results on electroweak probes, jets, high-pT hadrons, heavy-flavour and quarkonia production from the first two years of heavy-ion operation at the Large Hadron Collider (LHC) are briefly reviewed. Data measured at center-of-mass energies sqrt(s_NN) = 2.76 TeV in lead-lead (Pb-Pb) collisions are compared to proton-proton (p-p) measurements in order to extract information on the properties of hot and dense strongly-interacting matter.

d'Enterria, David

2012-01-01T23:59:59.000Z

335

Research and Development of Future Muon Collider  

SciTech Connect

Muon collider is a considerable candidate of the next generation high-energy lepton collider machine. A novel accelerator technology must be developed to overcome several intrinsic issues of muon acceleration. Recent research and development of critical beam elements for a muon accelerator, especially muon beam phase space ionization cooling channel, are reviewed in this paper.

Yonehara, K.; /Fermilab

2012-05-01T23:59:59.000Z

336

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

NLC Home Page NLC Technical SLAC The LCC Tech Note series was started in July 1998 to document the JLC/NLC collaborative design effort. The notes are numbered sequentially and may also be given a SLAC, FNAL, LBNL, LLNL and/or KEK publication number. The LCC notes will be distributed through the Web in electronic form as PDF files -- the authors are responsible for keeping the original documents. Other document series are the NLC Notes that were started for the SLAC ZDR, the KEK ATF Notes, and at some future time there should be a series of Technical (NLD) Notes to document work on detector studies for the next-generation linear collider. LCC-0001 "Memorandum of Understanding between KEK and SLAC," 2/98. LCC-0002 "Transparencies and Summaries from the 1st ISG meeting: January 1998," G. Loew, ed., 2/98.

337

X-ray emission from colliding laser plasmas  

SciTech Connect

Colliding Au, CD and Ti-Cr plasmas have been generated by illuminating two opposing foils each with a {approximately} 100J, 0.5 nsec, 2{omega} Nd-glass laser beam from the Trident laser facility at Los Alamos. The plasmas are being used to study plasma interactions which span the parameter regime from interpenetrating to collisional stagnation. X-ray emission during the laser target interaction and the subsequent collision is used to diagnose the initial plasma conditions and the colliding plasma properties. X-ray instrumentation consists of a 100 ps gated x-ray pinhole imager, a time-integratcd bremsstrahlung x-ray spectrograph and a gated x-ray spectrograph used to record isoelectronic spectra from the Ti-Cr plasmas. The imager has obtained multi-frame images of the collision and therefore, a measure of the stagnation length which is a function of the ion charge state and density and a strong function of the electron temperature. Other instrumentation includes a Thomson scattering spectrometer with probe beam, neutron detectors used to monitor the CD coated foil collisions and an ion spectrometer. We will describe the current status of the experiments and current results with emphasis on the x-ray emission diagnostics. We will also briefly describe the modeling using Lasnex and ISIS, a particle-in-cell code with massless fluid electrons and inter particle (classical) collisions.

Wilke, M.; Obst, A.W.; Winske, D. [and others

1995-09-01T23:59:59.000Z

338

Heat leak testing of a superconducting RHIC dipole magnet at Brookhaven National Laboratory  

SciTech Connect

Brookhaven National Laboratory is currently performing heat load tests on a superconducting dipole magnet. The magnet is a prototype of the 360, 8 cm bore, arc dipole magnets that will be used in the Relativistic Heavy Ion Collider (RMC). An accurate measurement of the heat load is needed to eliminate cumulative errors when determining the REUC cryogenic system load requirements. The test setup consists of a dipole positioned between two quadrupoles in a common vacuum tank and heat shield. Piping and instrumentation are arranged to facilitate measurement of the heat load on the primary 4.6 K magnet load and the secondary 55 K heat shield load. Initial results suggest that the primary heat load is well below design allowances. The secondary load was found to be higher than estimated, but remained close to the budgeted amount. Overall, the dipole performed to specifications.

DeLalio, J.T.; Brown, D.P.; Sondericker, J.H.

1993-09-01T23:59:59.000Z

339

The Large Hadron Electron Collider Project  

E-Print Network (OSTI)

A Conceptual Design Report (CDR) for the Large Hadron Electron Collider, the LHeC, is being prepared, to which an introduction was given for the plenary panel discussion on the future of deep inelastic scattering held at DIS09. This is briefly summarised here. The CDR will comprise designs of the ep/eA collider, based on ring and linear electron accelerators, of the interaction region, designed for simultaneous $ep$ and $pp$ operation, of a new, modular detector, and it will present basics on the physics motivation for a high luminous Tera scale electron-nucleon collider as a complement to the LHC.

Max Klein

2009-08-20T23:59:59.000Z

340

Direct photons measured by the PHENIX experiment at RHIC  

E-Print Network (OSTI)

Results from the PHENIX experiment at RHIC on direct photon production in p+p, d+Au, and Au+Au collisions at sqrt(s_NN) = 200 GeV are presented. In p+p collisions, direct photon production at high p_T behaves as expected from perturbative QCD calculations. The p+p measurement serves as a baseline for direct photon production in Au+Au collisions. In d+Au collisions, no effects of cold nuclear matter are found within the large uncertainty of the measurement. In Au+Au collisions, the production of high p_T direct photons scales as expected for particle production in hard scatterings. This supports jet quenching models, which attribute the suppression of high p_T hadrons to the energy loss of fast partons in the medium produced in the collision. Low p_T direct photons, measured via e+e- pairs with small invariant mass, are possibly related to the production of thermal direct photons.

Stefan Bathe; for the PHENIX Collaboration

2006-09-19T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Review of Recent Results from the RHIC Beam Energy Scan  

E-Print Network (OSTI)

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 Skellam expectations at lower energies. An outlook for the future BES Phase-II program is presented and efforts for the detailed study of QCD phase diagram are discussed.

Lokesh Kumar

2013-11-14T23:59:59.000Z

342

The ALICE Electromagnetic Calorimeter  

Science Conference Proceedings (OSTI)

ALICE (A Large Ion Collider Experiment) is the only LHC experiment at CERN fully dedicated to the study of the quark and gluon plasma. Driven by the RHIC results on jet quenching

S. Gadrat; The ALICE Collaboration

2010-01-01T23:59:59.000Z

343

Office of Educational Programs  

NLE Websites -- All DOE Office Websites (Extended Search)

a quick refueling, get ready to accelerate your knowledge of atoms and peek into the "Sub-Atomic World" by way of BNL's world-renowned Relativistic Heavy Ion Collider (RHIC)...

344

Measurement of charged particle multiplicity distribution in Au + Au collisions up to 200 GeV  

E-Print Network (OSTI)

Au+Au collisions in the Relativistic Heavy Ion Collider (RHIC) herald a new era of opportunities for studying hadronic matter under conditions of high energy density and nucleon density. The theory of strong interactions, ...

Sarin, Pradeep, 1975-

2003-01-01T23:59:59.000Z

345

Fermilab Now - LHC Large Hadron Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Large Hadron Collider (LHC) Over the next few months, a 12,500-ton detector will be lowered almost 300 feet below ground near the French-Swiss border. Dubbed "CMS," this detector...

346

Decoupling schemes for the SSC Collider  

Science Conference Proceedings (OSTI)

A decoupling system is designed for the SSC Collider. This system can accommodate three decoupling schemes by using 44 skew quadrupoles in the different configurations. Several decoupling schemes are studied and compared in this paper.

Cai, Y.; Bourianoff, G.; Cole, B.; Meinke, R.; Peterson, J.; Pilat, F.; Stampke, S.; Syphers, M.; Talman, R.

1993-05-01T23:59:59.000Z

347

Higgs Physics at the Large Hadron Collider  

E-Print Network (OSTI)

A major goal of the future Large Hadron Collider will be the Higgs boson search. In this paper the discovery In this paper the discovery potential is described as a function of the Higgs mass showing that a Standard Model Higgs boson can be discovered after less than two years of running of the collider. The MSSM Higgs searches and the precision achievable on the measurement of the Higgs boson parameters are also discussed.

Davide Costanzo

2001-05-15T23:59:59.000Z

348

Photon Linear Collider Gamma-Gamma Summary  

SciTech Connect

High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.

Gronberg, J

2012-02-27T23:59:59.000Z

349

The promise of the large collider  

E-Print Network (OSTI)

"In 2007, the most powerful particle accelerator ever built, CERN's new Large hadron Collider, will probe the secrets of matter in the energy states prevailing in the moments after the Big Bang. By colliding particles together when they are moving at close to the speed of ight, physicists hope to find out about matter in its earliest forms, using the energy produced by the collisions." (2 pages)

2007-01-01T23:59:59.000Z

350

Silicon Vertex Tracker for PHENIX Upgrade at RHIC: Capabilities and Detector Technology  

E-Print Network (OSTI)

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 nuclear collisions at RHIC. At the relatively low transverse momentum region, the collective motion of the heavy flavor will be a sensitive signal for the thermalization of light flavors. 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 8x1026 cm-2 s-1 for Au+Au, and 2x1032 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 Vertex Tracker (VTX). The VTX detector will provide us the tool to measure new physics observables that are not accessible at the present RHIC or available only with very limited accuracy. The VTX detector consists of four layers of barrel detectors located in the region of pseudorapidity |eta| technology choices used in the design, performance of individual silicon sensor and silicon detector prototype.

Rachid Nouicer; for the PHENIX Collaboration

2008-01-18T23:59:59.000Z

351

Exclusive processes in electron-ion collisions in the dipole formalism  

SciTech Connect

We compare the predictions of two saturation models for production of vector mesons and of photons in electron-ion collisions. The models considered are the b-CGC and the rcBK. The calculations were made in the kinematical range of the LHeC and of the future eRHIC.

Cazaroto, E. R.; Navarra, F. S. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05314-970 Sao Paulo, SP (Brazil); Carvalho, F. [Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, Campus Diadema, Rua Prof. Artur Riedel, 275, Jd. Eldorado, 09972-270 Diadema, SP (Brazil); Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, 96010-900 Pelotas, RS (Brazil)

2013-03-25T23:59:59.000Z

352

OVERVIEW OF BEAM STUDIES AT RHIC DURING THE YEAR 2000 RUN.  

SciTech Connect

During the Year 2000 run, RHIC has been commissioned and brought into operation reaching 10% of the design luminosity. A program for beam studies and machine development has been setup before the run with the goal of improving machine performance. The plan was implemented during the run in a series of beam studies, focusing initially on interaction region correction, intrabeam scattering, 3-dimensional beam reconstruction and luminosity optimization. An overview of the results is given with pointers to individual contributions where data are presented in more detail. The program for dedicated machine development at RHIC during the Year 2001 is reviewed and discussed.

PILAT,F.; BAI,M.; DREES,A.; FISCHER,W.

2001-06-18T23:59:59.000Z

353

EFFECT OF ORBIT DISTORTIONS LAND BETATRON TUNE ON THE RHIC POLARIZED BEAM.  

Science Conference Proceedings (OSTI)

Polarized protons have been stored and accelerated in RHIC from G{sub {gamma}} = 46.5 to 60 during Run2000 with only one Siberian snake installed. We simulated with the spin tracking code Spink the behavior of polarized protons, in particular the effect of closed orbit distortions and betatron tune variation on the spin dynamics. According to simulation results, closed orbit and tune effects will be translated into requirements for the tune and orbit correction systems for the RHIC polarized proton Run2001, when both Siberian snakes will be available.

LUCCIO,A.U.; PILAT,F.; PTITSYN,V.

2001-06-18T23:59:59.000Z

354

NNLO Benchmarks for Gauge and Higgs Boson Production at TeV Hadron Colliders  

E-Print Network (OSTI)

The inclusive production cross sections for $W^+, W^-$ and $Z^0$-bosons form important benchmarks for the physics at hadron colliders. We perform a detailed comparison of the predictions for these standard candles based on recent next-to-next-to-leading order (NNLO) parton parameterizations and new analyses including the combined HERA data, compare to all available experimental results, and discuss the predictions for present and upcoming RHIC, SPS, Tevatron and LHC energies. The rates for gauge boson production at the LHC can be rather confidently predicted with an accuracy of better than about 10% at NNLO. We also present detailed NNLO predictions for the Higgs boson production cross sections for Tevatron and LHC energies (1.96, 7, 8, 14 TeV), and propose a possible method to monitor the gluon distribution experimentally in the kinematic region close to the mass range expected for the Higgs boson. The production cross sections of the Higgs boson at the LHC are presently predicted with an accuracy of about 10--17%. The inclusion of the NNLO contributions is mandatory for achieving such accuracies since the total uncertainties are substantially larger at NLO.

S. Alekhin; J. Blmlein; P. Jimenez-Delgado; S. Moch; E. Reya

2010-11-29T23:59:59.000Z

355

The effect and correction of coupling generated by the RHIC triplet quadrupoles  

SciTech Connect

This study explores the possibility of operating the nominal RHIC coupling correction system in local decoupling mode, where a subset of skew quadrupoles are independently set by minimizing the coupling as locally measured by beam position monitors. The goal is to establish a correction procedure for the skew quadrupole errors in the interaction region triplets that does not rely on a priori knowledge of the individual errors. After a description of the present coupling correction scheme envisioned for RHIC, the basics of the local decoupling method will be briefly recalled in the context of its implementation in the TEAPOT simulation code as well as operationally. The method is then applied to the RHIC lattice: a series of simple tests establish that single triplet skew quadrupole errors can be corrected by local decoupling. More realistic correction schemes are then studied in order to correct distributed sources of skew quadrupole errors: the machine can be decoupled either by pure local decoupling or by a combination of global (minimum tune separation) and local decoupling. The different correction schemes are successively validated and evaluated by standard RHIC simulation runs with the complete set of errors and corrections. The different solutions and results are finally discussed together with their implications for the hardware.

Pilat, F.; Peggs, S.; Tepikian, S.; Trbojevic, D.; Wei, J.

1995-05-01T23:59:59.000Z

356

ATOMIC BEAM POLARIZATION MEASUREMENT OF THE RHIC POLARIZED H-JET TARGET.  

DOE Green Energy (OSTI)

The RHIC polarized H-Jet measures the polarization of the RHIC proton beam via elastic scattering off a nuclear polarized atomic hydrogen beam. The atomic beam is produced by a dissociator, a beam forming system and sextupole magnets. Nuclear polarization is achieved by exchanging occupation numbers of hyperfine states using high frequency transitions. The polarization was measured using a modified form of a Breit-Rabi polarimeter including focusing magnets and another set of high frequency transitions. The sampling of a large part of the beam and low noise electronics made it possible to measure the polarization to a high degree of accuracy in a very short time period (1 min). Using this system, we measured no depolarization of the atomic beam due to the RF fields of the bunched proton beam. Time-of-Flight measurements were done using a fast chopper and a QMA at the position of the RHIC interaction point to determine the areal density of the atomic beam seen by the RHIC beam.

MAKDISI,Y.; NASS,A.; GRAHAM,D.; KPONOU,A.; MAHLER,G.; MENG,W.; RITTER,J.; ET AL.

2005-01-28T23:59:59.000Z

357

Fluctuations of charge separation perpendicular to the event plane and local parity violation in sqrt(sNN)=200 GeV Au+Au collisions at RHIC  

E-Print Network (OSTI)

Previous experimental results based on data (15 million events) collected by the STAR detector at RHIC suggest event-by-event charge separation fluctuations perpendicular to the event plane in non-central heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high statistics 200 GeV Au+Au collisions data set (57 million events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same and opposite charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion.

STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; C. D. Anson; A. Aparin; D. Arkhipkin; E. Aschenauer; G. S. Averichev; J. Balewski; A. Banerjee; Z. Barnovska; D. R. Beavis; R. Bellwied; M. J. Betancourt; R. R. Betts; A. Bhasin; A. K. Bhati; Bhattarai; H. Bichsel; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; W. Borowski; J. Bouchet; A. V. Brandin; S. G. Brovko; E. Bruna; S. Bltmann; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Caldern de la Barca Snchez; D. Cebra; R. Cendejas; M. C. Cervantes; P. Chaloupka; Z. Chang; S. Chattopadhyay; H. F. Chen; J. H. Chen; J. Y. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; W. Christie; P. Chung; J. Chwastowski; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; X. Cui; S. Das; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; R. Derradi de Souza; S. Dhamija; B. di Ruzza; L. Didenko; Dilks; F. Ding; A. Dion; P. Djawotho; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; M. Elnimr; J. Engelage; K. S. Engle; G. Eppley; L. Eun; O. Evdokimov; R. Fatemi; S. Fazio; J. Fedorisin; R. G. Fersch; P. Filip; E. Finch; Y. Fisyak; C. E. Flores; C. A. Gagliardi; D. R. Gangadharan; D. Garand; F. Geurts; A. Gibson; S. Gliske; O. G. Grebenyuk; D. Grosnick; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; R. Haque; J. W. Harris; J. P. Hays-Wehle; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; C. Jena; E. G. Judd; S. Kabana; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; A. Kesich; D. P. Kikola; J. Kiryluk; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; W. Korsch; L. Kotchenda; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; S. LaPointe; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; L. M. Lima; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; X. Luo; G. L. Ma; Y. G. Ma; D. M. M. D. Madagodagettige Don; D. P. Mahapatra; R. Majka; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; T. S. McShane; S. Mioduszewski; M. K. Mitrovski; Y. Mohammed; B. Mohanty; M. M. Mondal; M. G. Munhoz; M. K. Mustafa; M. Naglis; B. K. Nandi; Md. Nasim; T. K. Nayak; J. M. Nelson; L. V. Nogach; J. Novak; G. Odyniec; A. Ogawa; K. Oh; A. Ohlson; V. Okorokov; E. W. Oldag; R. A. N. Oliveira; D. Olson; M. Pachr; B. S. Page; S. K. Pal; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; W. Peryt; P. Pile; M. Planinic; J. Pluta; D. Plyku; N. Poljak; J. Porter; A. M. Poskanzer; C. B. Powell; C. Pruneau; N. K. Pruthi; M. Przybycien; P. R. Pujahari; J. Putschke; H. Qiu; S. Ramachandran; R. Raniwala; S. Raniwala; R. L. Ray; C. K. Riley; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; J. F. Ross; A. Roy; L. Ruan; J. Rusnak; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; A. Sandacz; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; B. Schmidke; N. Schmitz; T. R. Schuster; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; M. Shao; B. Sharma; M. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. N. Singaraju; M. J. Skoby; D. Smirnov; N. Smirnov; D. Solanki; P. Sorensen; U. G. deSouza; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. C. Suarez; M. Sumbera; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; L. H. Tarini; T. Tarnowsky; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; B. A. Trzeciak; O. D. Tsai; J. Turnau; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; R. Vertesi; F. Videbk; Y. P. Viyogi; S. Vokal; S. A. Voloshin; A. Vossen; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; Q. Wang; X. L. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; H. Xu; N. Xu; Q. H. Xu; W. Xu; Y. Xu; Z. Xu; Yan; C. Yang; Y. Yang; Y. Yang; P. Yepes; L. Yi; K. Yip; I-K. Yoo; Y. Zawisza; H. Zbroszczyk; W. Zha; J. B. Zhang; S. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; F. Zhao; J. Zhao; C. Zhong; X. Zhu; Y. H. Zhu; Y. Zoulkarneeva; M. Zyzak

2013-02-15T23:59:59.000Z

358

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

SciTech Connect

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 saturation/CGC effects tend to decrease the Odderon intercept, possibly providing an explanation for the lack of experimental evidence for the Odderon so far. This has added further motivation for pursuing searches for the Odderon. During the workshop the status of the Odderon in QCD and its phenomenology were reviewed. The participants also agreed on the most promising observables for the Odderon search at RHIC, which we list. The conclusion of the workshop is that the best available setup to address experimental questions related to the search for the Odderon at RHIC is the proposed combination of STAR experiment and Roman pots of pp2pp experiment, described in the proposal ''Physics with Tagged Forward Protons with the STAR detector at RHIC''.

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

2005-10-25T23:59:59.000Z

359

Linear Collider Collaboration Tech Notes LCC-0100  

NLE Websites -- All DOE Office Websites (Extended Search)

100 100 August 2002 Systematic Ground Motion and Macroalignment for Linear Colliders Rainer Pitthan Stanford Linear Accelerator Center Stanford University Stanford, CA 94309, USA Abstract: Future colliders with their µm-range operational tolerances still need to be classically aligned to the 50 - 100 µm range, and kept there, over the km range. This requirement will not be a show-stopper, but not be trivial either. 50 µm movements over a betatron wavelength is a the range where systematic long term motions can prevent efficient operation. Systematic Ground Motion and Macro-Alignment for Linear Colliders Complete talk at: http://www-project.slac.stanford.edu/lc/wkshp/snowmass2001/t6/info/pitthan july

360

Fermilab | Muon Collider | Reports and Papers  

NLE Websites -- All DOE Office Websites (Extended Search)

Reports and Papers Reports and Papers Comprehensive Reports J. Gallardo, R. Palmer, A. Tollestrup, A. Sessler, A. Skrinsky et al., "μ+ μ- Collider: A Feasibility Study," DPF/DPB Summer Study on New Directions for High Energy Physics, Snow- mass, Colorado, 25 Jun - 12 Jul 1996, BNL - 52503, Fermilab - Conf - 96 - 092, LBNL - 38946, http://www.cap.bnl.gov/mumu/pubs/snowmass96.html C. Ankenbrandt et al.,"Status of muon collider research and development and future plans," Phys. Rev. ST Accel. Beams 2 (1999) 081001, http://prst-ab.aps.org/abstract/PRSTAB/v2/i8/e081001 M. M. Alsharo'a et al., "Recent progress in neutrino factory and muon collider research within the Muon Collaboration," Phys. Rev. ST Accel. Beams 6 (2003) 081001, http://prst-ab.aps.org/abstract/PRSTAB/v6/i8/e081001

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361

Non-photonic electron-hadron correlations and non-photonic electron $v_2$ at STAR/RHIC  

E-Print Network (OSTI)

Non-photonic electrons (when $p_T >$ 3 GeV/$c$) represent the directions of the parent heavy quarks, and their angular correlations with charged hadrons provide a unique tool to study the relative contributions from $D$ and B meson decays in p+p collisions, as well as the flavor-dependence of the energy loss mechanism in A+A collisions. We review the disentanglement of charm and bottom contributions to non-photonic electrons in p+p collisions at $\\sqrt{s} = 200$ GeV at RHIC. B decay contribution is approximately 50$ at the electron transverse momentum of $p_{T} > 5$ GeV/$c$ from STAR results. Incorporating the energy loss information of non-photonic electrons, the result indicates a B meson suppression at high $p_T$ in heavy ion collisions. We also present non-photonic electron-hadron correlations in d+Au collisions as a baseline reference for the investigation of the heavy quark energy loss in A+A collisions. Heavy quark energy loss and heavy quark evolution in the QCD medium can lead to a finite "elliptic flow" parameter ($v_2$) of $D$ and $B$ mesons which can be studied through $v_2$ of non-photonic electrons. Preliminary $v_2$ measurements for non-photonic electrons are shown to be lower than $v_2$ of charged hadrons (or $K_S^0$, $\\Lambda$) for 200 GeV Au+Au collisions.

Gang Wang

2010-11-25T23:59:59.000Z

362

Properties of Jets Measured with Charged Particles with the ATLAS Detector at the Large Hadron Collider  

E-Print Network (OSTI)

3 The Large Hadron Collider and ATLAS3.1 The Large Hadron Collider Complex . . . . . . . .of QCD at the Large Hadron Collider. These improvements will

Zenz, Seth Conrad

2011-01-01T23:59:59.000Z

363

Microsoft Word - WFnote-238_Summary of short pulse collider.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

electron-positron linear collider from the International Linear Collider (ILC) and Compact Linear Collider (CLIC) teams have been well established. Both proposed machines work...

364

International linear collider reference design report  

Science Conference Proceedings (OSTI)

The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

Aarons, G.

2007-06-22T23:59:59.000Z

365

Final Report for Project ``Theory of ultra-relativistic heavy-ion collisions''  

SciTech Connect

In the course of this project the Ohio State University group led by the PI, Professor Ulrich Heinz, developed a comprehensive theoretical picture of the dynamical evolution of ultra-relativistic heavy-ion collisions and of the numerous experimental observables that can be used to diagnose the evolving and short-lived hot and dense fireball created in such collisions. Starting from a qualitative understanding of the main features based on earlier research during the last decade of the twentieth century on collisions at lower energies, the group exploited newly developed theoretical tools and the stream of new high-quality data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory (which started operations in the summer of the year 2000) to arrive at an increasingly quantitative description of the experimentally observed phenomena. Work done at Ohio State University (OSU) was instrumental in the discovery during the years 2001-2003 that quark-gluon plasma (QGP) created in nuclear collisions at RHIC behaves like an almost perfect liquid with minimal viscosity. The tool of relativistic fluid dynamics for viscous liquids developed at OSU in the years 2005-2007 opened the possibility to quantitatively determine the value of the QGP viscosity empirically from experimental measurements of the collective flow patterns established in the collisions. A first quantitative extraction of the QGP shear viscosity, with controlled theoretical uncertainty estimates, was achieved during the last year of this project in 2010. OSU has paved the way for a transition of the field of relativistic heavy-ion physics from a qualitative discovery stage to a new stage of quantitative precision in the description of quark-gluon plasma properties. To gain confidence in the precision of our theoretical understanding of quark-gluon plasma dynamics, one must test it on a large set of experimentally measured observables. This achievement report demonstrates that we have, at different times, systematically investigated both so-called ``soft" and ``hard, penetrating" probes of the fireball medium: hadron yields and momentum spectra and their anisotropies, two-particle momentum correlations, high-energy partons fragmenting into jets, heavy quarks and heavy-flavor mesons, and electromagnetic probes (photons and dileptons). Our strongest emphasis, and our most significant achievements, has, however, always remained on understanding the bulk behavior of the heavy-ion fireball medium, for which soft probes provide the most abundantly available data and thus the most stringent constraints.

Ulrich W. Heinz

2012-11-09T23:59:59.000Z

366

Study of Isospin Correlation in High Energy Heavy Ion Interactions with the RHIC PHENIX. Final Report  

Science Conference Proceedings (OSTI)

This report describes the research work performed under the support of the DOE research grant E-FG02-97ER4108. The work is composed of three parts: (1) Visual analysis and quality control of the Micro Vertex Detector (MVD) of the PHENIX experiments carried out of Brookhaven National Laboratory. (2) Continuation of the data analysis of the EMU05/09/16 experiments for the study of the inclusive particle production spectra and multi-particle correlation. (3) Exploration of a new statistical means to study very high-multiplicity of nuclear-particle ensembles and its perspectives to apply to the higher energy experiments.

Takahashi, Y.

2003-06-08T23:59:59.000Z

367

PHYSICS WITH AND PHYSICS OF COLLIDING ELECTRON BEAMS  

E-Print Network (OSTI)

contributed so much to the physics of colliding beams, theyto reap so little from the physics with colliding beams.Conference on High-Energy Physics, Vienna" September 1968 (

Pellegrini, Claudio

2008-01-01T23:59:59.000Z

368

Tune spectra in the Tevatron Collider  

SciTech Connect

A variety of transverse and longitudinal tune studies have been made in the Tevatron with both single and colliding beams. Besides measuring such typical quantities as tunes and chromaticity, beam- beam tune shifts and coherent beam-beam normal mode oscillations have been observed. A number of measurements are reported where the beam response to stimulation is studied. 13 refs., 9 figs.

Jackson, G.

1989-03-01T23:59:59.000Z

369

QCD parton model at collider energies  

Science Conference Proceedings (OSTI)

Using the example of vector boson production, the application of the QCD improved parton model at collider energies is reviewed. The reliability of the extrapolation to SSC energies is assessed. Predictions at ..sqrt..S = 0.54 TeV are compared with data. 21 references.

Ellis, R.K.

1984-09-01T23:59:59.000Z

370

Linear Collider Physics Resource Book Snowmass 2001  

Science Conference Proceedings (OSTI)

The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.

Ronan (Editor), M.T.

2001-06-01T23:59:59.000Z

371

Status of RHIC head-on beam-beam compensation project  

Science Conference Proceedings (OSTI)

Two electron lenses are under construction for RHIC to partially compensate the head-on beam-beam effect in order to increase both the peak and average luminosities. The final design of the overall system is reported as well as the status of the component design, acquisition, and manufacturing. An overview of the RHIC head-on beam-beam compensation project is given in [1], and more details in [2]. With 2 head-on beam-beam interactions in IP6 and IP8, a third interaction with a low-energy electron beam is added near IP10 to partially compensate the the head-on beam-beam effect. Two electron lenses are under construction, one for each ring. Both will be located in a region common to both beams, but each lens will act only on one beam. With head-on beam-beam compensation up to a factor of two improvement in luminosity is expected together with a polarized source upgrade. The current RHIC polarized proton performance is documented in Ref. [4]. An electron lens (Fig. 1) consists of an DC electron gun, warm solenoids to focus the electron beam during transport, a superconducting main solenoid in which the interaction with the proton beam occurs, steering magnets, a collector, and instrumentation. The main developments in the last year are given below. The experimental program for polarized program at 100 GeV was expected to be finished by the time the electron lenses are commissioned. However, decadal plans by the RHIC experiments STAR and PHENIX show a continuing interest at both 100 GeV and 250 GeV, and a larger proton beam size has been accommodated in the design (Tab. 1). Over the last year beam and lattice parameters were optimized, and RHIC proton lattices are under development for optimized electron lens performance. The effect of the electron lens magnetic structure on the proton beam was evaluated, and found to be correctable. Experiments were done in RHIC and the Tevatron.

Fischer, W.; Anerella, M.; Beebe, E.; Bruno, D.; Gassner, D.M.; Gu, X.; Gupta, R.C.; Hock, J.; Jain, A.K.; Lambiase, R.; Liu, C.; Luo, Y.; Mapes, M.; Montag, C.; Oerter, B.; Okamura, M.; Pikin, A.I.; Raparia, D.; Tan, Y.; Than, R.; Thieberger, P.; Tuozzolo, J.; Zhang, W.

2011-03-28T23:59:59.000Z

372

Higgs boson and Z physics at the first muon collider  

SciTech Connect

The potential for the Higgs boson and Z-pole physics at the first muon collider is summarized, based on the discussions at the ``Workshop on the Physics at the First Muon Collider and at the Front End of a Muon Collider``.

Demarteau, M.; Han, T.

1998-01-01T23:59:59.000Z

373

A Moment Equation Approach to a Muon Collider Cooling Lattice  

E-Print Network (OSTI)

a Muon Collider Cooling Lattice C.M. Celata, A.M. Sessler,a Muon Collider Cooling Lattice C.M. Celata and A.M. SesslerMUON COLLIDER COOLING LATTICE eM. Celata and A. M. Sessler,

Celata, C.M.; Sessler, A.M.; Lee, P.B.; Shadwick, B.A.; Wurtele, S.

2008-01-01T23:59:59.000Z

374

A laser-based longitudinal density monitor for the large hadron collider  

E-Print Network (OSTI)

MONITOR FOR THE LARGE HADRON COLLIDER * J. -F. Beche, J.profile in the Large Hadron Collider (LHC). The technique

2004-01-01T23:59:59.000Z

375

Updated electron-cloud simulation results for the Large Hadron Collider (LHC)  

E-Print Network (OSTI)

RESULTS FOR THE LARGE HADRON COLLIDER LHC ? M. A. Furman andscreen of the Large Hadron Collider (LHC). We pay particular

Furman, M.A.; Pivi, M.

2001-01-01T23:59:59.000Z

376

Heavy-Ion Physics with CMS  

E-Print Network (OSTI)

This article presents a brief overview of the CMS experiment capabilities to study the hot and dense matter created in relativistic heavy-ion collisions. The CERN Large Hadron Collider will provide collisions of Pb nuclei at 5.5 TeV per nucleon. The CMS heavy ion group has developed a plethora of physics analyses addressing many important aspects of heavy-ion physics in preparation for a competitive and successful program.

Aneta Iordanova

2008-06-06T23:59:59.000Z

377

Energy Dependence of Moments of Net-proton Multiplicity Distributions at RHIC  

E-Print Network (OSTI)

We report the beam energy (\\sqrt s_{NN} = 7.7 - 200 GeV) and collision centrality dependence of the mean (M), standard deviation (\\sigma), skewness (S), and kurtosis (\\kappa) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y| < 0.5) and within the transverse momentum range 0.4 < pT < 0.8 GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the Quantum Chromodynamic (QCD) phase diagram. The products of the moments, S\\sigma and \\kappa\\sigma^{2}, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and anti-proton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation, and also to a hadron resonance gas model.

STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; C. D. Anson; A. Aparin; D. Arkhipkin; E. C. Aschenauer; G. S. Averichev; J. Balewski; A. Banerjee; Z. Barnovska; D. R. Beavis; R. Bellwied; A. Bhasin; A. K. Bhati; P. Bhattarai; H. Bichsel; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; W. Borowski; J. Bouchet; A. V. Brandin; S. G. Brovko; S. Bltmann; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Calderndela Barca Snchez; D. Cebra; R. Cendejas; M. C. Cervantes; P. Chaloupka; Z. Chang; S. Chattopadhyay; H. F. Chen; J. H. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; W. Christie; J. Chwastowski; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; X. Cui; S. Das; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; A. A. Derevschikov; R. Derradi de Souza; S. Dhamija; B. di Ruzza; L. Didenko; C. Dilks; F. Ding; P. Djawotho; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; J. Engelage; K. S. Engle; G. Eppley; L. Eun; O. Evdokimov; R. Fatemi; S. Fazio; J. Fedorisin; P. Filip; E. Finch; Y. Fisyak; C. E. Flores; C. A. Gagliardi; D. R. Gangadharan; D. Garand; F. Geurts; A. Gibson; M. Girard; S. Gliske; D. Grosnick; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; R. Haque; J. W. Harris; J. P. Hays-Wehle; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; H. Jang; E. G. Judd; S. Kabana; D. Kalinkin; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; A. Kesich; Z. H. Khan; D. P. Kikola; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; W. Korsch; L. Kotchenda; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; L. M. Lima; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; X. Luo; G. L. Ma; Y. G. Ma; D. M. M. D. Madagodagettige Don; D. P. Mahapatra; R. Majka; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; T. S. McShane; N. G. Minaev; S. Mioduszewski; B. Mohanty; M. M. Mondal; D. A. Morozov; M. G. Munhoz; M. K. Mustafa; B. K. Nandi; Md. Nasim; T. K. Nayak; J. M. Nelson; L. V. Nogach; S. Y. Noh; J. Novak; S. B. Nurushev; G. Odyniec; A. Ogawa; K. Oh; A. Ohlson; V. Okorokov; E. W. Oldag; R. A. N. Oliveira; M. Pachr; B. S. Page; S. K. Pal; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; W. Peryt; A. Peterson; P. Pile; M. Planinic; J. Pluta; D. Plyku; N. Poljak; J. Porter; A. M. Poskanzer; N. K. Pruthi; M. Przybycien; P. R. Pujahari; H. Qiu; A. Quintero; S. Ramachandran; R. Raniwala; S. Raniwala; R. L. Ray; C. K. Riley; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; J. F. Ross; A. Roy; L. Ruan; J. Rusnak; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; A. Sandacz; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; W. B. Schmidke; N. Schmitz; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; P. V. Shanmuganathan; M. Shao; B. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. N. Singaraju; M. J. Skoby; D. Smirnov; N. Smirnov; D. Solanki; P. Sorensen; U. G. deSouza; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. Sumbera; X. Sun; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; T. Tarnowsky; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; B. A. Trzeciak; O. D. Tsai; J. Turnau; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; A. N. Vasiliev; R. Vertesi; F. Videbk; Y. P. Viyogi; S. Vokal; A. Vossen; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; X. L. Wang; Y. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; H. Xu; N. Xu; Q. H. Xu; Y. Xu; Z. Xu; W. Yan; C. Yang; Y. Yang; Y. Yang; Z. Ye; P. Yepes; L. Yi; K. Yip; I-K. Yoo; Y. Zawisza; H. Zbroszczyk; W. Zha; J. B. Zhang; S. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; F. Zhao; J. Zhao; C. Zhong; X. Zhu; Y. H. Zhu; Y. Zoulkarneeva; M. Zyzak

2013-09-23T23:59:59.000Z

378

SciDAC advances in beam dynamics simulation: from light sources to colliders  

E-Print Network (OSTI)

accelerator facilities, e.g. LCLS, RHIC, Tevatron, LHC,generation and transport in the LCLS photoinjector. Figure 2vertical offsets through the LCLS photoinjector. With such a

Qiang, J.

2008-01-01T23:59:59.000Z

379

SciDAC advances in beam dynamics simulation: from light sources to colliders  

E-Print Network (OSTI)

accelerator facilities, e.g. LCLS, RHIC, Tevatron, LHC,generation and transport in the LCLS photoinjector. Figure 2vertical offsets through the LCLS photoinjector. With such a

Qiang, Ji

2009-01-01T23:59:59.000Z

380

Ig-0543.PDF  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

MARCH 2002 MARCH 2002 DOE/IG-0543 AUDIT REPORT RELATIVISTIC HEAVY ION COLLIDER PROJECT U.S. DEPARTMENT OF ENERGY OFFICE OF INSPECTOR GENERAL OFFICE OF AUDIT SERVICES MEMORANDUM FOR THE SECRETARY FROM: Gregory H. Friedman (Signed) Inspector General SUBJECT: INFORMATION: Audit Report on "Relativistic Heavy Ion Collider Project" BACKGROUND The Relativistic Heavy Ion Collider (RHIC), located at Brookhaven National Laboratory, is the world's newest and largest particle accelerator for nuclear physics research. RHIC was constructed between 1991 and 1999 at a reported cost of $617 million and is designed to enhance scientific exploration by advancing our understanding of the most basic constituents

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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381

Beam Energy Scan program at RHIC-experimental approach to the QCD Phase Diagram  

SciTech Connect

The Beam Energy Scan (BES) program at RHIC was launched with the specific aim to explore the QCD (Quantum Chromodynamics) Phase Diagram. Particular emphasis was given to the search for phase boundaries and the location of the Critical Point (CP). The first run with AuAu collisions at 7.7, 11.5, and 39 GeV took place in 2010, and the next one, with energies of 18 and 27 GeV, will start in a few months. The results of the first stage of the BES program obtained by the STAR (Solenoidal Tracker at RHIC) experiment are presented and discussed, as well as plans for the future of the program.

Odyniec, G., E-mail: G_Odyniec@lbl.gov [Lawrence Berkeley National Laboratory (United States)

2012-05-15T23:59:59.000Z

382

CAN RECENT CHARGE FLUCTUATION CALCULATIONS BE A RELIABLE SIGNAL FOR A QGP AT RHIC?  

Science Conference Proceedings (OSTI)

The recent papers of Jeon and Koch[l] and Asakawa, Heinz and Muller[2] propose that the event by event fluctuations of the ratio of the positively charged and negatively charged pions could provide a distinct signal for a QGP at RHIC/LHC due to differences in those from the QGP phase, and the Hadron Gas Phase. In this paper we point out that aside from the questionability of the many assumptions in the treatment used, even following their approach there are other effects not considered, e.g. color charge fluctuations which we show could significantly or completely wash out the proposed signal. Therefore lack of observation of these charge fluctuation signals cannot lead one to conclude that a QGP is not formed at RHIC. A general discussion of experimental requirements for observation of such signals (if they exist) and how to interpret them is included.

LINDENBAUM, S.J.; LONGACRE, R.S.

2001-08-01T23:59:59.000Z

383

Collaborating for a "Perfect" Scan of Nuclear Matter | Brookhaven and the  

NLE Websites -- All DOE Office Websites (Extended Search)

Collaborating for a "Perfect" Scan of Nuclear Matter Collaborating for a "Perfect" Scan of Nuclear Matter RHIC & LHC The Perfect Liquid The Critical Point superconducting magnets Superconducting magnets of the Large Hadron Collider (left) and Brookhaven's Relativistic Heavy Ion Collider (right). As the finishing touches are put on the world's most powerful particle accelerator in Switzerland, and plans for others pop up across the globe, Brookhaven's Relativistic Heavy Ion Collider (RHIC) continues to exploit its unique ability to explore the surprising features of matter bound by the strongest of Nature&'s forces. Although RHIC's overall mission is quite different from other machines on the horizon, new scientific facilities are incorporating heavy ion capabilities similar to RHIC. This healthy

384

A bunch to bucket phase detector for the RHIC LLRF upgrade platform  

SciTech Connect

As part of the overall development effort for the RHIC LLRF Upgrade Platform [1,2,3], a generic four channel 16 bit Analog-to-Digital Converter (ADC) daughter module was developed to provide high speed, wide dynamic range digitizing and processing of signals from DC to several hundred megahertz. The first operational use of this card was to implement the bunch to bucket phase detector for the RHIC LLRF beam control feedback loops. This paper will describe the design and performance features of this daughter module as a bunch to bucket phase detector, and also provide an overview of its place within the overall LLRF platform architecture as a high performance digitizer and signal processing module suitable to a variety of applications. In modern digital control and signal processing systems, ADCs provide the interface between the analog and digital signal domains. Once digitized, signals are then typically processed using algorithms implemented in field programmable gate array (FPGA) logic, general purpose processors (GPPs), digital signal processors (DSPs) or a combination of these. For the recently developed and commissioned RHIC LLRF Upgrade Platform, we've developed a four channel ADC daughter module based on the Linear Technology LTC2209 16 bit, 160 MSPS ADC and the Xilinx V5FX70T FPGA. The module is designed to be relatively generic in application, and with minimal analog filtering on board, is capable of processing signals from DC to 500 MHz or more. The module's first application was to implement the bunch to bucket phase detector (BTB-PD) for the RHIC LLRF system. The same module also provides DC digitizing of analog processed BPM signals used by the LLRF system for radial feedback.

Smith, K.S.; Harvey, M.; Hayes, T.; Narayan, G.; Polizzo, S.; Severino, F.

2011-03-28T23:59:59.000Z

385

Explaining Angular Correlations Observed at RHIC with Flow and Local Charge Conservation  

E-Print Network (OSTI)

The observation of fluctuations of parity-odd angular observables at RHIC has been interpreted as a signal of a local parity violation. We show how the observed signal can be explained by local charge conservation at freeze-out combined with elliptic flow. Calculations from a blast wave model, which overlays thermal emission onto a collective flow profile, are shown to account for the experimentally observed signal.

Soeren Schlichting; Scott Pratt

2010-05-28T23:59:59.000Z

386

EXPERIENCE IN REDUCING ELECTRON CLOUD AND DYNAMIC PRESSURE RISE IN WARM AND COLD REGIONS IN RHIC.  

SciTech Connect

The large scale application of non-evaporable getter coating in RHIC has been effective in reducing the electron cloud. Since beams with higher intensity and smaller bunch spacing became possible in operation, the emittance growth is of concern. Study results are reported together with experiences of machine improvements: saturated NEG coatings, anti-grazing ridges in warm sections, and the pre-pumping in cryogenic regions.

ZHANG, S.Y.; AHRENS,L.; ALLESI, J.; BAI, M.; BLASKIEWICZ, M.; CAMERON, P.; CONNOLLY, R.; DREES, A.; FISCHER, W.; GULLOTTA, J.; HE, P.; HSEUH, H.C.; HUANG, H.; LEE, R.; LITVINENKO, V.; MACKAY, W.W.; MONTAG, C.; NICOLETTI, A.; OERTER, B.; PILAT, F.; PTITSYN, V.; ROSER, T.; SATOGATA, T.; SMART, L.; SYNDSTRUP, L.; TEPIKIAN, S.; THIEBERGER, P.; TRBOJEVIC, D.; WEI, J.; ZENO, K.

2006-06-23T23:59:59.000Z

387

Buda-Lund hydro model and the elliptic flow at RHIC  

E-Print Network (OSTI)

The ellipsoidally symmetric Buda-Lund hydrodynamic model describes naturally the transverse momentum and the pseudorapidity dependence of the elliptic flow in Au+Au collisions at $\\sqrt{s_{NN}} = 130$ and 200 GeV. The result confirms the indication of quark deconfinement in Au+Au collisions at RHIC, obtained from Buda-Lund hydro model fits to combined spectra and HBT radii of BRAHMS, PHOBOS, PHENIX and STAR.

M. Csanad; T. Csorgo; B. Lorstad

2004-02-12T23:59:59.000Z

388

The RHIC Beam Energy Scan Program: Results from the PHENIX Experiment  

E-Print Network (OSTI)

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, and the skewness and kurtosis of net charge distributions. The data analyzed to date show no significant indications of the presence of the critical point.

J. T. Mitchell; for the PHENIX Collaboration

2012-11-26T23:59:59.000Z

389

A Complete Onium Program with R2D at RHIC II  

E-Print Network (OSTI)

Following on the discovery of a strongly interacting quark-gluon plasma (QGP) at RHIC, a program of detailed quarkonia measurements is crucial to understanding the nature of deconfinement. Lattice QCD calculations suggest a sequential melting of the quarkonia states in the deconfined medium. Such a melting would lead to a suppression in the measured charmonium and bottomonium yields. However, distinguishing a true suppression from shadowing, absorption, and recombination effects requires detailed measurements of the charmonium states (J/psi, psi', and chi_c) and bottomonium states (Y(1S), Y(2S), and Y(3S)). Also, since measurements are needed not only in A+A, but also in p+p for determining primary yields and in p+A for evaluating absorption, the detector should perform well in all collision environments. To fully realize the program outlined above, a new detector will be required at RHIC-II. We present a proposal for a complete quarkonia program and the abilities of a new detector, R2D, to meet the stated requirements. Comparisons will be made with proposed upgrades to existing RHIC detectors and with the upcoming LHC program.

Richard Witt

2006-05-16T23:59:59.000Z

390

Experience with low-energy gold-gold operations in RHIC during FY 2010  

SciTech Connect

During Run-10, RHIC operated at several different Au-Au collision energies, as requested mainly by the STAR collaboration in a quest to search for the critical point in the QGP phase diagram. The center-of-mass energies {radical}s{sub NN} are listed in Table 1, together with the respective start and end dates and the duration of the respective run at each energy. While STAR defines 'low energy' as anything below {radical}s{sub NN} = 39 GeV, we focus in the scope of this paper on energies below the regular RHIC injection energy of {radical}s{sub NN} {approx} 20 GeV, since this energy regime is particularly challenging for stable RHIC operations. Figures 1 and 2 show the evolution of beam intensity and luminosity during the course of the {radical}s{sub NN} = 7.7 GeV and 11.5 GeV run. In the following sections we will recapitulate the modifications during the run that led to significant performance improvements, and summarize what was learned at the various energies for possible application in future runs.

Montag, C.; Satogata, T.; Ahrens, L.A.; Bai, M.; Beebe-Wang, J.; Blacker, I.; et al

2011-10-07T23:59:59.000Z

391

Optimization Of Chromaticity Compensation And Dynamic Aperture In MEIC Collider Rings  

SciTech Connect

The conceptual design of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab relies on an ultra-small beta-star to achieve high luminosities of up to 10{sup 34} cm{sup -2} s{sup -1}. A low-beta insertion for interaction regions unavoidably induces large chromatic effects that demand a proper compensation. The present approach of chromatic compensation in the MEIC collider rings is based on a local correction scheme using two symmetric chromatic compensation blocks that includes families of sextupoles, and are placed in a beam extension area on both sides of a collision point. It can simultaneously compensate the first order chromaticity and chromatic beam smear at the IP without inducing significant second order aberrations. In this paper, we investigate both the momentum acceptance and dynamic aperture in the MEIC ion collider ring by considering the aberration effects up to the third order, such as amplitude dependent tune shift. We also explore the compensation of the third order effects by introducing families of octupoles in the extended beam area.

Fanglei Lin, Yaroslav Derbenev, Vasiliy Morozov, Yuhong Zhang, Kevin Beard

2012-07-01T23:59:59.000Z

392

Nonlinear Energy Collimation System for Linear Colliders  

E-Print Network (OSTI)

The post-linac energy collimation system of multi-TeV linear colliders is designed to fulfil an important function of protection of the Beam Delivery System (BDS) against miss-steered beams likely generated by failure modes in the main linac. For the case of the Compact Linear Collider (CLIC), the energy collimators are required to withstand the impact of a full bunch train in case of failure. This is a very challenging task, assuming the nominal CLIC beam parameters at 1.5 TeV beam energy. The increase of the transverse spot size at the collimators using nonlinear magnets is a potential solution to guarantee the survival of the collimators. In this paper we present an alternative nonlinear optics based on a skew sextupole pair for energy collimation. Performance simulation results are also presented.

Resta-Lopez, Javier

2011-01-01T23:59:59.000Z

393

mu+-mu? colliders: possibilities and challenges  

SciTech Connect

The current status of the mu+-mu? collider concept is reviewed and discussed. In a reference scenario, a high-intensity pulsed proton accelerator (of K-factory class) produces large numbers of secondary pi's in a nuclear target, which produce muons by decay. The muons are collected and cooled (by "ionization cooling") to form high-intensity bunches that are accelerated to high-energy collisions. High-luminosity mu+-mu? and mu?-p colliders at TeV or higher energy scales may be possible. Challenges in implementing the scenario are described. Possible variations in muon production, accumulation, and collisions are discussed; further innovations and improvements are encouraged.

David Neuffer

1994-10-01T23:59:59.000Z

394

Warped Views on the Large Hadron Collider  

E-Print Network (OSTI)

Models with warped extra dimensions, and their strongly coupled duals, offer a nice solution to the hierarchy problem and a very appealing realisation of flavour. Compatibility with the very stringent electroweak and flavour tests have made a generic picture emerge, with a composite Higgs, partial compositeness and custodial symmetry as the main ingredients. We review the main features of this picture and discuss how -and when- models with warped extra dimensions could be discovered at the Large Hadron Collider.

Jose Santiago

2011-03-21T23:59:59.000Z

395

Muon Collider Machine-Detector Interface  

SciTech Connect

In order to realize the high physics potential of a Muon Collider (MC) a high luminosity of {mu}{sup +}{mu}{sup -}-collisions at the Interaction Point (IP) in the TeV range must be achieved ({approx}10{sup 34} cm{sup -2}s{sup -1}). To reach this goal, a number of demanding requirements on the collider optics and the IR hardware - arising from the short muon lifetime and from relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling should be satisfied. These requirements are aggravated by limitations on the quadrupole gradients as well as by the necessity to protect superconducting magnets and collider detectors from muon decay products. The overall detector performance in this domain is strongly dependent on the background particle rates in various sub-detectors. The deleterious effects of the background and radiation environment produced by the beam in the ring are very important issues in the Interaction Region (IR), detector and Machine-Detector Interface (MDI) designs. This report is based on studies presented very recently.

Mokhov, Nikolai V.; /Fermilab

2011-08-01T23:59:59.000Z

396

Cryogenic studies for the proposed CERN large hadron electron collider (LHEC)  

Science Conference Proceedings (OSTI)

The LHeC (Large Hadron electron Collider) is a proposed future colliding beam facility for lepton-nucleon scattering particle physics at CERN. A new 60 GeV electron accelerator will be added to the existing 27 km circumference 7 TeV LHC for collisions of electrons with protons and heavy ions. Two basic design options are being pursued. The first is a circular accelerator housed in the existing LHC tunnel which is referred to as the "Ring-Ring" version. Low field normal conducting magnets guide the particle beam while superconducting (SC) RF cavities cooled to 2 K are installed at two opposite locations at the LHC tunnel to accelerate the beams. For this version in addition a 10 GeV re-circulating SC injector will be installed. In total four refrigerators with cooling capacities between 1.2 kW and 3 kW @ 4.5 K are needed. The second option

2012-01-01T23:59:59.000Z

397

Chromaticity correction for a muon collider optics  

Science Conference Proceedings (OSTI)

Muon Collider (MC) is a promising candidate for the next energy frontier machine. However, in order to obtain peak luminosity in the 10{sup 34} cm{sup 2}s{sup -1} range the collider lattice designmust satisfy a number of stringent requirements. In particular the expected large momentum spread of the muon beam and the very small {beta}* call for a careful correction of the chromatic effects. Here we present a particular solution for the interaction region (IR) optics whose distinctive feature is a three-sextupole local chromatic correction scheme. The scheme may be applied to other future machines where chromatic effects are expected to be large. The expected large muon energy spread requires the optics to be stable over a wide range of momenta whereas the required luminosity calls for {beta}* in the mm range. To avoid luminosity degradation due to hour-glass effect, the bunch length must be comparatively small. To keep the needed RF voltage within feasible limits the momentum compaction factor must be small over the wide range of momenta. A low {beta}* means high sensitivity to alignment and field errors of the Interaction Region (IR) quadrupoles and large chromatic effects which limit the momentum range of optics stability and require strong correction sextupoles, which eventually limit the Dynamic Aperture (DA). Finally, the ring circumference should be as small as possible, luminosity being inversely proportional to the collider length. A promising solution for a 1.5 TeV center of mass energy MC with {beta}* = 1 m in both planes has been proposed. This {beta}* value has been chosen as a compromise between luminosity and feasibility based on the magnet design and energy deposition considerations. The proposed solution for the IR optics together with a new flexible momentum compaction arc cell design allows to satisfy all requirements and is relatively insensitive to the beam-beam effect.

Alexahin, Y.; Gianfelice-Wendt, E.; Kapin, V.; /Fermilab

2011-03-01T23:59:59.000Z

398

Linear Collider Collaboration Tech Notes LCC-0108  

NLE Websites -- All DOE Office Websites (Extended Search)

8 8 TESLA 2002-10 CBP Tech Note-268 November 2002 Comparison of Emittance Tuning Simulations in the NLC and TESLA Damping Rings Andrej Wolski Lawrence Berkeley National Laboratory University of California Berkeley, CA Winfried Decking Deutsches Elektron Synchrotron (DESY) Hamburg, Germany Abstract: Vertical emittance is a critical issue for future linear collider damping rings. Both NLC and TESLA specify vertical emittance of the order of a few picometers, below values currently achieved in any storage ring. Simulations show that algorithms based on correcting the closed orbit and the vertical dispersion can be effective in reducing the vertical emittance to the required levels, in the presence of a limited subset of

399

Linear Collider Collaboration Tech Notes LCC-0104  

NLE Websites -- All DOE Office Websites (Extended Search)

4 4 October 2002 Beamstrahlung Photon Load on the TESLA Extraction Septum Blade Andrei Seryi Stanford Linear Accelerator Center Stanford, CA 94309, USA Abstract: This note describes work performed in the framework of the International Linear Collider Technical Review Committee [1] to estimate the power load on the TESLA extraction septum blade due to beamstrahlung photons. It is shown, that under realistic conditions the photon load can be several orders of magnitude higher than what was estimated in the TESLA TDR [2] for the ideal Gaussian beams, potentially representing a serious limitation of the current design. Beamstrahlung Photon Load on the TESLA Extraction Septum Blade ANDREI SERYI STANFORD LINEAR

400

String resonances at the Large Hadron Collider  

E-Print Network (OSTI)

The Large Hadron Collider promises to discover new physics beyond the Standard Model. An exciting possibility is the formation of string resonances at the TeV scale. In this article, we show how string resonances may be detected at the LHC in the $pp\\to\\gamma+jet$ channel. Our study is based on event shape variables, missing energy and momentum, maximum transverse momentum of photons and dijet invariant mass. These observables provide interesting signatures which enable us to discriminate string events from the Standard Model background.

Arunava Roy; Marco Cavaglia

2009-02-09T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Dijet asymmetry at the Large Hadron Collider  

E-Print Network (OSTI)

The MARTINI numerical simulation allows for direct comparison of theoretical model calculations and the latest results for dijet asymmetry from the ATLAS and CMS collaborations. In this paper, partons are simulated as undergoing radiative and collisional processes throughout the evolution of central lead-lead collisions at the Large Hadron Collider. Using hydrodynamical background evolution determined by a simulation which fits well with the data on charged particle multiplicities from ALICE and a value of $\\alpha_s\\approx 0.25-0.3$, the dijet asymmetry is found to be consistent with partonic energy loss in a hot, strongly-interacting medium.

Clint Young; Bjrn Schenke; Sangyong Jeon; Charles Gale

2011-03-29T23:59:59.000Z

402

Two gauge boson physics at future colliders  

SciTech Connect

Electroweak unification suggests that there should be WW and ZZ physics analogous to {gamma}{gamma} physics. Indeed, WW and ZZ collisions will provide an opportunity to search for the Higgs boson at future high energy colliders. Cross sections in the picobarn range are predicted for Higgs boson production at the proposed 40-TeV SSC. While other states may be produced by WW and ZZ collisions, it is the Higgs boson that looms as the most attractive objective. 31 refs., 5 figs.

Cahn, R.N.

1988-05-13T23:59:59.000Z

403

Optimization of muon timing and searches for heavy long-lived charged particles with the Compact Muon Solenoid detector at the Large Hadron Collider  

E-Print Network (OSTI)

Large Hadron Collider . . . . . . . . . . . . . . . . . . . . . . . .detector at the Large Hadron Collider A dissertationdetector at the Large Hadron Collider by Christopher Patrick

Farrell, Christopher Patrick

2013-01-01T23:59:59.000Z

404

Hadron production and QGP Hadronization in Pb--Pb collisions at $\\sqrt{s_{NN}}=2.76$ TeV  

E-Print Network (OSTI)

We show that all central rapidity hadron yields measured in Pb--Pb collisions at $\\sqrt{s_{NN}}=2.76$ TeV are well described by the chemical non-equilibrium statistical hadronization model (SHM), where the chemically equilibrated QGP source breaks up directly into hadrons. SHM parameters are obtained as a function of centrality of colliding ions, and we compare CERN Large Hadron Collider (LHC) with Brookhaven National Laboratory Relativistic Heavy Ion Collider (RHIC) results. We predict yields of unobserved hadrons and address anti-matter production. The physical properties of the quark--gluon plasma fireball particle source show universality of hadronization conditions at LHC and RHIC.

Michal Petran; Jean Letessier; Vojtech Petracek; Johann Rafelski

2013-03-08T23:59:59.000Z

405

Klystron switching power supplies for the Internation Linear Collider  

Science Conference Proceedings (OSTI)

The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

Fraioli, Andrea; /Cassino U. /INFN, Pisa

2009-12-01T23:59:59.000Z

406

Far Future Colliders and Required R&D Program  

Science Conference Proceedings (OSTI)

Particle colliders for high energy physics have been in the forefront of scientific discoveries for more than half a century. The accelerator technology of the collider has progressed immensely, while the beam energy, luminosity, facility size and the cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but its pace of progress has greatly slowed down. In this paper we very briefly review the R&D toward near future colliders and make an attempt to look beyond the current horizon and outline the changes in the paradigm required for the next breakthroughs.

Shiltsev, V.; /Fermilab

2012-06-01T23:59:59.000Z

407

LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS  

E-Print Network (OSTI)

LASER-PLASMA-ACCELERATOR-BASED ?? COLLIDERS ? C. B.linear col- lider based on laser-plasma-accelerators arediscussed, and a laser-plasma-accelerator-based gamma-

Schroeder, C. B.

2010-01-01T23:59:59.000Z

408

Long-Range And Head-On Beam-Beam Compensation Studies in RHIC With Lessons for the LHC  

Science Conference Proceedings (OSTI)

Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; /Brookhaven; Dorda, U.; Koutchouk, J.P.; Sterbini, G.; Zimmermann, F.; /CERN; Kim, H.J.; Sen, T.; Shiltsev, V.; Valishev, A.; /Fermilab; Qiang, J.; /LBL, Berkeley; Kabel, A.; /SLAC

2011-11-28T23:59:59.000Z

409

Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC  

SciTech Connect

Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J.-P.; Sterbini, G.; Zimmermann, F.; Kim, H.-J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.

2009-01-12T23:59:59.000Z

410

Optically pumped polarized ion sources  

SciTech Connect

Polarization transfer collisions between protons, atomic hydrogen, or deuterium and optically pumped alkali-metal vapour are implemented in the high current optically pumped polarized ion source (OPPIS) and the laser driven source (LDS) of nuclear polarized atoms for target applications. The OPPIS technique overcomes the limitations on intensity of the conventional atomic beam source technique and meets the requirements of the new generation of polarization experiments at multi-GeV accelerators and colliders. 17 refs., 3 figs.

Zelenski, A.N.

1995-12-31T23:59:59.000Z

411

Solenoid and monocusp ion source  

DOE Patents (OSTI)

An ion source which generates ions having high atomic purity incorporates a solenoidal magnetic field to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

1995-12-31T23:59:59.000Z

412

3-4 paragraphs on general advice on eRHIC organization  

NLE Websites -- All DOE Office Websites (Extended Search)

collider facility and associated experimental program are very compelling. The next 6 to 12 months are a critical time where the project will either be included as a high priority...

413

Systematics of Soft Particle Production at RHIC: Lessons from PHOBOS  

E-Print Network (OSTI)

The PHOBOS experiment has measured the properties of particle production in heavy ion collisions between sqrt(s_NN) of 20 and 200 GeV. The dependencies of charged particle yield on energy, system size, and both longitudinal and transverse momentum have been determined over close to the full kinematic range. Identified charged particles emitted near mid-rapidity have been studied over about 2 orders of magnitude in transverse momentum. This broad data set was found to be characterized by a small number of simple scalings which factorize to a surprising degree. This study has recently been extended by the addition of new data for Cu+Cu as well as new analyses of Au+Au data, including more peripheral collisions. In addition, the exploration of global properties has been expanded with the use of new techniques, including two-particle correlations, more sensitive searches for rare events, and more detailed studies of particles emitted at very forward rapidity. The characteristics of particle production which are revealed by this extensive data set will be described along with the implications for future data from the LHC.

G. S. F. Stephans

2007-05-25T23:59:59.000Z

414

EXTRACTION OF HIGHLY CHARGED AU IONS FROM A MULTIAMPHERE ELECTRON BEAM EBIS AT BNL.  

DOE Green Energy (OSTI)

Excellent progress has been made in the operation of the BNL Electron Beam Ion Source (EBIS), which is a prototype for an EBIS that could meet requirements for a RHIC preinjector. We have achieved very stable operation of the electron beam at 10 A through the EBIS trap. Ion injection of low charge gold ions from a LEVA [1] ion source and subsequent extraction of these ions with most probable charge state AU{sup 34+} has been demonstrated with electron beams up to 8A. The total ion charge for gold measured on current transformer at the EBIS exit was 55nC after a 30ms confinement period. This corresponds to {approx}85% of the theoretical ion trap capacity and exceeds our goal of 50% neutralization. The collected ion charge is proportional to the electron current and the gold charge state scales with the electron current density. Details of the EBIS configuration, total charge measurements, and TOF spectra are given.

BEEBE,E.N.; ALESSI,J.G.; GOULD,O.; GRAHAM,D.; KPONOU,A.; PIKIN,A.; PRELEC,K.; RITTER,J.

2001-09-02T23:59:59.000Z

415

Numerical spin tracking in a synchrotron computer code Spink: Examples (RHIC)  

Science Conference Proceedings (OSTI)

In the course of acceleration of polarized protons in a synchrotron, many depolarizing resonances are encountered. They are classified in two categories: Intrinsic resonances that depend on the lattice structure of the ring and arise from the coupling of betatron oscillations with horizontal magnetic fields, and imperfection resonances caused by orbit distortions due to field errors. In general, the spectrum of resonances vs spin tune G{gamma}(G = 1.7928, the proton gyromagnetic anomaly, and y the proton relativistic energy ratio) for a given lattice tune {nu}, or vs {nu} for a given G{gamma}, contains a multitude of lines with various amplitudes or resonance strengths. The depolarization due to the resonance lines can be studied by numerically tracking protons with spin in a model accelerator. Tracking will allow one to check the strength of resonances, to study the effects of devices like Siberian Snakes, to find safe lattice tune regions where to operate, and finally to study in detail the operation of special devices such as Spin Flippers. A few computer codes exist that calculate resonance strengths E{sub k} and perform tracking, for proton and electron machines. Most relevant to our work for the AGS and RHIC machines are the programs Depol and Snake. Depol, calculates the E{sub k}`s by Fourier analysis. The input to Depol is the output of a machine model code, such as Synch or Mad, containing all details of the lattice. Snake, does the tracking, starting from a synthetic machine, that contains a certain number of periods, of FODO cells, of Siberian snakes, etc. We believed the complexities of machines like the AGS or RHIC could not be adequately represented by Snake. Then, we decided to write a new code, Spink, that combines some of the features of Depol and Snake. I.E., Spink reads a Mad output like Depol and tracks as Snake does. The structure of the code and examples for RHIC are described in the following.

Luccio, A.

1995-09-14T23:59:59.000Z

416

Advances in Beam Cooling for Muon Colliders  

DOE Green Energy (OSTI)

A six-dimensional (6D) ionization cooling channel based on helical magnets surrounding RF cavities filled with dense hydrogen gas is the basis for the latest plans for muon colliders. This helical cooling channel (HCC) has solenoidal, helical dipole, and helical quadrupole magnetic fields, where emittance exchange is achieved by using a continuous homogeneous absorber. Momentum-dependent path length differences in the dense hydrogen energy absorber provide the required correlation between momentum and ionization loss to accomplish longitudinal cooling. Recent studies of an 800 MHz RF cavity pressurized with hydrogen, as would be used in this application, show that the maximum gradient is not limited by a large external magnetic field, unlike vacuum cavities. Two new cooling ideas, Parametric-resonance Ionization Cooling and Reverse Emittance Exchange, will be employed to further reduce transverse emittances to a few mm-mr, which allows high luminosity with fewer muons than previously imagined. We describe these new ideas as well as a new precooling idea based on a HCC with z dependent fields that is being developed for an exceptional 6D cooling demonstration experiment. The status of the designs, simulations, and tests of the cooling components for a high luminosity, low emittance muon collider will be reviewed.

R.P. Johnson, Y.S. Derbenev

2006-09-01T23:59:59.000Z

417

Ionization cooling in the muon collider  

SciTech Connect

The muon beams in a high luminosity muon collider are produced with a very large emittance. The process of ionization cooling offers a method for reducing the 6-dimensional normalized emittance of the beam by a factor of {approx} 10{sup 6}. A simple analytic theory has been developed that demonstrates the dependence of the net cooling on various experimental parameters. The simple theory has been checked and realistic arrangements have been examined using Monte Carlo simulations. Transverse cooling of the initial beam can be achieved using passive Li absorbers in a FOFO lattice. The last factor of 10 in transverse cooling probably requires the use of current-carrying Li lenses. Efficient longitudinal cooling requires the use of wedge shaped absorbers in a dispersive section of the beam line. An example, multi-stage cooling scenario has been developed that meets the requirements of the muon collider. Preliminary designs have been made of solenoids for use in the FOFO lattice and of solenoids and dipoles for use in the emittance exchange sections. Detailed simulation work, farther optimization, and preparations for experimental demonstrations of critical components are currently in progress.

Fernow, R.C.; Gallardo, J.C.; Kirk, H.G.; Palmer, R.B. [and others

1996-10-01T23:59:59.000Z

418

Trilepton Higgs boson signal at hadron colliders  

SciTech Connect

Most Higgs boson searches pursued at hadron colliders require Yukawa interactions either in the production or the decay of a Higgs boson. We propose a trilepton Higgs boson search based only upon the gauge interactions of the Higgs boson. This strategy can be utilized successfully for the standard model (SM) Higgs boson as well as nonstandard Higgs bosons which break electroweak symmetry but have little to do with fermion mass generation. The trileptons come from Wh production followed by Wh{r_arrow}WWW{sup ({asterisk})}{r_arrow}3l decays. A SM Higgs trilepton signal would be difficult to detect at the Fermilab Tevatron collider: with 100fb{sup {minus}1} of data, only a 3{sigma} signal above background can be achieved after cuts if 140GeV{lt}m{sub h{sub sm}{sup 0}}{lt}175GeV. Some discrimination of signal over background can be gained by analyzing the opposite sign dilepton p{sub T} distributions. At the CERN LHC with 30(100)fb{sup {minus}1} a clear discovery above the 5{sigma} level is possible for a Higgs boson mass in the range 140{endash}185(125{endash}200)GeV. Prospects for a trilepton Higgs boson discovery are greatly improved for models with nonstandard Higgs boson sectors where a Higgs boson couples preferentially to vector bosons rather than to fermions. {copyright} {ital 1998} {ital The American Physical Society}

Baer, H. [Department of Physics, Florida State University, Tallahassee, Florida32306 (United States); Wells, J.D. [Stanford Linear Accelerator Center, Stanford University, Stanford, California94309 (United States)

1998-04-01T23:59:59.000Z

419

Frequency scaling of linear super-colliders  

SciTech Connect

The development of electron-positron linear colliders in the TeV energy range will be facilitated by the development of high-power rf sources at frequencies above 2856 MHz. Present S-band technology, represented by the SLC, would require a length in excess of 50 km per linac to accelerate particles to energies above 1 TeV. By raising the rf driving frequency, the rf breakdown limit is increased, thereby allowing the length of the accelerators to be reduced. Currently available rf power sources set the realizable gradient limit in an rf linac at frequencies above S-band. This paper presents a model for the frequency scaling of linear colliders, with luminosity scaled in proportion to the square of the center-of-mass energy. Since wakefield effects are the dominant deleterious effect, a separate single-bunch simulation model is described which calculates the evolution of the beam bunch with specified wakefields, including the effects of using programmed phase positioning and Landau damping. The results presented here have been obtained for a SLAC structure, scaled in proportion to wavelength.

Mondelli, A.; Chernin, D.; Drobot, A.; Reiser, M.; Granatstein, V.

1986-06-01T23:59:59.000Z

420

Comments on momentum aperture of 100 GeV/n Au runs in RHIC  

Science Conference Proceedings (OSTI)

In RHIC 2010 100 GeV/n Au run, the momentum aperture has been an issue in the re-bucketing and the beam intensity lifetime in store. Both Blue and Yellow beams with comparable storage RF voltage and peak current have suffered more beam loss than in Run 2007. In this note, some comments are made for the momentum aperture of the lattices used from the Au runs in 2007, 2008 and 2010. From the wigglings and the beam decays of each lattice, information regarding the machine momentum aperture is presented. Several directions in further improvement are discussed.

Zhang, S.Y.

2011-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ion collider rhic" from the National Library of EnergyBeta (NLEBeta).
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421

Direct-Photon Production in Au+Au Collisions at RHIC  

E-Print Network (OSTI)

Results from the PHENIX experiment on direct-photon production in Au+Au collisions at sqrt{s_{NN}} = 200 GeV for transverse momenta 1 Direct-photon yields at high p_T scale as expected for particle production in hard processes. This supports jet-quenching models which attribute the suppression of high-p_T hadrons to the energy loss of fast partons in the quark-gluon plasma. The low-p_T direct-photon spectra, measured via e+e- pairs with small invariant masses, are possibly related to the production of thermal direct photons in Au+Au collisions at RHIC.

Klaus Reygers; for the PHENIX Collaboration

2006-08-24T23:59:59.000Z

422

A MAPS based vertex detector for the STAR experiment at RHIC  

Science Conference Proceedings (OSTI)

The STAR experiment at RHIC is in the process of upgrading the inner detector region of the experiment to improve the vertex resolution. We describe the current design of a MAPS based vertex detector, which is the innermost and highest resolution detector of the set of three planned upgrade detectors. This detector will enable the identification of decay vertices displaced from the interaction vertex by 100-150 {micro}m and extend the capabilities of the STAR detector in the heavy flavor domain. We present selected detector design characteristics and prototyping results, which help to validate the design in preparation for the construction of the detector.

Anderssen, E; Ritter, H G; Schambach, J; Sun, X; Szelezniak, M

2011-09-11T23:59:59.000Z

423

Hydro-inspired parameterizations of freeze-out in relativistic heavy-ion collisions  

E-Print Network (OSTI)

Popular parameterizations of the freeze-out conditions in relativistic heavy-ion collisions are discussed. Similarities and differences between the blast-wave model and the single-freeze-out model, both used recently to interpret the RHIC data, are outlined. A non-boost-invariant extension of the single-freeze-out model is proposed and applied to describe the recent BRAHMS data.

Wojciech Florkowski; Wojciech Broniowski

2004-10-19T23:59:59.000Z

424

Design considerations for a laser-plasma linear collider  

SciTech Connect

Design considerations for a next-generation electron-positron linear collider based on laser-plasma-accelerators are discussed. Several of the advantages and challenges of laser-plasma based accelerator technology are addressed. An example of the parameters for a 1 TeV laser-plasma based collider is presented.

Schroeder, C. B.; Esarey, E.; Geddes, C. G. R.; Toth, Cs.; Leemans, W. P.

2008-08-01T23:59:59.000Z

425

Minimum Bias Measurements with the ATLAS Detector at the CERN Large Hadron Collider  

E-Print Network (OSTI)

Experiment at the Large Hadron Collider. Masters thesis,1 ATLAS & LHC 1.1 Large Hadron Collider 1.2 Physics at theDetector at the CERN Large Hadron Collider by Michael A.

Leyton, Michael A.

2009-01-01T23:59:59.000Z

426

Strong WW scattering physics: A comparative study for the LHC, NLC and a Muon Collider  

SciTech Connect

We discuss the model independent parameterization for a strongly interacting electroweak sector. Phenomenological studies are made to probe such a sector for future colliders such as the LHC, e{sup +}e{sup -} Linear collider and a muon collider.

Han, Tao

1997-04-01T23:59:59.000Z

427

New capabilities in the HENP grand challenge storage access systemand its application at RHIC  

SciTech Connect

The High Energy and Nuclear Physics Data Access GrandChallenge project has developed an optimizing storage access softwaresystem that was prototyped at RHIC. It is currently undergoingintegration with the STAR experiment in preparation for data taking thatstarts in mid-2000. The behavior and lessons learned in the RHIC MockData Challenge exercises are described as well as the observedperformance under conditions designed to characterize scalability. Up to250 simultaneous queries were tested and up to 10 million events across 7event components were involved in these queries. The system coordinatesthe staging of "bundles" of files from the HPSS tape system, so that allthe needed components of each event are in disk cache when accessed bythe application software. The caching policy algorithm for thecoordinated bundle staging is described in the paper. The initialprototype implementation interfaced to the Objectivity/DB. In this latestversion, it evolved to work with arbitrary files and use CORBA interfacesto the tag database and file catalog services. The interface to the tagdatabase and the MySQL-based file catalog services used by STAR aredescribed along with the planned usage scenarios.

Bernardo, L.; Gibbard, B.; Malon, D.; Nordberg, H.; Olson, D.; Porter, R.; Shoshani, A.; Sim, A.; Vaniachine, A.; Wenaus, T.; Wu, K.; Zimmerman, D.

2000-04-25T23:59:59.000Z

428

MEASUREMENT OF THE ANALYZING POWER IN PP ELASTIC SCATTERING IN THE PEAK CNI REGION AT RHIC.  

DOE Green Energy (OSTI)

The analyzing power A{sub N} for pp elastic scattering is expected to reach a peak value of 0.045 in the Coulomb Nuclear Interference (CNI) region at a momentum transfer -t of 0.003 (GeV/c){sup 2}. During the 2004 RHIC Run, we completed a measurement of A{sub N} in the CNI region by detecting the recoil protons from pp elastic scattering using a polarized atomic hydrogen gas jet target and the 100 GeV RHIC proton beam. We report the first measurements of the A{sub N} absolute value and shape in the -t range from 0.0015 to 0.010 (GeV/c){sup 2} with a precision better than 0.005 for each A{sub N} data point. The recoil protons were detected with two arrays of Si detectors. The absolute target polarization as monitored by a Breit-Rabi polarimeter was stable at 0.924 {+-} 0.018. This result allows us to further investigate the spin dependence of elastic pp scattering in the very low -t region.

MAKDISI,Y.; OKADA,H.; ALEKSEEV,I.G.; BRAVAR,A.; BUNCE,G.; ET AL

2005-01-28T23:59:59.000Z

429

Measurements of leading neutron production in polarized pp collisions at RHIC-PHENIX  

SciTech Connect

In 2001-2002, we performed an experiment to search for non-zero single transverse spin asymmetry in very forward angle, 0-2.8 mrad, with first polarized pp collision in {radical}(s) = 200 GeV at RHIC, and an unexpected large asymmetry for leading neutron production was discovered. For further investigation, we have measured the cross section with the PHENIX detector in the similar kinematics region. The observed asymmetries are consistent with the previous results measured in an experiment at the 12 o'clock interaction point at RHIC. The measured cross section are consistent with the Feynman-x scaling claimed by the ISR experiments which measured leading neutrons in pp collisions at {radical}(s) = 30.6-62.7 GeV. These cross sections in large Feynman-x, as well as those in ep collisions at HERA experiments, are well described by a pion exchange model. Therefore, the observed large asymmetry for leading neutrons is considered to come from an interference between spin-flip amplitude with the pion exchange and non-flip with Reggeon exchanges.

Togawa, Manabu [RIKEN BNL Research Center, Bldg. 510, Brookhaven National Laboratory, Upton, NY, 11973-5000 (United States)

2009-03-23T23:59:59.000Z

430

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

DOE Green Energy (OSTI)

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.

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

2010-09-27T23:59:59.000Z

431

Linear Collider Collaboration Tech Notes LCC-0109  

NLE Websites -- All DOE Office Websites (Extended Search)

9 9 TESLA 2002-11 CBP Tech Note-269 November 2002 Alignment Stability Models for Damping Rings Andrej Wolski Lawrence Berkeley National Laboratory University of California Berkeley, CA Winfried Decking Deutsches Elektron Synchrotron (DESY) Hamburg, Germany Abstract: Linear collider damping rings are highly sensitive to magnet alignment. Emittance tuning simulations for current designs of damping rings for TESLA and NLC have given encouraging results, but depend on invasive measurements of dispersion. The frequency with which such measurements must be made is therefore an operational issue, and depends on the time stability of the alignment. In this note, we consider three effects that lead to misalignment and the need to retune the damping ring: (1)

432

Big Science and the Large Hadron Collider  

E-Print Network (OSTI)

The Large Hadron Collider (LHC), the particle accelerator operating at CERN, is probably the most complex and ambitious scientific project ever accomplished by humanity. The sheer size of the enterprise, in terms of financial and human resources, naturally raises the question whether society should support such costly basic-research programs. I address this question here by first reviewing the process that led to the emergence of Big Science and the role of large projects in the development of science and technology. I then compare the methodologies of Small and Big Science, emphasizing their mutual linkage. Finally, after examining the cost of Big Science projects, I highlight several general aspects of their beneficial implications for society.

Gian Francesco Giudice

2011-06-13T23:59:59.000Z

433

Ground motion data for International Collider models  

SciTech Connect

The proposed location for the International Linear Collider (ILC) in the Americas region is Fermilab in Batavia Illinois. If built at this location the tunnels would be located in the Galena Platteville shale at a depth of 100 or more meters below the surface. Studies using hydro static water levels and seismometers have been conducted in the MINOS hall and the LaFrange Mine in North Aurora Illinois to determine the level of ground motion. Both these locations are in the Galena Platteville shale and indicate the typical ground motion to be expected for the ILC. The data contains both natural and cultural noise. Coefficients for the ALT law are determined. Seismic measurements at the surface and 100 meters below the surface are presented.

Volk, J.T.; LeBrun, P.; Shiltsev, V.; Singatulin, S.; /Fermilab

2007-11-01T23:59:59.000Z

434

Optimal, real-time control--colliders  

Science Conference Proceedings (OSTI)

With reasonable definitions, optimal control is possible for both classical and quantal systems with new approaches called PISC(Parallel) and NISC(Neural) from analogy with RISC (Reduced Instruction Set Computing). If control equals interaction, observation and comparison to some figure of merit with interaction via external fields, then optimization comes from varying these fields to give design or operating goals. Structural stability can then give us tolerance and design constraints. But simulations use simplified models, are not in real-time and assume fixed or stationary conditions, so optimal control goes far beyond convergence rates of algorithms. It is inseparable from design and this has many implications for colliders. 12 refs., 3 figs.

Spencer, J.E.

1991-05-01T23:59:59.000Z

435

Broadband impedance calculations of the TAN vacuum chamber for the Large Hadron Collider (LHC)  

E-Print Network (OSTI)

CHAMBER FOR THE LARGE HADRON COLLIDER (LHC) ? D. Li , G.chamber for the Large Hadron Collider (LHC). The TAN is the

Li, D.; Lambertson, G.; Turner, W.

2001-01-01T23:59:59.000Z

436

Heavy flavor production and top quark search at hadron colliders  

SciTech Connect

We review heavy flavor production at hadron colliders, with an eye towards the physics of the top quark. Motivation for existence of top, and current status of top search are reviewed. The physics of event simulation at hadron colliders is reviewed. We discuss characteristics of top quark events at p{bar p} colliders that may aid in distinguishing the top quark signal from Standard Model backgrounds, and illustrate various cuts which may be useful for top discovery. Top physics at hadron supercolliders is commented upon, as well as top quark mass measurement techniques. 22 refs., 5 figs.

Baer, H.A.

1991-01-01T23:59:59.000Z

437

Prospects for heavy flavor physics at hadron colliders  

SciTech Connect

The role of hadron colliders in the observation and study of CP violation in B decays is discussed. We show that hadron collider experiments can play a significant role in the early studies of these phenomena and will play an increasingly dominant role as the effort turns towards difficult to measure decays, especially those of the B{sub s} meson, and sensitive searches for rare decays and subtle deviations from Standard Model predictions. We conclude with a discussion of the relative merits of hadron collider detectors with `forward` vs `central` rapidity coverage.

Butler, J.N.

1997-09-01T23:59:59.000Z

438

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

Science Conference Proceedings (OSTI)

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 28, 1998 and is still operational. A 10 teraflops QCDOC computer in under construction and expected to be completed this year.

OGAWA, A.

2005-04-11T23:59:59.000Z

439

Governance of the International Linear Collider Project  

SciTech Connect

Governance models for the International Linear Collider Project are examined in the light of experience from similar international projects around the world. Recommendations for one path which could be followed to realize the ILC successfully are outlined. The International Linear Collider (ILC) is a unique endeavour in particle physics; fully international from the outset, it has no 'host laboratory' to provide infrastructure and support. The realization of this project therefore presents unique challenges, in scientific, technical and political arenas. This document outlines the main questions that need to be answered if the ILC is to become a reality. It describes the methodology used to harness the wisdom displayed and lessons learned from current and previous large international projects. From this basis, it suggests both general principles and outlines a specific model to realize the ILC. It recognizes that there is no unique model for such a laboratory and that there are often several solutions to a particular problem. Nevertheless it proposes concrete solutions that the authors believe are currently the best choices in order to stimulate discussion and catalyze proposals as to how to bring the ILC project to fruition. The ILC Laboratory would be set up by international treaty and be governed by a strong Council to whom a Director General and an associated Directorate would report. Council would empower the Director General to give strong management to the project. It would take its decisions in a timely manner, giving appropriate weight to the financial contributions of the member states. The ILC Laboratory would be set up for a fixed term, capable of extension by agreement of all the partners. The construction of the machine would be based on a Work Breakdown Structure and value engineering and would have a common cash fund sufficiently large to allow the management flexibility to optimize the project's construction. Appropriate contingency, clearly apportioned at both a national and global level, is essential if the project is to be realised. Finally, models for running costs and decommissioning at the conclusion of the ILC project are proposed. This document represents an interim report of the bodies and individuals studying these questions inside the structure set up and supervised by the International Committee for Future Accelerators (ICFA). It represents a request for comment to the international community in all relevant disciplines, scientific, technical and most importantly, political. Many areas require further study and some, in particular the site selection process, have not yet progressed sufficiently to be addressed in detail in this document. Discussion raised by this document will be vital in framing the final proposals due to be published in 2012 in the Technical Design Report being prepared by the Global Design Effort of the ILC.

Foster, B.; /Oxford U.; Barish, B.; /Caltech; Delahaye, J.P.; /CERN; Dosselli, U.; /INFN, Padua; Elsen, E.; /DESY; Harrison, M.; /Brookhaven; Mnich, J.; /DESY; Paterson, J.M.; /SLAC; Richard, F.; /Orsay, LAL; Stapnes, S.; /CERN; Suzuki, A.; /KEK, Tsukuba; Wormser, G.; /Orsay, LAL; Yamada, S.; /KEK, Tsukuba

2012-05-31T23:59:59.000Z

440

Phenomenology of the minimal $B-L$ Model: the Higgs sector at the Large Hadron Collider and future Linear Colliders  

E-Print Network (OSTI)

This Thesis is devoted to the study of the phenomenology of the Higgs sector of the minimal $B-L$ extension of the Standard Model at present and future colliders. Firstly, the motivations that call for the minimal $B-L$ extension are summarised. In addition, the model is analysed in its salient parts. Moreover, a detailed review of the phenomenological allowed Higgs sector parameter space is given. Finally, a complete survey of the distinctive Higgs boson signatures of the model at both the Large Hadron Collider and the future linear colliders is presented.

Giovanni Marco Pruna

2011-06-23T23:59:59.000Z

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441

Commissioning of a beta* knob for dynamic IR correction at RHIC  

Science Conference Proceedings (OSTI)

In addition to the recent optics correction technique demonstrated at CERN and applied at RHIC, it is important to have a separate tool to control the value of the beta functions at the collision point ({beta}*). This becomes even more relevant when trying to reach high level of integrated luminosity while dealing with emittance blow-up over the length of a store, or taking advantage of compensation processes like stochastic cooling. Algorithms have been developed to allow modifying independently the beta function in each plane for each beam without significant increase in beam losses. The following reviews the principle of such algorithms and their experimental implementation as a dynamic {beta}-squeeze procedure.

Robert-Demolaize G.; Marusic, A.; Tepikian, S.; White, S.

2012-05-20T23:59:59.000Z

442

Buda-Lund hydro model for ellipsoidally symmetric fireballs and the elliptic flow at RHIC  

E-Print Network (OSTI)

The ellipsoidally symmetric extension of Buda-Lund hydrodynamic model is shown here to yield a natural description of the pseudorapidity dependence of the elliptic flow $v_2(\\eta)$, as determined recently by the PHOBOS experiment for Au+Au collisions at $\\sqrt{s_{NN}} = 130$ and 200 GeV. With the same set of parameters, the Buda-Lund model describes also the transverse momentum dependence of $v_2$ of identified particles at mid-rapidity. The results confirm the indication for quark deconfinement in Au+Au collisions at RHIC, obtained from a successful Buda-Lund hydro model fit to the single particle spectra and two-particle correlation data, as measured by the BRAHMS, PHOBOS, PHENIX and STAR collaborations.

M. Csanad; T. Csorgo; B. Lorstad

2003-10-13T23:59:59.000Z

443

Pion-nucleus interactions and the STAR experiment at RHIC. Progress report, 1990--1993  

Science Conference Proceedings (OSTI)

This report summarizes the work carried out by personnel from the University of Texas at Austin at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF) during the calendar years 1990--1993 and on the STAR experiment at RHIC under grant DE-FGO5-87ER40343 between the University of Texas at Austin and the United States Department of Energy. A brief overview of work supported by this grant is given in Section 2. An account of the study of the double giant resonances in pion double charge exchange forms Section 3. This report contains a list of published papers and preprints in Section 6, invited talks in Section 7, and abstracts in Section 8. These papers summarize experiments involving participants supported by this grant and indicate the work accomplished by these participants in this program of medium energy nuclear physics research. Section 9 contains a list of personnel who have participated in this research program.

Moore, C.F.

1993-09-01T23:59:59.000Z

444

First Beam for Large Hadron Collider | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Beam for Large Hadron Collider Beam for Large Hadron Collider First Beam for Large Hadron Collider September 10, 2008 - 3:20pm Addthis WASHINGTON, DC - An international collaboration of scientists today sent the first beam of protons zooming at nearly the speed of light around the world's most powerful particle accelerator-the Large Hadron Collider (LHC)-located at the CERN laboratory near Geneva, Switzerland. The U.S. Department of Energy (DOE) and the National Science Foundation (NSF) invested a total $531 million in the construction of the accelerator and its detectors, which scientists believe could help unlock extraordinary discoveries about the nature of the physical universe. Celebrations across the U.S. and around the world mark the LHC's first circulating beam, an occasion more than 15 years in the making. An

445

TESLA*HERA as Lepton (Photon)-Hadron Collider  

E-Print Network (OSTI)

New facilities for particle and nuclear physics research, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

O. Yavas; A. K. Ciftci; S. Sultansoy

2000-04-11T23:59:59.000Z

446

SCIENCE ON SATURDAY- "The Large Hadron Collider: big science...  

NLE Websites -- All DOE Office Websites (Extended Search)

5, 2013, 9:30am Science On Saturday MBG Auditorium SCIENCE ON SATURDAY- "The Large Hadron Collider: big science for big questions" Professor James Olsen Department of Physics,...

447

June 30, 2008: US portion of Large Hadron Collider completed  

Energy.gov (U.S. Department of Energy (DOE))

June 30, 2008The Department and the National Science Foundation announce that the U.S. contribution to the Large Hadron Collider (LHC) has been completed on budget and ahead of schedule. The LHC,...

448

Signatures of doubly-charged Higgsinos at colliders  

SciTech Connect

Several supersymmetric models with extended gauge structures predict light doubly-charged Higgsinos. Their distinctive signature at the large hadron collider is highlighted by studying its production and decay characteristics.

Demir, D. A. [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir (Turkey); Deutsches Elektronen-Synchrotron, DESY, D-22603 Hamburg (Germany); Frank, M.; Turan, I. [Department of Physics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec, H4B 1R6 (Canada); Huitu, K.; Rai, S. K. [Department of Physics, University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FIN-00014, Helsinki (Finland)

2008-11-23T23:59:59.000Z

449

Neutrino Factory and Muon Collider R&D  

E-Print Network (OSTI)

European, Japanese, and US Neutrino Factory designs are presented. The main R&D issues and associated R&D programs, future prospects, and the additional issues that must be addressed to produce a viable Muon Collider design, are discussed.

Steve Geer

2001-11-05T23:59:59.000Z

450

Microsoft Word - WFnote-239_short pulse collider.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

efficiency and the cost to sustain such a gradient should be considered as well in the optimization process of an overall design. We propose a high energy linear collider based...

451

Higgs boson production at hadron colliders: Signal and background processes  

SciTech Connect

We review the theoretical status of signal and background calculations for Higgs boson production at hadron colliders. Particular emphasis is given to missing NLO results, which will play a crucial role for the Tevatron and the LHC.

David Rainwater; Michael Spira; Dieter Zeppenfeld

2004-01-12T23:59:59.000Z

452

The polarized electron beam for the SLAC Linear Collider  

E-Print Network (OSTI)

The SLAC Linear Collider has been colliding a polarized electron beam with an unpolarized positron beam at the Z^0 resonance for the SLD experiment since 1992. An electron beam polarization of close to 80% has been achieved for the experiment at luminosities up to 8x10^29 cm^-2 s^-1. This is the world's first and only linear collider, and is a successful prototype for the next generation of high energy electron linear colliders. This paper discusses polarized beam operation for the SLC, and includes aspects of the polarized source, spin transport and polarimetry. Presented at the 12th International Symposium on High Energy Spin Physics held at Amsterdam, The Netherlands September 10-14, 1996.

M. Woods

1996-11-09T23:59:59.000Z

453

RHIC Videos  

NLE Websites -- All DOE Office Websites (Extended Search)

Because you are not running JavaScript or allowing active scripting, some features on this page my not work. >> Enable Javascript << Brookhaven National Laboratory search U.S....

454

Four-Lepton Resonance at the Large Hadron Collider  

E-Print Network (OSTI)

A spin-1 weakly interacting vector boson, Z', is predicted by many new physics theories. Searches at colliders for such a Z' resonance typically focus on lepton-antilepton or top-antitop events. Here we present a novel channel with a Z' resonance that decays to 4 leptons, but not to 2 leptons, and discuss its possible discovery at the Large Hadron Collider. This baryonic gauge boson is well motivated in a supersymmetry framework.

Vernon Barger; Hye-Sung Lee

2011-11-02T23:59:59.000Z

455

Flat beams in a 50 TeV hadron collider  

SciTech Connect

The basic beam dynamics of a next generation 50 x 50 TeV hadron collider based on a high field magnet approach have been outlined over the past several years. Radiation damping not only produces small emittances, but also flat beams, just as in electron machines. Based on {open_quotes}Snowmass 96{close_quotes} parameters, we investigate the issues associated with flat beams in very high energy hadron colliders.

Peggs, S.; Harrison, M.; Pilat, F.; Syphers, M.

1997-08-01T23:59:59.000Z

456

Relativistic heavy ion physics. Progress report, November 15, 1992--November 14, 1993  

SciTech Connect

This is a progress report for the period May 1992 through April 1993. The first section, entitled ``Purpose and Trends, gives background on the recent trends in the research program and its evolution from an emphasis on nuclear structure physics to its present emphasis on relativistic heavy ion and RHIC physics. The next section, entitled ``Physics Research Progress``, is divided into four parts: participation in the program to develop a large detector named PHENIX for the RHIC accelerator; joining E864 at the AGS accelerator and the role in that experiment; progress made in the study of electromagnetic dissociation highlight of this endeavor is an experiment carried out with the {sup 197}Au beam from the AGS accelerator in April 1992; progress in completion of the nuclear structure studies. In the final section a list of publications, invited talks, and contributed talks is given.

Hill, J.C.; Wohn, F.K.

1993-11-01T23:59:59.000Z

457

Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88)  

SciTech Connect

The interpretation of relativistic heavy-ion collisions at RHIC energies with thermal concepts is largely based on the relative success of ideal (nondissipative) hydrodynamics. This approach can describe basic observables at RHIC, such as particle spectra and momentum anisotropies, fairly well. On the other hand, recent theoretical efforts indicate that dissipation can play a significant role. Ideally viscous hydrodynamic simulations would extract, if not only the equation of state, but also transport coefficients from RHIC data. There has been a lot of progress with solving relativistic viscous hydrodynamics. There are already large uncertainties in ideal hydrodynamics calculations, e.g., uncertainties associated with initial conditions, freezeout, and the simplified equations of state typically utilized. One of the most sensitive observables to the equation of state is the baryon momentum anisotropy, which is also affected by freezeout assumptions. Up-to-date results from lattice quantum chromodynamics on the transition temperature and equation of state with realistic quark masses are currently available. However, these have not yet been incorporated into the hydrodynamic calculations. Therefore, the RBRC workshop 'Hydrodynamics in Heavy