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Sample records for rhic sextant commissioning

  1. Preparing accelerator systems for the RHIC sextant commissioning

    SciTech Connect

    Trbojevic, D.; Pilat, F.; Ahrens, L.

    1997-07-01

    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.

  2. Preparing Accelerator Systems for the RHIC Sextant Commissioning

    NASA Astrophysics Data System (ADS)

    Trbojevic, D.; Pilat, F.; Ahrens, L.; Barton, D.; Clifford, T.; Connoly, R.; Fischer, W.; Harrison, M.; Mackay, W.; Olsen, B.; Peggs, S.; Satogata, T.; Tepikian, S.; Thompson, P.; Trahern, C.; Witkover, R.

    1997-05-01

    The Relativistic Heavy Ion Collider (RHIC) construction is progressing steadily towards the beginning of the 1999 when beams will first be circulated in both collider rings. One of the major tests of the RHIC project is the commissioning of the first sextant with gold ion beams. This is a report on the preparation of the RHIC accelerator systems during the first sextant test, including 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 CYBASE data base 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.

  3. RHIC sextant test: Accelerator systems and performance

    SciTech Connect

    Pilat, F.; Trbojevic, D.; Ahrens, L.

    1997-08-01

    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.

  4. RHIC Sextant Test - Accelerator Systems and Performance

    NASA Astrophysics Data System (ADS)

    Pilat, F.; Ahrens, L.; Brown, K.; Connolly, R.; dell, G. F.; Fischer, W.; Kewisch, J.; Mackay, W.; Mane, V.; Peggs, S.; Satogata, T.; Tepikian, S.; Thompson, P.; Trbojevic, D.; Tsoupas, N.; Wei, J.

    1997-05-01

    One sextant of the RHIC collider and the full AtR (AGS to RHIC) transfer line have been commissioned in early 1997 with beam. We describe here the design and performance of the accelerator systems during the test, such as the magnet and power supply systems, instrumentation subsystems and application software. After reviewing the main milestones of the commissioning we describe a ramping test without beam that took place after the commissioning with beam. Finally, we analyze the implications of accelerator systems preformance and their impact on the plannig for RHIC installation and commissioning.

  5. RHIC Sextant Test -- Physics and performance

    SciTech Connect

    Wei, J.; Fischer, W.; Ahrens, L.

    1997-07-01

    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.

  6. RHIC Sextant Test --- Physics and Performance

    NASA Astrophysics Data System (ADS)

    Wei, J.; Fischer, W.; Ahrens, L.; Brennan, J. M.; Brown, K.; Connolly, R.; dell, G. F.; Harrison, M.; Kewisch, J.; Mackay, W. W.; Mane, V.; Peggs, S.; Pilat, F.; Satogata, T.; Tepikian, S.; Thompson, P.; Trahern, C. G.; Trbojevic, D.; Tsoupas, N.

    1997-05-01

    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. The flexibility of the ATR and RHIC Sextant lattices is demonstrated by a widely tunable range of phase advance per cell. Longitudinal tomography is employed to reconstruct beam motion in phase space. Digitized two-dimensional video profile monitors are used to measure transverse beam emittances and beamline optics. The gold ion beam parameters are shown to be comparable to the RHIC design requirements.

  7. Results from betatron phase measurements in RHIC during the sextant test

    SciTech Connect

    Trbojevic, D.; Connolly, R.; Fischer, W.

    1998-08-01

    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.

  8. RESULTS FROM BETATRON PHASE MEASUREMENTS IN RHIC DURING THE SEXTANT TEST.

    SciTech Connect

    TRBOJEVIC, D.

    1998-06-26

    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.

  9. Power Systems for the RHIC First Sextant Test

    NASA Astrophysics Data System (ADS)

    Lambiase, R. F.; Bruno, D.; Feng, P. K.; Haque, T.; Schultheiss, C.

    1997-05-01

    The first sextant test of the RHIC project is an opportunity to evaluate the many systems that must work together for the accelerator to operate. For the main dipole string, the actual main quadrupole power supply with its DSP regulator and output circuit compartments will be used. Temporary supplies will be used for the main quadrupole string, quadrupole offset, and quadrupole shunt supplies. This will let us both measure the performance of the main supply as well as determine the interaction among other power elements in the circuit. Correction elements will also be powered. The actual gamma-T power supplies will be used, as well as temporary supplies for the dipole correctors and sextupole supplies. Some of these units are required for beam to be transported, others are to be operated without beam to measure their performance, and how they interact with their superconducting loads. The power supply equipment, and that of other systems, required an infrastucture of AC power and output cable distribution in the RHIC tunnel, outlying service buildings, and interconnecting the tunnel to the service buildings. This note will describe the performance of the RHIC power supply systems during the sextant test, and the experience gained from this exercise.

  10. Power systems for the RHIC first sextant test

    SciTech Connect

    Schultheiss, C.; Bruno, D.; Feng, P.K.

    1997-07-01

    The first sextant test of the RHIC project is an opportunity to evaluate the many systems that must work together for the accelerator to operate. For the main dipole string, the actual main quadrupole power supply with its DSP regulator and output circuit compartment will be used. Temporary supplies will be used for the main quadrupole string, quadrupole offset, and quadrupole shunt supplies. This will let the authors both measure the performance of the main supply as well as determine the interaction among other power elements in the circuit. Correction elements will also be powered. The actual gamma-T power supplies will be used, as well as temporary supplies for the dipole correctors and sextupole supplies. Some of these units are required for beam to be transported, others are to be operated without beam to measure their performance, and how they interact with their superconducting loads. The power supply equipment, and that of other systems, required an infrastucture of AC power and output cable distribution in the RHIC tunnel, outlying service buildings, and interconnecting the tunnel to the service buildings. This note will describe the performance of the RHIC power supply systems during the sextant test, and the experience gained from this exercise.

  11. RHIC spin flipper commissioning results

    SciTech Connect

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

    2012-05-20

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

  12. COMMISSIONING OF RHIC AT 100 GEV / NUCLEON.

    SciTech Connect

    TRBOJEVIC,D.; AHRENS,L.; BLASKIEWICZ,M.; BRENNAN,J.M.; BAI,M.; CAMERON,P.; CARDONA,J.; CONNOLLY,R.; DREES,A.; FLILLER,R.P.; ET AL

    2002-06-02

    This report describes commissioning of the Relativistic Heavy Ion Collider (RHIC) for 100 GeV/nucleon collisions at designed luminosity. To achieve these goals new systems had to be commissioned: Gamma-t transition crossing jump quadrupoles, rebucketing with the new RF storage cavities, phase lock loop feedback, betatron and crystal collimation, beta squeeze along the ramp, Siberian snake magnets for the proton polarization run, AC dipole system chromaticity measurements along the acceleration ramp, orbit correction, new ramp management system, upgraded sequencer, new data instrumentation and logger acquisition system etc.

  13. THE RHIC INJECTION SYSTEM.

    SciTech Connect

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

    1999-03-29

    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.

  14. Beam Injection into RHIC

    NASA Astrophysics Data System (ADS)

    Fischer, W.; Hahn, H.; Mackay, W. W.; Tsoupas, N.

    1997-05-01

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

  15. Beam injection into RHIC

    SciTech Connect

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

    1997-07-01

    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.

  16. Commissioning results from the recently upgraded RHIC LLRF system

    SciTech Connect

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

    2011-03-28

    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.

  17. Physics of the AGS-to-RHIC transfer line commissioning

    SciTech Connect

    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.

    1996-07-01

    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.

  18. RHIC status

    SciTech Connect

    Peggs, S.

    1997-08-01

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

  19. How robust will the RHIC lattice be during commissioning

    SciTech Connect

    Ohnuma, S. )

    1991-09-01

    The question raised here is whether the RHIC lattice is robust enough to make all these commissioning manipulations possible. There are of course many factors involved in answering this question in a definitive manner. The purpose of this note is to see if there are any fundamental and serious shortcomings basic to the lattice. The lattice considered here is the one presented to the workshop by Steve Tepikian and called RHIC91. More specifically, we fix nine quadrupole parameters in all insertions except in the 6 o'clock insertion where the independent parameters is sixteen. The so-called perfect matching may require fourteen parameters instead of nine but the difference is insignificant. On the other hand, if the number of parameters is reduced from sixteen to nine in the 6 o'clock insertion, the mismatch in the arc beta function becomes non-trivial. For example, the horizontal beta may vary between 40m to 60m at QF locations.

  20. RHIC instrumentation

    NASA Astrophysics Data System (ADS)

    Shea, T. J.; Witkover, R. L.

    1998-12-01

    The Relativistic Heavy Ion Collider (RHIC) consists of two 3.8 km circumference rings utilizing 396 superconducting dipoles and 492 superconducting quadrupoles. Each ring will accelerate approximately 60 bunches of 1011 protons to 250 GeV, or 109 fully stripped gold ions to 100 GeV/nucleon. Commissioning is scheduled for early 1999 with detectors for some of the 6 intersection regions scheduled for initial operation later in the year. The injection line instrumentation includes: 52 beam position monitor (BPM) channels, 56 beam loss monitor (BLM) channels, 5 fast integrating current transformers and 12 video beam profile monitors. The collider ring instrumentation includes: 667 BPM channels, 400 BLM channels, wall current monitors, DC current transformers, ionization profile monitors (IPMs), transverse feedback systems, and resonant Schottky monitors. The use of superconducting magnets affected the beam instrumentation design. The BPM electrodes must function in a cryogenic environment and the BLM system must prevent magnet quenches from either fast or slow losses with widely different rates. RHIC is the first superconducting accelerator to cross transition, requiring close monitoring of beam parameters at this time. High space-charge due to the fully stripped gold ions required the IPM to collect magnetically guided electrons rather than the conventional ions. Since polarized beams will also be accelerated in RHIC, additional constraints were put on the instrumentation. The orbit must be well controlled to minimize depolarizing resonance strengths. Also, the position monitors must accommodate large orbit displacements within the Siberian snakes and spin rotators. The design of the instrumentation will be presented along with results obtained during bench tests, the injection line commissioning, and the first sextant test.

  1. RHIC instrumentation

    SciTech Connect

    Shea, T. J.; Witkover, R. L.

    1998-12-10

    The Relativistic Heavy Ion Collider (RHIC) consists of two 3.8 km circumference rings utilizing 396 superconducting dipoles and 492 superconducting quadrupoles. Each ring will accelerate approximately 60 bunches of 10{sup 11} protons to 250 GeV, or 10{sup 9} fully stripped gold ions to 100 GeV/nucleon. Commissioning is scheduled for early 1999 with detectors for some of the 6 intersection regions scheduled for initial operation later in the year. The injection line instrumentation includes: 52 beam position monitor (BPM) channels, 56 beam loss monitor (BLM) channels, 5 fast integrating current transformers and 12 video beam profile monitors. The collider ring instrumentation includes: 667 BPM channels, 400 BLM channels, wall current monitors, DC current transformers, ionization profile monitors (IPMs), transverse feedback systems, and resonant Schottky monitors. The use of superconducting magnets affected the beam instrumentation design. The BPM electrodes must function in a cryogenic environment and the BLM system must prevent magnet quenches from either fast or slow losses with widely different rates. RHIC is the first superconducting accelerator to cross transition, requiring close monitoring of beam parameters at this time. High space-charge due to the fully stripped gold ions required the IPM to collect magnetically guided electrons rather than the conventional ions. Since polarized beams will also be accelerated in RHIC, additional constraints were put on the instrumentation. The orbit must be well controlled to minimize depolarizing resonance strengths. Also, the position monitors must accommodate large orbit displacements within the Siberian snakes and spin rotators. The design of the instrumentation will be presented along with results obtained during bench tests, the injection line commissioning, and the first sextant test.

  2. RHIC instrumentation

    SciTech Connect

    Shea, T.J.; Witkover, R.L.

    1998-12-01

    The Relativistic Heavy Ion Collider (RHIC) consists of two 3.8 km circumference rings utilizing 396 superconducting dipoles and 492 superconducting quadrupoles. Each ring will accelerate approximately 60 bunches of 10{sup 11} protons to 250 GeV, or 10{sup 9} fully stripped gold ions to 100 GeV/nucleon. Commissioning is scheduled for early 1999 with detectors for some of the 6 intersection regions scheduled for initial operation later in the year. The injection line instrumentation includes: 52 beam position monitor (BPM) channels, 56 beam loss monitor (BLM) channels, 5 fast integrating current transformers and 12 video beam profile monitors. The collider ring instrumentation includes: 667 BPM channels, 400 BLM channels, wall current monitors, DC current transformers, ionization profile monitors (IPMs), transverse feedback systems, and resonant Schottky monitors. The use of superconducting magnets affected the beam instrumentation design. The BPM electrodes must function in a cryogenic environment and the BLM system must prevent magnet quenches from either fast or slow losses with widely different rates. RHIC is the first superconducting accelerator to cross transition, requiring close monitoring of beam parameters at this time. High space-charge due to the fully stripped gold ions required the IPM to collect magnetically guided electrons rather than the conventional ions. Since polarized beams will also be accelerated in RHIC, additional constraints were put on the instrumentation. The orbit must be well controlled to minimize depolarizing resonance strengths. Also, the position monitors must accommodate large orbit displacements within the Siberian snakes and spin rotators. The design of the instrumentation will be presented along with results obtained during bench tests, the injection line commissioning, and the first sextant test. {copyright} {ital 1998 American Institute of Physics.}

  3. Beam commissioning results for the RFQ and MEBT of the EBIS based preinjector for RHIC

    SciTech Connect

    Okamura, M.; Alessi, J.; Beebe, E.; Kondo, K.; Lambiase, R.; Lockey, R.; LoDestro, V.; Mapes, M.; McNerney, A.; Phillips, D.; Pikin, A.I.; Raparia, D.; Ritter, J.; Smart, L.; Snydstrup, L.; Zaltsman, A.; Tamura, J.; Schempp, A.; Zhang, C.; Schmidt, J.S.; Vossberg, M.; Kanesue, T.

    2010-09-12

    The EBIS based preinjector for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL) is now being commissioned at Brookhaven National Laboratory (BNL). In 2008, the RFQ for the project was delivered and commissioned using Test EBIS, which was built to demonstrate the high current EBIS's performance. A dedicated beamline after the RFQ was assembled to confirm the RFQ's performance, and the beam energy was measured by a bending dipole magnet. In November 2009, the RFQ was moved to the final location and the vanes were realigned. The beam commissioning with the RHIC-EBIS was started again during March 2010. The RFQ accelerates ions from 17 keV/u to 300 keV/u and operates at 100.625 MHz. It is followed by a short Medium Energy Beam Transport (MEBT), which consists of four quadrupoles and one buncher cavity. Some temporary diagnostics for this commissioning include an emittance probe, TOF system, fast Faraday cup, and beam current measurement units. As of September 2010, the RFQ and the MEBT show expected performance with He{sup +}, Au{sup 32+} and Fe{sup 20+} beams. Further commissioning for higher intensity beams is in progress.

  4. Beam commissioning of the RFQ for the RHIC-EBIS project

    SciTech Connect

    Okamura,M.; Alessi, J.; Beebe, E.; Lodestro, V.; Pikin, A.; Ritter, J.; Tamura, J.; Kanesue, T.; Schempp, A.; Schmidt, J.; Vossberg, M.

    2009-05-04

    Beam commissioning of a new 4 rod RFQ has started at Brookhaven National Laboratory (BNL). The RFQ will accelerate intense heavy ion beams provided by an Electron Beam ion Source (EBIS) up to 300 keV/u. The RFQ will accelerate a range of Q/M from 1 to 1/6, and the accelerated beam will be finally delivered to the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL). The first beam was successfully accelerated and the bunch structures of He{sup +} and Cu{sup 10+} beams were measured. The further beam tests are in progress.

  5. RHIC Status

    NASA Astrophysics Data System (ADS)

    Peggs, Steve

    1997-05-01

    The design and construction status of the Relativistic Heavy Ion Collider, RHIC, is discussed. Those novel performance features of a heavy ion collider that are distinct from hadron colliders in general are noted. These features are derived from the experimental requirements of operation with a variety of ion species over a wide energy range, including collisions between protons and ions, and between ions of unequal energies. The project is in the fifth year of a seven year construction cycle. A brief review of the recent Sextant Test is given, together with progress to date on machine construction.

  6. Solar disk sextant

    NASA Technical Reports Server (NTRS)

    Sofia, S.; Chiu, H.-Y.; Maier, E.; Schatten, K. H.; Minott, P.; Endal, A. S.

    1984-01-01

    This paper presents the conceptual design of an instrument, called the solar disk sextant, to be used in space to measure the shape and the size of the sun and their variations. The instrumental parameters required to produce sufficient sensitivity to address the problems of solar oblateness, solar pulsations, and global size changes of climatic importance are given.

  7. Commissioning of a beta* knob for dynamic IR correction at RHIC

    SciTech Connect

    Robert-Demolaize G.; Marusic, A.; Tepikian, S.; White, S.

    2012-05-20

    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.

  8. ?Vertical Sextants give Good Sights?

    NASA Astrophysics Data System (ADS)

    Richey, Michael

    Mark Dixon suggests (Forum, Vol. 50, 137) that nobody thus far has attempted to quantify the errors from tilt that arise while observing with the marine sextant. The issue in fact, with the related problem of what exactly is the axis about which the sextant is rotated whilst being (to define the vertical), was the subject of a lively controversy in the first two volumes of this Journal some fifty years ago. Since the consensus of opinion seems to have been that the maximum error does not necessarily occur at 45 degrees, whereas Dixon's table suggests that it does, some reiteration of the arguments may be in order.

  9. Stochastic cooling in RHIC

    SciTech Connect

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

    2009-05-04

    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.

  10. Vertical Sextants give Good Sights

    NASA Astrophysics Data System (ADS)

    Dixon, Mark

    Many texts stress the need for marine sextants to be held precisely vertical at the instant that the altitude of a heavenly body is measured. Several authors lay particular emphasis on the technique of the instrument in a small arc about the horizontal axis to obtain a good sight. Nobody, to the author's knowledge, however, has attempted to quantify the errors involved, so as to compare them with other errors inherent in determining celestial position lines. This paper sets out to address these issues and to pose the question: what level of accuracy of vertical alignment can reasonably be expected during marine sextant work at sea ?When a heavenly body is brought to tangency with the visible horizon it is particularly important to ensure that the sextant is held in a truly vertical position. To this end the instrument is rocked gently about the horizontal so that the image of the body describes a small arc in the observer's field of vision. As Bruce Bauer points out, tangency with the horizon must be achieved during the process of rocking and not a second or so after rocking has been discontinued. The altitude is recorded for the instant that the body kisses the visible horizon at the lowest point of the rocking arc, as in Fig. 2. The only other visual clue as to whether the sextant is vertical is provided by the right angle made by the vertical edge of the horizon glass mirror with the horizon. There may also be some input from the observer's sense of balance and his hand orientation.

  11. Solar disk sextant optical configuration

    NASA Technical Reports Server (NTRS)

    Chiu, H.-Y.; Maier, E.; Schatten, K. H.; Sofia, S.

    1984-01-01

    In this paper the performance of a plausible configuration for the solar disk sextant, an instrument to be used to monitor the solar diameter, is evaluated. Overall system requirements are evaluated, and tolerable uncertainties are obtained. It is concluded that by using a beam splitting wedge, a folded optics design can be used to measure the solar diameter to an accuracy of 10 to the -6th, despite the greater aberrations present in such optical systems.

  12. Sextant measures spacecraft altitude without gravitational reference

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Horizon-sensing sextant measures the altitude of an orbiting spacecraft without gravitational reference by optically measuring the dip angle to the horizon along a line of sight in each of two planes. The sextant scans over a relatively limited field of view.

  13. THE RHIC ACCELERATOR.

    SciTech Connect

    HARRISON,M.; PEGGS,S.; ROSER,T.

    2002-01-01

    This review discusses the design and initial operation of the Relativistic Heavy Ion Collider (RHIC), noting the novel features of a heavy ion collider that are distinct from conventional hadron colliders. These features reflect the experimental requirements of operation with a variety of ion species over a wide energy range, including collisions between ions of unequal energies and polarized protons. Other unique aspects of RHIC include intrabeam scattering, interaction-region error compensation, and transition crossing with a slow ramp rate. The RHIC facility has just completed the second physics run after beam commissioning in 2000.

  14. A prototype ionization profile monitor for RHIC

    SciTech Connect

    Connolly, R.; Cameron, P.; Ryan, W.

    1997-07-01

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

  15. Easily Constructed Mini-Sextant Demonstrates Optical Principles.

    ERIC Educational Resources Information Center

    Nenninger, Garet G.

    2000-01-01

    Examines the design and construction of a mini-sextant and its use in demonstrating Fresnel reflection, geometric optics, and several common optical techniques. A sidebar explains the basic use of the mini-sextant as a navigational tool. (WRM)

  16. ELECTRON COOLING FOR RHIC.

    SciTech Connect

    BEN-ZVI,I.

    2001-05-13

    The Accelerator Collider Department (CAD) at Brookhaven National Laboratory is operating the Relativistic Heavy Ion Collider (RHIC), which includes the dual-ring, 3.834 km circumference superconducting collider and the venerable AGS as the last part of the RHIC injection chain. CAD is planning on a luminosity upgrade of the machine under the designation RHIC II. One important component of the RHIC II upgrade is electron cooling of RHIC gold ion beams. For this purpose, BNL and the Budker Institute of Nuclear Physics in Novosibirsk entered into a collaboration aimed initially at the development of the electron cooling conceptual design, resolution of technical issues, and finally extend the collaboration towards the construction and commissioning of the cooler. Many of the results presented in this paper are derived from the Electron Cooling for RHIC Design Report [1], produced by the, BINP team within the framework of this collaboration. BNL is also collaborating with Fermi National Laboratory, Thomas Jefferson National Accelerator Facility and the University of Indiana on various aspects of electron cooling.

  17. RHIC BEAM LOSS MONITOR SYSTEM INITIAL OPERATION.

    SciTech Connect

    WITKOVER,R.L.; MICHNOFF,R.J.; GELLER,J.M.

    1999-03-29

    The RHIC Beam Loss Monitor (BLM) System is designed to prevent beam loss quenching of the superconducting magnets, and acquire loss data. Four hundred ion chambers are located around the rings to detect losses. The required 8-decade range in signal current is compressed using an RC pre- integrator ahead of a low current amplifier. A beam abort may be triggered if fast or slow losses exceed programmable threshold levels. A micro-controller based VME module sets references and gains and reads trip status for up to 64 channels. Results obtained with the detectors in the RHIC Sextant Test and the prototype electronics in the AGS-to-RHIC (AtR) transfer line are presented along with the present status of the system.

  18. RHIC PROGRESS REPORT

    SciTech Connect

    PEGGS, S.

    1998-06-26

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

  19. RHIC progress report

    SciTech Connect

    Peggs, S.

    1998-08-01

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

  20. RHIC INSERTION REGION, SHUNT POWER SUPPLY CURRENT ERRORS.

    SciTech Connect

    BRUNO,D.; GANETIS,G.; LAMBIASE,R.F.; SANDBERG,J.

    2001-06-18

    The Relativistic Heavy Ion Collider (RHIC) was commissioned in 1999 and 2000. RHIC requires power supplies to supply currents to highly inductive superconducting magnets. The RHIC Insertion Region contain's many shunt power supplies to trim the current of different magnet elements in a large superconducting magnet circuit. Power Supply current error measurements were performed during the commissioning of RHIC. Models of these power supply systems were produced to predict and improve these power supply current errors using the circuit analysis program MicroCap V by Spectrum Software (TM). Results of the power supply current errors are presented from the models and from the measurements performed during the commissioning of RHIC.

  1. The RHIC Injection Kicker

    NASA Astrophysics Data System (ADS)

    Hahn, H.; Tuozzolo, J. E.; Tsoupas, N.

    1997-05-01

    Beam transfer from the AGS to RHIC is performed in single-bunch mode. Close spacing of the bunches in the collider requires an injection kicker with a rise time of <95 nsec, suggesting adoption of a travelling wave solution. The required vertical kick of 0.186 T.m is provided by 4 units, each 1.12 m long with a 48.4× 48.4 mm aperture and operated at 1.6 kA. The kicker is constructed as a ``C'' cross section magnet, in which ferrite and high-permittivity ( ~ 100) dielectric sections alternate. The dielectric blocks provide the capacity necessary for the nominally 25 Ohm characteristic impedance of the travelling wave structure, but impose the practical limit on the peak voltage, and thus current, achievable. Computer studies to minimize local electric field enhancements resulted in a configuration capable of holding >50 kV, with adequate safety margin over the nominal 40 kV. Tests indicated the possibility of lowering the nominal voltage by operating mismatched into 20 Ohm terminations without degrading the pulse shape. In this paper, the experience gained in the fabrication of the four kicker units for the ``Sextant Test'' and the results from various single-unit tests and operation in beam are reported.

  2. The RHIC injection kicker

    SciTech Connect

    Hahn, H.; Tsoupas, N.; Tuozzolo, J.E.

    1997-07-01

    Beam transfer from the AGS to RHIC is performed in single-bunch mode. Close spacing of the bunches in the collider requires an injection kicker with a rise time of <90 nsec, suggesting adoption of a travelling wave structure. The required vertical kick of 0.186 t{center_dot}m is provided by 4 magnets, each 1.12 m long with a 48.4 x 48.4 mm aperture and operated at 1.6 kA. The kicker is constructed as a {open_quotes}C{close_quotes} cross section magnet, in which ferrite and high-permittivity dielectric sections alternate. The dielectric blocks provide the capacity necessary for the nominally 25 {Omega} characteristic impedance of the travelling wave structure, but impose the practical limit on the peak voltage, and thus current, achievable. Computer studies to minimize local electric field enhancements resulted in a configuration capable of holding {approximately} 50 kV, with adequate safety margin over the nominal 40 kV. Equivalent circuit analysis indicated the possibility of lowering the nominal voltage by operating mismatched into 20 {Omega} terminations without degrading the pulse shape. In this paper, the experience gained in the fabrication of the production units and the results from various single-unit tests and operation of four kickers with beam in the {open_quotes}Sextant Test{close_quotes} are reported.

  3. RHIC LUMINOSITY UPGRADE PROGRAM

    SciTech Connect

    Fischer, W.

    2010-05-23

    The Relativistic Heavy Ion Collider (RHIC) operates with either ions or polarized protons. After increasing the heavy ion luminosity by two orders of magnitude since its commissioning in 2000, the current luminosity upgrade program aims for an increase by another factor of 4 by means of 3D stochastic cooling and a new 56 MHz SRF system. An Electron Beam Ion Source is being commissioned that will allow the use of uranium beams. Electron cooling is considered for collider operation below the current injection energy. For the polarized proton operation both luminosity and polarization are important. In addition to ongoing improvements in the AGS injector, the construction of a new high-intensity polarized source has started. In RHIC a number of upgrades are under way to increase the intensity and polarization transmission to 250 GeV beam energy. Electron lenses will be installed to partially compensate the head-on beam-beam effect.

  4. Design and Operation of the RHIC 80-K Cooler

    NASA Astrophysics Data System (ADS)

    Nicoletti, A.; Reuter, A.; Sidi-Yekhlef, A.; Talty, P.; Quimby, E.

    2004-06-01

    A stand-alone cryogenic system designed to maintain the magnets of the Relativistic Heavy Ion Collider (RHIC) at between 80 and 100 K during accelerator shutdown periods has been conceived and designed at Brookhaven National Laboratory and built by PHPK Technologies of Columbus, Ohio. Since most thermal contraction occurs above this temperature, this unit, referred to as the 80-K Cooler, will eliminate the stresses associated with thermal cycling. The cooling system will provide the necessary refrigeration by circulating cooled helium gas at approximately 1500 kPA through the RHIC heat shields and magnets. This helium is cooled by heat exchange with liquid nitrogen and circulated via three cold centrifugal pumps. The nominal delivered cooling capacity required to maintain the magnets at temperature is approximately 36 kW, primarily intercepted at the heat shield. The system also has separate heat exchangers for use as a pre-cooler from room temperature to 82 K. Selection of sextant or sextants for pre-cooling is designed into the RHIC cryogenic distribution system. Topics covered include Cooler design decisions, details of the Cooler as built, integration into the existing RHIC cryogenic system and initial operating experience.

  5. Design and Operation of the RHIC 80-K Cooler

    SciTech Connect

    Nicoletti, A.; Reuter, A.; Sidi-Yekhlef, A.; Talty, P.; Quimby, E.

    2004-06-23

    A stand-alone cryogenic system designed to maintain the magnets of the Relativistic Heavy Ion Collider (RHIC) at between 80 and 100 K during accelerator shutdown periods has been conceived and designed at Brookhaven National Laboratory and built by PHPK Technologies of Columbus, Ohio. Since most thermal contraction occurs above this temperature, this unit, referred to as the 80-K Cooler, will eliminate the stresses associated with thermal cycling. The cooling system will provide the necessary refrigeration by circulating cooled helium gas at approximately 1500 kPA through the RHIC heat shields and magnets. This helium is cooled by heat exchange with liquid nitrogen and circulated via three cold centrifugal pumps. The nominal delivered cooling capacity required to maintain the magnets at temperature is approximately 36 kW, primarily intercepted at the heat shield. The system also has separate heat exchangers for use as a pre-cooler from room temperature to 82 K. Selection of sextant or sextants for pre-cooling is designed into the RHIC cryogenic distribution system. Topics covered include Cooler design decisions, details of the Cooler as built, integration into the existing RHIC cryogenic system and initial operating experience.

  6. DESIGN AND OPERATON OF THE RHIC 80K COOLER

    SciTech Connect

    NICOLETTI,A.REUTER,A.SIDI-YEKHLEF,A.TALTY,P.QUIMBY,E.

    2003-09-22

    A stand alone cryogenic system designed to maintain the magnets of the Relativistic Heavy Ion Collider (RHIC) at between 80 and 100 K during accelerator shutdown periods has been conceived and designed at Brookhaven National Laboratory and built by PHPK Technologies of Columbus, Ohio. Since most thermal contraction occurs above this temperature, this unit, referred to as the 80 K Cooler, will eliminate the stresses associated with thermal cycling. The cooling system will provide the necessary refrigeration by circulating cooled Helium gas at approximately 15 atmospheres through the RHIC heat shields and magnets. This Helium is cooled by heat exchange with liquid nitrogen and circulated via three cold centrifugal pumps. The nominal delivered cooling capacity required to maintain the magnets at temperature is approximately 36 kW, primarily intercepted at the heat shield. The system also has separate heat exchangers for use as a pre-Cooler from room temperature to 82 K. Selection of sextant or sextants for pre-cooling is designed into the RHIC cryogenic distribution system. Topics covered include Cooler design decisions, details of the Cooler as built, integration into the existing RHIC cryogenic system and initial operating experience.

  7. Evaluation of the solar disk sextant concept

    NASA Technical Reports Server (NTRS)

    Chiu, H.-Y.

    1984-01-01

    In this paper the viability of the solar disk sextant concept is evaluated, the optimum parameters required to carry out solar variability studies, which are the mission objectives, are derived. The experimental environment is first discussed, followed by the application of the finite Fourier transform definition (FFTD) to the detector array data. The requirements on the optical system are studied next. A computer program was carried out simulating solar edge data and FFTD. From this study, it is concluded that the required accuracy of measurement may be reached using currently available detector array technology, a focal ratio of the optical system in excess of 90, and an entrance aperture of 22 cm. The guidance error must be small enough to require no more than a correction rate of 0.1 arcsec/sec. All these conditions are well within current technology.

  8. RHIC electron lenses upgrades

    SciTech Connect

    Gu, X.; Altinbas, Z.; Bruno, D.; Binello, S.; Costanzo, M.; Drees, A.; Fischer, W.; Gassner, D. M.; Hock, J.; Hock, K.; Harvey, M.; Luo, Y.; Marusic, A.; Mi, C.; Mernick, K.; Minty, M.; Michnoff, R.; Miller, T. A.; Pikin, A. I.; Robert-Demolaize, G.; Samms, T.; Shrey, T. C.; Schoefer, V.; Tan, Y.; Than, R.; Thieberger, P.; White, S. M.

    2015-05-03

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

  9. X-ray Pulsar Navigation Algorithms and Testbed for SEXTANT

    NASA Technical Reports Server (NTRS)

    Winternitz, Luke M. B.; Hasouneh, Monther A.; Mitchell, Jason W.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven; Grendreau, Keith C.

    2015-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a NASA funded technologydemonstration. SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar-based Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper describes the basic design of the SEXTANT system with a focus on core models and algorithms, and the design and continued development of the GSFC X-ray Navigation Laboratory Testbed (GXLT) with its dynamic pulsar emulation capability. We also present early results from GXLT modeling of the combined NICER X-ray timing instrument hardware and SEXTANT flight software algorithms.

  10. Easily constructed mini-sextant demonstrates optical principles

    NASA Astrophysics Data System (ADS)

    Nenninger, Garet G.

    2000-04-01

    An easily constructed optical instrument for measuring the angle between the Sun and the horizon is described. The miniature sextant relies on multiple reflections to produce multiple images of the sun at fixed angles away from the true Sun.

  11. Optics measurements and corrections at RHIC

    SciTech Connect

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

    2012-05-20

    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.

  12. Ion optics of RHIC EBIS

    SciTech Connect

    Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Okamura, M.; Raparia, D.; Ritter, J.; Tan, Y.; Kuznetsov, G.

    2011-09-10

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

  13. RHIC beam loss monitor system design

    SciTech Connect

    Witkover, R.; Zitvogel, E.; Michnoff, R.

    1997-07-01

    The Beam Loss Monitor (BLM) System is designed to prevent the quenching of RHIC magnets due to beam loss, provide quantitative loss data, and the loss history in the event of a beam abort. The system uses 400 ion chambers of a modified Tevatron design. To satisfy fast (single turn) and slow (100 msec) loss beam criteria and provide sensitivity for studies measurements, a range of over 8 decades is needed. An RC pre-integrator reduces the dynamic range for a low current amplifier. This is digitized for data logging. The output is also applied to an analog multiplier which compensates the energy dependence, extending the range of the abort comparators. High and low pass filters separate the signal to dual comparators with independent programmable trip levels. Up to 64 channels, on 8 VME boards, are controlled by a micro-controller based VME module, decoupling it from the front-end computer (FEC) for real-time operation. Results with the detectors in the RHIC Sextant Test and the electronics in the AGS-to-RHIC (AtR) transfer line will be presented.

  14. Helium release rates and ODH calculations from RHIC magnet cooling line failure

    SciTech Connect

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28

    A catastrophic failure of the magnet cooling lines, similar to the LHC superconducting bus failure incident, could discharge cold helium into the RHIC tunnel and cause an Oxygen Deficiency Hazard (ODH) problem. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the insulating vacuum volumes and discharging via the reliefs into the RHIC tunnel, had been developed. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces are included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Results, including helium discharge rates, helium inventory loss, and the resulting oxygen concentration in the RHIC tunnel area, are reported. Good agreement had been achieved when comparing the simulation results, a RHIC sector depressurization test measurement, and some simple analytical calculations.

  15. Performance of the RHIC Injection Line Instrumentation Systems

    NASA Astrophysics Data System (ADS)

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

    1997-05-01

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

  16. Octants and Sextants before the 1860s Preserved in Japan

    NASA Astrophysics Data System (ADS)

    Nakamura, Tsuko

    2012-09-01

    The octant was invented in 1731 independently in the UK and US, and the sextant by John Campbell around 1757. Octants were brought to Japan in the 1770s by ships of the Dutch East India Company. A Dutch booklet manual on octants ``Beschryvinge van het Octant en deszelfs Gebruik" (Description of the octant and its usage) written in 1749 by Cornelis Douwes was translated into Japanese at Nagasaki in the 1780s--90s. This translation triggered serious attention of Japanese astronomers to octants. Because those instruments had no chance to be used in ocean navigation due to the strict seclusion policy forced by the then Shogunal government, the Japanese instead devised methods to use octants and sextants for land surveying. Sextants specially designed for the ground measurements were made, and even precursor instruments of the modern range finder were also produced. In this paper we report results of our recent survey investigation of octants and sextants preserved in Japan, which were imported or home-made before the 1860s. About ten objects were identified. We describe their characteristics in terms of originality and influence from overseas products. We also plan to report on accurate measurements of some of domestic products of the 19th century using a modern standard scale, in an attempt to infer how the Japanese artisans at that time could inscribe the graduation without such as a Ramsden's dividing machine.

  17. A Prototype Ionization Profile Monitor for RHIC.

    NASA Astrophysics Data System (ADS)

    Connolly, R.; Cameron, P.; Ryan, W.; Shea, T.; Sikora, R.; Tsoupas, N.

    1997-05-01

    Transverse beam profiles in the Relativistic Heavy-Ion Collider (RHIC) will be measured with ionization profile monitors (IPMs). Each IPM will measure the integrated distribution of electrons in one plane resulting from residual gas ionization during bunch passage. The high space-charge electric field of the beam makes it necessary to image with electrons which are guided by a magnetic field. A prototype detector was tested in the injection line during the RHIC Sextant Test. It consists of a collector circuit board mounted on one side of the beam and a parallel electrode on the other to provide an electric sweep field. The collector board has 48 electrodes oriented parallel to the beam with a chevron microchannel plate amplifier mounted in front of the collection traces. The detector vacuum chamber is placed in the gap of a magnet. At each bunch passage the charge pulses are integrated, amplified, and digitized for display as a profile histogram. This paper describes the prototype detector and gives results from the beam tests.

  18. RHIC PERFORMANCE AND FUTURE PLANS

    SciTech Connect

    FISCHER,W.

    2004-10-10

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, consisting of two 3.8 km long superconducting rings, was commissioned in 1999. Since then the machine collided fully stripped gold ions at five different energies, up to 100 GeV/u, deuterons with gold ions at 100 GeV/u, and protons at 100 GeV with a beam polarizations of up 45%. Over four operating periods the heavy ion luminosity has increased by two orders of magnitude, and now exceeds the design value by a factor of 2. Another factor of 2 is targeted for the next 4 years, as well as a more than 10-fold increase in the proton luminosity and a 2-fold increase in the polarization. Possible further upgrades include an Electron Beam Ion Source (EBIS), stochastic and electron cooling, and an electron ring to form an electron-ion collider (eRHIC).

  19. Characterization of prostate cancer missed by sextant biopsy.

    PubMed

    Bak, John B; Landas, Steve K; Haas, Gabriel P

    2003-09-01

    There is a trend to increase the number of prostate biopsies taken to increase the detection rate of prostate cancer. We examined radical prostatectomy specimens and correlated the findings to those of preoperative sextant biopsy in an effort to identify the characteristics of tumors that went undetected by our biopsy regimen. Seventy-one patients diagnosed with prostate cancer based on sextant biopsy who underwent radical prostatectomy at our institution from June 1995 to November 2001 had prostatectomy specimens and biopsy slides reviewed. These specimens were step-sectioned and whole-mounted. The location, size, and grade of individual cancer foci in the prostatectomy specimens were correlated with results of the original sextant biopsies. Clinically significant tumors were defined as those with volume > 0.5 mL or Gleason score > or= 7 and extracapsular extension. In 33 patients (46%), there was concordance of biopsy and prostatectomy findings. In 38 patients (54%), additional lesions were demonstrated in the prostatectomy specimens that were not detected by our sextant biopsies. These included 13 cases (34%) with tumors > 0.5 mL and 25 cases in which the lesions were < 0.5 mL in size. However, 7 of these cases contained tumors with Gleason score > or =7. Tumors were located in the transition zone in 8 of these 38 cases (21%), and the remaining tumors were located in the peripheral zone (79%). No tumors with extracapsular extension were missed. Thus, 20 of the 71 cases (28%) had clinically significant cancers that went undetected by the traditional sextant biopsy method. Greater than 50% of patients who underwent sextant biopsy of the prostate had additional tumors that were missed when compared to the pathologic specimen. As many as 28% of these patients had clinically significant cancer based on size and grade criteria. A strategy of increased numbers of biopsies would improve the detection rate of these clinically important tumors. However, the ideal strategy

  20. Global Orbit Feedback in RHIC

    SciTech Connect

    Minty, M.; Hulsart, R.; Marusic, A.; Michnoff, R.; Ptitsyn, V.; Robert-Demolaize, G.; Satogata, T.

    2010-05-23

    For improved reproducibility of good operating conditions and ramp commissioning efficiency, new dual-plane slow orbit feedback during the energy ramp was implemented during run-10 in the Relativistic Heavy Ion Collider (RHIC). The orbit feedback is based on steering the measured orbit, after subtraction of the dispersive component, to either a design orbit or to a previously saved reference orbit. Using multiple correctors and beam position monitors, an SVD-based algorithm is used for determination of the applied corrections. The online model is used as a basis for matrix computations. In this report we describe the feedback design, review the changes made to realize its implementation, and assess system performance.

  1. Experiments with RHIC

    SciTech Connect

    Westfall, Gary D.

    2000-12-31

    Experiments with the Relativistic Heavy Ion Collider (RHIC) will begin in December 1999. RHIC consists of two superconducting rings capable of accelerating and storing Au beams of 100 GeV/nucleon and proton beams of 250 GeV. Four experiments are being prepared for RHIC: STAR, PHENIX, PHOBOS, and BRAHMS. These detector systems are designed to search for signals of the quark gluon plasma in Au-Au collisions. A spin physics program using polarized protons will also be carried out at RHIC.

  2. Stochastic cooling in RHIC

    SciTech Connect

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

    2012-05-20

    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.

  3. Longitudinal impedance of RHIC

    SciTech Connect

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

    2015-05-03

    The longitudinal impedance of the two RHIC rings has been measured using the effect of potential well distortion on longitudinal Schottky measurements. For the blue RHIC ring Im(Z/n) = 1.5±0.2Ω. For the yellow ring Im(Z/n) = 5.4±1Ω.

  4. Thermal effects in the Solar Disk Sextant telescope

    NASA Astrophysics Data System (ADS)

    Spagnesi, Chiara; Vannoni, Maurizio; Molesini, Giuseppe; Righini, Alberto

    2004-02-01

    The Solar Disk Sextant (SDS) is an instrument conceived to monitor the diameter of the Sun and its oscillations. A key component of the SDS is the Beam Splitting Wedge (BSW), whose function is to provide calibration to the geometry of the focal plane. The thermal behavior of the BSW is critical, as it affects the overall performance of the instrument. Modeling the elements of the BSW and the basic thermal processes is shown to account for experimental evidences of defocusing observed in early measurements with a balloon borne prototype. Basic requirements for accurate thermal stabilization on board of the final instrument are derived.

  5. RHIC Renaissance Celebration

    SciTech Connect

    Brookhaven Lab

    2009-07-31

    A celebration of the contribution that Renaissance Technologies, Inc., made to the Relativistic Heavy Ion Collider, during which the entire Lab community participated in a series of RHIC Renaissance events, beginning with the Roads to Discovery ceremony,

  6. RHIC progress and future

    SciTech Connect

    Montag,C.

    2009-05-04

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

  7. Can the conventional sextant prostate biopsy accurately predict unilateral prostate cancer in low-risk, localized, prostate cancer?

    PubMed

    Mayes, Janice M; Mouraviev, Vladimir; Sun, Leon; Tsivian, Matvey; Madden, John F; Polascik, Thomas J

    2011-01-01

    We evaluate the reliability of routine sextant prostate biopsy to detect unilateral lesions. A total of 365 men with complete records including all clinical and pathologic variables who underwent a preoperative sextant biopsy and subsequent radical prostatectomy (RP) for clinically localized prostate cancer at our medical center between January 1996 and December 2006 were identified. When the sextant biopsy detects unilateral disease, according to RP results, the NPV is high (91%) with a low false negative rate (9%). However, the sextant biopsy has a PPV of 28% with a high false positive rate (72%). Therefore, a routine sextant prostate biopsy cannot provide reliable, accurate information about the unilaterality of tumor lesion(s).

  8. SEXTANT - Station Explorer for X-ray Timing and Navigation Technology

    NASA Technical Reports Server (NTRS)

    Mitchell, Jason W.; Hasouneh, Munther Abdel Hamid; Winternitz, Luke M. B.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Arzoumanian, Zaven; Ray, Paul S.; Wood, Kent S.; Litchford, Ronald J.; Gendreau, Keith C.

    2015-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission, which is scheduled to launch in late 2016 and will be hosted as an externally attached payload on the International Space Station (ISS) via the ExPRESS Logistics Carrier (ELC). During NICER's 18-month baseline science mission to understand ultra-dense matter though observations of neutron stars in the soft X-ray band, SEXTANT will, for the first-time, demonstrate real-time, on-board X-ray pulsar navigation, which is a significant milestone in the quest to establish a GPS-like navigation capability that will be available throughout our Solar System and beyond. Along with NICER, SEXTANT has proceeded through Phase B, Mission Definition, and received numerous refinements in concept of operation, algorithms, flight software, ground system, and ground test capability. NICER/SEXTANT's Phase B work culminated in NASA's confirmation of NICER to Phase C, Design and Development, in March 2014. Recently, NICER/SEXTANT successfully passed its Critical Design Review and SEXTANT received continuation approval in September 2014. In this paper, we describe the X-ray pulsar navigation concept and provide a brief history of previous work, and then summarize the SEXTANT technology demonstration objective, hardware and software components, and development to date.

  9. Efficacy of CPITN sextant scores for detection of periodontitis disease activity.

    PubMed

    Rams, T E; Listgarten, M A; Slots, J

    1996-04-01

    The relationship between CPITN sextant scores and periodontitis recurrence at individual tooth sites was evaluated in a longitudinal study in 83 treated adult periodontitis patients receiving systematic 3-month maintenance care. At baseline and semi-annual examinations over 36 months, CPITN scores were assigned to each dentition sextant using probing depths and gingival index scores, and relative periodontal attachment level was assessed at individual tooth sites using an occlusal reference stent. Periodontitis recurrence was defined as any periodontal site exhibiting either a probing depth increase of > or = 3 mm from baseline, or a probing depth increase of > or = 1 mm from baseline together with a loss of relative periodontal attachment of > or = 2 mm from baseline. 49 (59.0%) subjects developed periodontitis recurrence in 147 (29.8%) sextants at 181 (2.2%) individual periodontal sites during the 36-month study period. Baseline CPITN scores of 4 were more common in disease-active subjects than clinically-stable subjects (p = 0.003, t-test), and were associated with a statistically significant 1.66 relative risk of periodontitis recurrence within 36 months. CPITN sextant scores of 3 or 4 showed low specificity and low positive predictive values as indicators of periodontitis recurrence at > or = 1 individual sites within the affected sextant. In comparison, low CPITN sextant scores (0-2) provided high specificity (96.2-100%), high positive predictive values (99.5-100%), and a summary odds ratio of 24.2 as an indicator of clinical stability at all periodontal sites within a given dentition sextant. Changes in sextant scores for CPITN over 6-month periods showed no relationship with periodontitis recurrence at individual periodontal sites. This study suggests that while CPITN is inadequate for detection of periodontitis recurrence, low CPITN scores provide rapid presumptive identification of clinically-stable sextants in adult periodontitis patients on maintenance

  10. The RHIC project -- Physical challenges

    SciTech Connect

    Wei, J.

    1997-11-01

    The design and construction status of the Relativistic Heavy Ion Collider, RHIC, is discussed. Those novel features of a heavy ion Collider that are distinct from conventional hadron Colliders in general are noted. These features are derived from the experimental requirements of operation with a variety of ion species over a wide energy range including collisions between ions of unequal energies. The project is in the fifth year of a seven-year construction cycle. A review of the superconducting magnet program is given together with progress to date on the machine construction and commissioning. Emphasis is made on challenging issues including intrabeam scattering, interaction-region error compensation, magnet alignments, and matched transition-energy jump.

  11. Coordinating the 2009 RHIC Run

    ScienceCinema

    Brookhaven Lab - Mei Bai

    2016-07-12

    Physicists working at the Brookhaven National Lab's Relativistic Heavy Ion Collider (RHIC) are exploring the puzzle of proton spin as they begin taking data during the 2009 RHIC run. For the first time, RHIC is running at a record energy of 500 giga-elect

  12. Coordinating the 2009 RHIC Run

    SciTech Connect

    Brookhaven Lab - Mei Bai

    2009-04-13

    Physicists working at the Brookhaven National Lab's Relativistic Heavy Ion Collider (RHIC) are exploring the puzzle of proton spin as they begin taking data during the 2009 RHIC run. For the first time, RHIC is running at a record energy of 500 giga-elect

  13. RHIC FY15 pp Run RHIC and AGS polarization analysis

    SciTech Connect

    Huang, H.; Adams, P.

    2016-02-20

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

  14. RHIC STATUS AND PLANS.

    SciTech Connect

    PILAT,R.

    2002-06-02

    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.

  15. STOCHASTIC COOLING FOR RHIC.

    SciTech Connect

    BLASKIEWICZ,M.BRENNAN,J.M.CAMERON,P.WEI,J.

    2003-05-12

    Emittance growth due to Intra-Beam Scattering significantly reduces the heavy ion luminosity lifetime in RHIC. Stochastic cooling of the stored beam could improve things considerably by counteracting IBS and preventing particles from escaping the rf bucket [1]. High frequency bunched-beam stochastic cooling is especially challenging but observations of Schottky signals in the 4-8 GHz band indicate that conditions are favorable in RHIC [2]. We report here on measurements of the longitudinal beam transfer function carried out with a pickup kicker pair on loan from FNAL TEVATRON. Results imply that for ions a coasting beam description is applicable and we outline some general features of a viable momentum cooling system for RHIC.

  16. Station Explorer for X-Ray Timing and Navigation Technology (SEXTANT)

    NASA Technical Reports Server (NTRS)

    Mitchell, Jason W.

    2015-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a NASA funded technology- demonstration. SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar-based Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper describes the basic design of the SEXTANT system with a focus on core models and algorithms, and the design and continued development of the GSFC X-ray Navigation Laboratory Testbed (GXLT) with its dynamic pulsar emulation capability. We also present early results from GXLT modeling of the combined NICER X-ray timing instrument hardware and SEXTANT flight software algorithms.

  17. SEXTANT - Station Explorer for X-Ray Timing and Navigation Technology

    NASA Technical Reports Server (NTRS)

    Mitchell, Jason; Hasouneh, Monther; Winternitz, Luke; Valdez, Jennifer; Price, Sam; Semper, Sean; Yu, Wayne; Gaebler, John; Ray, Paul; Wood, Kent; Arzoumanian, Zaven; Litchford, Ronald J.; Gendreau, Keith

    2015-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a NASA funded technology- demonstration. SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar-based Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper describes the basic design of the SEXTANT system with a focus on core models and algorithms, and the design and continued development of the GSFC X-ray Navigation Laboratory Testbed (GXLT) with its dynamic pulsar emulation capability. We also present early results from GXLT modeling of the combined NICER X-ray timing instrument hardware and SEXTANT flight software algorithms.

  18. Use of step-section histopathology to evaluate 18F-fluorocholine PET sextant localization of prostate cancer.

    PubMed

    Kwee, Sandi A; Thibault, Gregory P; Stack, Richard S; Coel, Marc N; Furusato, Bungo; Sesterhenn, Isabell A

    2008-01-01

    To assess positron emission tomography (PET) with fluorine-18 fluorocholine for sextant localization of malignant prostate tumors. Histopathologic analysis was performed on step-sectioned whole-mounted prostate specimens from 15 patients who underwent PET with fluorocholine prior to radical prostatectomy. The maximum standardized uptake value (SUVmax) corresponding to prostate sextants on PET was measured by region of interest analysis and compared with histopathologic results. Histopathology demonstrated malignant involvement in 61 of 90 prostate sextants. The mean total tumor volume per specimen was 4.9 mL (range 0.01-28.7 mL). Mean SUVmax was 6.0+/-2.0 in malignant sextants and 3.8+/-1.4 in benign sextants (p<.0001). The area under the receiver operating characteristic curve was 0.82 for sextant detection of malignancy based on SUVmax measurement. Tumor diameter directly correlated with sextant SUVmax in malignant sextants (r=.54, p<.05). In 13 subjects, the largest tumor in the specimen corresponded to the sextant with the highest SUVmax. Fluorocholine PET can serve to localize dominant areas of malignancy in patients with prostate cancer. However, PET with fluorocholine may fail to identify sextants with smaller volumes of malignancy.

  19. Loss maps of RHIC

    SciTech Connect

    Robert-Demolaize,G.

    2007-10-01

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

  20. RHIC SPIN FLIPPER

    SciTech Connect

    BAI,M.; ROSER, T.

    2007-06-25

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

  1. SPIN FLIPPING IN RHIC.

    SciTech Connect

    BAI,M.; LEHRACH,A.; LUCCIO,A.; MACKAY,W.W.; ROSER,T.; TSOUPAS,N.

    2001-06-18

    At the Relativistic Heavy Ion Collider (RHIC), polarized protons will be accelerated and stored for spin physics experiments. Two full helical snakes will be used to eliminate the depolarization due to imperfection and intrinsic spin resonances. Since no resonances are crossed in RHIC, the beam polarization remains fixed through acceleration. However, in order to reduce systematic errors, the experiment often requires the polarization direction reversed. This paper presents a method of using an ac dipole to obtain a full spin flip in the presence of two full snakes [1]. A similar method of using an rf solenoid for spin flip was tested at IUCF [2,3].

  2. Virtual Tour of RHIC

    SciTech Connect

    Brookhaven Lab

    2009-06-11

    An animation that follows polarized protons as they travel through the Relativistic Heavy Ion Collider (RHIC) accelerator complex to the experiments. The arrows indicate the direction of each proton's spin. The animation concludes with a fly-by of the RHI

  3. Virtual Tour of RHIC

    ScienceCinema

    Brookhaven Lab

    2016-07-12

    An animation that follows polarized protons as they travel through the Relativistic Heavy Ion Collider (RHIC) accelerator complex to the experiments. The arrows indicate the direction of each proton's spin. The animation concludes with a fly-by of the RHI

  4. The RHIC cryogenic control system

    SciTech Connect

    Farah, Y.; Sondericker, J.

    1993-08-01

    A cryogenic process control system for the RHIC Project is discussed. It is independent of the main RHIC Control System, consisting of an upgrade of the existing 24.8 Kw helium refrigerator control section with the addition of a ring control section that regulates and monitors all cryogenic signals in the RHIC tunnel. The system is fully automated, which can run without the continuous presence of operators.

  5. RHIC Prefire Protection Masks

    SciTech Connect

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

    2015-01-07

    The protection of the RHIC experimental detectors from damage due to beam hitting close upstream elements in cases of abort kicker prefires requires some dedicated precautionary measures with two general options: to bring the beam close to a limiting aperture (i.e. the beam pipe wall), as far upstream of the detector components as possible or, alternatively, to bring a limiting aperture close to the circulating beam. During the FY 2014 RHIC Heavy Ion run the first option was chosen because of the limited time available for preparation before the start of the run. For future runs the second option, in this case the installation of dual-sided movable masks, is preferred. The installation of the masks, one per ring, is planned before the start of the FY 2015 run.

  6. RHIC PLANS TOWARDS HIGHER LUMINOSITY

    SciTech Connect

    FEDOTOV,A.

    2007-06-25

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide luminosity over a wide range of beam energies and species, including heavy ions, polarized protons, and tric beam collisions. In the first seven years of operation there has been a rapid increase in the achieved peak and average luminosity, substantially exceeding design values. Work is presently underway to achieve the Enhanced Design parameters. Planned major upgrades include the Electron Beam Ion Source (EBIS), RHIC-11, and construction of an electron-ion collider (eRHIC). We review the expected RHIC upgrade performance. Electron cooling and its impact on the luminosity both for heavy ions and protons are discussed in detail.

  7. RHIC - Exploring the Universe Within

    ScienceCinema

    BNL

    2016-07-12

    A guided tour of Brookhaven's Relativistic Heavy Ion Collider (RHIC) conducted by past Laboratory Director John Marburger. RHIC is a world-class scientific research facility that began operation in 2000, following 10 years of development and construction. 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. What physicists learn from these collisions may help us understand more about why the physical world works the way it does, from the smallest subatomic particles, to the largest stars.

  8. RHIC - Exploring the Universe Within

    SciTech Connect

    BNL

    2008-08-12

    A guided tour of Brookhaven's Relativistic Heavy Ion Collider (RHIC) conducted by past Laboratory Director John Marburger. RHIC is a world-class scientific research facility that began operation in 2000, following 10 years of development and construction. 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. What physicists learn from these collisions may help us understand more about why the physical world works the way it does, from the smallest subatomic particles, to the largest stars.

  9. Rf systems for RHIC

    SciTech Connect

    Rose, J.; Brodowski, J.; Connolly, R.; Deng, D.P.; Kwiatkowski, S.; Pirkl, W.; Ratti, A.

    1995-05-01

    The RHIC rf systems must capture the injected beam, accelerate it through transition to top energy, shorten the bunches prior to rebucketing, and store the beam for 10 hours in the presence of strong intra-beam scattering. These different functions are met by three independent systems. An accelerating system at 26.7 Mhz (h = 342), a storage system at 196.1 MHz (h = 2508), and a wideband system for the damping of injection efforts.

  10. RHIC The Perfect Liquid

    ScienceCinema

    BNL

    2016-07-12

    Evidence to date suggests that gold-gold collisions the Relativistic Heavy Ion Collider at Brookhaven are indeed creating a new state of hot, dense matter, but one 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 appears to be more like a "perfect" liquid.

  11. RHIC spin program

    SciTech Connect

    Bunce, G.

    1995-12-31

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

  12. Polarized protons at RHIC

    SciTech Connect

    Makdisi, Y.

    1992-01-01

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 {times} 10{sup 32}/cm{sup 2}/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined.

  13. Polarized protons at RHIC

    SciTech Connect

    Makdisi, Y.

    1992-10-01

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 {times} 10{sup 32}/cm{sup 2}/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined.

  14. The RHIC status update

    SciTech Connect

    Ozaki, S.

    1995-07-15

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

  15. Polarized proton collider at RHIC

    NASA Astrophysics Data System (ADS)

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

    2003-03-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998 [2]), reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to s=500 GeV.

  16. RHIC Polarized proton operation

    SciTech Connect

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

    2011-03-28

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

  17. OVERVIEW OF THE AGS COLD SNAKE POWER SUPPLIES AND THE NEW RHIC SEXTUPOLE POWER SUPPLIES

    SciTech Connect

    BRUNO,D.; GANETIS, G.; SANDBERG, J.; LOUIE, W.

    2007-06-25

    The two rings in the Relativistic Heavy Ion Collider (RHIC) were originally constructed with 24 sextupole power supplies, 12 for each ring. Before the start of Run 7, 24 new sextupole power supplies were installed, 12 for each ring. Individual sextupole power supplies are now each connected to six sextupole magnets. A superconducting snake magnet and power supplies were installed in the Alternating Gradient Synchrotron (AGS) and commissioned during RHIC Run 5, and used operationally in RHIC Run 6. The power supply technology, connections, control systems and interfacing with the Quench Protection system for both these systems will be presented.

  18. The RHIC project

    SciTech Connect

    Harrison, M.A.

    1996-07-01

    The design and construction status of the Relativistic Heavy Ion collider (RHIC) is discussed. Those novel features of a heavy ion collider that are distinct from hadron colliders in general are noted. These features are derived from the experimental requirements of operation with a variety of ion species over a wide energy range including collisions between ions of unequal energies. The project is in the fourth year of a seven year construction cycle. A review of the superconducting magnet program is given together with progress to date on the machine construction.

  19. RAMP MANAGEMENT IN RHIC.

    SciTech Connect

    KEWISCH,J.; VAN ZEIJTS,J.; PEGGS,S.; SATOGATA,T.

    1999-03-29

    In RHIC, magnets and RF cavities are controlled by Wave Form Generators (WFGs), simple real time computers which generate the set points. The WFGs are programmed to change set points from one state to another in a synchronized way. Such transition is called a ''Ramp'' and consists of a sequence of ''stepping stones'' which contain the set point of every WFG controlled device at a point in time. An appropriate interpolation defines the set points between these stepping stones. This report describes the implementation of the ramp system. The user interface, tools to create and modify ramps, interaction with modeling tools and measurements and correction programs are discussed.

  20. Relativistic Heavy Ion Collider spin flipper commissioning plan

    SciTech Connect

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

    2010-09-27

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

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

    SciTech Connect

    SOFFER,J.

    1999-10-06

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

  2. PHOBOS experiment at RHIC

    SciTech Connect

    Wozniak, K.; PHOBOS Collaboration

    1995-12-01

    The study of relativistic heavy nuclei collisions at RHIC opens a new area of physics--the physics of hadronic matter at very high energy densities. The conditions necessary to create a new state of matter, never before seen in the laboratory, may be reached. It gives a chance to study the quantum chromodynamics predictions of the phase transition from hadronic matter to a quark-gluon plasma. The PHOBOS experiment will investigate almost all predicted signals of the QGP formation. General event properties (angular distribution of charged particles, total multiplicity) will be combined with detailed information on particles emitted in the central rapidity region (particle ratios {pi}/K/p, p{sub t} spectra, correlations, {phi} meson properties). Similar studies will be done also in the other three experiments at RHIC, but there are many important observables for which PHOBOS will provide unique information. The multiplicity detector covers almost a full phase space, recording all charged particles with pseudorapidities {vert_bar}{eta}{vert_bar} {le} 5.4. In the PHOBOS spectrometer particles emitted in the central rapidity region will be measured and identified starting from lowest transverse momenta (20 MeV/c for pions). The high rate unbiased trigger gives a chance to see unpredicted phenomena and enables the study of very rare processes that require large statistics. The measurements of the converting photons planned for some runs will be used to study the {pi}{sup 0}/({pi}{sup +} + {pi}{sup {minus}}) ratio in selected phase space intervals.

  3. Direct Photons at RHIC

    SciTech Connect

    Gabor,D.

    2008-07-29

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

  4. SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

    NASA Technical Reports Server (NTRS)

    Winternitz, Luke M. B.; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven; Gendreau, Keith C.

    2016-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission. NICER is a NASA Explorer Mission of Opportunity that will be hosted on the International Space Station (ISS). SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper gives an overview of the SEXTANT system architecture and describes progress prior to environmental testing of the NICER flight instrument. It provides descriptions and development status of the SEXTANT flight software and ground system, as well as detailed description and results from the flight software functional and performance testing within the highfidelity Goddard Space Flight Center (GSFC) X-ray Navigation Laboratory Testbed (GXLT) software and hardware simulation environment. Hardware-in-the-loop simulation results are presented, using the engineering model of the NICER timing electronics and the GXLT pulsar simulator-the GXLT precisely controls NASA GSFC's unique Modulated X-ray Source to produce X-rays that make the NICER detector electronics appear as if they were aboard the ISS viewing a sequence of millisecond pulsars.

  5. Lexicon Sextant: Modeling a Mnemonic System for Customizable Browser Information Organization and Management

    ERIC Educational Resources Information Center

    Shen, Siu-Tsen

    2016-01-01

    This paper presents an ongoing study of the development of a customizable web browser information organization and management system, which the author has named Lexicon Sextant (LS). LS is a user friendly, graphical web based add-on to the latest generation of web browsers, such as Google Chrome, making it easier and more intuitive to store and…

  6. SEXTANT: A Demonstration of X-ray Pulsar-Based Navigation Using NICER

    NASA Astrophysics Data System (ADS)

    Ray, Paul S.; Mitchell, Jason W; Winternitz, Luke M; Hasouneh, Monther A; Price, Samuel R; Valdez, Jennifer; Yu, Wayne H; Semper, Sean R; Wood, Kent S.; Wolff, Michael Thomas; Arzoumanian, Zaven; Litchford, Ronald J; Gendreau, Keith

    2014-08-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology-demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission. NICER is a NASA Explorer Mission of Opportunity that will be hosted on the International Space Station (ISS). SEXTANT will, for the first time, demonstrate real-time, on-board X-ray pulsar-based navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. The SEXTANT XNAV demonstration will exploit the large collecting area (>1800 cm^2), low background (<0.2 counts/s), and precise timing (<300 ns) of the NICER X-ray Timing Instrument (XTE). Taking advantage of NICER’s science observations of X-ray emitting millisecond pulsars, which are nature’s most stable clocks, the SEXTANT flight software will demonstrate real-time orbit determination with error less than 10 km in any direction, through measurements made over 2 weeks or less in the highly dynamic low-Earth ISS orbit. The completed technology demonstration will bring the XNAV concept and algorithms to a Technology Readiness Level of 8 and will inform the design and configuration of future practical XNAV implementations.

  7. SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

    NASA Technical Reports Server (NTRS)

    Winternitz, Luke; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven; Gendreau, Keith C.

    2016-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission. NICER is a NASA Explorer Mission of Opportunity that will be hosted on the International Space Station (ISS). SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper gives an overview of the SEXTANT system architecture and describes progress prior to environmental testing of the NICER flight instrument. It provides descriptions and development status of the SEXTANT flight software and ground system, as well as detailed description and results from the flight software functional and performance testing within the high-fidelity Goddard Space Flight Center (GSFC) X-ray Navigation Laboratory Testbed (GXLT) software and hardware simulation environment. Hardware-in-the-loop simulation results are presented, using the engineering model of the NICER timing electronics and the GXLT pulsar simulator-the GXLT precisely controls NASA GSFC's unique Modulated X-ray Source to produce X-rays that make the NICER detector electronics appear as if they were aboard the ISS viewing a sequence of millisecond pulsars

  8. ACCELERATING AND COLLIDING POLARIZED PROTONS IN RHIC WITH SIBERIAN SNAKES.

    SciTech Connect

    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.; ET AL

    2002-06-02

    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. We report on our experiences during commissioning and operation of collider with polarized protons.

  9. POLARIZED PROTON COLLISIONS AT RHIC.

    SciTech Connect

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

    2005-05-16

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

  10. Concept and architecture of the RHIC LLRF upgrade platform

    SciTech Connect

    Smith, K.S.; Hayes, T.; Severino, F.

    2011-03-28

    The goal of the RHIC LLRF upgrade has been the development of a stand alone, generic, high performance, modular LLRF control platform, which can be configured to replace existing systems and serve as a common platform for all new RF systems. The platform is also designed to integrate seamlessly into a distributed network based controls infrastructure, be easy to deploy, and to be useful in a variety of digital signal processing and data acquisition roles. Reuse of hardware, software and firmware has been emphasized to minimize development effort and maximize commonality of system components. System interconnection, synchronization and scaling are facilitated by a deterministic, high speed serial timing and data link, while standard intra and inter chassis communications utilize high speed, non-deterministic protocol based serial links. System hardware configuration is modular and flexible, based on a combination of a main carrier board which can host up to six custom or commercial daughter modules as required to implement desired functionality. This paper will provide an overview of the platform concept, architecture, features and benefits. The RHIC LLRF Upgrade Platform has been developed with the goal of providing a flexible, modular and scalable architecture which will support our current applications and satisfy new ones for the foreseeable future. The platform has been recently commissioned at both RHIC and the RHIC EBIS injector. To date the platform has demonstrated its versatility and utility, meeting the design goals as originally defined.

  11. A hardware overview of the RHIC LLRF platform

    SciTech Connect

    Hayes, T.; Smith, K.S.

    2011-03-28

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

  12. Analysis of failed ramps during the RHIC FY09 run

    SciTech Connect

    Minty, M.

    2014-08-15

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

  13. RHIC 10 Hz global orbit feedback system

    SciTech Connect

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

    2011-03-28

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

  14. Acceptance and adaptation of octants and sextants in Japan during the eighteenth and nineteenth centuries

    NASA Astrophysics Data System (ADS)

    Nakamura, Tsuko

    2002-06-01

    This paper overviews the introduction, acceptance, and adaptation of octants and sextants in in Japan during the eighteenth and nineteenth centuries. Octants first appear in the Japanese literature in the 1770s. In 1783 Motoki Ryoei, a well-known interpreter and scholar, first translated a Dutch book on octants by Cornelis Douwes. From that date, octants continued to attract wide interest from Japanese professional and amateur astronomers and land surveyors, and a considerable number of books on octants and sextants were published up to the 1860s. Around 1806, an octant was made for the first time in Japan. Owing to the strict seclusion policy adopted by the Tokugawa shogunate during the Edo period, the Japanese adopted octants as a convenient instrument for land surveying rather than for navigation, and even unique range finders were also invented as a modification. It was not until after the mid-1850s that octants were used for maritime navigation.

  15. FAST AUTOMATED DECOUPLING AT RHIC.

    SciTech Connect

    BEEBE-WANG,J.J.

    2005-05-16

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

  16. RESEARCH PLAN FOR SPIN PHYSICS AT RHIC.

    SciTech Connect

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

    2005-02-01

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

  17. CONFIGURATION MANUAL POLARIZED PROTON COLLIDER AT RHIC.

    SciTech Connect

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

    2001-03-01

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

  18. Configuration Manual Polarized Proton Collider at RHIC

    SciTech Connect

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

    2006-01-01

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

  19. Star magnitude and manual navigation sighting accuracy using the Apollo T2 sextant.

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Mayhew, L. B., Jr.

    1971-01-01

    This laboratory study investigated the effect of four star magnitudes (0, +1, +2, +3) upon the angular sighting accuracy attainable between a star and a lunar limb using a space-rated sextant with an 8-power telescope. Four males were tested. The results indicated that over a series of daily sightings sighting accuracy increases as star magnitude decreases; i.e., the angle between the actual lunar limb and the perceived lunar limb decreases as the intensity of the star increases. The significant subject and day main effects that were found indicate that each individual must be calibrated against himself and that extreme care must be taken to center the various images correctly within the sextant's field of view each time the instrument is set up. These findings are discussed in relation to further refinement of a graphic model of the distribution of energy on the retina. A discussion is also presented on the differences between sextant sighting research conducted in the laboratory and in the real, high-altitude or space environment.

  20. Superconducting Storage Cavity for RHIC

    SciTech Connect

    Ben-Zvi,I.

    2009-01-02

    This document provides a top-level description of a superconducting cavity designed to store hadron beams in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It refers to more detailed documents covering the various issues in designing, constructing and operating this cavity. The superconducting storage cavity is designed to operate at a harmonic of the bunch frequency of RHIC at a relatively low frequency of 56 MHz. The current storage cavities of RHIC operate at 197 MHz and are normal-conducting. The use of a superconducting cavity allows for a high gap voltage, over 2 MV. The combination of a high voltage and low frequency provides various advantages stemming from the resulting large longitudinal acceptance bucket.

  1. Two photon physics at RHIC

    SciTech Connect

    Klein, S.

    1995-05-01

    Because the two photon cross section is proportional to Z{sup 4}, heavy ion colliders offer an unmatched luminosity. However, because nuclei have finite sizes, the photon spectrum is gradually cut off by a nuclear form factor. For RHIC, this cutoff occurs at a few GeV; below this energy, RHIC will have the highest {gamma}{gamma} luminosity in the world when it turns on. In addition to the high rates, because Z{alpha} {approximately} 0.6, the nuclear environment provides a window to strong field QED and new phenomena like multiple pair production. To study {gamma}{gamma} physics, regions where the nuclei interact hadronically must be avoided; this leads to roughly a factor of two loss in usable luminosity. The rates expected by the Solenoidal Tracker at RHIC (STAR) collaboration will be given. Backgrounds will be discussed, along with several rejection techniques.

  2. Magnetic correction of RHIC triplets

    SciTech Connect

    Wei, J.; Gupta, R.; Peggs, S.

    1993-01-01

    Triplets of large bore quadrupoles will be antisymmetrically placed on either side of all six intersection points of the Relativistic Heavy Ion collider (RHIC). In RHIC collision optics, the tiplets at the two experimental detectors are intended to enable the collision beta function to be reduced to the design goal of [beta][sup *] = 1.0 meter in both planes, in order to minimize the spot size and maximize the luminosity. This requires running with [beta][sub max] [approx] 1400 meters in the triplet, where the beams will have their largest size, both absolutely and as a fraction of the available aperture. Hence, the ultimate performance of RHIC rests on achieving the highest possible magnetic field quality in the triplets. This paper discusses the correction of magnetic errors expected in the quadrupole bodies and ends, using both these limped correctors and also quadrupole body tuning shims.

  3. Magnetic correction of RHIC triplets

    SciTech Connect

    Wei, J.; Gupta, R.; Peggs, S.

    1993-06-01

    Triplets of large bore quadrupoles will be antisymmetrically placed on either side of all six intersection points of the Relativistic Heavy Ion collider (RHIC). In RHIC collision optics, the tiplets at the two experimental detectors are intended to enable the collision beta function to be reduced to the design goal of {beta}{sup *} = 1.0 meter in both planes, in order to minimize the spot size and maximize the luminosity. This requires running with {beta}{sub max} {approx} 1400 meters in the triplet, where the beams will have their largest size, both absolutely and as a fraction of the available aperture. Hence, the ultimate performance of RHIC rests on achieving the highest possible magnetic field quality in the triplets. This paper discusses the correction of magnetic errors expected in the quadrupole bodies and ends, using both these limped correctors and also quadrupole body tuning shims.

  4. ADVANCEMENT OF THE RHIC BEAM ABORT KICKER SYSTEM.

    SciTech Connect

    ZHANG,W.AHRENS,L.MI,J.OERTER,B.SANDBERG,J.WARBURTON,D.

    2003-05-12

    As one of the most critical system for RHIC operation, the beam abort kicker system has to be highly available, reliable, and stable for the entire operating range. Along with the RHIC commission and operation, consistent efforts have been spend to cope with immediate issues as well as inherited design issues. Major design changes have been implemented to achieve the higher operating voltage, longer high voltage hold-off time, fast retriggering and redundant triggering, and improved system protection, etc. Recent system test has demonstrated for the first time that both blue ring and yellow ring beam abort systems have achieved more than 24 hours hold off time at desired operating voltage. In this paper, we report break down, thyratron reverse arcing, and to build a fast re-trigger system to reduce beam spreading in event of premature discharge.

  5. POLARIZED NEUTRONS IN RHIC

    SciTech Connect

    COURANT,E.D.

    1998-04-27

    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.

  6. Lateral biopsies added to the traditional sextant prostate biopsy pattern increases the detection rate of prostate cancer.

    PubMed

    Bauer, J J; Zeng, J; Zhang, W; McLeod, D G; Sesterhenn, I A; Connelly, R R; Mun, S K; Moul, J W

    2000-07-01

    Urologists routinely use the systematic sextant needle biopsy technique to detect prostate cancer. However, recent evidence suggests that this technique has a significant sampling error and data based upon whole-mounted step-sectioned radical prostatectomy specimens using a three-dimensional computer-assisted prostate biopsy simulator suggests that an increased detection rate is possible using laterally placed biopsies. The simulated 10-core biopsy pattern (traditional sextant biopsy cores and four laterally placed biopsies in the right and left apex and mid portion of the prostate gland) was shown to be superior to the traditional sextant biopsy. The objective of this pilot study was to confirm the higher prostate cancer detection rate obtained using the 10-core biopsy pattern in patients. We reviewed data on 35 consecutive patients with a pathologic diagnosis of prostate cancer biopsied by a single urologist using the 10-core biopsy pattern. The frequency of positive biopsy was determined for each core. Additionally, the sextant and 10-core prostate biopsy patterns were compared with respect to prostate cancer detection rate. Of the 35 patients diagnosed with prostate cancer, 54.3%(19/35) were diagnosed by the sextant biopsy only. The 10-core pattern resulted in an additional 45.7%(16/35) of patients being diagnosed solely with the laterally placed biopsies. The laterally placed biopsies had the highest frequency of positive biopsies when compared to the sextant cores. In conclusion, biopsy protocols that use laterally placed biopsies based upon a five region anatomical model are superior to the routinely used sextant prostate biopsy pattern. Prostate Cancer and Prostatic Diseases (2000) 3, 43-46

  7. Helium pressures in RHIC vacuum cryostats and relief valve requirements from magnet cooling line failure

    SciTech Connect

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28

    A catastrophic failure of the RHIC magnet cooling lines, similar to the LHC superconducting bus failure incident, would pressurize the insulating vacuum in the magnet and transfer line cryostats. Insufficient relief valves on the cryostats could cause a structural failure. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the vacuum cryostat and discharging via the reliefs into the RHIC tunnel, had been developed to calculate the helium pressure inside the cryostat. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces were included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Existing relief valve sizes were reviewed to make sure that the maximum stresses, caused by the calculated maximum pressures inside the cryostats, did not exceed the allowable stresses, based on the ASME Code B31.3 and ANSYS results. The conclusions are as follows: (1) The S/F simulation results show that the highest internal pressure in the cryostats, due to the magnet line failure, is {approx}37 psig (255115 Pa); (2) Based on the simulation, the temperature on the cryostat chamber, INJ Q8-Q9, could drop to 228 K, which is lower than the material minimum design temperature allowed by the Code; (3) Based on the ASME Code and ANSYS results, the reliefs on all the cryostats inside the RHIC tunnel are adequate to protect the vacuum chambers when the magnet cooling lines fail; and (4) In addition to the pressure loading, the thermal deformations, due to the temperature decrease on the cryostat chambers, could also cause a high stress on the chamber, if not properly supported.

  8. RHIC BBLR measurements in 2009

    SciTech Connect

    Calaga, R.; Robert-Demolaize, G.; Fischer, W.

    2010-05-23

    Long range beam-beam experiments were conducted during the Run 2009 in the Yellow and the Blue beams of the RHIC accelerator with DC wires. The effects of a long-range interaction with a DC wire on colliding and non-colliding bunches with the aid of beam losses, orbits, tunes were studied. Results from distance scans and an attempt to compensate a long-range interaction with a DC wire is presented. Two DC wires in the vertical plane were installed in the RHIC accelerator in 2006 with the aim of investigating long range (LR) beam-beam effects and a potential compensation. Extensive experiments were conducted focusing mainly on the effect of a wire on single ion beams from 2006-2009. A unique opportunity to compare the effect of the wire on colliding beams and compensation of a single LR beam-beam interaction were conducted in Run2009 with protons at 100 GeV. Due to aperture considerations for decreasing {beta}*, the Blue wire was removed during the shutdown after the Run2009 and the Yellow wire is foreseen to be removed in the near future. Therefore, these experiments serve as the final set of measurements for LR beam-beam with RHIC as a test bed. The relevant RHIC beam and lattice parameters are listed in Table 1 for the experiments in Run2009.

  9. [Is sextant biopsy a valid method in diagnosis of prostatic cancer?].

    PubMed

    Kiknavelidze, K G; Chanturaia, Z M; Silagava, D D; Nikoleishvili, D O; Tsintsadze, O V; Managadze, L G

    2006-01-01

    We evaluated effectiveness of a laterally directed sextant biopsy on large prostates and analysed the results of this biopsy technique in a group of men with obstructive voiding symptoms and suspected prostatic cancer (PC). Biopsy was performed in 386 men because of elevated PSA and/or abnormality in digital rectal examinations (DRE). The mean prostate volume was 79.6 +/- 39.1 cm3, and in 72.3% of the cases the volume of the prostate was > or = 50 cm3. PC was diagnosed in 107 of 386 cases (27.7%). In groups of patients with < 50 cm3 (small), 50 to 79 cm3 (medium) and > or = 80 cm3 (large) prostate volume and normal DRE, PC was detected in 27.5, 19.4 and 9.5% of cases, respectively (p < 0.018). PC detection rate was statistically insignificant (SI) in the same groups of patients with abnormal findings at DRE, 49.2, 54.2 and 51.9%, respectively (SI). Repeat sextant biopsy revealed PC in 14.5% patients. After TURP prostatic cancer was found in 7.7% patients who had undergone biopsy two times before. Thus, our results show that laterally directed sextant biopsy is an effective method of PC detection among suspected patients (PSA > 4 ng/ml) with large volume prostates and abnormal findings at DRE. An extensive biopsy protocol should be considered as a more appropriate method for markedly enlarged prostates with normal DRE findings but also for repeat biopsies.

  10. The Solar Disk Sextant - Monitoring the size and shape of the sun

    NASA Technical Reports Server (NTRS)

    Sofia, Sabatino; Maier, Eugene; Twigg, Laurence

    1991-01-01

    The Solar Disk Sextant (SDS) is a space instrument whose objective is to measure the solar diameter, at different orientations, as a function of time. Results would include the solar oblateness, the oscillation spectrum for use in helioseismology, and the rate of the secular variation of the solar diameter. The required instrumentation precision (a few milliarcsec) is attained by means of an objective beam splitting wedge which produces multiples solar images through consecutive reflections. In order to test the SDS concept a balloonborne version of the instrument has been fabricated and flown on three occasions. Preliminary results of the May 1990 flight are presented.

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

    SciTech Connect

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

    2011-08-09

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

  12. Reproducibility of image interpretation in MRI of the prostate: application of the sextant framework by two different radiologists.

    PubMed

    Mueller-Lisse, Ullrich; Mueller-Lisse, Ulrike; Scheidler, Juergen; Klein, Gerhardt; Reiser, Maximilian

    2005-09-01

    The aim of this study was to reproduce prostate cancer (PCA) localization by MRI based on prostatic sextants (right and left base, middle, and apex) with minimal systematic error. Combined endorectal/body-phased-array-coil MRI of the prostate at 1.5 T was retrospectively evaluated twice, with an interval of more than 1 month, by each of two independent radiologists (R1 readings R11 and R12, and R2 readings R21 and R22) in 23 patients (age 51-75 years) who had radical prostatectomy within 1 month of MRI. PCA stage was pT2 in 14 patients, and pT3 in nine. Median Gleason score was 7 (range 5-9). Histopathology showed 83 sextants with PCA and 55 without. Reproducibility of sextant positions was within one MRI slice (3 mm) in over 80% of cases. For PCA localization, ROC analysis (AUC=0.584+/-0.048-0.724+/-0.043) yielded no significant intra-reader differences. R11 and R21 differed slightly (P=0.035). Intra-observer agreement (kappa=0.52-0.58) exceeded inter-observer agreement (kappa=0.35-0.45). Intra-observer Spearman correlation (r=0.72-0.74) exceeded inter-observer correlation (r=0.43-0.51) for sextants with PCA, but not for sextants without (r=0.69-0.74). Per-sextant localization and reporting provides a highly reliable framework in MRI of the prostate. MRI of the prostate should be followed up by the same radiologists to minimize systematic error of interpretation.

  13. Physics with tagged forward protons at RHIC

    SciTech Connect

    Yip,K.

    2009-08-30

    The physics reach of the STAR detector at RHIC has been extended to include elastic and inelastic diffraction measurements with tagged forward protons. This program has started 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.

  14. Highlights from BNL and RHIC 2014

    NASA Astrophysics Data System (ADS)

    Tannenbaum, M. J.

    The following sections are included: * Introduction * News from BNL since ISSP2013 * RHIC Operations and accelerator future plans * Detector issues in A+A compared to p+p collisions * Nch, ET distributions and constituent-quarks as the fundamental elements of particle production * Collective Flow * RHIC Beam Energy Scan (BES)-in search of the critical point * Jet quenching, RHIC's main claim to fame * References

  15. Workshop on the RHIC performance

    SciTech Connect

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

    1988-07-01

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

  16. The PHENIX experiment at RHIC

    SciTech Connect

    Morrison, D.P.; Akiba, Y.; Alford, O.; PHENIX Collaboration

    1997-12-01

    The primary goals of the heavy-ion program of the PHENIX collaboration are the detection of the quark-gluon plasma and the subsequent characterization of its physical properties. To address these aims, PHENIX will pursue a wide range of high energy heavy-ion physics topics. The breadth of the physics program represents the expectation that it will require the synthesis of a number of measurements to investigate the physics of the quark-gluon plasma. The broad physics agenda of the collaboration is also reflected in the design of the PHENIX detector itself, which is capable of measuring hadrons, leptons and photons with excellent momentum and energy resolution. PHENIX has chosen to instrument a selective acceptance with multiple detector technologies to provide very discriminating particle identification abilities. Additionally, PHENIX will take advantage of RHIC`s capability to collide beams of polarized protons with a vigorous spin physics program, a subject covered in a separable contribution to these proceedings.

  17. RHIC CHALLENGES FOR LOW ENERGY OPERATIONS

    SciTech Connect

    SATOGATA,T.; BRENNAN, J.M.; DREES, A.; FEDOTOV, A.; ROSER, T.; TSOUPAS, N.

    2007-06-25

    There is significant interest in RHIC heavy ion collisions at {radical}s =5-50 GeV/u, motivated by a search for the QCD phase transition critical point. The lowest energies are well below the nominal RHIC gold injection {radical}s = 19.6 GeV/u. There are several challenges that face RHIC operations in this regime, including longitudinal acceptance, magnet field quality, lattice control, and luminosity monitoring. We report on the status of work to address these challenges, including results from beam tests of low energy RHIC operations with protons and gold.

  18. Monolithic readout circuits for RHIC

    SciTech Connect

    O`Connor, P.; Harder, J.

    1991-12-31

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

  19. RHIC and its upgrade programmes.

    SciTech Connect

    Roser,T.

    2008-06-23

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

  20. High intensity protons in RHIC

    SciTech Connect

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

    2012-01-05

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

  1. Future Physics Capabilities of RHIC

    NASA Astrophysics Data System (ADS)

    Johnson, B. M.

    2007-05-01

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is a versatile facility for both heavy-ion and polarized-proton collision physics. The initial heavy-ion runs (Au+Au, Cu+Cu, and d+Au) have led to the unexpected discoveries at RHIC that (1) the new state of matter produced is a "nearly-perfect" fluid, (2) fast quarks (jets) lose large amounts of energy, when traversing the medium, (3) the quarks themselves are observed to flow, and (4) forward particle production is lower than expected. The polarized proton (p+p) program has discovered that gluons do not make a maximal contribution to the spin of the proton. Substantial upgrades to the accelerator and experimental detectors are ushering in an exciting transition from discovery to understanding. RHIC is poised to address these fundamental questions of broad significance: (a) What are the phases of QCD matter? (b) What is the wave function of the proton? (c) What is the wave function of a heavy nucleus? (d) What is the nature of non-equilibrium processes in a fundamental theory? After a brief introduction this talk and paper give an abbreviated overview of what has been learned so far, the plan for the mid-term (2006-2011), and the long-range plan (2012 and beyond).

  2. RHIC stochastic cooling motion control

    SciTech Connect

    Gassner, D.; DeSanto, L.; Olsen, R.H.; Fu, W.; Brennan, J.M.; Liaw, CJ; Bellavia, S.; Brodowski, J.

    2011-03-28

    Relativistic Heavy Ion Collider (RHIC) beams are subject to Intra-Beam Scattering (IBS) that causes an emittance growth in all three-phase space planes. The only way to increase integrated luminosity is to counteract IBS with cooling during RHIC stores. A stochastic cooling system for this purpose has been developed, it includes moveable pick-ups and kickers in the collider that require precise motion control mechanics, drives and controllers. Since these moving parts can limit the beam path aperture, accuracy and reliability is important. Servo, stepper, and DC motors are used to provide actuation solutions for position control. The choice of motion stage, drive motor type, and controls are based on needs defined by the variety of mechanical specifications, the unique performance requirements, and the special needs required for remote operations in an accelerator environment. In this report we will describe the remote motion control related beam line hardware, position transducers, rack electronics, and software developed for the RHIC stochastic cooling pick-ups and kickers.

  3. Prostate cancer detection rate in patients with obstructive voiding symptoms by sextant biopsy: preliminary results.

    PubMed

    Kiknavelidze, K; Tsintsadze, O; Goguadze, M; Pertia, A; Managadze, L

    2006-04-01

    To evaluate the effectiveness of a laterally directed sextant biopsy in the group of high volume prostate patients with obstructive voiding symptoms and suspected of prostate cancer. Biopsy was performed in 197 men (age: median 63 years, range 47 to 82 years) because of elevated PSA and/or abnormality in digital rectal examinations (DRE). In most cases, a markedly enlarged prostate was noted: the mean prostate volume was 79,9+/-38,5 cc, and in 73% of the cases, the volume of the prostate was >50 cc. Prostate cancer was diagnosed in 56 of 197 cases (28,4%). The prostate cancer detection rate among patients with a prostate volume of 80cc (high volume) were 39,6%, 32,8% and 18,6%, respectively. Our results showed that the laterally directed sextant biopsy with the overall detection rate as high as 28,4% and very low complications is an effective method for the detection of prostate cancer among the suspected patients with obstructive voiding symptoms and markedly enlarged prostates.

  4. Percutaneous Transpedicular Fixation: Technical tips and Pitfalls of Sextant and Pathfinder Systems

    PubMed Central

    Hassan, Ahmed Salah Aldin

    2016-01-01

    Study Design The efficacy of the operative techniques, possible benefits as well as pitfalls and limitations of the techniques are discussed. Potential drawbacks are also detected. Purpose This study aims to report indications, techniques, and our experience with the use of the Sextant and PathFinder percutaneous transpedicular screw fixation systems. Overview of Literature Percutaneous pedicle screw insertion is a novel technique. Successful percutaneous placement of pedicle screws requires surgical skill and experience because of lack of anatomic surface landmarks. Fluoroscopy-guided percutaneous placement of pedicle screws is effective. Many systems are now available. Methods We conducted a prospective operative and postoperative analysis of 40 patients with absolute indication for thoracic or lumbar instability between January 2009 and June 2013. All procedures were performed with the Sextant (group A) and PathFinder (group B) systems under fluoroscopic guidance. Operative techniques are discussed and the results compared. Results Percutaneous transpedicular screw fixation minimizes the morbidity associated with open techniques without compromising the quality of fixation. A total of 190 screws were inserted. There was no additional morbidity. Postoperative computed tomography images and plain X-rays were analyzed. Reduction of visual analog scale scores of back pain was evident. Conclusions Fluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done. Current systems allow multi-segmental fixation with significantly less difficulties. The described techniques have acceptable intra- and postoperative complication rates, and overall sufficient pain control with early mobilization of patients. PMID:26949466

  5. The SEXTANTS beamline at SOLEIL: a new facility for elastic, inelastic and coherent scattering of soft X-rays

    NASA Astrophysics Data System (ADS)

    Sacchi, M.; Jaouen, N.; Popescu, H.; Gaudemer, R.; Tonnerre, J. M.; Chiuzbaian, S. G.; Hague, C. F.; Delmotte, A.; Dubuisson, J. M.; Cauchon, G.; Lagarde, B.; Polack, F.

    2013-03-01

    SEXTANTS is a new SOLEIL beamline dedicated to soft X-ray scattering techniques. The beamline, covering the 50-1700 eV energy range, features two Apple-II undulators for polarization control and a fixed-deviation monochromator. Two branch-lines host three end-stations for elastic, inelastic and coherent scattering experiments.

  6. BUNCH PATTERNS AND PRESSURE RISE IN RHIC.

    SciTech Connect

    FISCHER,W.IRISO-ARIZ,U.

    2004-07-05

    The RHIC luminosity is limited by pressure rises with high intensity beams. At injection and store, the dominating cause for the pressure rise was shown to be electron clouds. We discuss bunch distributions along the circumference that minimize the electron cloud effect in RHIC. Simulation results are compared with operational observations.

  7. Elastic proton-proton scattering at RHIC

    SciTech Connect

    Yip, K.

    2011-09-03

    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.

  8. Variation of the diameter of the Sun as measured by the Solar Disk Sextant (SDS)

    NASA Astrophysics Data System (ADS)

    Sofia, S.; Girard, T. M.; Sofia, U. J.; Twigg, L.; Heaps, W.; Thuillier, G.

    2013-12-01

    The balloon-borne Solar Disk Sextant (SDS) experiment has measured the angular size of the Sun on seven occasions spanning the years 1992 to 2011. The solar half-diameter - observed in a 100 nm wide passband centred at 615 nm - is found to vary over that period by up to 200 mas, while the typical estimated uncertainty of each measure is 20 mas. The diameter variation is not in phase with the solar activity cycle; thus, the measured diameter variation cannot be explained as an observational artefact of surface activity. Other possible instrument-related explanations for the observed variation are considered but found unlikely, leading us to conclude that the variation is real. The SDS is described here in detail, as is the complete analysis procedure necessary to calibrate the instrument and allow comparison of diameter measures across decades.

  9. Variation of the Diameter of the Sun as Measured by the Solar Disk Sextant (SDS)

    NASA Astrophysics Data System (ADS)

    Girard, Terrence; Sofia, S.; Sofia, U. J.; Twigg, L. W.; Heaps, W.; Thuillier, G.

    2014-01-01

    The balloon-borne Solar Disk Sextant (SDS) experiment has measured the angular size of the Sun on seven occasions spanning the years 1992 to 2011. The solar half-diameter -- observed in a 100-nm wide passband centered at 615 nm -- is found to vary over that period by up to 200 mas, while the typical estimated uncertainty of each measure is 20 mas. The diameter variation is not in phase with the solar activity cycle; thus, the measured diameter variation cannot be explained as an observational artifact of surface activity. Other possible instrument-related explanations for the observed variation are considered and found unlikely, leading us to conclude that the variation is real. The SDS and its results are presented here, including the analysis procedure necessary to calibrate the instrument and allow comparison of diameter measures across decades.

  10. HIGH PERFORMANCE EBIS FOR RHIC.

    SciTech Connect

    ALESSI,J.; BEEBE, E.; GOULD, O.; KPONOU, A.; LOCKEY, R.; PIKIN, A.; RAPARIA, D.; RITTER, J.; SNYDSTRUP, L.

    2007-06-25

    An Electron Beam Ion Source (EBIS), capable of producing high charge states and high beam currents of any heavy ion species in short pulses, is ideally suited for injection into a synchrotron. An EBIS-based, high current, heavy ion preinjector is now being built at Brookhaven to provide increased capabilities for the Relativistic Heavy Ion Collider (RHIC), and the NASA Space Radiation Laboratory (NSRL). Benefits of the new preinjector include the ability to produce ions of any species, fast switching between species to serve the simultaneous needs of multiple programs, and lower operating and maintenance costs. A state-of-the-art EBIS, operating with an electron beam current of up to 10 A, and producing multi-milliamperes of high charge state heavy ions, has been developed at Brookhaven, and has been operating very successfully on a test bench for several years. The present performance of this high-current EBIS is presented, along with details of the design of the scaled-up EBIS for RHIC, and the status of its construction. Other aspects of the project, including design and construction of the heavy ion RFQ, Linac, and matching beamlines, are also mentioned.

  11. SPIN MATCHING FROM AGS TO RHIC.

    SciTech Connect

    MACKAY,W.W.; TSOUPAS,N.

    2002-11-06

    With a partial Siberian snake in the AGS and transport lines with interspersed horizontal and vertical bends, the incoming spin direction at the injection points of both the collider rings is not likely to match the ideal vertical stable spin direction of RHIC which has two full helical Siberian snakes per ring. In this paper we examine the matching of a polarized beam transferred from the AGS into RHIC. The present 5% partial solenoidal snake as well as a proposed 20% superconducting helical are considered for the AGS. Solutions with retuned snakes in RHIC to better match the incoming beam have been found.

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

    SciTech Connect

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

    2011-03-28

    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.

  13. STATUS AND RECENT PERFORMANCE OF THE ACCELERATORS THAT SERVE AS GOLD INJECTOR FOR RHIC.

    SciTech Connect

    AHRENS,L.; ALESSI,J.; VAN ASSELT,W.; BENJAMIN,J.; BLASKIEWICZ,M.; BRENNAN,J.M.; BROWN,K.A.; CARLSON,C.; DELONG,J.; GARDNER,C.J.; GLENN,J.W.; HAYES,T.; ROSER,T.; SMITH,K.S.; STESKI,D.; TSOUPAS,N.; ZENO,K.; ZHANG,S.Y.

    2001-06-18

    The recent successful commissioning and operation [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) requires the injection of gold ions of specified energy and intensity with longitudinal and transverse emittances small enough to meet the luminosity requirements of the collider. Ion beams with the desired characteristics are provided by a series of three accelerators, the Tandem, Booster and AGS. The current status and recent performance of these accelerators are reviewed in this paper.

  14. Summary of the RHIC Retreat 2007

    SciTech Connect

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

    2008-08-01

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

  15. Hot Quark Soup Produced at RHIC

    ScienceCinema

    None

    2016-07-12

    The Relativistic Heavy Ion Collider (RHIC, http://www.bnl.gov/rhic) is a 2.4-mile-circumference particle accelerator/collider that has been operating at Brookhaven Lab since 2000, delivering collisions of heavy ions, protons, and other particles to an international team of physicists investigating the basic structure and fundamental forces of matter. In 2005, RHIC physicists announced that the matter created in RHICs most energetic collisions behaves like a nearly perfect liquid in that it has extraordinarily low viscosity, or resistance to flow. Since then, the scientists have been taking a closer look at this remarkable form of matter, which last existed some 13 billion years ago, a mere fraction of a second after the Big Bang. Scientists have revealed new findings, including the first measurement of temperature very early in the collision events, and their implications for the nature of this early-universe matter.

  16. RHIC low energy tests and initial operations

    SciTech Connect

    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.

    2009-05-04

    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.

  17. GLOBAL DECOUPLING ON THE RHIC RAMP.

    SciTech Connect

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

    2005-05-16

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

  18. Central exclusive production at RHIC

    SciTech Connect

    Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek

    2014-11-10

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity | | < 1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.

  19. ABORT GAP CLEANING IN RHIC.

    SciTech Connect

    DREES,A.; AHRENS,L.; III FLILLER,R.; GASSNER,D.; MCINTYRE,G.T.; MICHNOFF,R.; TRBOJEVIC,D.

    2002-06-03

    During the RHIC Au-run in 2001 the 200 MHz storage cavity system was used for the first time. The rebucketing procedure caused significant beam debunching in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam could account for approximately 30%-40% of the total beam intensity. Some of it will be in the abort gap. In order to minimize the risk of magnet quenching due to uncontrolled beam losses at the time of a beam dump, a combination of a fast transverse kicker and copper collimators were used to clean the abort gap. This report gives an overview of the gap cleaning procedure and the achieved performance.

  20. HIGH PT MEASUREMENT AT RHIC.

    SciTech Connect

    MIODUSZEWSKI,S.

    2003-01-06

    We present recent high transverse momentum measurements in Au+Au and p+p collisions at the Relativistic Heavy Ion Collider (RHIC). We define and show the nuclear modification factor for neutral pions and charged hadrons and discuss the particle species dependence. By means of the nuclear modification factor, we observe a suppression factor at high p{sub T} of 5-6 for neutral pions and 3-4 for charged hadrons in central Au+Au collisions relative to the binary-scaled yields in p+p (or peripheral) collisions. Finally we present strong evidence for the observation of jets in Au+Au collisions and the disappearance of the away-side jet in central Au+Au collisions.

  1. Superconducting RF systems for eRHIC

    SciTech Connect

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

    2012-05-20

    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.

  2. ANALYSIS OF ELECTRON CLOUD AT RHIC.

    SciTech Connect

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

    2004-07-05

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

  3. RHIC Polarized proton performance in run-8

    SciTech Connect

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

    2008-10-06

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

  4. Polarized Proton Acceleration in AGS and RHIC

    SciTech Connect

    Roser, Thomas

    2008-02-06

    As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species including polarized proton beams. The acceleration of polarized beams in both the injector and the collider rings is complicated by numerous depolarizing spin resonances. Partial and full Siberian snakes have made it possible to overcome the depolarization and beam polarizations of up to 65% have been reached at 100 GeV in RHIC.

  5. POLARIZED PROTON ACCELERATION IN AGS AND RHIC.

    SciTech Connect

    ROSER,T.

    2007-09-10

    As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species including polarized proton beams. The acceleration of polarized beams in both the injector and the collider rings is complicated by numerous depolarizing spin resonances. Partial and full Siberian snakes have made it possible to overcome the depolarization and beam polarizations of up to 65% have been reached at 100 GeV in RHIC.

  6. Reliable operation of the Brookhaven EBIS for highly charged ion production for RHIC and NSRL

    SciTech Connect

    Beebe, E. Alessi, J. Binello, S. Kanesue, T. McCafferty, D. Morris, J. Okamura, M. Pikin, A. Ritter, J. Schoepfer, R.

    2015-01-09

    An Electron Beam Ion Source for the Relativistic Heavy Ion Collider (RHIC EBIS) was commissioned at Brookhaven in September 2010 and since then it routinely supplies ions for RHIC and NASA Space Radiation Laboratory (NSRL) as the main source of highly charged ions from Helium to Uranium. Using three external primary ion sources for 1+ injection into the EBIS and an electrostatic injection beam line, ion species at the EBIS exit can be switched in 0.2 s. A total of 16 different ion species have been produced to date. The length and the capacity of the ion trap have been increased by 20% by extending the trap by two more drift tubes, compared with the original design. The fraction of Au{sup 32+} in the EBIS Au spectrum is approximately 12% for 70-80% electron beam neutralization and 8 pulses operation in a 5 Hertz train and 4-5 s super cycle. For single pulse per super cycle operation and 25% electron beam neutralization, the EBIS achieves the theoretical Au{sup 32+} fractional output of 18%. Long term stability has been very good with availability of the beam from RHIC EBIS during 2012 and 2014 RHIC runs approximately 99.8%.

  7. PROGRESS IN TUNE, COUPLING, AND CHROMATICITY MEASUREMENT AND FEEDBACK DURING RHIC RUN 7

    SciTech Connect

    CAMERON,P.; DELLAPENNA, A.; HOFF, L.; LUO, Y.; MARUSIC, A.; SCHULTHEISS, C.; TEPIKIAN, S.; ET AL.

    2007-06-25

    Tune feedback was first implemented in RHIC in 2002, as a specialist activity. The transition of the tune feedback system to full operational status was impeded by dynamic range problems, as well as by overall loop instabilities driven by large coupling. The dynamic range problem was solved by the CERN development of the Direct Diode Detection Analog Front End. Continuous measurement of all projections of the betatron eigenmodes made possible the world's first implementation of coupling feedback during beam acceleration, resolving the problem of overall loop instabilities. Simultaneous tune and coupling feedbacks were utilized as specialist activities for ramp development during the 2006 RHIC run. At the beginning of the 2007 RHIC run there remained two obstacles to making these feedbacks fully operational in RHIC - chromaticity measurement and control, and the presence of strong harmonics of the power line frequency in the betatron spectrum. We report on progress in tune, coupling, and chromaticity measurement and feedback, and discuss the relevance of our results to LHC commissioning.

  8. Reliable operation of the Brookhaven EBIS for highly charged ion production for RHIC and NSRL

    NASA Astrophysics Data System (ADS)

    Beebe, E.; Alessi, J.; Binello, S.; Kanesue, T.; McCafferty, D.; Morris, J.; Okamura, M.; Pikin, A.; Ritter, J.; Schoepfer, R.

    2015-01-01

    An Electron Beam Ion Source for the Relativistic Heavy Ion Collider (RHIC EBIS) was commissioned at Brookhaven in September 2010 and since then it routinely supplies ions for RHIC and NASA Space Radiation Laboratory (NSRL) as the main source of highly charged ions from Helium to Uranium. Using three external primary ion sources for 1+ injection into the EBIS and an electrostatic injection beam line, ion species at the EBIS exit can be switched in 0.2 s. A total of 16 different ion species have been produced to date. The length and the capacity of the ion trap have been increased by 20% by extending the trap by two more drift tubes, compared with the original design. The fraction of Au32+ in the EBIS Au spectrum is approximately 12% for 70-80% electron beam neutralization and 8 pulses operation in a 5 Hertz train and 4-5 s super cycle. For single pulse per super cycle operation and 25% electron beam neutralization, the EBIS achieves the theoretical Au32+ fractional output of 18%. Long term stability has been very good with availability of the beam from RHIC EBIS during 2012 and 2014 RHIC runs approximately 99.8%.

  9. Transverse profile of the electron beam for the RHIC electron lenses

    NASA Astrophysics Data System (ADS)

    Gu, X.; Altinbas, Z.; Costanzo, M.; Fischer, W.; Gassner, D. M.; Hock, J.; Luo, Y.; Miller, T.; Tan, Y.; Thieberger, P.; Montag, C.; Pikin, A. I.

    2015-10-01

    The transverse profile of the electron beam plays a very important role in assuring the success of the electron lens beam-beam compensation, as well as its application in space charge compensation. To compensate for the beam-beam effect in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, we recently installed and commissioned two electron lenses. In this paper, we describe, via theory and simulations using the code Parmela, the evolution of the density of the electron beam with space charge within an electron lens from the gun to the main solenoid. Our theoretical analysis shows that the change in the beam transverse density is dominated by the effects of the space charge induced longitudinal velocity reduction, not by those of transverse Coulomb collisions. We detail the transverse profile of RHIC electron-lens beam, measured via the YAG screen and pinhole detector, and also describe its profile that we assessed from the signal of the electron-backscatter detector (eBSD) via scanning the electron beam with respect to the RHIC beam. We verified, in simulations and experiments, that the distribution of the transverse electron beam is Gaussian throughout its propagation in the RHIC electron lens.

  10. LHeC and eRHIC

    SciTech Connect

    Litvinenko,V.

    2009-07-16

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

  11. The RHIC project: design, status, challenges, and perspectives

    SciTech Connect

    Wei, J.; Harrison, M.

    1997-04-01

    The design and construction status of the Relativistic Heavy Ion Collider, RHIC, is discussed. Those novel features of a heavy ion Collider that are distinct from conventional hadron Colliders in general are noted. These features are derived from the experimental requirements of operation with a variety of ion species over a wide energy range including collisions between ions of unequal energies. The project is in the fifth year of a seven-year construction cycle. A review of the superconducting magnet program is given together with progress to date on the machine construction and commissioning. Emphasis is made on challenging issues including intrabeam scattering, interaction-region error compensation, magnet alignments, and matched transition-energy jump.

  12. Processing Method Effects on Solar Diameter Measurements: Use of Data Gathered by the Solar Disk Sextant

    NASA Astrophysics Data System (ADS)

    Djafer, D.; Thuillier, G.; Sofia, S.; Egidi, A.

    2008-02-01

    To determine the apparent diameter of the Sun, it is first necessary to measure the shape of the intensity profile of the solar limb with an imaging optical system (hereafter denoted as a solar-limb profile). The inflection point of the limb profile is usually used as a reference for calculating the diameter. Because this point may be difficult to determine in the presence of noise, it is necessary to define an appropriate filtering process that eliminates noise while preserving the position of the inflection point. In this paper we study two filtering techniques, one based on the compact wavelet transform and the other on the finite Fourier transform definition, that meet these requirements. The application of these two techniques to data gathered by the Solar Disk Sextant experiment shows that the solar radius increased from 1992 to 1996 by about 197 mas. However, a previous analysis of the same data and our present analysis provide a difference in the measured radii of about 92 mas. We show that this difference is entirely traced to the filtering process.

  13. Preliminary results of a balloon flight of the solar disk sextant

    NASA Technical Reports Server (NTRS)

    Maier, E.; Twigg, L.; Sofia, S.

    1992-01-01

    Preliminary results of a balloon flight on October 11, 1991, of the solar disk sextant (SDS) experiment are reported. The SDS is an instrument which measures the solar diameter at different orientations with respect to the solar polar axis. Fitting straight lines through two fixed-angle data sets with time as the independent variable yields slopes of (7.1 +/ - 1.5) x 10 exp -3 and (6.7 +/- 1.6) x 10 exp -3/mas s, consistent with the value of 6.47 x 10 exp -3/mas s expected from the earth's approach to the sun due to the orbital motion toward perihelion. Upon the instrument's rotation on its axis a sinusoidal component of the diameter measurement was observed in each rotation cycle, with a variable amplitude of about 150 mas. The present result is epsilon of (5.6 +/- 6.3) x 10 exp -6, about 30 deg offset from the polar-equator position. The absolute diameter obtained by means of the FFT definition is found to be 1919.269 +/- 0.240 arcsec or 1919.131 +/- 0.240 arcsec, depending on the orientation mode of the measurement.

  14. Quantitative GSTP1 methylation and the detection of prostate adenocarcinoma in sextant biopsies.

    PubMed

    Harden, Susan V; Sanderson, Harriette; Goodman, Steven N; Partin, Alan A W; Walsh, Patrick C; Epstein, Jonathan I; Sidransky, David

    2003-11-05

    Hypermethylation of the 5' promoter region of the glutathione S-transferase pi gene (GSTP1) occurs at a very high frequency in prostate adenocarcinoma. We compared the results of blinded histologic review of sextant biopsy samples from 72 excised prostates with those obtained using a quantitative methylation-specific polymerase chain reaction assay (QMSP) for GSTP1. Formal surgical pathologic review of the resected prostates was used to determine the number of patients with (n = 61) and without (n = 11) prostate cancer. Histology alone detected prostate carcinoma with 64% sensitivity (95% confidence interval [CI] = 51% to 76%) and 100% specificity (95% CI = 72% to 100%), whereas the combination of histology and GSTP1 QMSP at an assay threshold greater than 10 detected prostate carcinoma with 75% sensitivity (95% CI = 63% to 86%) and 100% specificity (95% CI = 72% to 100%), an 11% improvement (95% CI = 5% to 22%) in sensitivity over histology alone. The combination of histology and GSTP1 QMSP at an assay threshold greater than 5 detected prostate adenocarcinoma with 79% sensitivity (95% CI = 68% to 89%), a 15% improvement (95% CI = 7% to 26%) over histology alone. Thus, GSTP1 QMSP improved the sensitivity of histologic review of random needle biopsies for prostate cancer diagnosis. Further studies should determine whether detection of GSTP1 hypermethylation in a biopsy sample with normal histology indicates the need for an early repeat biopsy at the same site.

  15. Medium energy heavy ion operations at RHIC

    SciTech Connect

    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.

    2011-03-28

    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.

  16. WHAT ARE WE LEARNING FROM RHIC?

    SciTech Connect

    KHARZEEV,D.

    2002-06-24

    Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory on Long Island, New York, began operation in 2000 culminating over ten years of development and construction, and a much longer period of theoretical speculations about the properties of hot QCD matter produced in nuclear collisions in the collider regime. RHIC's 2.4mile rings contain superconducting magnets, which operate at minus 451.6 degrees Fahrenheit, 4.5 degrees above the absolute zero. RHIC collides two intersecting heavy ion beams at center-of-mass energy of up to 200 GeV/A (at luminosity of up to 10{sup 26}sec{sup -1}cm{sup 2}, which can be further increased in the future), and polarized proton beams at c.m.s. energy of up to 500 GeV. The total energy in the gold-gold collision thus reaches 40 TeV, which is at present the World's record collision energy. In the pp mode, the unique possibility offered by RHIC for the first time is the study of double spin asymmetries and other spin observables. This talk is an attempt to summarize some of the first results obtained at RHIC. The author discusses the significance of these measurements for establishing the properties of hot and dense QCD matter and for understanding the dynamics of the theory at the high parton density, strong color field frontier.

  17. Central exclusive production at RHIC

    DOE PAGES

    Adamczyk, Leszek; Guryn, Włodek; Turnau, Jacek

    2014-11-10

    The present status and future plans of the physics program of Central Exclusive Production (CEP) at RHIC are described. The measurements are based on the detection of the forward protons from the Double Pomeron Exchange (DPE) process in the Roman Pot system and of the recoil system of charged particles from the DPE process measured in the STAR experiment’s Time Projection Chamber (TPC). The data described here were taken using polarized proton-proton collisions at ps = 200 GeV. The preliminary spectra of two pion and four pion invariant mass reconstructed by STAR TPC in central region of pseudo-rapidity | |more » < 1, are presented. Near future plans to take data with the current system at center-of-mass energy ps = 200 GeV and plans to upgrade the forward proton tagging sys- tem are presented. Also a possible addition of the Roman Pots to the sPHENIX detector is discussed.« less

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

    SciTech Connect

    BLAND,L.; SAITO,N.

    2001-10-10

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

  19. Recent Results from RHIC: The Perfect Liquid

    SciTech Connect

    Westfall, Gary

    2006-07-19

    In the past two years we have witnessed a leap forward in the understanding high temperature, high density, and strongly interacting matter produced in ultra-relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. Combining measurements of Au+Au, d+Au, and p+p collisions at energies up to 200 GeV per nucleon pair in the center of mass frame, the four RHIC experimental groups, STAR, PHENIX, PHOBOS, and BRAHMS, have produced impressive experimental evidence for the existence of a new form of matter. In this Colloquium, I will present an overview of recent experimental results from RHIC including evidence for thermalization, hydrodynamic behavior of a perfect fluid, the partonic origin of flow, and jet suppression. These measurements point to the observation of a hot, dense, strongly interacting matter produced in central Au+Au collisions at the highest available energies.

  20. RHIC BPM SYSTEM MODIFICATIONS AND PERFORMANCE.

    SciTech Connect

    SATOGATA, T.; CALAGA, R.; CAMERON, P.; ET AL.

    2005-05-16

    The RHIC beam position monitor (BPM) system provides independent average orbit and turn-by-turn (TBT) position measurements. In each ring, there are 162 measurement locations per plane (horizontal and vertical) for a total of 648 BPM planes in the RHIC machine. During 2003 and 2004 shutdowns, BPM processing electronics were moved from the RHIC tunnel to controls alcoves to reduce radiation impact, and the analog signal paths of several dozen modules were modified to eliminate gain-switching relays and improve signal stability. This paper presents results of improved system performance, including stability for interaction region beam-based alignment efforts. We also summarize performance of recently-added DSP profile scan capability, and improved million-turn TBT acquisition channels for 10 Hz triplet vibration, nonlinear dynamics, and echo studies.

  1. The RHIC polarized H- ion source

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  2. Commissioning MMS

    NASA Technical Reports Server (NTRS)

    Wood, Paul; Gramling, Cheryl; Stone, John; Smith, Patrick; Reiter, Jenifer

    2016-01-01

    This paper discusses commissioning of NASAs Magnetospheric MultiScale (MMS) Mission. The mission includes four identical spacecraft with a large, complex set of instrumentation. The planning for and execution of commissioning for this mission is described. The paper concludes by discussing lessons learned.

  3. RHIC ABORT KICKER WITH REDUCED COUPLING IMPEDANCE.

    SciTech Connect

    HAHN,H.; DAVINO,D.

    2002-06-02

    Kicker magnets typically represent the most important contributors to the transverse impedance budget of accelerators and storage rings. Methods of reducing the impedance value of the SNS extraction kicker presently under construction and, in view of a future performance upgrade, that of the RHIC abort kicker have been thoroughly studied at this laboratory. In this paper, the investigation of a potential improvement from using ferrite different from the BNL standard CMD5005 is reported. Permeability measurements of several ferrite types have been performed. Measurements on two kicker magnets using CMD5005 and C2050 suggest that the impedance of a magnet without external resistive damping, such as the RHIC abort kicker, would benefit.

  4. BUNCHED BEAM STOCHASTIC COOLING PROJECT FOR RHIC.

    SciTech Connect

    BRENNAN, J.M.; BASKIEWICZ, M.M.

    2005-09-18

    The main performance limitation for RHIC is emittance growth caused by IntraBeam Scattering during the store. We have developed a longitudinal bunched-beam stochastic cooling system in the 5-8 GHz band which will be used to counteract IBS longitudinal emittance growth and prevent de-bunching during the store. Solutions to the technical problems of achieving sufficient kicker voltage and overcoming the electronic saturation effects caused by coherent components within the Schottky spectrum are described. Results from tests with copper ions in RHIC during the FY05 physics run, including the observation of signal suppression, are presented.

  5. SIMULATION OF PARTICLE SPECTRA AT RHIC.

    SciTech Connect

    KAHANA,D.E.; KAHANA,S.H.

    2001-09-04

    A purely hadronic simulation is performed of the recently reported data from PHOBOS at energies of {radical}s = 56, 130 GeV using the relativistic heavy ion cascade LUCIFER which had previously given a good description of the NA49 inclusive spectra at {radical}s = 17.2 GeV/A. The results compare well with these early measurements at RHIC and indeed successfully predict the increase in multiplicity now seen by PHOBOS and the other RHIC detectors at the nominal maximum energy of {radical}s = 200 GeV/A, suggesting that evidence for quark-gluon matter remains elusive.

  6. Summary of the RHIC Retreat 2008

    SciTech Connect

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

    2008-08-01

    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.

  7. QUADRUPOLE BEAM-BASED ALIGNMENT AT RHIC.

    SciTech Connect

    NIEDZIELA, J.; MONTAG, C.; SATOGATA, T.

    2005-05-16

    Successful implementation of a beam-based alignment algorithm, tailored to different types of quadrupoles at RHIC, provides significant benefits to machine operations for heavy ions and polarized protons. This algorithm was used to calibrate beam position monitor centers relative to interaction region quadrupoles to maximize aperture. This approach was also used to determine the optimal orbit through transition jump quadrupoles to minimize orbit changes during the transition jump for heavy ion acceleration. This paper provides background discussion and results from first measurements during the RHIC 2005 run.

  8. HYDROGEN AND ITS DESORPTION IN RHIC.

    SciTech Connect

    HSEUH,H.C.

    2002-11-11

    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.

  9. RHIC BPM SYSTEM PERFORMANCE, UPGRADES, AND TOOLS.

    SciTech Connect

    SATOGATA,T.; CAMERON,P.; CERNIGLIA,P.; CUPOLO,J.; DAWSON,C.; DEGEN,C.; MEAD,J.; PTITSYN,V.; SIKORA,R.

    2002-06-02

    During the RHIC 2001-2 run, the beam position monitor (BPM) system provided independent average orbit and turn-by-turn (TBT) position measurements at 162 locations in each measurement plane and RHIC ring. TBT acquisition was successfully upgraded from 128 turns to 1024 turns per trigger, including injection. Closed orbits were acquired and automatically archived every two seconds through each acceleration ramp for orbit analysis and feed-forward orbit correction. This paper presents the overall system performance during this run, including precision, reproducibility, radiation damage, and analysis tools. We also summarize future plans, including million-turn TBT acquisition for nonlinear dynamics studies.

  10. RHIC CRITICAL POINT SEARCH: ASSESSING STARs CAPABILITIES.

    SciTech Connect

    SORENSEN,P.

    2006-07-03

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

  11. DVCS with an EIC/eRHIC

    SciTech Connect

    Fazio, Salvatore

    2011-07-15

    An overview of the status of the diffractive physics program with the future EIC/eRHIC will be given. eRHIC is a machine designed to collide an electron beam with energies ranging from 5 GeV up to 20(30)GeV with a hadron beam (protons, nuclei) at an energy, which can be varied from 50 GeV up to 325 GeV. The high luminosity of the machine, expected in the order of 10{sup 34} cm{sup -2} s{sup -1}, will open the opportunity for very high precision measurements.

  12. SNAKE DEPLORIZING RESONANCE STUDY IN RHIC

    SciTech Connect

    BAI,M.; CAMERON, P.; LUCCIO, A.; HUANG, H.; PITISYN, V.; ET AL.

    2007-06-25

    Snake depolarizing resonances due to the imperfect cancellation of the accumulated perturbations on the spin precession between snakes were observed at the Relativistic Heavy Ion Collider (RHIC). During the RHIC 2005 and 2006 polarized proton runs, we mapped out the spectrum of odd order snake resonance at Q{sub y} = 7/10. Here, Q, is the beam vertical betatron tune. We also studied the beam polarization after crossing the 7/10th resonance as a function of resonance crossing rate. This paper reports the measured resonance spectrum as well as the results of resonance crossing.

  13. Heavy Nuclei, From RHIC to The Cosmos

    SciTech Connect

    Klein, Spencer R.

    2002-11-01

    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.

  14. MULTI - MILLION - TURN BEAM POSITION MONITORS FOR RHIC.

    SciTech Connect

    SATOGATA,T.CAMERON,P.CERNIGLIA,P.CUPOLO,J.DAWSON,CDEGEN,CMEAD,JVETTER,K

    2003-05-12

    During the RHIC 2003 run, two beam position monitors (BPMs) in each transverse plane in the RHIC blue ring were upgraded with high-capacity mezzanine cards. This upgrade provided these planes with the capability to digitize up to 128 million consecutive turns of RHIC beam, or almost 30 minutes of continuous beam centroid phase space evolution for a single RHIC bunch. This paper describes necessary hardware and software changes and initial system performance. We discuss early uses and results for diagnosis of coherent beam oscillations, turn-by-turn (TBT) acquisition through a RHIC acceleration ramp, and ac-dipole nonlinear dynamics studies.

  15. Transrectal ultrasound guided biopsy of the prostate: random sextant versus biopsies of sono-morphologically suspicious lesions.

    PubMed

    Loch, Tillmann; Eppelmann, Ursula; Lehmann, Jan; Wullich, Bernd; Loch, Annemie; Stöckle, Michael

    2004-11-01

    Transrectal ultrasound (TRUS) guided multiple systematic random biopsies are presently the method of choice for determining the presence or absence of prostate cancer. TRUS image information is only used to guide the biopsy needle into the prostate, but not to localize and target cancerous lesions. Our aim in this study was to evaluated the possible predictive value of tumor suspicious endosonographic lesions of the prostate for prostate biopsies. We prospectively compared six systematic biopsies with lesion guided biopsies in a consecutive series of 217 patients. All patients had a prostate specific antigen (PSA) level of >4 ng/ml without a history of prostate disease. In a subgroup of 145 men with sonomorphologic lesions suggestive for prostate cancer (hypoechoic areas or asymmetries predominantly in the peripheral zone), lesion-guided biopsies were taken in addition to the systematic biopsies. We evaluated the number of tumors which were diagnosed or missed by both of the biopsy strategies. Of the 217 evaluated patients, 64 (29%) had histology confirmed cancer. Four patients with negative sextant biopsies had a positive TRUS guided biopsy. Out of 145 patients with a normal TRUS, three were cancer positive by sextant biopsy. A total of 1,387 individual biopsy cores were evaluated. Of the 1,304 systematic biopsy cores, 182 (14%) were positive and 1,122 (86%) negative. Of the 329 TRUS lesion guided biopsy cores 139 (42%) were positive and 190 (58%) negative. Patients with tumor suggestive TRUS lesions have a considerably higher risk of being diagnosed with prostate cancer compared to patients without such lesions. Both systematic sextant and TRUS lesion guided biopsies missed detectable prostate cancer in a minority of patients. Taking the endosonographic morphology of the prostate gland into consideration for biopsy strategies may improve the quality of the biopsy and avoid unnecessary invasive procedures in selected cases.

  16. WITHDRAWN: Can the conventional sextant prostate biopsy reliably diagnose unilateral prostate cancer in low-risk, localized, prostate cancer?

    PubMed

    Mayes, J M; Mouraviev, V; Sun, L; Madden, J F; Polascik, T J

    2008-05-13

    The authors hereby retract the e-publication dated 13 May 2008 and entitled, 'Can the conventional sextant prostate biopsy reliably diagnose unilateral prostate cancer in low-risk, localized, prostate cancer?' The authors are submitting a revised version with the same title. This article's statistics were performed for predicting bilateral prostate cancer outcomes. The article was written to help predict unilateral prostate cancer. Although the statistical numbers are correct, they are backwards. We apologize that the statistics indicate a contrary outcome (eg predicting bilateral cancer instead of unilateral disease).

  17. Joint Commission

    MedlinePlus

    Skip to main content The Joint Commission Log In | Request Guest Access Forgot password? | Log In Help Contact Us | Careers | JCR Web Store | Press Room Search Home Accreditation Accreditation Ambulatory Health ...

  18. Brahms Experiment at RHIC Day-1 Physics

    SciTech Connect

    Videbaek, Flemming

    1999-03-23

    The BRAHMS experiment is designed to measure semi-inclusive spectra of charged hadron over a wide range of rapidity. It will yield information on particle production, both at central rapidity and in the baryon rich fragmentation region. The physics plans for measurements in the first year of running at RHIC are discussed.

  19. First Polarized Proton Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    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.; Glenn, W.; Huang, H.; Luccio, A. U.; MacKay, W. W.; Makdisi, Y.; Montag, C.; Pilat, F.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; van Zeijts, J.; Zelenski, A.; Zeno, K.; Deshpande, A.; Kurita, K.; Krueger, K.; Spinka, H.; Underwood, D.; Syphers, M.; Alekseev, I.; Svirida, D.; Ranjbar, V.; Tojo, J.; Jinnouchi, O.; Okamura, M.; Saito, N.

    2003-05-01

    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° about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV.

  20. Polarized proton beam for eRHIC

    SciTech Connect

    Huang, H.; Meot, F.; Ptitsyn, V.; Roser, T.

    2015-05-03

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

  1. MEASUREMENT OF LINEAR COUPLING RESONANCE IN RHIC.

    SciTech Connect

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

    2002-05-12

    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.

  2. RHIC Proton Luminosity and Polarization Improvement

    SciTech Connect

    Zhang, S. Y.

    2014-01-17

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

  3. Hybrid helical snakes and rotators for RHIC

    SciTech Connect

    Courant, E.D.

    1995-06-13

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

  4. Status of RHIC head-on beam-beam compensation project

    SciTech Connect

    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.

    2011-03-28

    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.

  5. Small gap magnets and vacuum chambers for eRHIC

    SciTech Connect

    Meng,W.; Bengtsson, J.; Hao, Y.; Mahler, G.; Tuozzolo, J.; Litvinenko, V. N.

    2009-05-04

    eRHIC[1][2][3], a future high luminosity electron-ion collider at Brookhaven National Laboratory (BNL), will add polarized electrons to the list of colliding species in RHIC. A 10-30 GeV electron energy recovery linac (ERL) will require up to six passes around the RHIC 3.8 km circumference. We are developing and testing small (5 mm) gap dipole and quadrupole magnets and vacuum chambers for cost-effective eRHIC passes [4]. We are also studying the sensitivity of eRHIC pass optics to magnet and alignment errors in such a small magnet structure. We present the magnetic and mechanical designs of the small gap eRHIC components and prototyping test progress.

  6. The measuring accuracy of Tycho's large sextant. (German Title: Die Meßgenauigkeit von Tycho Brahes großem Sextanten)

    NASA Astrophysics Data System (ADS)

    Wünsch, Johann

    We considered angular separations between planets and fixed stars. The scatter of Tycho Brahe's sextant measurements was studied by forming (O-C). Samples for Saturn showed a standard deviation of ±80″ (n=66 measurements), whereas Jupiter and Mars had ±89″ (n=62 and n=83).

  7. Heavy Flavor Measurements at RHIC in the Near Future

    SciTech Connect

    Xu, Nu

    2006-12-01

    We discuss the recent results on open charm measurements at RHIC. The heavy flavor upgrade program for both PHENIX and STAR experiments are briefly discussed. The completion of the program will yield important information on light flavor thermalization of the partonic matter created in high-energy nuclear collisions at RHIC. A new era of RHIC is ahead of us with the progress of the upgrade program.

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

    SciTech Connect

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

    2011-03-28

    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.

  9. SUCCESSFUL BUNCHED BEAM STOCHASTIC COOLING IN RHIC.

    SciTech Connect

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

    2006-06-23

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

  10. Studies of eRHIC coherent instabilities

    SciTech Connect

    Wang G.; Blaskiewicz, M.

    2012-05-20

    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.

  11. Beam-beam experience in RHIC

    SciTech Connect

    Montag, C.; Heimerle, M.

    2010-07-29

    The Relativistic Heavy Ion Collider RHIC consists of two superconducting storage rings that intersect at six locations around the ring circumference. Two of these interaction regions are currently equipped with experiment detectors, namely STAR at the “6 o’clock” interaction point (IP), and PHENIX at “8 o’clock”. The two beams collide only at these two interaction regions, while they are vertically separated by typically 6-10mm at the other IPs. Together with the separator dipoles located at roughly 10m from the IP, and a distance between bunches of 30m, this avoids any parasitic beam-beam collisions. RHIC is capable of colliding any ion species at magnetic rigidities up to B × r = 830T × m , corresponding to 250 GeV for proton beams, or 100 GeV/n for fully stripped gold ions.

  12. RHIC Au beam in Run 2014

    SciTech Connect

    Zhang, S. Y.

    2014-09-15

    Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014 is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.

  13. OBSERVATIONS OF SNAKE RESONANCE IN RHIC.

    SciTech Connect

    BAI, M.; HUANG, H.; MACKAY, W.W.; PITISYN, V.; ROSER, T.; TEPIKIAN, S.

    2005-05-16

    Siberian snakes now become essential in the polarized proton acceleration. With proper configuration of Siberian snakes, the spin precession tune of the beam becomes 1/2 which avoids all the spin depolarizing resonance. However, the enhancement of the perturbations on the spin motion can still occur when the spin precession tune is near some low order fractional numbers, called snake resonances, and. the beam can be depolarized when passing through the resonance. The snake resonances have been confirmed in the spin tracking calculations, and observed in RHIC with polarized proton beam. Equipped with two full Siberian snakes in each ring, RHIC provides us a perfect facility for snake resonance studies. This paper presents latest experimental results. New insights are also discussed.

  14. Ferrite HOM Absorber for the RHIC ERL

    SciTech Connect

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

    2008-10-01

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

  15. IBS suppression lattice in RHIC: theory and experimental verification

    SciTech Connect

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

    2008-08-25

    Intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for Relativistic Heavy Ion Collider (RHIC) operation with heavy ions. Over the last few years the process of IBS was carefully studied in RHIC with dedicated IBS measurements and their comparison with the theoretical models. A new lattice was recently designed and implemented in RHIC to suppress transverse IBS growth, which lowered the average arc dispersion by about 20% [1]. This lattice became operational during RHIC Run-8. We review the IBS suppression mechanism, IBS measurements before and after the lattice change, and comparisons with predictions.

  16. Conceptual design of a quadrupole magnet for eRHIC

    SciTech Connect

    Witte, H.; Berg, J. S.

    2015-05-03

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

  17. Analysis of RHIC beam dump pre-fires

    SciTech Connect

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

    2011-03-28

    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.

  18. ANALYSIS OF AVAILABILITY AND RELIABILITY IN RHIC OPERATIONS.

    SciTech Connect

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

    2006-06-26

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

  19. PRESSURE OSCILLATION IN RHIC CRYOGENIC SYSTEM.

    SciTech Connect

    JIA,L.MONTAG,C.TALLERICO,T.HIRZEL,W.NICOLETTI,A.

    2003-09-22

    HORIZONTAL BEAM VIBRATION AROUND 10HZ IN THE RELATIVISTIC HEAVY ION COLLIDER (RHIC) HAVE BEEN IDENTIFIED AND THE POSSIBLE SOURCES TO CAUSE THIS VIBRATION HAVE BEEN INVESTIGATED. TO DETERMINE THE HETIUM PRESSURE OSCILLATIONS AS A POSSIBLE PRIMARY VIBRATION SOURCE, HELIUM PRESSURE MEASUREMENTS WERE CARRIED OUT IN THE FIVE CRYOGENIC TRANSFER LINES AT 2 VALVE BOXES AND 6 LEAD PORTS AT 2 TRIPLET CRYOSTAT FOR BOTH MAGNET RINGS. ADDITIONALLY, COLD MA...

  20. STOCHASTIC COOLING STUDIES IN RHIC, II.

    SciTech Connect

    BLASKIEWICZ,M.BRENNAN,J.M.WEI,J.

    2004-07-05

    Intra-beam scattering (IBS) is unavoidable for highly charged heavy ions and causes emittance growth during the store for collision physics. A longitudinal bunched beam stochastic cooling system will confine the bunch within the RF bucket increasing the useful luminosity. We describe a series of measurements in RHIC that have been used to verify our understanding of the relevant physics and the cooling system architecture that is being prototyped.

  1. eRHIC ERL modeling in Zgoubi

    SciTech Connect

    Meot, F.; Brooks, S.; Hao, Y.; Jing, Y.; Ptitsyn, V.; Trbojevic, D.; Tsoupas, N.

    2016-01-01

    This Note discusses on-going work regarding the modeling of eRHIC ERL in the ray-tracing code Zgoubi. The various pieces of the recirculator puzzle, their optical properties and their assemblage into an operational input data file in are addressed. The Note reports in particular on preparatory stages toward extensive end-to-end 6D polarized electron bunch transport simulations, which yield methods, as well a series of preliminary qualitative outcomes, discussed as well.

  2. The Relativistic Heavy Ion Collider, Rhic

    NASA Astrophysics Data System (ADS)

    Foelsche, H.; Hahn, H.; Harrison, M.; Ozaki, S.; Rhoades-Brown, M. J.

    1993-03-01

    The scope of the first relativistic energy heavy ion collider, RHIC, is discussed. Particular attention is paid to those novel features of a heavy ion collider that are distinct from the more usual proton machines. These features are derived from the experimental requirements of operation with a variety of ion species over a wide energy range as well as the increased demands on available ion sources and injector complexes. Storage of heavy ion beams for many hours is severely impacted by intrabeam scattering.

  3. OPERATION OF THE RHIC RF SYSTEMS.

    SciTech Connect

    BRENNAN,J.M.; BLASKIEWICZ,M.; DELONG,J.; FISCHER,W.; HAYES,T.; SMITH,K.S.; ZALTSMAN,A.

    2003-05-12

    Operational aspects of the RHIC rf system are described. To date three different beam combinations have been collided for physics production: gold-gold, deuteron-gold, and proton-proton(polarized). To facilitate this flexibility the rf systems of the two rings are independent and self-sufficient. Techniques to cope with problems such as, injection/capture, beam loading, bunch shortening, and rf noise have evolved and are explained.

  4. The RHIC project -- Status and plans

    SciTech Connect

    Harrison, M.

    1995-05-01

    The Relativistic Heavy Ion Collider (RHIC) Project is in the 4th year of an estimated 8 year construction cycle at Brookhaven National Laboratory. The accelerator complex is designed to collide a variety of ion species at center-of-mass energies up to 100 GeV/nucleon in a two ring superconducting structure. Industrial magnet production is in progress as well as the other accelerator systems. This presentation will outline the status of the construction effort, near and long term goals.

  5. Building the RHIC tracking lattice model

    SciTech Connect

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

    2010-01-27

    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.

  6. INTRA - BEAM SCATTERING MEASUREMENTS IN RHIC.

    SciTech Connect

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

    2002-06-02

    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.

  7. RHIC polarized proton performance in run-8.

    SciTech Connect

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

    2008-06-23

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

  8. RHIC spin program. Revision 07/97

    SciTech Connect

    Bunce, G.

    1997-07-01

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

  9. ELECTRON CLOUD OBSERVATIONS AND CURES IN RHIC

    SciTech Connect

    FISCHER,W.; BLASKIEWICZ, M.; HUANG, H.; HSEUH, H.C.; ET AL.

    2007-06-25

    Since 2001 RHIC has experienced electron cloud effects, which have limited the beam intensity. These include dynamic pressure rises - including pressure instabilities, tune shifts, a reduction of the stability threshold for bunches crossing the transition energy, and possibly incoherent emittance growth. We summarize the main observations in operation and dedicated experiments, as well as countermeasures including baking, NEG coated warm beam pipes, solenoids, bunch patterns, anti-grazing rings, pre-pumped cold beam pipes, scrubbing, and operation with long bunches.

  10. RHIC low-energy challenges and plans

    SciTech Connect

    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.

    2009-06-08

    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.

  11. Estimation of collective instabilities in RHIC

    SciTech Connect

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

    1995-05-01

    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.

  12. RHIC spin flipper AC dipole controller

    SciTech Connect

    Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

    2011-03-28

    The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

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

    SciTech Connect

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

    2008-03-30

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

  14. THE RHIC INJECTOR ACCELERATORS CONFIGURATIONS, AND PERFORMANCE FOR THE RHIC 2003 AU - D PHYSICS RUN.

    SciTech Connect

    Ahrens, L; Benjamin, J; Blaskiewicz, M; Brennan, J M; Brown, K A; Carlson, K A; Delong, J; D'Ottavio, T; Frak, B; Gardner, C J; Glenn, J W; Harvey, M; Hayes, T; Hseuh, H- C; Ingrassia, P; Lowenstein, D; Mackay, W; Marr, G; Morris, J; Roser, T; Satogata, T; Smith, G; Smith, K S; Steski, D; Tsoupas, N; Thieberger, P; Zeno, K; Zhang, S Y

    2003-05-12

    The RHIC 2003 Physics Run [1] required collisions between gold ions and deuterons. The injector necessarily had to deliver adequate quality (transverse and longitudinal emittance) and quantity of both species. For gold this was a continuing evolution from past work [2]. For deuterons it was new territory. For the filling of the RHIC the injector not only had to deliver quality beams but also had to switch between these species quickly. This paper details the collider requirements and our success in meeting these. Some details of the configurations employed are given.

  15. High-Precision Measurements of the Solar Diameter and Oblateness by the Solar Disk Sextant (SDS) Experiment

    NASA Astrophysics Data System (ADS)

    Egidi, A.; Caccin, B.; Sofia, S.; Heaps, W.; Hoegy, W.; Twigg, L.

    2006-05-01

    We reduce and analyze, in a uniform way, all of the data obtained by the Solar Disk Sextant (SDS) experiment, concerning high-precision measurements of the solar radius and oblateness, in the bandwidth 590 {-} 670 nm, made onboard stratospheric balloons during a series of flights carried out in 1992, 1994, 1995, and 1996. The measured radius value appears anti-correlated with the level of solar activity, ranging from about 959.5 to 959.7 arcsec. Its variation from year to year is outside the error range, which is mostly due to a systematic diurnal behavior, particularly evident in the 1996 flight. The oblateness shows an analogous temporal behavior, ranging from about (4.3 to 10.3) × 10-6.

  16. Expert systems for the analysis of transients on nuclear reactors: SEXTANT, a general-purpose physical analyzer

    SciTech Connect

    Barbet, N.; Dumas, M.; Mihelich, G.; Souchet, Y.; Thomas, J.B.

    1988-12-01

    Two expert systems for on-line analysis of nuclear reactor transients are reported. During a hypothetical crisis in a nuclear facility, a team of the Institute for Protection and Nuclear Safety must assess the risk to the local population. Expert systems are intended to assist in this analysis. The first deals with the availability of the safety systems of the plant (e.g., emergency core cooling system), depending on the functional state of the support systems. A second expert system will be built to study the physical transient of the reactor (mass and energy balance, pressure, flows). To do this, as in the development of the other expert systems, a physical analyzer is required. This is the aim of SEXTANT, which combines several knowledge bases concerning measurements, models, and qualitative behavior of the plant with a conjecture-refutation mechanism and a set of simplified models of the current physical state. A prototype is being assessed with integral test facility transients.

  17. The solar diameter and oblateness measured by the solar disk sextant on the 1992 September 30 balloon flight

    NASA Technical Reports Server (NTRS)

    Sofia, S.; Heaps, W.; Twigg, L. W.

    1994-01-01

    This paper reports the results of a balloon flight of the Solar Disk Sextant (SDS) on 1992 September 30. This was the first flight in which the SDS used a wedge assembly fabricated by molecular contact in order to eliminate the wedge angle variations observed in previous flights. The instrument performed as designed. The main results obtained are values of the solar diameter for a number of discrete heliocentric latitudes, and the solar oblateness. The accuracy of the diameter values is better than 0.2 sec whereas the precision is approximately 1-2 mas. The equatorial solar diameter, at 1 AU, was 1919.06 sec +/- 0.12 sec, and the oblateness epsilon = 8.63 +/- 0.88 x 10(exp -6).

  18. Quantifying the sQGP - Heavy Ion Collisions at RHIC

    SciTech Connect

    Seto, Richard

    2014-12-01

    This is the closeout for DE-FG02-86ER40271 entitled Quantifying the sQGP - Heavy Ion Collisions at the RHIC. Two major things were accomplished. The first, is the physics planning, design, approval, construction, and commissioning of the MPC-EX. The MPC-EX is an electromagnetic calorimeter covering a rapidity of 3<|eta|<4, which was added to the PHENIX detector. Its primary aim is to measure low-x gluons, in order to understand the suppression seen in a variety of signatures, such as the J/Psi. A candidate to explain this phenomena is the Color Glass Condensate (CGC) A second task was to look at collisions of asymmetric species, in particularly Cu+Au. The signature was the suppression of J/Psi mesons at forward and backward rapidity, where a stronger suppression was seen in the copper going direction. While the blue of the suppression is due to hot nuclear matter effects (e.g. screening) the increase in suppression on the Au side was consistent with cold nuclear matter effects seen in d+Au collisions. A major candidate for the explanation of this phenomena is the aforementioned CGC. Finally the work on sPHENIX, particularly an extension to the forward region, called fsPHENIX is described.

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

    SciTech Connect

    Wilson, W.K.

    1995-07-15

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

  20. Experimental effects of orbit on polarization loss in RHIC

    SciTech Connect

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

    2012-05-20

    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.

  1. RHIC polarized proton-proton operation at 100 GeV in Run 15

    SciTech Connect

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

    2015-05-03

    The first part of RHIC Run 15 consisted of ten weeks of polarized proton on proton collisions at a beam energy of 100 GeV at two interaction points. In this paper we discuss several of the upgrades to the collider complex that allowed for improved performance. The largest effort consisted in commissioning of the electron lenses, one in each ring, which are designed to compensate one of the two beam-beam interactions experienced by the proton bunches. The e-lenses raise the per bunch intensity at which luminosity becomes beam-beam limited. A new lattice was designed to create the phase advances necessary for a beam-beam compensation with the e-lens, which also has an improved off-momentum dynamic aperture relative to previous runs. In order to take advantage of the new, higher intensity limit without suffering intensity driven emittance deterioration, other features were commissioned including a continuous transverse bunch-by-bunch damper in RHIC and a double harmonic RF cature scheme in the Booster. Other high intensity protections include improvements to the abort system and the installation of masks to intercept beam lost due to abort kicker pre-fires.

  2. THE RHIC BEAM ABORT KICKER SYSTEM.

    SciTech Connect

    HAHN,H.

    1999-03-29

    THE ENERGY STORED IN THE RHIC BEAM IS ABOUT 200 KJ PER RING AT DESIGN ENERGY AND INTENSITY. TO PREVENT QUENCHING OF THE SUPERCONDUCTING MAGNETS OR MATERIAL DAMAGE, THE BEAM WILL BE SAFELY DISPOSED OF BY AN INTERNAL BEAM ABORT SYSTEM, WHICH INCLUDES THE KICKER MAGNETS, THE PULSED POWER SUPPLIES, AND THE DUMP ABSORBER. DISPOSAL OF HEAVY IONS, SUCH AS GOLD, IMPOSES DESIGN CONSTRAINTS MORE SEVERE THAN THOSE FOR PROTON BEAMS OF EQUAL INTENSITY. IN ORDER TO MINIMIZE THE THERMAL SHOCK IN THE CARBON-FIBER DUMP BLOCK, THE BUNCHES MUST BE LATERALLY DISPERSED.

  3. Recent Triplet Vibration Studies in RHIC

    SciTech Connect

    Thieberger, P.; Bonati, R.; Corbin, G.; Jain, A.; Minty, M.; McIntyre, G.; Montag, C.; Muratore, J.; Schultheiss, C.; Seberg, S.; Tuozzolo, J.

    2010-05-23

    We report on recent developments for mitigating vibrations of the quadrupole magnets near the interaction regions of the Relativistic Heavy Ion Collider (RHIC). High precision accelerometers, geophones, and a laser vibrometer were installed around one of the two interaction points to characterize the frequencies of the mechanical motion. In addition actuators were mounted directly on the quadrupole cryostats. Using as input the locally measured motion, dynamic damping of the mechanical vibrations has been demonstrated. In this report we present these measurements and measurements of the beam response. Future options for compensating the vibrations are discussed.

  4. RHIC operation with asymmetric collisions in 2015

    SciTech Connect

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

    2015-08-07

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

  5. LEPTON AND PHOTON PHYSICS AT RHIC.

    SciTech Connect

    TANNENBAUM,M.J.

    2003-01-06

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

  6. On perturbative azimuthal asymmetry at RHIC

    SciTech Connect

    Rezaeian, A. H.

    2008-10-13

    We investigate the azimuthal asymmetry of partons and photons produced at the initial stage of nuclear collisions at the RHIC energy originating from quark-nucleus collisions. In our approach, the azimuthal asymmetry results from the correlation between color dipole orientation and impact parameter of the collision. The asymmetry is sensitive to the rapid variation of the nuclear density at the nuclear periphery. We either introduce the color-dipole orientation into the improved Born approximation, or model the dipole partial amplitude which satisfies available DIS data. We conclude that the azimuthal asymmetry coming from these mechanisms can be sizable.

  7. A LOW NOISE RF SOURCE FOR RHIC.

    SciTech Connect

    HAYES,T.

    2004-07-05

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

  8. Some calculations for the RHIC kicker

    SciTech Connect

    Claus, J.

    1996-12-01

    This paper starts with a brief discussion of the design of the RHIC injection kicker magnets which calls for longitudinal and capacitive sections of the same order as the aperture, not much larger nor much smaller. This makes accurate analytical prediction of their behavior very difficult. In order to gain at least some qualitative insight of that behavior, the author preformed calculations which are based on the actual dimensions of the kickers but which neglect the end effects of the individual sections. The effects of the sectionalization are therefore exaggerated relative to reality in the results.

  9. Polarization response of RHIC electron lens lattices

    NASA Astrophysics Data System (ADS)

    Ranjbar, V. H.; Méot, F.; Bai, M.; Abell, D. T.; Meiser, D.

    2016-10-01

    Depolarization response for a system of two orthogonal snakes at irrational tunes is studied in depth using lattice independent spin integration. In particular we consider the effect of overlapping spin resonances in this system, to understand the impact of phase, tune, relative location and threshold strengths of the spin resonances. These results are benchmarked and compared to two dimensional direct tracking results for the RHIC e-lens lattice and the standard lattice. Finally we consider the effect of longitudinal motion via chromatic scans using direct six dimensional lattice tracking.

  10. Properties of a symmetric RHIC insertion

    SciTech Connect

    Lee, S.Y.

    1991-07-01

    This report evaluates the lattice functions of the symmetric insertion proposed by A.G. Ruggiero for the RHIC insertion. The crossing geometry, Inner and Outer matching sections, and chromatic properties are studied in detail. Some properties of the missing dipole dispersion correction scheme are also discussed. We found that the chromatic properties of the symmetric insertion is not better than the antisymmetric insertion. The problem is that the four family sextupole correction scheme seems not able to improve the chromatic distortion. Analytic understanding of the failure of the four family sextupole correction scheme will be very useful. 9 figs., 1 tab.

  11. TRANSVERSE OPTICS IMPROVEMENTS FOR RHIC RUN 4.

    SciTech Connect

    VAN ZEIJTS,J.

    2004-07-05

    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.

  12. FEASIBILITY OF INCREASING THE ENERGY OF RHIC.

    SciTech Connect

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

    2001-06-18

    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.

  13. RHIC on "How the Universe Works"

    SciTech Connect

    Lisa, Mike

    2014-08-11

    If you want to know how the universe works, part of the answer lies in understanding the building blocks of matter—before they became inextricably bound within the protons, neutrons, and atoms that make up everything visible in our universe today. That’s why producers for the Science Channel’s documentary series “How the Universe Works” made a point of stopping by the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, where physicists recreate post-Big Bang “primal matter” millions of times each day. Learn about RHIC’s role in exploring the building blocks of matter by watching this segment.

  14. Construction progress of the RHIC electron lenses

    SciTech Connect

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

    2012-05-20

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

  15. RHIC spin physics: Proceedings. Volume 7

    SciTech Connect

    1998-12-01

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

  16. Current status of PHOBOS{at}RHIC

    SciTech Connect

    Betts, R.R. |; PHOBOS Collaboration

    1996-05-01

    Four experiments are currently approved for the first measurements with colliding heavy ion beams from the Relativistic Heavy Ion Collider (RHIC) which is scheduled to come into operation in Spring 1999. These experiments are named STAR, Phoenix, PHOBOS and Brahms. It is expected that central collisions of 100 GeV/u Au + Au at RHIC will lead to energy densities far above any so far attained in the laboratory and it is suspected and hoped that this situation will lead to qualitatively new physics perhaps associated with the creation of a large volume containing a plasma of deconfined quarks and gluons. All four experiments attempt to search for signatures of new physics through combinations of measurements of quantities such as the multiplicity of produced particles, the average transverse momentum of these particles, fluctuations in their multiplicity distribution, their flavor composition, the size scales of the volume from which they are emitted, mass shifts and changes in the decay widths of resonances which decay inside the high energy density volume etc. The PHOBOS detector addresses these issues with a Multiplicity Array which covers the pseudo-rapidity region {minus}5.3 {le} {eta} {le} 5.3 with a coverage of 85% of 4{pi} and also incorporates a Vertex Detector. The Multiplicity Array is complemented by two Multi-Particle Spectrometers, each of which cover the range 0.5 {le} {eta} {le} 1.5 and azimuthal angle range {Delta}{phi} = 11{degree}. Various trigger and monitor detectors complete PHOBOS.

  17. Upgrade scenario for the RHIC collimation system

    SciTech Connect

    Robert-Demolaize, G.; Drees, A.

    2012-01-19

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

  18. UP-GRADED RHIC INJECTION SYSTEM.

    SciTech Connect

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

    2003-05-12

    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.

  19. CONTINUOUS ABORT GAP CLEANING AT RHIC.

    SciTech Connect

    DREES,A.FLILLER,R.III.FU,W.MICHNOFF,R.

    2004-07-05

    Since the RHIC Au-Au run in the year 2001 the 200 MHz cavity system was used at storage and a 28 MHz system during injection and acceleration. The rebucketing procedure potentially causes a higher debunching rate of heavy ion beams in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam can easily account for more than 50% of the total beam intensity. This effect is even stronger with the achieved high intensities of the RHIC Au-Au run in 2004. A beam abort at the presence of a lot of debunched beam bears the risk of magnet quenching and experimental detector damage due to uncontrolled beam losses. Thus it is desirable to avoid any accumulation of debunched beam from the beginning of each store, in particular to anticipate cases of unscheduled beam aborts due to a system failure. A combination of a fast transverse kickers and the new 2-stage copper collimator system are used to clean the abort gap continuously throughout the store with a repetition rate of 1 Hz. This report gives. an overview of the new gap cleaning procedure and the achieved performance.

  20. High luminosity electron-hadron collider eRHIC

    SciTech Connect

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

    2011-03-28

    We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

  1. Predictors of random sextant biopsy outcome in screened men with PSA > 4 ng/mL and a negative sextant biopsy at previous screening. Experience in a population-based screening program in Florence.

    PubMed

    Ciatto, S; Lombardi, C; Rubeca, T; Zappa, M

    2004-01-01

    The aim of this study was to evaluate possible pedictors of the outcome of repeat random sextant biopsy of the prostate prompted by a rise in prostate-specific antigen (PSA). Random biopsies performed for PSA elevation (>4 ng/mL) in the course of a randomized study of screening efficacy were reviewed, and 87 consecutive biopsies (carcinoma = 13, high-grade prostatic intraepithelial neoplasia = 6, negative = 68) performed in subjects with a negative random biopsy at the previous screening round were considered. Findings at digital rectal examination or transrectal ultrasonography and total PSA value were not useful predictors of repeat biopsy outcome, whereas PSA velocity was significantly associated with biopsy outcome. The positive predictive value for a cancer biopsy was 2.7% (1/36), 28.5% (2/7), and 22.7% (10/44) for PSA velocity values of <0.1, 0.1-0.19, and >0.19 ng/mL/yr, respectively. A cutoff of 0.1 ng/mL/yr for PSA velocity would have allowed to avoid approximately half (35/74 = 47.2%) of the benign biopsies while decreasing the sensitivity by 7.6% (1/13), and is thus suggested as a possible criterion for the indication of repeat random biopsy for persistent PSA elevation.

  2. Status of Proton Polarization in Rhic and AGS

    NASA Astrophysics Data System (ADS)

    Mackay, W. W.; Bai, M.; Huang, H.; Ahrens, L.; Alekseev, I. G.; Bravar, A.; Brown, K.; Bunce, G.; Calaga, R.; Courant, E. D.; Drees, A.; Fischer, W.; Gardner, C.; Glenn, J. W.; Gupta, R.; Igo, G.; Iriso, U.; Jinnouchi, O.; Kurita, K.; Luccio, A. U.; Luo, Y.; Makdisi, Y.; Marr, G.; Montag, C.; Nass, A.; Okada, H.; Okamura, M.; Pilat, F.; Ptitsyn, V.; Roser, T.; Saito, N.; Satogata, T.; Spinka, H.; Stephenson, E. J.; Svirida, D. N.; Takano, J.; Tepikian, S.; Tomas, R.; Tsoupas, N.; Underwood, D.; Whitten, C.; Wood, J.; Zeijts, J. Van; Zelenski, A.; Zeno, K.; Zhang, S. Y.

    2005-08-01

    The Relativistic Heavy Ion Collider (RHIC) has collided protons with both transverse and longitudinal polarization at a centre-of-mass energy of 200 GeV. Future running will extend this to 500 GeV. This paper describes the methods used to accelerate and manipulate polarized proton beams in RHIC and its injectors. Special techniques include the use of a partial Siberian snake and an AC dipole in the AGS. In RHIC we use superconducting helical Siberian snakes for acceleration, and eight superconducting helical rotators for independent control of polarization directions at two interaction regions. The present status and future plans for the polarized proton program will be reviewed.

  3. MEASUREMENT AND CORRECTION OF NONLINEAR CHROMATICITY IN RHIC.

    SciTech Connect

    TEPIKIAN, S.; CAMERON, P.; DELLA PENNA, A.; PTITSYN, V.

    2005-05-16

    To improve luminosity in RHIC by using smaller {beta}*, higher order chromatic effects may need to be corrected [1]. Measuring of higher order chromaticities is discussed and compared to a model of RHIC, showing agreement. Assuming round beams, four families of octupoles are used to correct the second order chromaticities while keeping under control the amplitude dependent betatron tune spread in the beams. We show that the octupoles can reduce the second order chromaticity in RHIC, but they have insufficient strength for complete correction.

  4. IBS simulation with different RF configurations in RHIC

    SciTech Connect

    Liu, C.; Fedotov, A.; Minty, M.; Ptitsyn, V.

    2016-11-07

    It is a crucial task to understand the beam emittance growth during RHIC cycle and the underlying causes. One would benefit not just for the current operation of RHIC, also for the design of eRHIC. This report focuses on the Intra-Beam Scattering (IBS) contribution to the emittance growth of the proton beam with two different configurations of RF system. The answers to these questions will be given in the end of the report; can IBS explain the emittance growth all alone? What’s the difference of IBS growth rates for different RF configurations?

  5. A number of upgrades on RHIC power supply system

    SciTech Connect

    Mi, C.; Bruno, D.; Drozd, J.; Nolan, T.; Orsatti, F.; Heppener, G.; Di Lieto, A.; Schultheiss, C.; Samms, T.; Zapasek, R.; Sandberg, J.

    2015-05-03

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

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

    SciTech Connect

    BUNCE, G.; VIGDOR, S.

    2001-03-15

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

  7. PROGRESS OF HIGH-ENERGY ELECTRON COOLING FOR RHIC.

    SciTech Connect

    FEDOTOV,A.V.

    2007-09-10

    The fundamental questions about QCD which can be directly answered at Relativistic Heavy Ion Collider (RHIC) call for large integrated luminosities. The major goal of RHIC-I1 upgrade is to achieve a 10 fold increase in luminosity of Au ions at the top energy of 100 GeV/nucleon. Such a boost in luminosity for RHIC-II is achievable with implementation of high-energy electron cooling. The design of the higher-energy cooler for RHIC-II recently adopted a non-magnetized approach which requires a low temperature electron beam. Such electron beams will be produced with a superconducting Energy Recovery Linac (ERL). Detailed simulations of the electron cooling process and numerical simulations of the electron beam transport including the cooling section were performed. An intensive R&D of various elements of the design is presently underway. Here, we summarize progress in these electron cooling efforts.

  8. Experience with IBS-suppression lattice in RHIC

    SciTech Connect

    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.

    2008-06-23

    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.

  9. Beam dynamics limits for low-energy RHIC operation

    SciTech Connect

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

    2008-08-25

    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 QCD 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. Here we summarize dynamic effects limiting beam lifetime and possible improvement with electron cooling.

  10. ON THE FEASIBILITY OF POLARIZED HEAVY IONS IN RHIC.

    SciTech Connect

    MACKAY, W.W.

    2006-06-23

    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.

  11. Lattice design for the ERL electron ion collider in RHIC

    SciTech Connect

    Trbojevic, D.; Beebe-Wang, J.; Tsoupas, N.; Chang, X.; Kayran, D.; Ptitsyn, V.; Litvinenko, V.; Hao, Y.; Parker, B.; Pozdeyev, E.

    2010-05-23

    We present electron ion collider lattice design for the Relativistic Heavy Ion Collider (eRHIC) where the electrons have multi-passes through recirculating linacs (ERL) and arcs placed in the existing RHIC tunnel. The present RHIC interaction regions (IR's), where the electron ion collisions will occur, are modified to allow for the large luminosity. Staging of eRHIC will bring the electron energy from 4 up to 20 (30) GeV as the superconducting cavities are built and installed sequentially. The synchrotron radiation from electrons at the IR is reduced as they arrive straight to the collision while ions and protons come with 10 mrad crossing angle using the crab cavities.

  12. Status of superconducting magnet development (SSC, RHIC, LHC)

    SciTech Connect

    Wanderer, P.

    1993-12-31

    This paper summarize recent superconducting accelerator magnet construction and test activities at the Superconducting Super Collider Laboratory (SSC), the Large Hadron Collider at CERN (LHC), and the Relativistic Heavy Ion Collider at Brookhaven (RHIC). Future plan are also presented.

  13. Note on polarized RHIC bunch arrangement

    SciTech Connect

    Underwood, D.

    1996-08-30

    We discuss what combinations of bunch polarization in the two RHIC rings are necessary to do the physics measurements at various interaction regions. We also consider the bunches for both the pion inclusive and p-p elastic polarization measurements. Important factors to consider are the direction of the polarization with respect to the momentum in each bunch, the beam gas backgrounds, and the simulation of zero - polarization in one beam by averaging + and - helicity, and luminosity monitoring for normalization. These considerations can be addressed by setting the relative number of each of the 9 combinations possible at each of the 6 interaction regions. The combinations are (+ empty -) yellow X (+ empty -)blue, where yellow and blue are the counter-rotating rings.

  14. RHIC on "How the Universe Works"

    ScienceCinema

    Lisa, Mike

    2016-07-12

    If you want to know how the universe works, part of the answer lies in understanding the building blocks of matter—before they became inextricably bound within the protons, neutrons, and atoms that make up everything visible in our universe today. That’s why producers for the Science Channel’s documentary series “How the Universe Works” made a point of stopping by the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, where physicists recreate post-Big Bang “primal matter” millions of times each day. Learn about RHIC’s role in exploring the building blocks of matter by watching this segment.

  15. Hadron spectroscopy and B physics at RHIC

    SciTech Connect

    Chung, S.U.; Weygand, D.P.; Willutzki, H.J.

    1991-11-01

    A description is given of the physics opportunities at RHIC regarding quark-gluon spectroscopy. The basic idea is to isolate with appropriate triggers the sub-processes pomeron + pomeron {yields} hadrons and {gamma}{sup *} + {gamma}{sup *} {yields} hadrons with the net effective mass of hadrons in the range of 1.0 to 10.0 GeV, in order to study the hadronic states composed of quarks and gluons. The double-pomeron interactions are expected to produce glueballs and hybrids preferentially, while the two-offshell-photon initial states should couple predominantly to quarkonia and multiquark states. Of particular interest is the possibility of carrying out a CP-violation study in the self-tagging B decays, B{sub d}{sup 0} {yields} K{sup +}{pi}{sup {minus}} and {bar B}{sub d}{sup 0} {yields} K{sup {minus}}{pi}{sup +}. 20 refs., 4 figs.

  16. MEASUREMENT OF TRANSVERSE ECHOES IN RHIC.

    SciTech Connect

    FISCHER, W.; SATOGATA, T.; TOMAS. R.

    2005-05-16

    Beam echoes are a very sensitive method to measure diffusion, and longitudinal echo measurements were performed in a number of machines. In RHIC, for the first time, a transverse beam echo was observed after applying a dipole kick followed by a quadrupole .kick. After application of the dipole kick, the dipole moment decohered completely due to lattice nonlinearities. When a quadrupole kick is applied at time {tau} after the dipole kick, the beam re-cohered at time 2{tau} thus showing an echo response. We describe the experimental setup and measurement results. In the measurements the dipole and quadrupole kick amplitudes, amplitude dependent tune shift, and the time between dipole and quadrupole kick were varied. In addition, measurements were taken with gold bunches of different intensities. These should exhibit different transverse diffusion rates due to intra-beam scattering.

  17. Code generation of RHIC accelerator device objects

    SciTech Connect

    Olsen, R.H.; Hoff, L.; Clifford, T.

    1995-12-01

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

  18. COUPLING MEASUREMENT AND CORRECTION AT RHIC.

    SciTech Connect

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

    2002-06-02

    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.

  19. Physics at Relativistic Heavy Ion Collider (RHIC)

    SciTech Connect

    Shuryak, E.V.

    1990-08-01

    This introductory talk contains a brief discussion of future experiments at RHIC related to physics of superdense matter. In particular, we consider the relation between space-time picture of the collision and spectra of the observed secondaries. We discuss where one should look for QGP signals and for possible manifestation of the phase transition. We pay more attention to a rather new topic: hadron modification in the gas phase, which is interesting by itself as a collective phenomenon, and also as a precursor indicating what happens with hadrons near the phase transition. We briefly review current understanding of the photon physics, dilepton production, charm and strangeness and J/{psi} suppression. At the end we try to classify all possible experiments. 47 refs., 3 figs.

  20. Breakthrough: RHIC Explores Matter at the Dawn of Time

    SciTech Connect

    Paul Sorensen

    2012-06-24

    Physicist Paul Sorensen describes discoveries made at the Relativistic Heavy Ion Collider (RHIC), a particle accelerator at the U.S. Department of Energy's Brookhaven National Laboratory. At RHIC, scientists from around the world study what the universe may have looked like in the first microseconds after its birth, helping us to understand more about why the physical world works the way it does -- from the smallest particles to the largest stars.

  1. Tracking studies in eRHIC energy-recovery recirculator

    SciTech Connect

    Meot, F.; Brooks, S.; Ptitsyn, V.; Trbojevic, D.; Tsoupas, N.

    2015-07-13

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

  2. COOLING DYNAMICS STUDIES AND SCENARIOS FOR THE RHIC COOLER.

    SciTech Connect

    FEDOTOV,A.V.; BEN-ZVI,I.; LITVINENKO, V.

    2005-05-16

    In this paper, we discuss various electron cooling dynamics studies for RHIC. We also present simulations [1] of various possibilities of using electron cooling at RHIC, which includes cooling at the top energy, pre-cooling at low energy, aspects of transverse and longitudinal cooling and their impact on the luminosity. Electron cooling at various collision energies both for heavy ions and protons is also discussed.

  3. Breakthrough: RHIC Explores Matter at the Dawn of Time

    ScienceCinema

    Paul Sorensen

    2016-07-12

    Physicist Paul Sorensen describes discoveries made at the Relativistic Heavy Ion Collider (RHIC), a particle accelerator at the U.S. Department of Energy's Brookhaven National Laboratory. At RHIC, scientists from around the world study what the universe may have looked like in the first microseconds after its birth, helping us to understand more about why the physical world works the way it does -- from the smallest particles to the largest stars.

  4. Polarized proton acceleration program at the AGS and RHIC

    SciTech Connect

    Lee, Y.Y.

    1995-06-01

    Presented is an overview of the program for acceleration of polarized protons in the AGS and their injection into the RHIC collider. The problem of depolarizing resonances in strong focusing circulator accelerators is discussed. The intrinsic resonances are jumped over by the fast tune jump, and a partial Siberian Snake is used to compensate for over forty imperfection resonances in the AGS. Two sets of full Siberian Snake and spin rotators will be employed in RHIC.

  5. MEASUREMENT OF MULTIPOLE STRENGTHS FROM RHIC BPM DATA.

    SciTech Connect

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

    2004-07-05

    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.

  6. MEASURING LOCAL GRADIENT AND SKEW QUADRUPOLE ERRORS IN RHIC IRS.

    SciTech Connect

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

    2004-07-05

    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.

  7. Polarization simulations in the RHIC run 15 lattice

    SciTech Connect

    Meot, F.; Huang, H.; Luo, Y.; Ranjbar, V.; Robert-Demolaize, G.; White, S.

    2015-05-03

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

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

    SciTech Connect

    Makdisi, Y.; Stevens, A.J.

    1991-12-31

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

  9. ELECTRON COOLING SIMULATIONS FOR LOW-ENERGY RHIC OPERATION.

    SciTech Connect

    FEDOTOV,A.V.; BEN-ZVI, I.; CHANG, X.; KAYRAN, D.; SATOGATA, T.

    2007-09-10

    Recently, a strong interest emerged in running the Relativistic Heavy Ion Collider (RHIC) at low beam total energies of 2.5-25 GeV/nucleon, substantially lower than the nominal beam total energy of 100 GeV/nucleon. Collisions in this low energy range are motivated by one of the key questions of quantum chromodynamics (QCD) about the existence and location of critical point on the QCD phase diagram. Applying electron cooling directly at these low energies in RHIC would result in significant luminosity increase and long beam stores for physics. Without direct cooling in RHIC at these low energies, beam lifetime and store times are very short, limited by strong transverse and longitudinal intrabeam scattering (IBS). In addition, for the lowest energies of the proposed energy scan, the longitudinal emittance of ions injected from the AGS into RHIC may be too big to fit into the RHIC RF bucket. An improvement in the longitudinal emittance of the ion beam can be provided by an electron cooling system at the AGS injection energy. Simulations of electron cooling both for direct cooling at low energies in RHIC and for injection energy cooling in the AGS were performed and are summarized in this report.

  10. High Luminosity Heavy Quark and Electromagnetic Probes at RHIC

    SciTech Connect

    David, G; Frawley, A D; Rapp, R; Ullrich, T; Vogt, R; Xu, Z

    2008-03-30

    The Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory was designed to study the properties of quantum chromodynamics (QCD) in a hot and dense medium. The first years of RHIC operation and accompanying theoretical studies have helped pinpoint certain classes of measurements needed to more fully probe the medium and determine its properties. The medium created in these heavy-ion (AA) collisions appears to thermalize quickly and exhibits collective flow patterns consistent with hydrodynamic predictions. The initial temperature of the medium is not known and it is not yet understood whether deconfinement and chiral symmetry restoration are realized during its evolution. The answers to these questions require higher luminosities and detector upgrades, referred to as RHIC-II. The goal of RHIC II is to achieve the answers to the above questions by increasing the ion luminosity. The measurements thus far at RHIC could not fully address these fundamental questions, either due to incomplete detection capabilities or insufficient statistics to draw meaningful and robust conclusions. Working groups were formed to determine which physics topics could best be addressed by the combination of planned upgrades and increased luminosity. Reports from each working group were used to prepare a white paper for RHIC II, along with additional inputs from the conveners of all working groups.

  11. Status and Outlook for the RHIC Luminosity Upgrade

    NASA Astrophysics Data System (ADS)

    Bai, Mei

    2010-02-01

    As the world highest energy heavy ion collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been the center for exploring the universe at its infant stage. The operations of RHIC over the past decade has produced many results. A new state of matter, the quark-gluon plasma which is believed to only have existed right after the birth of the universe, was first observed at RHIC during the collisions of Au ions. The experimental data also revealed that this new state of matter behaves like a perfect fluid. In addition to the heavy ion program, RHIC is also capable to accelerate polarized proton beams to high energy, which allows one to explore the spin structure of polarized protons. Both the heavy ion program and spin physics program require high luminosities at RHIC. Various efforts aimed at increasing the RHIC luminosity of heavy ion and polarized proton collisions, such as NEG coating beam pipes to reduce electron clouds, using intrabeam scattering lattice for heavy ion operations as well as longitudinal stochastic cooling. The average store luminosity of Au collisions at a beam energy of 100 GeV/u has reached 1027cm-2s-1. The average store luminosity of RHIC polarized proton collisions at a beam energy of 100 GeV reached 28x1030cm-2s-1 and 55x1030 cm-2s-1 for the polarized proton collisions at a beam energy 250 GeV. Currently, the luminosity is limited by beam-beam effects for polarized proton collisions and intrabeam scattering for heavy ion collisions. Novel techniques are explored and under development to address these issues. The addition of transverse stochastic cooling will minimize the beam size growth due to intrabeam scattering and increase the heavy ion luminosity lifetime. The technique of using 9MHz cavity to accelerate polarized protons minimizes the electron cloud effect, which can cause emittance blowup. It also helps to preserve the longitudinal emittance and yields shorter bunches. The technique of employing an

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

    SciTech Connect

    Gardner, C. J.

    2015-10-02

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

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

    SciTech Connect

    Gardner, C. J.

    2015-08-25

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

  14. Commissioning and performance of the BNL EBIS LLRF system

    SciTech Connect

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

    2011-03-28

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

  15. Electron cooling for low-energy RHIC program

    SciTech Connect

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

    2009-08-31

    Electron cooling was proposed to increase luminosity of the RHIC collider for heavy ion beam energies below 10 GeV/nucleon. Providing collisions at such energies, termed RHIC 'low-energy' operation, will help to answer one of the key questions in the field of QCD about existence and location of critical point on the QCD phase diagram. The electron cooling system should deliver electron beam of required good quality over energies of 0.9-5 MeV. Several approaches to provide such cooling were considered. The baseline approach was chosen and design work started. Here we describe the main features of the cooling system and its expected performance. We have started design work on a low-energy RHIC electron cooler which will operate with kinetic electron energy range 0.86-2.8 (4.9) MeV. Several approaches to an electron cooling system in this energy range are being investigated. At present, our preferred scheme is to transfer the Fermilab Pelletron to BNL after Tevatron shutdown, and to use it for DC non-magnetized cooling in RHIC. Such electron cooling system can significantly increase RHIC luminosities at low-energy operation.

  16. Fulfilling the RHIC mission with sPHENIX

    NASA Astrophysics Data System (ADS)

    Connors, Megan

    2016-08-01

    RHIC has made groundbreaking contributions to the understanding of QCD under extreme conditions with the discovery of the quark gluon plasma (QGP) as a perfect fluid and first observations of energy loss. It continues to play a crucial role in understanding and quantifying the properties of the QGP as well as mapping out the QCD phase diagram. However, detailed questions concerning partonic energy loss in the QGP remain. There is a need to build a new detector at RHIC to measure important rare probes of the QGP. A new detector will benefit from advances in reconstructing jets in heavy ion collisions and the increased luminosity achievable with RHIC. Constraining models at RHIC and LHC energies are crucial for extracting the temperature dependence of transport properties of the QGP. To measure newly developed observables made at the LHC with high precision at RHIC, a detector with full azimuthal coverage and spanning a pseudorapidity range between -1.1 and 1.1, known as sPHENIX, has been proposed. The capabilities of the new detector will allow for a full understanding of jet energy loss and upsilon suppression. The goals for sPHENIX and route to achieving these goals along with the current status of the detector will be presented on behalf of the new collaboration.

  17. eRHIC - Future Electron-Ion Collider at BNL

    SciTech Connect

    Ptitsyn, V.

    2006-07-11

    The work on the detailed design of electron-ion collider, eRHIC, on the basis of existing RHIC machine is underway. eRHIC aims to be an instrument for the exploration of important QCD aspects using collisions of polarized electrons and positrons on ions and polarized protons in the center of mass energy range of 30-100 GeV, with a luminosity of 1032-1034 cm-2s-1 for c-p and 1030-1032 cm-2s-1 for c-Au collisions. An electron accelerator, which delivers about 0.5A polarized electron beam current in the electron energy range of 5 to 10 GeV, would be constructed at BNL, near the existing RHIC complex and would intersect an ion ring in at least one of the available ion ring interaction regions. One design option considers the circular electron machine based on the accelerator technology similar to that of storage rings at the e+-e- B-factories. Another pursued design option employs an energy recovery linac for electron acceleration. This option paves way to higher luminosities but meets challenges of developments of high current electron polarized source and high beam power ERL technologies. To maximize the collider luminosity certain upgrades are considered for RHIC ion rings.

  18. Strangeness in STAR experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Shi, Shusu; STAR collaboration

    2017-01-01

    We present the recent results of strangeness production at the mid-rapidity in Au + Au collisions at RHIC, from to 200 GeV. Elliptic asymmetry v 2 of multi-strange baryon Ω and φ mesons are similar to that of pions and protons in the intermediate pT range (2 - 5 GeV/c) in GeV Au + Au collisions, indicating that the major part of collective ow has been built up at partonic stage. The breaking of mass ordering between φ mesons and protons in the low pT range (< 1 GeV/c) is consistent with a picture that φ mesons are less sensitive to later hadronic interaction. The nuclear modification factor R CP and baryon to meson ratio change dramatically when the collision energy is lower than 19.6 GeV. It suggests a possible change of the created QCD medium properties at lower energies compared to those from high energies.

  19. Pixel telescope test in STAR at RHIC

    NASA Astrophysics Data System (ADS)

    Sun, Xiangming; Szelezniak, Michal; Greiner, Leo; Matis, Howard; Vu, Chinh; Stezelberger, Thorsten; Wieman, Howard

    2007-10-01

    The STAR experiment at RHIC is designing a new inner vertex detector called the Heavy Flavor Tracker (HFT). The HFT's innermost two layers is called the PIXEL detector which uses Monolithic Active Pixel Sensor technology (MAPS). To test the MAPS technology, we just constructed and tested a telescope. The telescope uses a stack of three MIMOSTAR2 chips, Each MIMOSTAR2 sensor, which was designed by IPHC, is an array of 132x128 pixels with a square pixel size of 30 μ. The readout of the telescope makes use of the ALICE DDL/SIU cards, which is compatible with the future STAR data acquisition system called DAQ1000. The telescope was first studied in a 1.2 GeV/c electron beam at LBNL's Advanced Light Source. Afterwards, the telescope was outside the STAR magnet, and then later inside it, 145 cm away from STAR's center. We will describe this first test of MAPS technology in a collider environment, and report on the occupancy, particle flux, and performance of the telescope.

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

    SciTech Connect

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

    2011-10-10

    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.

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

    SciTech Connect

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

    2016-02-15

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

  2. Transverse impedance measurement in RHIC and the AGS

    SciTech Connect

    Biancacci, Nicolo; Blaskiewicz, M.; Dutheil, Y.; Liu, C.; Mernick, M.; Minty, M.; White, S. M.

    2014-05-12

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

  3. Experimental Studies of Quark Gluon Plasma at RHIC

    NASA Astrophysics Data System (ADS)

    Esumi, ShinIchi

    2010-05-01

    A new state of matter, Quark Gluon Plasma (QGP) is supposed to exist under extreme temperature and/or density conditions just as a beginning of this early universe after the Big Bang. High energy nucleus-nucleus collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) has been used to form the QGP and to study the properties of QGP. The recent progress on the experimental research of QGP at RHIC experiments and the understanding of the properties are discussed. Major discoveries at RHIC experiments are very strong energy loss of high energy partons in central Au+Au collisions and very large elliptic and collective expansion given by the initial almond geometry in non-central Au+Au collisions. Those two finding and related physics explanations as well as future plans are presented.

  4. Experimental Studies of Quark Gluon Plasma at RHIC

    SciTech Connect

    Esumi, ShinIchi

    2010-05-12

    A new state of matter, Quark Gluon Plasma (QGP) is supposed to exist under extreme temperature and/or density conditions just as a beginning of this early universe after the Big Bang. High energy nucleus-nucleus collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) has been used to form the QGP and to study the properties of QGP. The recent progress on the experimental research of QGP at RHIC experiments and the understanding of the properties are discussed. Major discoveries at RHIC experiments are very strong energy loss of high energy partons in central Au+Au collisions and very large elliptic and collective expansion given by the initial almond geometry in non-central Au+Au collisions. Those two finding and related physics explanations as well as future plans are presented.

  5. Opportunities for Drell-Yan Physics at RHIC

    SciTech Connect

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

    2011-05-24

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

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

    SciTech Connect

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

    2011-10-01

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

  7. RHIC beam permit and quench detection communications system

    SciTech Connect

    Conkling, C.R. Jr.

    1997-07-01

    A beam permit module has been developed to concentrate RHIC, subsystem sensor outputs, permit beam, and initiate emergency shutdowns. The modules accept inputs from the vacuum, cryogenic, power supply, beam loss, and superconducting magnet quench detection systems. Modules are located at equipment locations around the RHIC ring. The modules are connected by three fiberoptic communications links; a beam permit link, and two magnet power supply interlock links. During operation, carrier presence allows beam. If a RHIC subsystem detects a fault, the beam permit carrier terminates - initiating a beam dump. If the fault was a superconducting magnet quench, a power supply interlock carrier terminates - initiating an emergency magnet power dump. In addition, the master module triggers an event to cause remote sensors to log and hold data at the time-of-failure.

  8. LHC beam-beam compensation studies at RHIC

    SciTech Connect

    Fischer,W.; Abreu, N.; Calaga, R.; Robert-Demolaize, G.; Luo, Y.; Montag, C.

    2009-05-04

    Long-range and head-on beam-beam effects are expected to limit the LHC performance with design parameters. 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. To reduce the head-on beam-beam effect electron lenses were proposed for both the LHC and RHIC. We present the experimental long-range beam-beam program and report on head-on compensations studies at RHIC, which are based on simulations.

  9. Beam lifetime and limitations during low-energy RHIC operation

    SciTech Connect

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

    2011-03-28

    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.

  10. Spin tune dependence on closed orbit in RHIC

    SciTech Connect

    Ptitsyn, V.; Bai, M.; Roser, T.

    2010-05-23

    Polarized proton beams are accelerated in RHIC to 250 GeV energy with the help of Siberian Snakes. The pair of Siberian Snakes in each RHIC ring holds the design spin tune at 1/2 to avoid polarization loss during acceleration. However, in the presence of closed orbit errors, the actual spin tune can be shifted away from the exact 1/2 value. It leads to a corresponding shift of locations of higher-order ('snake') resonances and limits the available betatron tune space. The largest closed orbit effect on the spin tune comes from the horizontal orbit angle between the two snakes. During RHIC Run in 2009 dedicated measurements with polarized proton beams were taken to verify the dependence of the spin tune on the local orbits at the Snakes. The experimental results are presented along with the comparison with analytical predictions.

  11. BEAM-BASED SEXTUPOLE POLARITY VERIFICATION IN THE RHIC

    SciTech Connect

    LUO,Y.; SATOGATA, T.; CAMERON, P.; DELLAPENNA, A.; TRBOJEVIC, D.

    2007-06-25

    This article presents a beam-based method to check RHIC arc sextupole polarities using local horizontal orbit three-bumps at injection energy. We use 11 bumps in each arc, each covering two SFs (focusing sextupoles) and one SD (defocusing sextupole). If there are no wrong sextupole polarities, the tune shifts from bump to bump and the tune shift patterns from arc to arc should be similar. Wrong sextupole polarities can be easily identified from mismatched signs or amplitudes of tune shifts from bump to bump and/or from arc to arc. Tune shifts in both planes during this study were tracked with a high-resolution base-band tunemeter (BBQ) system. This method was successfully used to the sextupole polarity check in RHIC Blue and Yellow rings in the RHIC 2006 and 2007 runs.

  12. AN ENGINEERING SOLUTION TO THE RHIC BEAM ABORT KICKER UPGRADE.

    SciTech Connect

    ZHANG,W.ROSER,T.SANDBERG,J.TAN,Y.ET AL.

    2004-05-23

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is the world largest superconducting accelerator for nuclear energy research. Particle beams traveling in opposite directions in two accelerator rings, Blue and Yellow, collide at six interaction regions to create phenomena of the early universe. There are more than 1700 superconducting magnets and very sophisticate and delicate large detectors inside the RHIC tunnel. With high beam intensity and ultra high beam energy, an inadvertent loss of beam can result severe damage to the superconducting magnets and detectors. Beam abort kickers are used to remove beam safely from the ring. The large inductive load, high current capability, short beam gap, and high reliability are the challenging issues of this system design. With high intensity and high momentum beam operation, it is desirable to have all high voltage modulators located outside of RHIC tunnel. However, to generate 22 kA output current per modulator with fast rise time, a conventional low impedance PFN and matched transmission cable design can push the operation voltage easily into 100 kV range. The large quantity of high voltage pulse transmission cables required by conventional design is another difficult issue. Therefore, the existing system has all ten high voltage modulators located inside RHIC tunnel. More than a hundred plastic packaged mineral oil filled high voltage capacitors raise serious concerns of fire and smoking threats. Other issues, such as kicker misfire, device availability in the future, and inaccessibility during operation, also demand an engineering solution for the future upgrade. In this paper, we investigate an unconventional approach to meet the technical challenges of RHIC beam abort system. The proposed design has all modulators outside of the RHIC tunnel. It will transmit output pulse through high voltage cables. The modulators will utilize solid-state switches, and operate at a maximum voltage in 30 to

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

    SciTech Connect

    Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W.; Liko, D.; Cramer, J.; Prindle, D.; Trainor, T.; Braithwaite, W.

    1991-12-31

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

  14. RHIC local orbit control and power supply resolution

    SciTech Connect

    Satogata, T.

    2009-12-01

    Slow global orbit correction at store, running every 30-60 minutes, has been in place since RHIC Run-8. This correction should include tight orbit drift tolerances at the interaction point and collimators, as these are locations where orbit drift of a few hundred microns is observable in backgrounds and luminosity. Future improvements in low beta optics will only lower these tolerances. runfy09 attempts to control the collimator orbit with local three-bumps after global orbit corrections appeared to be limited by corrector power supply resolution. This paper evaluates orbit control in the context of existing corrector power supply resolution, and makes recommendations for planned RHIC operations scenarios.

  15. The PHOBOS experiment at RHIC - physics and capabilities.

    SciTech Connect

    Back, B. B.

    1998-11-17

    The PHOBOS experiment at RHIC is designed to study multiplicity distributions and fluctuations over all of 4{pi}, as well as particle spectra and correlations at mid rapidity, with a particular emphasis on physics at low p{sub T}. The experiment is relatively small and relies almost entirely on silicon pad detector technology. The flexibility of the design, the conservative nature of the technologies used, and the ability to take data at high rates place the experiment in a good position to search for exotic physics from heavy-ion collisions at the early stages of RHIC operations.

  16. Beam-beam collisions and crossing angles in RHIC

    SciTech Connect

    Peggs, S.

    1999-06-01

    This paper evaluates the strength of head on and parasitic beam-beam collisions in RHIC when the crossing angle is zero. A non-zero crossing angle is not required in normal operation with 120 bunches, thanks to the early separation of the two beams. The RHIC lattice is shown to easily accommodate even conservatively large crossing angles, for example in beam dynamics studies, or in future operational upgrades to as many as 360 bunches per ring. A modest loss in luminosity is incurred when gold ions collide at an angle after 10 hours of storage.

  17. Overview of magnetic nonlinear beam dynamics in the RHIC

    SciTech Connect

    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.

    2009-05-04

    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.

  18. SUMMARY OF BEAM BEAM OBSERVATIONS DURING STORES IN RHIC.

    SciTech Connect

    FISCHER,W.

    2003-05-19

    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.

  19. Study of orbit correction for eRHIC FFAG design

    SciTech Connect

    Liu, C.; Hao, Y.; Litvinenko, V.; Meot, F.; Minty, M.; Ptitsyn, V.; Trbojevic, D.

    2015-05-03

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

  20. Experimental overview on small colliding systems at RHIC

    NASA Astrophysics Data System (ADS)

    Stankus, Paul

    2016-12-01

    Beginning with the observation of ridge/flow-like features in pair correlations measurements in p+Pb, d+Au and high-density p+p events at RHIC and LHC, the last few years have seen a great surge of interest in the question of whether anything like a hot, locally-equilibrated QCD medium is formed in the small systems at collider energies. Many intriguing and suggestive results have been presented, but conclusions about medium formation must be approached with care. This presentation will attempt to summarize the experimental results from small colliding systems measured at RHIC, as part of a careful and objective evaluation of this question.

  1. RHIC electron lens beam transport system design considerations

    SciTech Connect

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

    2010-10-01

    To apply head-on beam-beam compensation for RHIC, two electron lenses are designed and will be installed at IP10. Electron beam transport system is one of important subsystem, which is used to transport electron beam from electron gun side to collector side. This system should be able to change beam size inside superconducting magnet and control beam position with 5 mm in horizontal and vertical plane. Some other design considerations for this beam transport system are also reported in this paper. The head-on beam-beam effect is one of important nonlinear source in storage ring and linear colliders, which have limited the luminosity improvement of many colliders, such as SppS, Tevatron and RHIC. In order to enhance the performance of colliders, beam-beam effects can be compensated with direct space charge compensation, indirect space charge compensation or betatron phase cancellation scheme. Like other colliders, indirect space charge compensation scheme (Electron Lens) was also proposed for Relativistic Heavy Ion Collider (RHIC) beam-beam compensation at Brookhaven National Laboratory. The two similar electron lenses are located in IR10 between the DX magnets. One RHIC electron lens consists of one DC electron gun, one superconducting magnet, one electron collector and beam transport system.

  2. Measurement of HOMs in the RHIC RF Cavities

    SciTech Connect

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

    2009-01-07

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

  3. Beam experiments towards high-intensity beams in RHIC

    SciTech Connect

    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.

    2012-05-20

    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.

  4. Analysis and correction of vertical dispersion in RHIC

    SciTech Connect

    Liu, C.; Minty, M.

    2011-09-14

    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.

  5. Helical dipole magnets for polarized protons in RHIC

    SciTech Connect

    Syphers, M.; Courant, E.; Fischer, W.

    1997-07-01

    Superconducting helical dipole magnets will be used in the Brookhaven Relativistic Heavy Ion Collider (RHIC) to maintain polarization of proton beams and to perform localized spin rotations at the two major experimental detector regions. Requirements for the helical dipole system are discussed, and magnet prototype work is reported.

  6. Probing the Nucleus with Deuteron+Gold Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Citron, Zvi Hirsh

    2011-12-01

    The Relativistic Heavy Ion Collider (RHIC) was built to produce and study Quark Gluon Plasma (QGP), the phase of matter thought to exist under conditions sufficiently hot and dense to create a medium in which the degrees of freedom are quarks and gluons rather than color neutral hadrons. Already in its early years of running, the data from RHIC provided tantalizing evidence of QGP signatures in Au+Au collisions at sNN = 200 GeV. A crucial part of understanding the putative QGP in Au+Au collisions is to have both a well understood reference as well as a robust control experiment. Proton-proton collisions at the same sNN serve as the baseline for heavy ion collisions at RHIC, and play an invaluable role in setting our frame of reference in interactions that do not create any nuclear medium. For the control experiment, RHIC's ability to collide asymmetric beams is utilized and d+Au collisions are used. Unlike p+p collisions, in the d+Au system there is a nuclear medium present---the heavy Au nucleus---and so we may study this system to distinguish initial state cold nuclear matter effects from final state effects that occur in the hot dense medium of Au+Au collisions. Beyond its use as a control experiment, the d+Au collision system presents the opportunity for important study of nuclear and nucleonic structure, it is after all necessary for our colored parton theory to operate in the nucleus as well as in a QGP. Deuteron - gold collisions at RHIC are a powerful tool for shedding light on cold nuclear matter effects. This thesis describes two analyses of d+Au collisions measured by the PHENIX experiment at RHIC. The first is a measurement of the midrapidity yield of unidentified charged hadrons in the 2003 RHIC run. This is used a key baseline for understanding particle production in Au+Au collisions as well as a detailed look at the Cronin effect. The second analysis measures rapidity separated two-particle production where one of the particles is at either forward

  7. PHYSICS OF POLARITY AT RHIC-VOLUME 10.

    SciTech Connect

    IMAI,K.; FIELDS,D.

    1998-08-04

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

  8. Commissioning HVAC systems

    SciTech Connect

    Schiess, K.

    1995-12-01

    In recent years, commissioning has been viewed as a separate process that had to be specified and implemented by a specialized entity. This article discusses commissioning in the HVAC field and looks at it from an international perspective. The author has worked in Europe, South Africa (British system) and the USA. The differences between the British and the American methods of commissioning are discussed, with examples given where the American way was unsuccessful. It is the design engineer`s job to test and accept (commission) an installation after the contractor has demonstrated the performance to the satisfaction of the design engineer. Once the plant is commissioned, it is put into service.

  9. 77 FR 70204 - Commission Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... From the Federal Register Online via the Government Publishing Office SUSQUEHANNA RIVER BASIN COMMISSION Commission Meeting AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold its regular business meeting on December 14, 2012, in...

  10. 78 FR 12412 - Commission Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-22

    ... From the Federal Register Online via the Government Publishing Office ] SUSQUEHANNA RIVER BASIN COMMISSION Commission Meeting AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold its regular business meeting on March 21, 2013, in...

  11. 78 FR 32295 - Commission Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... From the Federal Register Online via the Government Publishing Office SUSQUEHANNA RIVER BASIN COMMISSION Commission Meeting AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold its regular business meeting on June 20, 2013, in...

  12. RHIC injector complex online model status and plans

    SciTech Connect

    Schoefer,V.; Ahrens, L.; Brown, K.; Morris, J.; Nemesure, S.

    2009-05-04

    An online modeling system is being developed for the RHIC injector complex, which consists of the Booster, the AGS and the transfer lines connecting the Booster to the AGS and the AGS to RHIC. Historically the injectors have been operated using static values from design specifications or offline model runs, but tighter beam optics constraints required by polarized proton operations (e.g, accelerating with near-integer tunes) have necessitated a more dynamic system. An online model server for the AGS has been implemented using MAD-X [1] as the model engine, with plans to extend the system to the Booster and the injector transfer lines and to add the option of calculating optics using the Polymorphic Tracking Code (PTC [2]) as the model engine.

  13. Polarized Proton Collisions at 205GeV at RHIC

    NASA Astrophysics Data System (ADS)

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

    2006-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

  14. Helical Dipole Magnets for Polarized Protons in RHIC

    NASA Astrophysics Data System (ADS)

    Syphers, M.; Courant, E.; Fischer, W.; Luccio, A.; Mariam, F.; Peggs, S.; Pilat, F.; Roser, T.; Tepikian, S.; Tsoupas, N.; Willen, E.; Katayama, T.; Hatanaka, K.; Kawaguchi, T.; Okamura, M.; Tominaka, T.; Wu, H.; Ptitsin, V.; Shatunov, Y.

    1997-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) will be able to support experiments using polarized proton beams. Siberian Snakes are used to maintain polarization in this high energy superconducting collider. To make efficient use of available space while taking advantage of high field superconducting magnets, 4 Tesla helical dipole magnets will be used. These magnets generate a central dipole field in which the field direction rotates through 360^circ about the longitudinal axis over the length of the device. An arrangement of four such magnets can produce the desired change in the spin direction while keeping the proton orbit outside of the ``Snake'' unaltered. Similar magnet arrangements will be used to produce longitudinal polarization at the two major interaction points in RHIC. The basic requirements and layout of these magnets are described, as well as tolerances on field quality and integrated field strengths. First results of tests of prototype helical magnets will be discussed.

  15. LUMINOSITY OPTIMIZATION USING AUTOMATED IR STEERING AT RHIC.

    SciTech Connect

    DREES,A.D'OTTAVIO,T.

    2004-07-05

    The goal of the RHIC 2004 Au-Au run was to maximize the achieved integrated luminosity. One way is to increase beam currents and minimize beam transverse emittances. Another important ingredient is the minimization of time spent on activities postponing the declaration of ''physics conditions'', i.e. stable beam conditions allowing the experimental detectors to take data. Since collision rates are particularly high in the beginning of the store the integrated luminosity benefits considerably from any minute saved early in the store. In the RHIC run 2004 a new IR steering application uses luminosity monitor signals as a feedback for a fully automated steering procedure. This report gives an overview of the used procedure and summarizes the achieved results.

  16. Intra-beam Scattering Theory and RHIC Experiments

    SciTech Connect

    Wei, J.; Fedotov, A.; Fischer, W.; Malitsky, N.; Parzen, G.; Qiang, J.

    2005-06-08

    Intra-beam scattering is the leading mechanism limiting the luminosity in heavy-ion storage rings like the Relativistic Heavy Ion Collider (RHIC). The multiple Coulomb scattering among the charged particles causes transverse emittance growth and longitudinal beam de-bunching and beam loss, compromising machine performance during collision. Theoretically, the original theories developed by Piwinski, Bjorken, and Mtingwa only describe the rms beam size growth of an unbounded Gaussian distribution. Equations based on the Fokker-Planck approach are developed to further describe the beam density profile evolution and beam loss. During the 2004 RHIC heavy-ion operation, dedicated IBS experiments were performed to bench-mark the rms beam size growth, beam loss, and profile evolution both for a Gaussian-like and a longitudinal hollow beam. This paper summarizes the IBS theory and discusses the experimental bench-marking results.

  17. Multigap RPCs in the STAR experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Llope, W. J.; STAR Collaboration

    2012-01-01

    A large-area (50 m2) Time-of-Flight system has recently been installed in the STAR experiment at RHIC. The detectors are Multigap Resistive Plate Chambers (MRPCs) and are digitized using custom electronics based on the CERN “NINO” and “HPTDC” chips. Several different prototype systems were built and operated in STAR from 2002 to 2006. The design and performance of the prototypes and the ˜70% installed final system during the 2009 RHIC Run will be presented. A possible future upgrade to the STAR experiment is the Muon Telescope Detector (MTD). This system will use very large MRPCs with double-ended read-out to identify via time of flight the muons that pass through steel back-legs of the STAR magnet. The design of this system and the performance of MTD prototype systems will also be presented.

  18. RHIC D0 INSERTION DIPOLE DESIGN ITERATIONS DURING PRODUCTION.

    SciTech Connect

    SCHMALZLE,J.; ANERELLA,M.; GANETIS,G.; GHOSH,A.; GUPTA,R.; JAIN,A.; KAHN,S.; MORGAN,G.; MURATORE,J.; SAMPSON,W.; WANDERER,P.; WILLEN,E.

    1997-05-12

    Iterations to the cross section of the Relativistic Heavy Ion Collider (RHIC) D0 Insertion Dipole magnets were made during the production. This was included as part of the production plan because no R&D or pre-production magnets were built prior to the start of production. The first magnet produced had the desired coil pre-stress and low field harmonics in the body of the magnet and is therefore being used in the RHIC Machine. On the first eight magnets, iterations were carried out to minimize the iron saturation and to compensate for the end harmonics. This paper will discuss the details of the iterations made, the obstacles encountered, and the results obtained. Also included will be a brief summary of the magnet design and performance.

  19. Reduction of beta* and increase of luminosity at RHIC

    SciTech Connect

    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.

    2009-05-04

    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.

  20. OPTIMIZATION OF THE PHASE ADVANCE BETWEEN RHIC INTERACTION POINTS.

    SciTech Connect

    TOMAS, R.; FISCHER, W.

    2005-05-16

    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.

  1. Matter in extremis: Ultrarelativistic nuclear collisions at RHIC

    SciTech Connect

    Jacobs, Peter; Wang, Xin-Nian

    2004-08-20

    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.

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

    SciTech Connect

    Minty, M.; Connolly, R; Liu, C.; Summers, T.; Tepikian, S.

    2014-08-15

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

  3. Polarized proton collisions at 205 GeV at RHIC.

    PubMed

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

    2006-05-05

    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.

  4. SETUP AND PERFORMANCE OF THE RHIC INJECTOR ACCELERATORS FOR THE 2007 RUN WITH GOLD IONS

    SciTech Connect

    GARDNER,C.; AHRENS, L.; ALESSI, J.; BENJAMIN, J.; BLASKIEWICZ, M.; ET AL.

    2007-06-25

    Gold ions for the 2007 run of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of this chain of accelerators is reviewed with a focus on improvements in the quality of beam delivered to RHIC. In particular, more uniform stripping foils between Booster and AGS7 and a new bunch merging scheme in AGS have provided beam bunches with reduced longitudinal emittance for RHIC.

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

    SciTech Connect

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

    2003-05-12

    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].

  6. Calirimeter/absorber optimization for a RHIC dimuon experiment

    SciTech Connect

    Aronson, S.H.; Murtagh, M.J.; Starks, M.; Liu, X.T.; Petitt, G.A.; Zhang, Z.; Ewell, L.A.; Hill, J.C.; Wohn, F.K.; Costales, J.B.; Namboodiri, M.N., Sangster, T.C.; Thomas, J.H.; Gavron, A.; Waters, L.; Kehoe, W.L.; Steadman, S.G.; Awes, T.C.; Obenshain, F.E.; Saini, S.; Young, G.R.; Chang, J.; Fung, S.Y.; Kang, J.H.; Kreke, J.; He, Xiaochun, Sorensen, S.P.; Cornell, E.C.; Maguire, C.F.

    1991-12-31

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

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

    SciTech Connect

    Alley, G.T.; Britton, C.L. Jr.; Kennedy, E.J.; Newport, D.F.; Wintenberg, A.L.; Young, G.R.

    1991-12-31

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

  8. Frequency choice of eRHIC SRF linac

    SciTech Connect

    Xu, W.; Ben-Zvi, I.; Roser, T.; Ptitsyn, V.

    2016-01-05

    eRHIC is a FFAG lattice based multipass ERL [1]. The eRHIC SRF linac has been decided to change from 422 MHz 5-cell cavity to 647 MHz 5-cell cavity. There are several considerations affecting the frequency choice for a high current multipass-ERL: the beam structure, bunch length, energy spread, beam-break-up (BBU) threshold, SRF loss considerations. Beyond the physics considerations, cost and complexity or risk is an important consideration for the frequency choice, especially when we are designing a machine to be built in a few years. Although there are some benefits of using a 422 MHz cavity for eRHIC ERL, however, there are some very critical drawbacks, including lack of facilities to fabricate a 422 MHz 5-cell cavity, very few facilities to process such a cavity and no existing facility to test the cavity anywhere. As the cavity size is big and its weight is large, it is difficult to handle it during fabrication, processing and testing and no one has experience in this area. As the cavity size is large, the cryomodule becomes big as well. All of these considerations drive the risk of building eRHIC ERL with 422 MHz cavities to a very high level. Therefore, a decision was made to change the frequency of main linac to be 647 MHz 5-cell cavities. This note will compare these two linacs: 422MHz 5-cell cavity linac and 647Mz 5-cell cavity SRF linac, from both practical point of view and physics point of view.

  9. QCD Predictions for Charm and Bottom Production at RHIC

    SciTech Connect

    Cacciari, Matteo; Nason, Paolo; Vogt, Ramona

    2005-09-01

    We make up-to-date QCD predictions for open charm and bottom production at RHIC in nucleon-nucleon collisions at {radical}S = 200 GeV. We also calculate the electron spectrum resulting from heavy flavor decays to allow direct comparison to the data. A rigorous benchmark, including the theoretical uncertainties, is established against which nuclear collision data can be compared to obtain evidence for nuclear effects.

  10. RHIC electron lens beam transport system design considerations

    SciTech Connect

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

    2010-08-03

    To apply head-on beam-beam compensation for RHIC, two electron lenses are designed and will be installed at IP6 and IP8. Each electron lens has several sub-systems, including electron gun, electron collector, superconducting main solenoid (SM), diagnostics system and power supply system. In addition to these systems, beam transport system which can transport electron beam from electron gun side to collector side is also needed.

  11. Simulations of Gaussian electron guns for RHIC electron lens

    SciTech Connect

    Pikin, A.

    2014-02-28

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

  12. LINEAR OPTICS DURING THE RHIC 2001 - 2 RUN.

    SciTech Connect

    SATOGATA,T.; CARDONA,J.; PTITSYN,V.; TEPIKIAN,S.; VAN ZEIJTS,J.

    2002-06-02

    The RHIC 2001-2 Au and polarized proton runs used several different low-beta optics configurations. Low-beta squeezes were routinely performed through the Au acceleration ramp to optimize injection and transition optics; the polarized proton run injected and accelerated with constant low-beta optics to optimize polarization preservation. This paper summarizes tools, methods and results for linear optics measurement and correction during these runs as well as future plans.

  13. NON-LINEAR MODELING OF THE RHIC INTERACTION REGIONS.

    SciTech Connect

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

    2004-07-05

    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.

  14. Guidelines for residential commissioning

    SciTech Connect

    Wray, Craig P.; Walker, Iain S.; Sherman, Max H.

    2003-01-31

    Currently, houses do not perform optimally or even as many codes and forecasts predict, largely because they are field assembled and there is no consistent process to identify problems or to correct them. Residential commissioning is a solution to this problem. This guide is the culmination of a 30-month project that began in September 1999. The ultimate objective of the project is to increase the number of houses that undergo commissioning, which will improve the quality, comfort, and safety of homes for California citizens. The project goal is to lay the groundwork for a residential commissioning industry in California focused on end-use energy and non-energy issues. As such, we intend this guide to be a beginning and not an end. Our intent is that the guide will lead to the programmatic integration of commissioning with other building industry processes, which in turn will provide more value to a single site visit for people such as home energy auditors and raters, home inspectors, and building performance contractors. Project work to support the development of this guide includes: a literature review and annotated bibliography, which facilitates access to 469 documents related to residential commissioning published over the past 20 years (Wray et al. 2000), an analysis of the potential benefits one can realistically expect from commissioning new and existing California houses (Matson et al. 2002), and an assessment of 107 diagnostic tools for evaluating residential commissioning metrics (Wray et al. 2002). In this guide, we describe the issues that non-experts should consider in developing a commissioning program to achieve the benefits we have identified. We do this by providing specific recommendations about: how to structure the commissioning process, which diagnostics to use, and how to use them to commission new and existing houses. Using examples, we also demonstrate the potential benefits of applying the recommended whole-house commissioning approach to

  15. Future Physics Opportunities in Beam Energy Scan at RHIC

    NASA Astrophysics Data System (ADS)

    Xu, Nu

    2015-10-01

    In the first phase of the beam energy scan program (BES-I) at RHIC, we have collected data from Au +Au collisions at the center of mass energy range from 7.7 GeV to 39 GeV, corresponding to the baryonic chemical potential of 420 MeV to 120 MeV, respectively. We have observed the disappearance of the suppression of leading hadrons at large pT, break down of the quark scaling in the identified particle elliptic flow, the net-proton directed flow slope dv1/dy shows a minimum with negative sign, and a non-monotonical behavior of the net-proton correlation function (the fourth order) at the energy less than 20 GeV. All of these observations indicate that the property of the medium at high baryon density is dramatically different from that created at the RHIC top energy where the baryon density is small and partonic interactions are dominant. In this talk I will first review what we have learned in RHIC BES-I. Then I will discuss the opportunities in the future bean energy scan program in order to address key questions regarding the QCD phase structure including the illusive critical point. I will stress that adequate detector upgrades, focused at the large baryon density region, are essential for the physics program.

  16. DESIGN OF AN AC-DIPOLE FOR USE IN RHIC.

    SciTech Connect

    PARKER,B.; BAI,M.; JAIN,A.; MCINTYRE,G.; METH,M.; PEGGS,S.; ROSER,T.; SANDERS,R.; TRBOJEVIC,D.

    1999-03-29

    We present two options for implementing a pair of AC-dipoles in RHIC for spin flipping, measuring linear optical functions and nonlinear diagnostics. AC-dipoles are magnets that can be adiabatically excited and de-excited with a continuous sine-wave in order to coherently move circulating beam out to large betatron amplitudes without incurring emittance blow up [1]. The AGS already uses a similar device for getting polarized proton beams through depolarizing resonances [2]. By placing the magnets in the IP4 common beam region, two AC-dipoles are sufficient to excite both horizontal and vertical motion in both RHIC rings. While we initially investigated an iron-dominated magnet design using available steel tape cores; we now favor a new air coil plus ferrite design featuring mechanical frequency tuning, in order to best match available resources to demanding frequency sweeping requirements. Both magnet designs are presented here along with model magnet test results. The challenge is to make AC-dipoles available for year 2000 RHIC running.

  17. Modeling the Hydrodynamical Properties of the QGP at RHIC

    NASA Astrophysics Data System (ADS)

    Garishvili, Irakli; Soltz, Ron; Pratt, Scott; Cheng, Micael; Glenn, Andrew; Newby, Jason; Linden-Levy, Loren; Abelev, Betty

    2010-11-01

    Comparisons of the RHIC data to various theoretical models suggest that the evolution of the QGP, a state of matter believed to be created in early stages of heavy ion collisions at RHIC, is qualitatively well described by hydrodynamics. However, the key properties of the QGP, such as initial temperature, Tinit, and the ratio of shear viscosity to entropy density of matter, η/s, are not precisely known. To constrain these properties we have developed a multi-stage hydrodynamics/hadron cascade model of heavy ion collisions which incorporates Glauber initial state conditions, pre-equilibrium flow, the UVH2+1 viscous hydro model, Cooper-Frye freezeout, and the UrQMD hadronic cascade model. To test the sensitivity of the observables to the equation of state (EoS), we use several different EoS in the hydrodynamic evolution, including those derived from the hadron resonance gas model and lattice QCD. This framework has an ability to predict key QGP observables, such as, elliptic flow, spectra, and HBT radii for various particle species. For each set of model's input parameters (Tinit, η/s and initial flow) we perform a simultaneous comparison to spectra, elliptic flow, and HBT measured at RHIC. Based on this analysis the determinations of Tinit and η/s will be presented.

  18. SDRC I-DEAS and RHIC (Relativistic Heavy Ion Collider)

    SciTech Connect

    Goggin, C.M.

    1989-01-01

    In August 1984, Brookhaven National Laboratory submitted a proposal to the Department of Energy (DOE) for the construction of a Relativistic Heavy Ion Collider (RHIC). Since then funding has continued for the detailed design of RHIC. The hardware for RHIC consists of two concentric rings of superconducting magnets in a 2.4 mile circumference with six intersections. Bunches of ions will travel in opposite directions in each of the two rings and eventually collide head on at one of the six intersections. The hardware design involves complicated facilities for liquid helium cryogens, cryostat design, and pipe systems. The greatest challenge however is the ion beam position relative to the geometric center of the rings. There are three hundred and seventy-two dipole magnets that are ten meters long and weigh 4300 Kg (4.5 tons) each. Each dipole must be positioned in the ring to {plus minus} 0.5 mm. In addition, there are four hundred and ninety-two quadrupole magnets that must be positioned to {plus minus} 0.1 mm which is a total position error. This total position error includes all the surveying and part tolerance. To accomplish this task requires detailed planning and design of the cryostats which contain each magnet and the tunnel assembly throughout the 2.4 mile circumference. The IDEAS' software package provides a way to analyze this large scale problem. 11 figs.

  19. PROCESSING AND ANALYSIS OF THE MEASURED ALIGNMENT ERRORS FOR RHIC.

    SciTech Connect

    PILAT,F.; HEMMER,M.; PTITSIN,V.; TEPIKIAN,S.; TRBOJEVIC,D.

    1999-03-29

    All elements of the Relativistic Heavy Ion Collider (RHIC) have been installed in ideal survey locations, which are defined as the optimum locations of the fiducials with respect to the positions generated by the design. The alignment process included the presurvey of all elements which could affect the beams. During this procedure a special attention was paid to the precise determination of the quadrupole centers as well as the roll angles of the quadrupoles and dipoles. After installation the machine has been surveyed and the resulting as-built measured position of the fiducials have been stored and structured in the survey database. We describe how the alignment errors, inferred by comparison of ideal and as-built data, have been processed and analyzed by including them in the RHIC modeling software. The RHIC model, which also includes individual measured errors for all magnets in the machine and is automatically generated from databases, allows the study of the impact of the measured alignment errors on the machine.

  20. Potential for luminosity improvement for low-energy RHIC operation

    SciTech Connect

    Fedotov A. V.

    2012-05-20

    At the Brookhaven National Laboratory, a physics program, motivated by the search of the QCD phase transition critical point, requires operation of the Relativistic Heavy Ion Collider (RHIC) with heavy ions at very low beam energies corresponding to 2.5-20 GeV/n. Several physics runs were already successfully performed at these low energies. However, the luminosity is very low at lowest energies of interest (< 10 GeV/n) limited by the intra-beam scattering and space-charge, as well as by machine nonlinearities. At these low energies, electron cooling could be very effective in counteracting luminosity degradation due to the IBS, while it is less effective against other limitations. Overall potential luminosity improvement for low-energy RHIC operation from cooling is summarized for various energies, taking into account all these limitations as well as beam lifetime measured during the low-energy RHIC runs. We also explore a possibility of further luminosity improvement under the space-charge limitation.

  1. Quadrupole beam-based alignment in the RHIC interaction regions

    SciTech Connect

    Ziegler, J.; Satogata, T.

    2011-03-28

    Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements. BBA data has been collected over the past two runs for all three of the active experimental IRs at RHIC, updating results from the 2005 run which were taken with incorrectly installed offsets. The technique was successfully applied to expose a systematic misuse of the BPM survey offsets in the control system. This is likely to benefit polarized proton operations as polarization transmission through acceleration ramps depends on RMS orbit control in the arcs, but a quantitative understanding of its impact is still under active investigation. Data taking is ongoing as are refinements to the BBA technique aimed at reducing systematic errors and properly accounting for dispersive effects. Further development may focus on non-triplet BPMs such as those located near snakes, or arc quadrupoles that do not have individually shunted power supplies (a prerequisite for the current method) and as such, will require a modified procedure.

  2. The Building Commissioning Handbook.

    ERIC Educational Resources Information Center

    Heinz, John A.; Casault, Rick

    This book discusses building commissioning, which is the process of certifying that a new facility meets the required specifications. As buildings have become more complex, the traditional methods for building start-up and final acceptance have been proven inadequate, and building commissioning has been developed, which often necessitates the use…

  3. Commissioning of HVAC systems

    SciTech Connect

    Schiess, K.

    1995-06-01

    In recent years various presentation and discussions have taken place which looked at commissioning as a separate process that had to be specified and implemented by a specialized entity in a project. This presentation discusses commissioning in the HVAC field and looks at it from an international perspective. The author has worked in Europe, South Africa (British system) and in the USA. The differences are discussed between the British and the American methods with some examples where the American way of commissioning was unsuccessful. The conclusion is that it is the design engineer`s job to test and accept (commission) an installation after the contractor has demonstrated the performance to the satisfaction of the design engineer. Once the plant is commissioned, it is put into service.

  4. SETUP AND PERFORMANCE OF THE RHIC INJECTOR ACCELERATORS FOR THE 2005 RUN WITH COPPER IONS.

    SciTech Connect

    AHRENS, L.; ALESSI, J.; GARDNER, C.J.

    2005-05-16

    Copper ions for the 2005 run [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of these accelerators with copper are reviewed in this paper.

  5. State Emergency Response Commissions

    EPA Pesticide Factsheets

    The Governor of each state has designated a State Emergency Response Commission (SERC) that is responsible for implementing the Emergency Planning and Community Right-to-Know Act (EPCRA) provisions within its state.

  6. Nuclear Regulatory Commission issuances

    SciTech Connect

    Not Available

    1994-03-01

    This report includes the issuances received during the specified period from Commission (CLI), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judges (ALJ), the Directors` Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

  7. Nuclear Regulatory Commission Issuances

    SciTech Connect

    1996-12-01

    This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judges (ALJ), the Directors Decisions (DD), and the Decisions on Petitions for Rulemaking (DPRM).

  8. Commissioning the LCLS Injector

    SciTech Connect

    Akre, R.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Iverson, R.; Limborg-Deprey, C.; Loos, H.; Miahnahri, A.; Schmerge, J.; Turner, J.; Welch, J.; White, W.; Wu, J.; /SLAC

    2007-11-28

    The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) project presently under construction at SLAC. The injector section, from drive laser and RF photocathode gun through first bunch compressor chicane, was installed in fall 2006. Initial system commissioning with an electron beam was completed in August 2007, with the goal of a 1.2-micron emittance in a 1-nC bunch clearly demonstrated. The second phase of commissioning, including second bunch compressor and full linac, is planned for 2008, with FEL commissioning in 2009. We report experimental results and experience gained in the first phase of commissioning, including the photo-cathode drive laser, RF gun, photocathode, S-band and X-band RF systems, first bunch compressor, and the various beam diagnostics.

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

    SciTech Connect

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

    2009-08-31

    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.

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

    SciTech Connect

    Tsoupas, N.; Hahn, H.; Meng, W.; Severance, Michael; McMahan, Brandon

    2014-08-26

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

  11. Commission 51: Bioastronomy

    NASA Astrophysics Data System (ADS)

    Irvine, William; Ehrenfreund, Pascale; Boss, Alan; Cosmovici, Cristiano; Kwok, Sun; Levasseur-Regourd, Anny-Chantal; Morrison, David; Udry, Stephane

    2010-05-01

    Commission 51 met on August 12, 2009. Outgoing President Alan Boss chaired the meeting, and there were several dozen members present, including incoming President William Irvine, incoming Vice President Pascale Ehrenfreund, and outgoing Past President Karen Meech. Commission 51 (C51) was re-authorized for a term of six more years at the 2006 Prague General Assembly of the IAU, and hence comes up for renewal at the 2012 IAU General Assembly in Beijing, China.

  12. SPEAR3 Commissioning

    SciTech Connect

    Harkay, K.; Sajaev, V.; Boland, M.J.; Tan, Y.E.; Krinsky, S.; Podobedov, B.; Decking, W.; Ropert, A.; Byrd, J.M.; Robin, D.; Scarvie, T.; Steier, C.; Fedurin, M.G.; Jines, P.; Chang, H.-P.; Kuo, C.-C.; Tsai, H.-J.; Yoon, M.H.; Boge, M.; Allison, S.; Bellomo, P.; /SLAC, SSRL /SOLEIL, Saint-Aubin

    2005-05-09

    The successful commissioning of the new SPEAR3 light source at the Stanford Synchrotron Radiation Laboratory (SSRL) will be reviewed. Orbit control, beam-based alignment, and an orbit interlock were commissioned. Orbit motion was characterized as a function of frequency. The linear optics was corrected for ID focusing and coupling errors. The nonlinear optics were investigated with dynamic aperture measurements as a function of energy and tune.

  13. Detectors for low energy electron cooling in RHIC

    SciTech Connect

    Carlier, F. S.

    2016-02-15

    Low energy operation of RHIC is of particular interest to study the location of a possible critical point in the QCD phase diagram. The performance of RHIC at energies equal to or lower than 10 GV/nucleon is limited by nonlinearities, Intra-BeamScattering (IBS) processes and space-charge effects. To successfully address the luminosity and ion store lifetime limitations imposed by IBS the method of electron cooling has been envisaged. During electron cooling processes electrons are injected along with the ion beam at the nominal ion bunch velocities. The velocity spread of the ion beam is reduced in all planes through Coulomb interactions between the cold electron beam and the ion beam. The electron cooling system proposed for RHIC will be the first of its kind to use bunched beams for the delivery of the electron bunches, and will therefore be accompanied by the necessary challenges. The designed electron cooler will be located in IP2. The electron bunches will be accelerated by a linac before being injected along side the ion beams. Thirty consecutive electron bunches will be injected to overlap with a single ion bunch. They will first cool the yellow beam before being extracted turned by 180-degrees and reinjected into the blue beam for cooling. As such, both the yellow and blue beams will be cooled by the same ion bunches. This will pose considerable challenges to ensure proper electron beam quality to cool the second ion beam. Furthermore, no ondulator will be used in the electron cooler so radiative recombination between the ions and the electrons will occur.

  14. Recent results on Quarkonium production from LHC and RHIC

    NASA Astrophysics Data System (ADS)

    Scomparin, Enrico

    2016-03-01

    The study of quarkonium production in nuclear collisions at ultrarelativistic energies is a crucial tool for the determination of the properties of the Quark-Gluon Plasma (QGP) created in such collisions. After a pioneering phase at the CERN SPS, a large amount of results were obtained at the RHIC collider, at a center of mass energy per nucleon-nucleon collisions √{sNN} = 0 . 2 TeV and, more recently, at the LHC at √{sNN} = 2 . 76 TeV. In a QGP, the binding of the heavy quark pair (either c c or b b) that forms the quarkonium states is screened by the high density of surrounding color charges, leading to a suppression of the yield of such states. At the same time, re-combination processes involving the heavy quarks may lead to a re-generation of the quarkonia that partly counterbalances their suppression. Ultimately, these studies can provide information on the temperature of the QGP and on its degree of thermalization. In this talk, after an introduction of the main physics concepts, I will review recent experimental results obtained at RHIC and LHC in the study of c c (J/ Ψ and Ψ (2 S)) and b b (Γ (1 S) , Γ (2 S) and Γ (3 S)) states. Most results refer to Au-Au (at RHIC) and Pb-Pb collisions (at LHC), but also heavier (U-U) and lighter (Cu-Cu) systems were investigated as well. Prospects for future studies, and in particular first results, if available, from the LHC Run 2 at √{sNN} = 5 . 02 TeV, will also be discussed.

  15. Study of beam-beam effects in eRHIC

    SciTech Connect

    Hao, Y.; Litvinenko, V.; Ptitsyn, V.

    2010-05-23

    Beam-beam effects in eRHIC have a number of unique features, which distinguish them from both hadron and lepton colliders. Due to beam-beam interaction, both electron and hadron beams would suffer quality degradation or beam loss from without proper treatments. Those features need novel study and dedicate countermeasures. We study the beam dynamics and resulting luminosity of the characteristics, including mismatch, disruption and pinch effects on electron beam, in additional to their consequences on the opposing beam as a wake field and other incoherent effects of hadron beam. We also carry out countermeasures to prevent beam quality degrade and coherent instability.

  16. First results from the PHOBOS experiment at RHIC.

    SciTech Connect

    Wuosmaa, A. H.; Back, B. B.; Baker, M. D.; Barton, D. S.; Basilev, S.; Betts, B. B.; PHOBOS Collaboration

    2000-10-02

    The PHOBOS experiment at RHIC has measured the charged-particle density dN/d{eta} at mid-rapidity for central Au+Au collisions at center of mass energies of {radical}s{sub NN} = 56, and 130 GeV. We deduce that dN/d{eta} = 408 {+-} 12(stat) {+-}30(syst) and 555 {+-} 12(stat) {+-} 35(syst) for collision energies of 56, and 130, GeV, respectively. These numbers suggest energy densities that are some 70% higher than have been achieved in any heavy-ion collisions previously studied, and also 25-40% higher than nucleon-nucleon collisions at comparable center of mass energies.

  17. Experimental background due to particle induced gas desorption in RHIC

    SciTech Connect

    Zhang,S.Y.; Trbojevic, D.

    2008-08-10

    Beam-gas collision created experimental background, i.e., singles, has affected heavy ion and polarized proton operations in Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The gas molecules in interaction region are mainly caused by the electron induced gas desorption. and the electrons are produced from the beam induced electron multipacting, or called electron cloud. The background has a dependence on the usual electron cloud related parameters, such as the bunch intensity, bunch spacing, and the solenoid field. With the RHIC upgrade plan, the experimental background may become a luminosity limiting factor. Mitigations are discussed.

  18. Elliptic flow in Au+Au collisions at RHIC.

    SciTech Connect

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; George, N.; Wuosmaa, A.; Physics; Massachusetts Inst. of Tech.; BNL; Univ. of Illinois at Chicago

    2005-01-01

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

  19. Alignment and survey of the elements in RHIC

    SciTech Connect

    Trbojevic, D.; Cameron, P.; Ganetis, G.L.

    1995-05-01

    The Relativistic Heavy Ion Collider (RHIC) consists of two rings with cryogenic magnets at a 4.5K operating temperature. Control of positions of the dipole and quadrupole cold masses (iron laminations) and the beam position monitors (BPM`s) during production and installation is presented. The roll of the dipoles is controlled by a combination of rotating coil measurements with the surveying measurements. The center of the quadrupole magnetic field is obtained by direct measurement of the field shape within a colloidal cell placed inside the quadrupoles. Special attention is given to the triplet quadrupole alignment and determination of the field center position.

  20. Construction details and test results from RHIC sextupoles

    SciTech Connect

    Lindner, M.; Anerella, M.; Ganetis, G.

    1993-12-31

    Four 8 cm aperture sextupoles have been built at BNL to verify the magnetic performance of this magnet in the RHIC installation. Two significantly different mechanical configurations have been designed, and two magnets of each design have been built, and successfully tested, and have exceeded the required minimum quench current by a substantial margin. This report describes the assembly details of the second configuration, which is the final production configuration. In addition the first industry built production sextupole has been delivered and tested. This report presents the results of quench tests on all 5 magnets and field measurements on the first production sextupole.

  1. Open and hidden charm production at RHIC and LHC

    SciTech Connect

    Vogt, R.

    2005-10-12

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

  2. DESIGN OF A FAST CHROMATICITY JUMP IN RHIC.

    SciTech Connect

    MONTAG,C.KEWISCH,J.BRUNO,D.GANETIS,G.LOUIE, W.

    2003-05-12

    During transition crossing in the .Relativistic Heavy Ion Collider (RHIC), chromaticities have to change sign. This sign change is partially accomplished by the {gamma}{sub t} quadrupole jump; however, the resulting chromaticity jump is only {Delta}{xi}{sub x} = 2.1 in the horizontal and {Delta}{xi}{sub y} = 2.4 in the vertical plane. To increase the jump height, a dedicated chromaticity jump scheme has been designed, consisting of fast power supplies connected to six sextupoles per ring, which is capable of providing a chromaticity jump of {Delta}{xi} = 6.

  3. Predictions for RHIC: Critical Overview of Microscopic Models

    NASA Astrophysics Data System (ADS)

    Gyulassy, Miklos

    1998-10-01

    The first measurements of inverse alchemy (Au+Auarrow; ?) at E_cm=200 AGeV will begin next year at RHIC. Some theorists are sticking their necks out to predicthadronic observables in this unknown energy domain, rather than fit fireballs to data as is popular at SPS. I will focus on the key uncertain assumptions and dynamical elements in current microscopic event generators and hadronic/partonic transport codes which are likely to cause neck aches next year. Topics will include entropy production and transverse energy systematics, baryon stopping, and flavor equilibration.

  4. GAS DISCHARGE SWITCH EVALUATION FOR RHIC BEAM ABORT KICKER APPLICATION.

    SciTech Connect

    ZHANG,W.; SANDBERG,J.; SHELDRAKE,R.; PIRRIE,C.

    2002-06-30

    A gas discharge switch EEV HX3002 is being evaluated at Brookhaven National Laboratory as a possible candidate of RHIC Beam Abort Kicker modulator main switch. At higher beam energy and higher beam intensity, the switch stability becomes very crucial. The hollow anode thyratron used in the existing system is not rated for long reverse current conduction. The reverse voltage arcing caused thyratron hold-off voltage de-rating has been the main limitation of the system operation. To improve the system reliability, a new type of gas discharge switch has been suggested by Marconi Applied Technology for its reverse conducting capability.

  5. Design and test of the RHIC CMD10 abort kicker

    SciTech Connect

    Hahn, H.; Blaskiewicz, M.; Drees, A.; Fischer, W.; Mi, J.; Meng, W.; Montag, C.; Pai, C.; Sandberg, J.; Tsoupas, N.; Tuozzolo, J. E.; Zhang, W.

    2015-05-03

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

  6. Simultaneous global coupling and vertical dispersion correction in RHIC

    SciTech Connect

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

    2012-05-20

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

  7. Central Diffractive Processes at the Tevatron, RHIC and LHC

    SciTech Connect

    Harland-Lang, L. A.; Stirling, W. J.; Khoze, V. A.; Ryskin, M. G.

    2011-07-15

    Central exclusive production (CEP) processes in high-energy hadron collisions offer a very promising framework for studying both novel aspects of QCD and new physics signals. We report on the results of a theoretical study of the CEP of heavy quarkonia ({chi} and {eta}) at the Tevatron, RHIC and LHC (see for details [1]-[3]). These processes provide important information on the physics of bound states and can probe the current ideas and methods of QCD, such as effective field theories and lattice QCD.

  8. Energy loss of coasting gold ions and deuterons in RHIC.

    SciTech Connect

    Abreu,N.; Blaskiewicz, M.; Brown, K.A.; Butler, J.J.; FischW; Harvey, M.; Tepikian, S.

    2008-06-23

    The total energy loss of coasting gold ion beams was measured at RHIC at two energies, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.

  9. Structure and design of the electron lens for RHIC

    SciTech Connect

    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.

    2011-03-28

    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.

  10. Designing a beam transport system for RHIC's electron lens

    SciTech Connect

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

    2011-03-28

    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.

  11. Commissioning Experience of SNS

    SciTech Connect

    Plum, Michael A

    2007-07-01

    The Spallation Neutron Source accelerator complex consists of a 2.5 MeV H{sup -} front-end injector system, a 186 MeV normal-conducting linear accelerator, a 1 GeV superconducting linear accelerator, an accumulator ring, and associated beam transport lines. The linac was commissioned in five discrete runs, starting in 2002 and completed in 2005. The accumulator ring and associated beam transport lines were commissioned in two runs in January-February and April 2006. With the completed commissioning of the SNS accelerator, the facility has begun initial low-power operations. In the course of beam commissioning, most beam performance parameters and beam intensity goals have been achieved at low duty factor. A number of beam dynamics measurements have been performed, including emittance evolution, transverse coupling in the ring, beam instability thresholds, and beam distributions on the target. The commissioning results, achieved beam performance and initial operating experience of the SNS linac will be presented.

  12. Central exclusive production in the STAR experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Sikora, Rafal

    2017-03-01

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) performs studies of diffractive processes with the focus on the exclusive production of particles in central range of rapidity. In 2015 STAR collected 18 pb-1 of data in polarized proton+proton collisions at √{s }=200 GeV to measure Central Exclusive Production (CEP) process pp → pX p through Double Pomeron Exchange (DPE) mechanism. The intact protons moving inside the RHIC beampipe after the collision were measured in silicon strip detectors (SSD), which were placed in the Roman Pot vessels. This enables full control over interaction kinematics and verification of the exclusivity of the reaction by measuring the total (missing) transverse momenta of all final state particles: the central diffractive system in the Time Projection Chamber (TPC) and the forward protons in the Roman Pots. With the use of ionization energy loss in the TPC, dE/dx, it was possible to discriminate various production channels in pp → pX p reaction. This paper presents results on exclusive production of two charged particles (π+π- and K+ K-) in mid-rapidity region, -1 < η < 1, with small squared four-momentum transfer of forward protons, 0.03 < -t < 0.3 (GeV/c)2, obtained using 2.5% of full statistics.

  13. RELATIVISTIC HEAVY ION PHYSICS : RESULTS FROM AGS TO RHIC.

    SciTech Connect

    STEINBERG,P.

    2002-06-20

    High-energy collisions of heavy ions provide a means to study QCD in a regime of high parton density, and may provide insight into its phme structure. Results from the four experiments at RHIC (BRAHMS, PHENIX, PHOBOS and STAR) are presented, and placed in context with the lower energy data from the AGS and SPS accelerators. The focus is on the insights these measurements provide into the time history of the collision process. Taken together, the data point to the creation of a deconfined state of matter that forms quickly, expands rapidly and freezes out suddenly. With the new RHIC data, systematic data now exists for heavy ion collisions as a function of {radical}s over several orders of magnitude and as a function of impact parameter. These data test the interplay between hard and soft processes in a large-volume system where nucleons are struck multiple times. The data is consistent with creating a deconfined state (jet quenching) that forms quickly (saturation models), expands rapidly (radial and elliptic flow) and freezes out suddenly (single freezeout and blast wave fits). There are also intriguing connections with particle production in elementary systems, which point to the role of the energy available for particle production on the features of the final state. Many in this field are optimistic that the careful understanding of this experimental data may lead t o the theoretical breakthroughs that will connect these complex systems to the fundamental lattice predict ions.

  14. RHIC GAMMA TRANSITION JUMP POWER SUPPLY PROTOTYPE TEST.

    SciTech Connect

    MI,J.; GANETIS,G.; LOUIE,W.; BRUNO,D.; ZAPASEK,R.; SANDBERG,J.; ZHANG,W.

    2001-06-18

    This paper describes the principle and test results of the prototype RHIC Gamma Transition Jump Power Supply. The jump power supply principle is introduced and illustrated along with diagrams in this paper. The prototype is built with Insulated Gate Bipolar Transistors (IGBT) as current direction switch components. Optically coupled IGBT drivers are used for the jump control switch. The jump time among the power supplies is synchronized from 40 to 60 milliseconds to meet the RHIC beam transition-crossing requirement. The short jump time is needed to avoid particle loss and to preserve the initial bunch area during the transition, thus successfully transferring the ion beams from the acceleration RF system to storage system. There are a total of twenty four jump power supplies that will be used. They synchronously switch the direction of the magnets current while the beam is being accelerated through the transition to reach the top storage energy. Each power supply will energize a group of super conducting magnets, which consists of four magnets that are connected in series. At the end, test results are listed, accompanied with the dummy load current waveform and prototype power supply picture.

  15. Measurement and simulation of the RHIC abort kicker longitudinal impedence

    SciTech Connect

    Abreu,N.P.; Hahn,H.; Choi, E.

    2009-09-01

    In face of the new upgrades for RHIC the longitudinal impedance of the machine plays an important role in setting the threshold for instabilities and the efficacy of some systems. In this paper we describe the measurement of the longitudinal impedance of the abort kicker for RHIC as well as computer simulations of the structure. The impedance measurement was done by the S{sub 21} wire method covering the frequency range from 9 kHz to 2.5 GHz. We observed a sharp resonance peak around 10 MHz and a broader peak around 20 MHz in both, the real and imaginary part, of the Z/n. These two peaks account for a maximum imaginary longitudinal impedance of j15 {Omega}, a value an order of magnitude larger than the estimated value of j0.2 {Omega}, which indicates that the kicker is one of the main sources of longitudinal impedance in the machine. A computer model was constructed for simulations in the CST MWS program. Results for the magnet input and the also the beam impedance are compared to the measurements. A more detail study of the system properties and possible changes to reduce the coupling impedance are presented.

  16. Monte Carlo simulations for BNL RHIC spin physics

    SciTech Connect

    Guellenstern, S. ); Gornicki, P. ); Mankiewicz, L. ); Schaefer, A. )

    1995-04-01

    Direct photon production in longitudinally polarized proton-proton collisions offers the most direct and unproblematic possibility for determining the polarized gluon distribution of a proton. This information could play a major role for improving our understanding of the nucleon structure and QCD in general. It is hoped that such experiments will be done at the BNL RHIC. We present results of detailed Monte Carlo simulations using a code called SPHINX. We find that for RHIC energies and large gluon polarization the Compton graph dominates allowing for a direct test of [Delta][ital g]. Triggering on away-side jets with the envisaged jet criteria should allow to obtain more detailed information on [Delta][ital g]([ital x]). The photon asymmetry resulting from the asymmetry of produced [pi][sup 0]'s provides an additional signal, which is complementary to the other two. For small gluon polarization, i.e., [Delta][ital g][le]0.5, or very soft polarized gluon distributions the envisaged experiments will require a highly sophisticated simulation and large statistics to extract more than upper bounds for [vert bar][Delta][ital g]([ital x])[vert bar].

  17. Head-on beam-beam compensation in RHIC

    SciTech Connect

    Fischer, W.; Heimerle, M.; Luo, Y.; Pikin, A.; Beebe, E.; Bruno, D.; Gassner, D.; Gu, X.; Gupta, R. C.; Hock, J.; Jain, A.; Lambiase, R.; Mapes., M.; Meng, W.; Montag, C.; Oerter, B.; Okamura, M.; Raparia, D.; Tan, Y.; Than, R.; Tuozzolo, J.; Zhang, w.

    2010-07-29

    Head-on beam-beam compensation with electron lenses had been proposed for the SSC, LHC, and the Tevatron [1,2]. Two electron lenses are installed in the Tevatron [2-4], where they are routinely used as gap cleaner and have been tested in many other configurations. In RHIC there are 2 head-on beam-beam interactions at IP6 and IP8, and 4 long-range beam-beam interactions with large separation (10 mm) at the other IPs. We consider the partial indirect compensation of the head-on beam-beam effect with one electron lens in each ring. Together with intensity and emittance upgrades [5,6] our goal is to approximately double the luminosity over what can be achieved without these upgrades. A RHIC electron lens consists of: a DC electron gun, an electron beam transport to the main solenoid, the superconducting main solenoid in which the interaction with the hadron beam occurs, an electron beam transport to the collector, and an electron collector. The 2 electron lenses are located in IR10 between the DX beam separation dipoles. The proton beams pass through the main solenoids of both electron lenses, and interact head-on with one of them. The following is a slightly modified version of Ref. [7]. The table shows the main parameters of the proton beam and the electron lenses. References [8-11] present simulations for and discuss beam dynamics problems.

  18. ATF2 Commissioning

    SciTech Connect

    Seryi, A.; Christian, G.; Parker, B.; Schulte, D.; Delahaye, J.-P.; Tomas, R.; Zimmermann, F.; Wolski, A.; Elsen, E.; Sanuki, T.; Gianfelice-Wendt, E.; Ross, M.; Wendt, M.; Takahashi, T.; Bai, S.; Gao, J.; Bolzon, B.; Geffroy, N.; Jeremie, A.; Apsimon, R.; Burrows, P.; /Oxford U., JAI /Kyoto U., Inst. Chem. Res. /Kyungpook Natl. U. /Orsay, LAL /Phang Accelerator Lab /Royal Holloway, U. of London /SLAC /Daresbury /University Coll. London /Manchester U. /Univ. of Tokyo U.

    2009-10-30

    ATF2 is a final-focus test beam line that aims to focus the low-emittance beam from the ATF damping ring to a beam size of about 37 nm, and at the same time to demonstrate nm beam stability, using numerous advanced beam diagnostics and feedback tools. The construction has been finished at the end of 2008 and the beam commissioning of ATF2 has started in December of 2008. ATF2 is constructed and commissioned by ATF international collaborations with strong US, Asian and European participation.

  19. 77 FR 28420 - Commission Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... From the Federal Register Online via the Government Publishing Office SUSQUEHANNA RIVER BASIN COMMISSION Commission Meeting AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold its regular business meeting on June 7, 2012, in Binghamton,...

  20. A Lattice for the Muon Collider Demonstration Ring in the RHIC Tunnel

    NASA Astrophysics Data System (ADS)

    Trbojevic, D.; Ng, K. Y.; Courant, E. D.; Tepikian, S.

    1997-05-01

    The future μ^+μ^- Muon Collider should have a luminosity of the order of 10^35 cm-2s-1, at the energy of 2×2 TeV. We present here a demonstration machine at a lower energy to test the feasibility of all components involved, that could be placed inside the existing Relativistic Heavy Ion Collider (RHIC) tunnel. The maximum energy of the muons in the RHIC tunnel collider depends on the maximum attainable field in the dipoles. The maximum energy in the existing RHIC rings for protons is 250 GeV, where the strength of the magnetic field in the dipoles is 3.458 T.

  1. Effect of the electron lenses on the RHIC proton beam closed orbit

    SciTech Connect

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

    2011-02-01

    We are designing two electron lenses (E-lens) to compensate for the large beam-beam tune spread from proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). They will be installed at RHIC IR10. The transverse fields of the E-lenses bending solenoids and the fringe field of the main solenoids will shift the proton beam. We calculate the transverse kicks that the proton beam receives in the electron lens via Opera. Then, after incorporating the simplified E-lens lattice in the RHIC lattice, we obtain the closed orbit effect with the Simtrack Code.

  2. RHIC PHYSICS: THE QUARK GLUON PLASMA AND THE COLOR GLASS CONDENSATE: 4 LECTURES

    SciTech Connect

    MCLERRAN,L.

    2003-01-01

    The purpose of these lectures is to provide an introduction to the physics issues which are being studied in the RHIC heavy ion program. These center around the production of new states of matter. The Quark Gluon Plasma is thermal matter which once existed in the big bang which may be made at RHIC. The Color Glass Condensate is a universal form of matter which controls the high energy limit of strong interactions. Both such forms of matter might be produced and probed at RHIC.

  3. The effects of betatron phase advances on beam-beam and its compensation in RHIC

    SciTech Connect

    Luo, Y.; Fischer, W.; Gu, X.; Tepikian, S.; Trbojevic, D.

    2011-03-28

    In this article we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used in this study. We also scan the betatron phase advances between IP8 and the electron lens for the proposed Blue ring lattice with head-on beam-beam compensation.

  4. Explore the possibility of accelerating polarized He-3 beam in RHIC

    SciTech Connect

    Bai M.; Courant, E.; Fischer, W.; Ptitsyn, V.; Roser, T.

    2012-05-20

    As the world's first high energy polarized proton collider, RHIC has made significant progresses in measuring the proton spin structure in the past decade. In order to have better understanding of the contribution of up quarks and down quarks to the proton spin structure, collisions of high energy polarized neutron beams are required. Polarized He-3 beams offer an effectiveway to provide polarized neutron beams. In this paper, we present studies of accelerating polarized He-3 in RHIC with the current dual snake configuration. Possibilities of adding two more pairs of snakes for accelerating polarized He-3 were explored. Results of six snake configuration in RHIC are also reported in the paper.

  5. eRHIC, the BNL design for a future Electron-Ion Collider

    NASA Astrophysics Data System (ADS)

    Roser, Thomas

    2016-03-01

    With the addition of a 20 GeV polarized electron accelerator to the existing Brookhaven Relativistic Heavy Ion Collider (RHIC), the world's only high energy heavy ion and polarized proton collider, a future eRHIC facility will be able to produce polarized electron-nucleon collisions at center-of-mass energies of up to 145 GeV and cover the whole science case as outlined in the Electron-Ion Collider White Paper and endorsed by the 2015 Nuclear Physics Long Range Plan with high luminosity. The presentation will describe the eRHIC design concepts and recent efforts to reduce the technical risks of the project.

  6. Commission on Liberal Learning

    ERIC Educational Resources Information Center

    Hazzard, George W.

    1976-01-01

    Study emphasis within the Commission on Liberal Learning during the year was on the role of liberal education in the society of the future. The relationship of undergraduate liberal education to the world macro-problem--population growth, industrial production, food, materials and energy scarcities, pollution and environmental degradation--was…

  7. Nuclear Regulatory Commission issuances

    SciTech Connect

    1997-11-01

    This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judges (ALJ), the Directors` Decisions (DD), and the Decisions on Petitions for Rulemaking (DPRM). The summaries and headnotes preceding the opinions reported herein are not to be deemed a part of those opinions or have any independent legal significance.

  8. Nuclear Regulatory Commission Issuances

    SciTech Connect

    Not Available

    1994-10-01

    This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judges (ALJ), the Directors Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM). The summaries and headnotes preceding the opinions reported herein are not to be deemed a part of those opinions or have any independent legal significance.

  9. Nuclear Regulatory Commission issuances

    SciTech Connect

    1997-09-01

    This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judges (ALJ), the Directors` Decisions (DD), and the Decisions on Petitions for Rulemaking (DPRM). The summaries and headnotes preceding the opinions reported herein are not to be deemed a part of those opinions or have any independent legal significance.

  10. Legal Commission Report

    ERIC Educational Resources Information Center

    American Indian Journal, 1977

    1977-01-01

    The Legal Commission of the International Non-Governmental Organizations Conference on Discrimination Against Indigenous Populations adopted the following agenda: legal status of indigenous populations; the land question; indigenous laws and courts; discrimination against indigenous peoples in existing laws and their application; and creation of…

  11. IBS and possible luminosity improvement for RHIC operation below transition energy

    SciTech Connect

    Fedotov,A.V.

    2009-05-04

    There is a strong interest in low-energy RHIC collisions in the energy range below present RHIC transition energy. These collisions win help to answer one of the key questions in the field of QCD about the existence and location of a critical point on the QCD phase diagram. For such 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. In this paper, we explore an Intrabeam Scattering (IBS) feature below transition energy that drives the transverse and longitudinal beam temperatures towards equilibrium to see whether we can minimize longitudinal diffusion due to IBS and predict some luminosity improvement for the low-energy RHIC project.

  12. The electromagnetic calorimeter for the solenoidal tracker at RHIC. A Conceptual Design Report

    SciTech Connect

    Beddo, M.E.; Bielick, E.; Dawson, J.W.; The STAR EMC Collaboration

    1993-09-22

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

  13. Gatling gun: high average polarized current injector for eRHIC

    SciTech Connect

    Litvinenko, V.N.

    2010-01-01

    This idea was originally developed in 2001 for, at that time, an ERL-based (and later recirculating-ring) electron-ion collider at JLab. Naturally the same idea is applicable for any gun requiring current exceeding capability of a single cathode. ERL-based eRHIC is one of such cases. This note related to eRHIC was prepared at Duke University in February 2003. In many case photo-injectors can have a limited average current - it is especially true about polarized photo-guns. It is know that e-RHIC requires average polarized electron current well above currently demonstrated by photo-injectors - hence combining currents from multiple guns is can be useful option for eRHIC.

  14. SPIN TRANSPORT FROM AGS TO RHIC WTIH TWO PARTIAL SNAKES IN AGS.

    SciTech Connect

    MACKAY, W.W.; LUCCIO, A.U.; TSOUPAS, N.; TAKANO, J.

    2006-06-23

    The stable spin direction in the RHIC rings is vertical. With one or two partial helical Siberian snakes in the AGS, the stable spin direction at extraction is not vertical. Interleaved vertical and horizontal bends in the transport line between AGS and the RHIC rings also tend to tip the spin away from the vertical. In order to maximize polarization in RHIC, we examined several options to improve the matching of the stable spin direction during beam transfer from the AGS to each of the RHIC rings. While the matching is not perfect, the most economical method appears to be a lowering of the injection energy by one unit of G{gamma} from 46.5 to 45.5.

  15. Nuclear Regulatory Commission issuances

    SciTech Connect

    1996-04-01

    This report includes the issuances received during the April 1996 reporting period from the Commission, the Atomic Safety and Licensing Boards, the Administrative Law Judges, the Directors` Decisions, and the Decisions on Petitions for Rulemaking. Included are issuances pertaining to: (1) Yankee Nuclear Power Station, (2) Georgia Tech Research Reactor, (3) River Bend Station, (4) Millstone Unit 1, (5) Thermo-Lag fire barrier material, and (6) Louisiana Energy Services.

  16. Commission 42: Close Binaries

    NASA Astrophysics Data System (ADS)

    Rucinski, Slavek M.; Ribas, Ignasi; Giménez, Alvaro; Harmanec, Petr; Hilditch, Ronald W.; Kaluzny, Janusz; Niarchos, Panayiotis; Nordström, Birgitta; Oláh, Katalin; Richards, Mercedes T.; Scarfe, Colin D.; Sion, Edward M.; Torres, Guillermo; Vrielmann, Sonja

    2010-05-01

    During the commission business session, the past President presented the new Organizing Committee which was selected by the OC through a e-mail vote conducted during the months before the Rio de Janeiro General Assembly. The new OC will consist of Ignasi Ribas (President), Mercedes Richards (Vice President), and Slavek Rucinski (Past President) with the members: David Bradstreet, Petr Harmanec, Janusz Kaluzny, Joanna Mikolajewska, Ulisse Munari, Panos Niarchos, Katalin Olah, Theo Pribulla, Colin Scarfe and Guillermo Torres.

  17. Operation experience of p-Carbon polarimeter in RHIC

    SciTech Connect

    Huang, H.; Alekseev, I. G.; Aschenauer, E. C.; Atoian, G.; Bazilevsky, A.; Eyser, O.; Kalinkin, D.; Kewisch, J.; Makdisi, Y.; Nemesure, S.; Poblaguev, A.; Schmidke, W. B.; Svirida, D.; Steski, D.; Webb, G.; Zelenski, A.; Tip, K.

    2015-05-03

    The spin physics program in Relativistic Heavy Ion Collider (RHIC) requires fast polarimeter to monitor the polarization evolution on the ramp and during stores. Over past decade, the polarimeter has evolved greatly to improve its performance. These include dual chamber design, monitoring camera, Si detector selection (and orientation), target quality control, and target frame modification. The preamp boards have been modified to deal with the high rate problem, too. The ultra thin carbon target lifetime is a concern. Simulations have been carried out on the target interaction with beam. Modification has also been done on the frame design. Extra caution has been put on RF shielding to deal with the pickup noises from the nearby stochastic cooling kickers. This paper summarizes the recent operation performance of this delicate device.

  18. RHIC 100 GeV Polarized Proton Luminosity

    SciTech Connect

    Zhang, S. Y.

    2014-01-17

    A big problem in RHIC 100 GeV proton run 2009 was the significantly lower luminosity lifetime than all previous runs. It is shown in this note that the beam intensity decay in run 2009 is caused by the RF voltage ramping in store. It is also shown that the beam decay is not clearly related to the beam momentum spread, therefore, not directly due to the 0.7m. β* Furthermore, the most important factor regarding the low luminosity lifetime is the faster transverse emittance growth in store, which is also much worse than the previous runs, and is also related to the RF ramping. In 100 GeV proton run 2012a, the RF ramping was abandoned, but the β* was increased to 0.85m, with more than 20% loss of luminosity, which is not necessary. It is strongly suggested to use smaller β* in 100 GeV polarized proton run 2015/2016

  19. R AND D TOWARDS COOLING OF THE RHIC COLLIDER.

    SciTech Connect

    BEN-ZVI,I.SRINIVASAN-RAO,T.ET AL.

    2003-05-12

    We introduce the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon bunched-beam ion collider at storage energy using 54 MeV electrons. The electron source will be an RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum bunch frequency is 28.15 MHz, with bunch charge of 10 nC. The R&D program has the following components: The photoinjector, the superconducting linac, start-to-end beam dynamics with magnetized electrons, electron cooling calculations and development of a large superconducting solenoid.

  20. Superconducting magnet designs for the SSC and RHIC

    SciTech Connect

    Thompson, P.A.; Cottingham, J.; Dahl, P.; Brown, D.; Garber, M.; Ghosh, A.K.; Goodzeit, C.; Greene, A.; Hahn, H.; Herrera, J.

    1988-01-01

    This paper reviews the main dipoles for RHIC, which are 9.7 meters long with an operating field of 3.45 T. Four full size dipoles have been tested and all exceeded the operating field. The main dipoles for the SSC project are 17 meters in length with an operating field of 6.6 T. Five of these have been tested. Rough calculations show that the possibility of operating future such large colliders at approx. 80 K instead of approx. 4 K is unlikely to have a major impact upon their cost or feasibility. However, increasing the critical field of practical superconductors (either by lowering the operating temperature of further conductor development) could have a major impact upon the specialized magnets used in the intersection regions of such machines.

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

    SciTech Connect

    ZAJC,W.ET. AL.

    2003-11-30

    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

  2. Strangeness production in small and large collision systems at RHIC

    NASA Astrophysics Data System (ADS)

    Heinz, Mark T.

    2006-07-01

    We present measurements of strange and multi-strange hadrons in p+p collisions at √s =200 GeV measured by STAR. We will compare these preliminary results to leading-order (LO) and next-to-leading order (NLO) perturbative QCD models widely believed to describe the production mechanisms. In particular we will point out recent changes of the model calculations which improve the agreement with our data significantly and will discuss the physics consequences. In larger collision systems, produced with heavy ions at RHIC, we observe the centrality dependence of strange and multi-strange particle production. The non-linear dependency between (anti)-hyperon yields and the system size Npart seems to indicate that the correlation volume does not scale exactly with Npart in contradiction to previous assumptions by thermal models.

  3. Simulations to study the static polarization limit for RHIC lattice

    NASA Astrophysics Data System (ADS)

    Duan, Zhe; Qin, Qing

    2016-01-01

    A study of spin dynamics based on simulations with the Polymorphic Tracking Code (PTC) is reported, exploring the dependence of the static polarization limit on various beam parameters and lattice settings for a practical RHIC lattice. It is shown that the behavior of the static polarization limit is dominantly affected by the vertical motion, while the effect of beam-beam interaction is small. In addition, the “nonresonant beam polarization” observed and studied in the lattice-independent model is also observed in this lattice-dependent model. Therefore, this simulation study gives insights of polarization evolution at fixed beam energies, that are not available in simple spin tracking. Supported by the U.S. Department of Energy (DE-AC02-98CH10886), Hundred-Talent Program (Chinese Academy of Sciences), and National Natural Science Foundation of China (11105164)

  4. Residual-gas-ionization beam profile monitors in RHIC

    SciTech Connect

    Connolly, R.; Fite, J.; Jao, S.; Trabocchi, C.

    2010-05-02

    Four ionization profile monitors (IPMs) are in RHIC to measure vertical and horizontal beam profiles in the two rings. These work by measuring the distribution of electrons produced by beam ionization of residual gas. During the last two years both the collection accuracy and signal/noise ratio have been improved. An electron source is mounted across the beam pipe from the collector to monitor microchannel plate (MCP) aging and the signal electrons are gated to reduce MCP aging and to allow charge replenishment between single-turn measurements. Software changes permit simultaneous measurements of any number of individual bunches in the ring. This has been used to measure emittance growth rates on six bunches of varying intensities in a single store. Also the software supports FFT analysis of turn-by-turn profiles of a single bunch at injection to detect dipole and quadrupole oscillations.

  5. Systematic Study of Elliptic Flow at RHIC-PHENIX

    SciTech Connect

    Shimomura, Maya

    2009-03-23

    In non-central high energy heavy ion collisions, the initial spatial anisotropy is transferred to the final momentum anisotropy due to a pressure gradient in the collision participants, p{sub T} and centrality dependences of the azimuthal anisotropy ({nu}{sub 2}) are measured for charged hadrons in different energies and collision systems by the PHENIX experiment at RHIC. It was newly found that {nu}{sub 2} divided by the geometrical participant eccentricity is exponentially increasing with the number of the participants to the 1/3, and there is the universal scaling for {nu}{sub 2} with different energies and collision sizes with eccentricity and number of quark scalings. The results indicate that {nu}{sub 2} is not only determinated by the geometrical eccentricity, but {sub 2} is evolving during the finite time which could be related to the size of collisions.

  6. Physics with the collider detectors at RHIC and the LHC

    SciTech Connect

    Thomas, J.; Hallman, T.

    1995-07-15

    On January 8, 1995, over 180 participants gathered to hear the QM95 preconference workshop on `Physics with the Collider Detectors at RHIC and the LHC`. The goal was to bring together the experimentalists from a wide community of hadron and heavy ion collider detector collaborations. The speakers were encouraged to present the current status of their detectors, with all the blemishes, and the audience was encouraged to share their successes and failures in approaching similar detector design issues. The presentations were excellent and the discussions were lively and stimulating. The editors hope that the reader will find these proceedings to be equally stimulating. Separate abstracts have been submitted to the energy database from articles in this report.

  7. Modeling of RHIC insulating vacuum for system pumpdown characteristics

    SciTech Connect

    Todd, R.J.; Pate, D.J.; Welch, K.M.

    1993-06-01

    This paper presents a model for predicting the pumpdown characteristics of a 480 m RHIC (Relativistic Heavy Ion Collider) vacuum cryostat. The longitudinal and transverse conductances of a typical cryostat were calculated. A voltage analogue of these conductances was constructed for room temperature conditions. The total longitudinal conductance of a room temperature cryostat was thereby achieved. This conductance was then used to calculate the diameter of an equivalent long outgassing tube, having more convenient analytical expressions for pressure profiles when pumped. The equivalent of a unit outgassing rate for this tube was obtained using previously published MLI (multi-layer insulation) outgassing data. With this model one is then able to predict a cryostat pumpdown rate as a function of the location and size of roughing pumps.

  8. REAL-WORLD SORTING OF RHIC SUPERCONDUCTING MAGNETS.

    SciTech Connect

    WEI,J.; GUPTA,R.; HARRISON,M.; JAIN,A.; PEGGS,S.; THOMPSON,P.; TRBOJEVIC,D.; WANDERER,P.

    1999-03-29

    During the seven-year construction of the Relativistic Heavy Ion Collider (RHIC), more than 1700 superconducting dipoles, quadrupoles, sextupoles, and multi-layer correctors have been constructed and installed. These magnets have been sorted at several production stages to optimize their performance and reliability. For arc magnets, priorities have been put first on quench performance and operational risk minimization, second on field transfer function and other first-order quantities, and finally on nonlinear field errors which were painstakingly optimized at design. For Interaction-Region (IR) magnets, sorting is applied to select the best possible combination of magnets for the low-{beta}* interaction points (IP). This paper summarizes the history of this real-world sorting process.

  9. Equivalent circuit analysis of the RHIC injection kicker

    SciTech Connect

    Hahn, H.; Ratti, A.

    1997-07-01

    The RHIC injection kicker is built as a traveling wave structure in order to assure the required 95 nsec risetime in the deflection strength. The kicker is constructed from 14 cells, each 7.5 cm long, with alternating ferrite and high-permittivity dielectric sections. The cell structure permits an analysis of the electrical properties of the kicker using lumped L, C, and R circuit elements. Their values are obtained directly from impedance measurements of the full-length kicker, the inductance and shunt capacitance values by measuring the input impedance at 1 MHz with the output shorted and open, respectively. A lossy series resonance circuit in each cell is found to reproduce the measured input impedance of the terminated kicker up to {approximately}100 MHz. The validity of the equivalent circuit was confirmed by comparing the measured output current pulse shape time with that computed by the P-Spice program.

  10. Removal of Axial Twist in RHIC Insertion Quadrupole Magnets

    NASA Astrophysics Data System (ADS)

    Cozzolino, J.; Anerella, M.; Jain, A.; Louie, W.; Muratore, P.

    1997-05-01

    The focusing triplets located on either side of the six interaction points of RHIC each consist of three 13cm aperture quadrupoles with magnetic lengths of 1.44m (Q1), 3.40m (Q2), and 2.10m (Q3). The field quality and alignment of these magnets are most critical to the performance of the accelerator. The maximum allowable axial twist of the cold mass, defined as the standard deviation in the quadrupole roll angle, is 0.5 mrad. This requirement has occasionally exceeded the capabilities of the assembly fixturing and the procedures used to complete the axial welding of the shell halves around the cold mass yoke. A corrective shell welding technique has been successfully employed to remove excessive axial twist of the 13cm quadrupoles. This ``custom straightening" method will be described along with the before and after mechanical inspection data. The magnetic results which confirm the untwisting procedure shall also be discussed.

  11. LINEAR AND NONLINEAR CORRECTIONS IN THE RHIC INTERACTION REGIONS.

    SciTech Connect

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

    2002-06-02

    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.

  12. The first operation of 56 MHz SRF cavity in RHIC

    SciTech Connect

    Wu, Q.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M.; DeSanto, L.; Goldberg, D.; Harvey, M.; Hayes, T.; McIntyre, G.; Mernick, K.; Orfin, P.; Seberg, S.; Severino, F.; Smith, K.; Than, R.; Zaltsman, A.

    2015-05-03

    A 56 MHz superconducting RF cavity has been designed, fabricated and installed in the Relativistic Heavy Ion Collider (RHIC). The cavity operates at 4.4 K with a “quiet helium source” to isolate the cavity from environmental acoustic noise. The cavity is a beam driven quarter wave resonator. It is detuned and damped during injection and acceleration cycles and is brought to operation only at store energy. For a first test operation, the cavity voltage was stabilized at 300 kV with full beam current. Within both Au + Au and asymmetrical Au + He3 collisions, luminosity improvement was detected from direct measurement, and the hourglass effect was reduced. One higher order mode (HOM) coupler was installed on the cavity. We report in this paper on our measurement of a broadband HOM spectrum excited by the Au beam.

  13. Recent developments on the STAR detector system at RHIC

    SciTech Connect

    Wieman, H.; Adams, D.L.; Added, N.

    1997-12-01

    The STAR detector system is designed to provide tracking, momentum analysis and particle identification for many of the mid-rapidity charged particles produced in collisions at the RHIC collider. A silicon vertex detector (SVT) provides three layers of tracking near the interaction point. This is followed by the main time projection chamber (TPC), which continues tracking out to 200 cm radial distance from the interaction region. The detector design also includes an electromagnetic calorimeter, various trigger detectors, and radial TPCs in the forward region. The entire system is enclosed in a 0.5 T solenoid magnet. A progress report is given for the various components of the STAR detector system. The authors report on the recent developments in the detector proto-typing and construction, with an emphasis on the main TPC, recent TPC cosmic ray testing and shipping to Brookhaven National Laboratory.

  14. Phenomenological predictions for uranium + uranium collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Nepali, Chandra Shekhar

    One of the main goals of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is to produce very hot, dense nuclear matter by colliding two heavy ions at relativistic energy. The matter produced under these extreme conditions is supposed to be in a deconfined phase, commonly known as Quark Gluon Plasma (QGP), which is believed to have existed for a very short time after the Big Bang. RHIC is devoted to the study of the QGP phase. One of the probes that carry information of this hot matter is the elliptic flow (azimuthal asymmetry in particle production). The elliptic flow occurs due to the spatial asymmetry of the overlap region of the two colliding nuclei at non-zero impact parameter. Particle production is azimuthally asymmetric due to asymmetry in the pressure gradient. The matter formed in central collisions of Au+Au at 200 GeV at RHIC seems to behave like a perfect fluid. This conclusion is based in part on approximate agreement between non-viscous hydrodynamic calculations and the experimental data on elliptic flow. The hydrodynamic calculations predict the saturation of the strength of the elliptic flow, v2, with increase in transverse particle density, (1/ S)(dNch/dy), at fixed impact parameter. The transverse particle density in central Au+Au is not enough to confirm this. Uranium + uranium (U+U) collisions have the potential to produce more extreme conditions of excited matter then is possible using spherical nuclei like gold or lead at the same incident energy. Uranium has quadrupole deformed shape. The collisions of special interest are the "ideal tip-tip" orientation in which the long axes of both deformed nuclei are aligned with the beam axis at zero impact parameter, and the "ideal body-body" orientation in which the long axes are both perpendicular to the beam axis and parallel to each other at zero impact parameter. The "ideal tip-tip" and "ideal body-body" collision events allow to test the hydro prediction by varying

  15. IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy

    SciTech Connect

    Fedotov,A.

    2009-01-02

    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.

  16. HOTTER, SMALLER, DENSER, FASTER...AND NEARLY-PERFECT: WHAT IS THE MATTER AT RHIC?

    SciTech Connect

    STEINBERG,P.

    2006-07-03

    The experimental and theoretical status of the ''near perfect fluid'' at RHIC is discussed. While the hydrodynamic paradigm for understanding collisions at RHIC is well established, there remain many important open questions to address in order to understand its relevance and scope. It is also a crucial issue to understand how the early equilibration is achieved, requiring insight into the active degrees of freedom at early times.

  17. Beam dynamics and expected RHIC performance with 56MHz RF upgrade

    SciTech Connect

    Fedotov,A.V.; Ben-Zvi, I.

    2009-05-04

    An upgrade of the RHIC storage RF system with a superconducting 56 MHz cavity was recently proposed. This upgrade will provide a significant increase in the acceptance of the RHIC 197 MHz storage RF bucket. This paper summarizes simulations of beam evolution due to intra-beam scattering (IBS) for beam parameters expected with the 56 MHz SRF cavity upgrade. Expected luminosity improvements are shown for Au ions at 100 GeV/nucleon and protons at 250 GeV.

  18. A LOW GAMMA_T INJECTION LATTICE FOR POLARIZED PROTONS IN RHIC

    SciTech Connect

    MONTAG,C.

    2007-06-25

    Polarized protons are injected into the Relativistic Heavy Jon Collider (RHIC) just above transition energy. When installation of a cold partial Siberian snake in the AGS required lowering the injection energy by {Delta}{gamma} = 0.56, the transition energy in RHIC had to be lowered accordingly to ensure proper longitudinal matching. This paper presents lattice modifications implemented to lower the transition energy by {Delta}{gamma}{sub t} = 0.8.

  19. Optics correction for the multi-pass FFAG ERL machine eRHIC

    SciTech Connect

    Liu, C.; Brooks, S.; Litvinenko, V.; Minty, M.; Ptitsyn, V.; Trbojevic, D.

    2015-05-03

    Gradient errors in the multi-pass Fixed Field Alternating Gradient (FFAG) Energy Recovery Linac (ERL) machine, eRHIC, distort the beam orbit and therefore cause emittance increase. The localization and correction of gradient errors are essential for an effective orbit correction and emittance preservation. In this report, the methodology and simulation of optics correction for the multi-pass FFAG ERL machine eRHIC will be presented.

  20. Numerical studies of Siberian snakes and spin rotators for RHIC

    SciTech Connect

    Luccio, A.

    1995-04-17

    For the program of polarized protons in RHIC, two Siberian snakes and four spin rotators per ring will be used. The Snakes will produce a complete spin flip. Spin Rotators, in pairs, will rotate the spin from the vertical direction to the horizontal plane at a given insertion, and back to the vertical after the insertion. Snakes, 180{degrees} apart and with their axis of spin precession at 90{degrees} to each other, are an effective means to avoid depolarization of the proton beam in traversing resonances. Classical snakes and rotators are made with magnetic solenoids or with a sequence of magnetic dipoles with fields alternately directed in the radial and vertical direction. Another possibility is to use helical magnets, essentially twisted dipoles, in which the field, transverse the axis of the magnet, continuously rotates as the particles proceed along it. After some comparative studies, the authors decided to adopt for RHIC an elegant solution with four helical magnets both for the snakes and the rotators proposed by Shatunov and Ptitsin. In order to simplify the construction of the magnets and to minimize cost, four identical super conducting helical modules will be used for each device. Snakes will be built with four right-handed helices. Spin rotators with two right-handed and two left-handed helices. The maximum field will be limited to 4 Tesla. While small bore helical undulators have been built for free electron lasers, large super conducting helical magnets have not been built yet. In spite of this difficulty, this choice is dictated by some distinctive advantages of helical over more conventional transverse snakes/rotators: (i) the devices are modular, they can be built with arrangements of identical modules, (ii) the maximum orbit excursion in the magnet is smaller, (iii) orbit excursion is independent from the separation between adjacent magnets, (iv) they allow an easier control of the spin rotation and the orientation of the spin precession axis.

  1. Novel deflecting cavity design for eRHIC

    SciTech Connect

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

    2011-07-25

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

  2. A Guide to Building Commissioning

    SciTech Connect

    Baechler, Michael C.

    2011-09-01

    Commissioning is the process of verifying that a building's heating, ventilation, and air conditioning (HVAC) and lighting systems perform correctly and efficiently. Without commissioning, system and equipment problems can result in higher than necessary utility bills and unexpected and costly equipment repairs. This report reviews the benefits of commissioning, why it is a requirement for Leadership in Energy and Environmental Design (LEED) certification, and why building codes are gradually adopting commissioning activities into code.

  3. Nuclear Regulatory Commission information digest

    SciTech Connect

    None,

    1990-03-01

    The Nuclear Regulatory Commission information digest provides summary information regarding the US Nuclear Regulatory Commission, its regulatory responsibilities, and areas licensed by the commission. This is an annual publication for the general use of the NRC Staff and is available to the public. The digest is divided into two parts: the first presents an overview of the US Nuclear Regulatory Commission and the second provides data on NRC commercial nuclear reactor licensees and commercial nuclear power reactors worldwide.

  4. SNS Cryogenic Systems Commissioning

    SciTech Connect

    D. Hatfield; F. Casagrande; I. Campisi; P. Gurd; M. Howell; D. Stout; H. Strong; D. Arenius; J. Creel; K. Dixon; V. Ganni; and P. Knudsen

    2005-08-29

    The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning and future plans will be presented.

  5. Commission 31: Time

    NASA Astrophysics Data System (ADS)

    Defraigne, Pascale; Manchester, Richard; Matsakis, Demetrios; Petit, Gerard; Hosokawa, Mizuhiko; Leschiutta, Sigfrid; Zhai, Zao-Cheng

    2010-05-01

    Dr R. N. Manchester and Dr M. Hosokawa have been elected as, respectively, the new President and Vice-President of the Commission for the next term, 2009-2012. Concerning the Organizing Committee (OC) Members, we welcome as new members: Felicitas Aris (BIPM, France), Philip Tuckey (LNE-SYRTE, France), Vladimir Zharov (MSU, Russia), and Shougang Zhang (NTSC, China) and we acknowledge the outgoing members: Demetrios Matsakis, Gerard Petit, Mizuhiko Hosokawa, Sigfrid Leschiutta and Zao-Cheng Zhai. P. Defraigne remains on the OC as immediate Past-President.

  6. The SNS RFQ Commissioning

    SciTech Connect

    Ratti, A.; Ayers, J.; Doolittle, L.; DiGennaro, R.; Gough, R.A.; Hoff, M.; Keller, R.; MacGill, J.; Staples, J.; Thomae, R.; Virostek, S.; Yourd, R.; Aleksandrov, A.

    2002-08-16

    LBNL has built for the Spallation Neutron Source (SNS) project a 402.5 MHz RFQ that is designed to accelerate up to 60 mA H{sup -} from 65 keV to 2.5 MeV [1]. A one millisecond pulse length at 60 Hz provides a 6% duty factor. The RFQ has now been built, conditioned at full duty factor and tested with beam. This paper will present results from the final installation, tuning and beam commissioning. Beam measurements include acceleration and transport efficiencies and transverse emittances. The LEBT optics were tuned for best results. Performance testing of the RF power distribution is also discussed here.

  7. SNS Cryogenic Systems Commissioning

    NASA Astrophysics Data System (ADS)

    Hatfield, D.; Casagrande, F.; Campisi, I.; Gurd, P.; Howell, M.; Stout, D.; Strong, H.; Arenius, D.; Creel, J.; Dixon, K.; Ganni, V.; Knudsen, P.

    2006-04-01

    The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning and future plans will be presented.

  8. [Prostate histopathology of NIH category IV prostatitis detected by sextant prostate needle biopsy from the patients with high prostatic specific antigen].

    PubMed

    Shimomura, Tatsuya; Kiyota, Hiroshi; Takahashi, Hiroyuki; Madarame, Jun; Kimura, Takahiro; Onodera, Shouichi

    2003-08-01

    Asymptomatic prostatitis is classified as category IV in NIH classification of prostatitis syndrome (1999). No report concerning this category has been present. We investigated this category histopathologically and clinically, in order to clarify the histopathological distribution and its correlation to the clinical features, in this study. Among 785 patients who were suspected prostate cancer because of their high prostatic specific antigen (PSA) values and to have a sextant prostate needle biopsy was performed between January, 1996 and December, 2000, 88 patients (11.2%) were diagnosed as NIH category IV prostatitis (asymptomatic prostatitis). We observed all pathological specimens stained with Hematoxylin-Eosine, and classified them into subtypes according to the classification criteria for prostatitis defined by True et al. (1999). We also investigated the relationship between histopathological distribution and clinical features such as PSA values, PSA density, the incidence of pyuria or bacteriuria. In the histopathological study, grade distributions were 12.5% (11/88) in mild, 71.6% (63/88) in moderate, and 15.9% (14/88) in severe. Location distributions were 2.3% (2/88) in glandular, 68.2% (60/88) in periglandular, and 29.5% (26/88) in stromal. No relationship between these subtypes and clinical features was recognized statistically. However, 7 patients (7.95%) were diagnosed as prostate cancers, later. Pyuria was found in 29.1% (23/79). Bacteriuria was present in 14.3% (11/77). Isolated bacteria were 4 strains of Enterococcus faccalis, 2 strains of each of Pseudomonas aeruginosa and Staphylococcus aureus, and one strain of each of Escherichia coli, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Staphylococcus haemolyticus, and Staphylococcus epidermidis. Gram positive rod, and Candida sp. No relationship between these subtypes and bacterial species was recognized. These results indicated that the incidence of NIII category IV prostatits

  9. Energy Scaling of Spin Tune due to RHIC Snakes

    SciTech Connect

    MacKay,W.W.

    2009-01-02

    For a ring like RHIC with two full Siberian snakes on opposite sides of the ring, the spin tune for a flat orbit will be 1/2 if the snake rotation axes are perpendicular, {Delta}{phi} = {phi}{sub 9}-{phi}{sub 3} = {pi}/2. Here {phi}{sup 9} and {phi}{sub 3} are respectively the direction of the rotation axes of the 9 o'clock and 3 o'clock snakes relative to the design trajectory as shown in Figure 1. If the two snakes are slightly detuned by the same amount such that the rotation axes are no longer perpendicular, then the deviation of the closed-orbit spin tune {nu}{sub 0} from 1/2 is given by {Delta}{nu}{sub 0} {approx_equal} ({Delta}{mu}){sup 2}/4{pi} cosG{gamma}{pi} - 2{Delta}{phi}/{pi} {approx_equal} 2{Delta}{phi}/180{sup o} with G{gamma} at a half integer, and where {Delta}{mu} is the deviation of snake rotation angle from 180{sup o}. It should be noted that there is a sign ambiguity in {Delta}{mu}{sub 0} since a spin tune of 0.495 is also a spin tune of 0.505, depending on the direction taken along the stable spin axis. In order to understand the effect of energy scaling on the snake axis direction, I have integrated the trajectory and spin rotation through a model of a RHIC snake (bi9-snk7) and found the energy (U) dependence of the snake axis angle {phi}{sub 9} and rotation angle {mu} as shown. A {approx_equal} p{sup -2} scaling of errors is typical in helical snakes. To first order, the orbit excursion drops as p{sup -1} and the spin precessions about transverse fields increase as {gamma} giving an approximate cancellation with energy, so we do not expect much change during the field ramp. The next order term which comes in is primarily proportional to p{sup -2}; although naively one might expect a slight effect inversely proportional to the velocity since {gamma}/p {proportional_to} c/{nu} {approx_equal} 1 + 1/2{gamma}{sup 2}.

  10. Commission 10: Solar Activity

    NASA Astrophysics Data System (ADS)

    van Driel-Gesztelyi, Lidia; Schrijver, Carolus J.; Klimchuk, James A.; Charbonneau, Paul; Fletcher, Lyndsay; Hasan, S. Sirajul; Hudson, Hugh S.; Kusano, Kanya; Mandrini, Cristina H.; Peter, Hardi; Vršnak, Bojan; Yan, Yihua

    2012-04-01

    Commission 10 of the International Astronomical Union has more than 650 members who study a wide range of activity phenomena produced by our nearest star, the Sun. Solar activity is intrinsically related to solar magnetic fields and encompasses events from the smallest energy releases (nano- or even picoflares) to the largest eruptions in the Solar System, coronal mass ejections (CMEs), which propagate into the Heliosphere reaching the Earth and beyond. Solar activity is manifested in the appearance of sunspot groups or active regions, which are the principal sources of activity phenomena from the emergence of their magnetic flux through their dispersion and decay. The period 2008-2009 saw an unanticipated extended solar cycle minimum and unprecedentedly weak polar-cap and heliospheric field. Associated with that was the 2009 historical maximum in galactic cosmic rays flux since measurements begun in the middle of the 20th Century. Since then Cycle 24 has re-started solar activity producing some spectacular eruptions observed with a fleet of spacecraft and ground-based facilities. In the last triennium major advances in our knowledge and understanding of solar activity were due to continuing success of space missions as SOHO, Hinode, RHESSI and the twin STEREO spacecraft, further enriched by the breathtaking images of the solar atmosphere produced by the Solar Dynamic Observatory (SDO) launched on 11 February 2010 in the framework of NASA's Living with a Star program. In August 2012, at the time of the IAU General Assembly in Beijing when the mandate of this Commission ends, we will be in the unique position to have for the first time a full 3-D view of the Sun and solar activity phenomena provided by the twin STEREO missions about 120 degrees behind and ahead of Earth and other spacecraft around the Earth and ground-based observatories. These new observational insights are continuously posing new questions, inspiring and advancing theoretical analysis and

  11. Commission 45: Spectral Classification

    NASA Astrophysics Data System (ADS)

    Giridhar, Sunetra; Gray, Richard O.; Corbally, Christopher J.; Bailer-Jones, Coryn A. L.; Eyer, Laurent; Irwin, Michael J.; Kirkpatrick, J. Davy; Majewski, Steven; Minniti, Dante; Nordström, Birgitta

    This report gives an update of developments (since the last General Assembly at Prague) in the areas that are of relevance to the commission. In addition to numerous papers, a new monograph entitled Stellar Spectral Classification with Richard Gray and Chris Corbally as leading authors will be published by Princeton University Press as part of their Princeton Series in Astrophysics in April 2009. This book is an up-to-date and encyclopedic review of stellar spectral classification across the H-R diagram, including the traditional MK system in the blue-violet, recent extensions into the ultraviolet and infrared, the newly defined L-type and T-type spectral classes, as well as spectral classification of carbon stars, S-type stars, white dwarfs, novae, supernovae and Wolf-Rayet stars.

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

    SciTech Connect

    Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; D’Ottavio, 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.

    2010-05-23

    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.

  13. SUMMARY OF THE RHIC PERFORMANCE DURING THE FY07 HEAVY ION RUN

    SciTech Connect

    DREES,A.; AHRENS, L.; ALESSI, J.; BAI, M.; BARTON, D.; ET AL.

    2007-06-25

    After the last successful RHIC Au-Au run in 2004 (Run-4), RHIC experiments now require significantly enhanced luminosity to study very rare events in heavy ion collisions. RHIC has demonstrated its capability to operate routinely above its design average luminosity per store of 2x10{sup 25}cm{sup -2}s{sup -1}. In Run-4 we already achieved 2.5 times the design luminosity in RHIC. This luminosity was achieved with only 40% of the total possible number of bunches filled, and with $'* = 1 m. However, the goal is to reach 4 times the design luminosity, an average of 8x 1 by reducing the P* value and increasing the number of bunches to the accelerator maximum of Figure 1 : Integrated delivered luminosity for the four IRs with 11 1. In addition, the average time at store was expected to the minimum and maximum predictions up to June 18,2007. be increased by a factor of 1.1 to about 60% of calendar time. We present an overview of the changes that increased the instantaneous luminosity, luminosity lifetime and integrated luminosity of RHIC Au-Au operations during Run-7 even though the goal of 60% time at store could not be reached.

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

    SciTech Connect

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

    2011-03-28

    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.

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

    SciTech Connect

    Bai, Mei

    2007-03-28

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

  16. ERL with non-scaling fixed field alternating gradient lattice for eRHIC

    SciTech Connect

    Trbojevic, D.; Berg, J. S.; Brooks, S.; Hao, Y.; Litvinenko, V. N.; Liu, C.; Meot, F.; Minty, M.; Ptitsyn, V.; Roser, T.; Thieberger, P.; Tsoupas, N.

    2015-05-03

    The proposed eRHIC electron-hadron collider uses a "non-scaling FFAG" (NS-FFAG) lattice to recirculate 16 turns of different energy through just two beam lines located in the RHIC tunnel. This paper presents lattices for these two FFAGs that are optimized for low magnet field and to minimize total synchrotron radiation across the energy range. The higher number of recirculations in the FFAG allows a shorter linac (1.322GeV) to be used, drastically reducing cost, while still achieving a 21.2 GeV maximum energy to collide with one of the existing RHIC hadron rings at up to 250GeV. eRHIC uses many cost-saving measures in addition to the FFAG: the linac operates in energy recovery mode, so the beams also decelerate via the same FFAG loops and energy is recovered from the interacted beam. All magnets will be constructed from NdFeB permanent magnet material, meaning chillers and large magnet power supplies are not needed. This paper also describes a small prototype ERL-FFAG accelerator that will test all of these technologies in combination to reduce technical risk for eRHIC.

  17. Magic Lenses for RHIC: Compensating Beam-beam Interaction (488th Brookhaven Lecture)

    SciTech Connect

    Luo, Yun

    2013-07-17

    Scientists at Brookhaven Lab’s Relativistic Heavy Ion Collider (RHIC) smash atomic particles together to understand more about why the physical world works the way it does. Increasing rates of particle collisions, or luminosity, at RHIC is no small challenge, but the results—more data for better clues—are crucial for scientists trying answer big questions about the origins of matter and mass. When scientists at RHIC collide protons, they don’t hope for a head-on crash by focusing only two particles roaring toward each other from opposite directions. For all intents and purposes, that would be impossible. The scientists can smash protons because they significantly increase the likelihood of collisions by steering hundreds of billions clumped into bunches, which at RHIC are about 3.5 meters long and less than 1 millimeter tall. The particles of these bunches are all positively charged, so when they interact, they repel outwardly—think how magnets repel when their same poles are pushed together. Although this decreases the density of each bunch, reducing luminosity, scientists in Brookhaven Lab’s Collider-Accelerator Department (C-AD) have a solution. After more than seven years of development, the scientists have designed an electron-lens system that uses electrons’ negative charges to attract positively charged proton bunches and minimize their repelling tendencies. Combined with other upgrades to the RHIC accelerator complex, these lenses are important components in efforts towards the major task of doubling the luminosity for proton-proton collisions.

  18. Future of the Beam Energy Scan program at RHIC

    SciTech Connect

    Odyniec, Grazyna; Bravina, L.; Foka, Y.; Kabana, S.

    2015-05-29

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of the QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation.

  19. Beam optics and the pp2pp experiment at RHIC

    SciTech Connect

    Pile P. H.; Guryn, W.; Lee, J.H.; Tepikian, S.; Yip, K.

    2012-05-20

    The newly installed forward detector system at the STAR experiment at RHIC measures small angle elastic and inelastic scattering of polarized protons on polarized protons. The detector system makes use of a pair of Roman Pot (RP) detectors, instrumented with silicon detectors, and located on either side of the STAR intersection region downstream of the DX and D0 dipoles and quadrupole triplets. The parallel to point optics is designed so that scattering angles are determined from position measurements at the RP's with small error. The RP setup allows measurement of position and angle for a subset of the scattered protons. With this position/angle correlations at the RP's can be compared with optics model predictions to get a measure of the accuracy of the quadrupole triplet current settings. The current in each quadrupole in the triplets is comprised of sums and differences of up to six power supplies and an overall 1% error in the triplet field strengths results in a 4% error in four-momentum transfer squared. This technique is also useful to check the polarity of the skew elements located in each quadrupole triplet. Results of the analysis will be presented.

  20. Future of the Beam Energy Scan program at RHIC

    DOE PAGES

    Odyniec, Grazyna; Bravina, L.; Foka, Y.; ...

    2015-05-29

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of themore » QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation.« less

  1. STUDY OF THE RHIC BPM SMA CONNECTOR FAILURE PROBLEM

    SciTech Connect

    LIAW,C.; SIKORA, R.; SCHROEDER, R.

    2007-06-25

    About 730 BPMs are mounted on the RHIC CQS and Triplet super-conducting magnets. Semi-rigid coaxial cables are used to bring the electrical signal from the BPM feedthroughs to the outside flanges. at the ambient temperature. Every year around 10 cables will lose their signals during the operation. The connection usually failed at the warm end of the cable. The problems were either the solder joint failed or the center conductor retracted out of the SMA connector. Finite element analyses were performed to understand the failure mechanism of the solder joint. The results showed that (1) The SMA center conductor can separate from the mating connector due to the thermal retraction. (2) The maximum thermal stress at the warm end solder joint can exceed the material strength of the Pb37/Sn63 solder material and (3) The magnet ramping frequency (-10 Hz), during the machine startup, can possibly resonant the coaxial cable and damage the solder joints, especially when a fracture is initiated. Test results confirmed that by using the silver bearing solder material (a higher strength material) and by crimping the cable at the locations close to the SMA connector (to prevent the center conductor from retracting) can effectively resolve the connector failure problem.

  2. Conceptual design report for the Solenoidal Tracker at RHIC

    SciTech Connect

    Not Available

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it's experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  3. Conceptual design report for the Solenoidal Tracker at RHIC

    SciTech Connect

    The STAR Collaboration

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it`s experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  4. SEXTANT: Navigating by Cosmic Beacon

    NASA Video Gallery

    Imagine a technology that would allow space travelers to transmit gigabytes of data per second over interplanetary distances or to navigate to Mars and beyond using powerful beams of light emanatin...

  5. Model Commissioning Plan and Guide Specifications

    SciTech Connect

    1997-03-01

    The objectives of Model Commissioning Plan and Guide Specifications are to ensure that the design team applies commissioning concepts to the design and prepares commissioning specifications and a commission plan for inclusion in the bid construction documents.

  6. Commissioning of NSLS-II

    SciTech Connect

    Willeke, F.

    2015-05-03

    NSLS-II, the new 3rd generation light source at BNL was designed for a brightness of 1022 photons s-1mm-2mrad-2 (0.1%BW)-1. It was constructed between 2009 and 2014. The storage ring was commissioned in April 2014 which was followed by insertion device and beamline commissioning in the fall of 2014. All ambitious design parameters of the facility have already been achieved except for commissioning the full beam intensity of 500mA which requires more RF installation. This paper reports on the results of commissioning.

  7. LIGO Detector Commissioning

    NASA Astrophysics Data System (ADS)

    Raab, Frederick

    2003-04-01

    The initial LIGO interferometer design was based on more than 20 years of experience with test interferometers, but the increase in scale, new operating environments and extreme technical requirements presented challenges for commissioning. Detector installation began in 1998 with injection optics at Hanford, WA. By 1999, light was resonating in a single 2-km Fabry-Perot arm cavity. Subsequent engineering runs tested stability and analyzed environmental influences, particularly the earth tides and the microseism. By October 2000, the first lock of a kilometer-scale, power recycled Fabry-Perot-Michelson interferometer was obtained, using an automated system to analyze optical signals and reconfigure control loops as the mirrors are drawn into position. The many control loops that minimize length and angle fluctuations of the mirrors relative to the laser light were tuned and noise sources were identified and reduced iteratively as sensitivity improved by several orders of magnitude. Following installation of the last LIGO mirror in 2001, engineering run 7 provided the first triple-coincidence operation of LIGO's interferometers at Hanford and Livingston, LA in early 2002. Clear signals of mirrors recoiling from the Brownian motion of the suspension-wire violin modes first emerged from the noise during science run 1 in September 2002, at approximately the expected amplitude. Detector robustness has steadily improved and uninterrupted locking on a dark fringe for more than a day has been achieved. The support of the US National Science Foundation under Cooperative Agreement No. PHY-0107417 is gratefully acknowledged.

  8. National Knowledge Commission

    NASA Astrophysics Data System (ADS)

    Pitroda, Sam

    2007-04-01

    India's National Knowledge Commission (NKC) established by the prime minister is focused on building institutions and infrastructure in Education, Science and Technology, Innovation etc. to meet the challenges of the knowledge economy in the 21st century and increase India's competitive advantage in the global market. India today stands poised to reap the benefits of a rapidly growing economy and a major demographic advantage, with 550 million young people below the age of 25 years, the largest in the world. The NKC is focused on five critical areas of knowledge related to access, concepts, creation, applications and services. This includes a variety of subject areas such as language, translations, libraries, networks, portals, affirmative action, distance learning, intellectual property, Entrepreneurship, application in Agriculture, health, small and medium scale industries, e-governance etc. One of the keys to this effort is to build a national broadband gigabit of networks of 500 nodes to connect universities, Libraries, Laboratories, Hospitals, Agriculture institutions etc. to share resources and collaborate on multidisciplinary activities. This presentation will introduce the NKC, discuss methodology, subject areas, specific recommendation and outline a plan to build knowledge networks and specifics on network architecture, applications, and utilities.

  9. Commissioning the SNO+ detector

    NASA Astrophysics Data System (ADS)

    Descamps, Freija; SNO+ Collaboration

    2016-09-01

    The SNO+ experiment is the successor to the Sudbury Neutrino Observatory (SNO), in which SNO's heavy water is replaced by approximately 780T of liquid scintillator (LAB). The combination of the 2km underground location, the use of ultra-clean materials and the high light-yield of the liquid scintillator means that a low background level and a low energy threshold can be achieved. This creates a new multipurpose neutrino detector with the potential to address a diverse set of physics goals, including the detection of reactor, solar, geo- and supernova neutrinos. A main physics goal of SNO+ is the search for neutrinoless double beta decay. By loading the liquid scintillator with 0.5% of natural Tellurium, resulting in about 1300kg of 130Te (isotopic abundance is slightly over 34%), a competitive sensitivity to the effective neutrino mass can be reached. This talk will present the status of the SNO+ detector, specifically the results and status of the detector commissioning with water.

  10. Electron lenses for head-on beam-beam compensation in RHIC

    NASA Astrophysics Data System (ADS)

    Gu, X.; Fischer, W.; Altinbas, Z.; Anerella, M.; Bajon, E.; Bannon, M.; Bruno, D.; Costanzo, M.; Drees, A.; Gassner, D. M.; Gupta, R. C.; Hock, J.; Harvey, M.; Jain, A. K.; Jamilkowski, J. P.; Kankiya, P.; Lambiase, R.; Liu, C.; Luo, Y.; Mapes, M.; Marusic, A.; Mi, C.; Michnoff, R.; Miller, T. A.; Minty, M.; Nemesure, S.; Ng, W.; Phillips, D.; Pikin, A. I.; Rosas, P. J.; Robert-Demolaize, G.; Samms, T.; Sandberg, J.; Schoefer, V.; Shrey, T. C.; Tan, Y.; Than, R.; Theisen, C.; Thieberger, P.; Tuozzolo, J.; Wanderer, P.; Zhang, W.; White, S. M.

    2017-02-01

    Two electron lenses (e -lenses) have been in operation during the 2015 RHIC physics run as part of a head-on beam-beam compensation scheme. While the RHIC lattice was chosen to reduce the beam-beam-induced resonance-driving terms, the electron lenses reduced the beam-beam-induced tune spread. This has been demonstrated for the first time. The beam-beam compensation scheme allows for higher beam-beam parameters and therefore higher intensities and luminosity. In this paper, we detail the design considerations and verification of the electron beam parameters of the RHIC e -lenses. Longitudinal and transverse alignments with ion beams and the transverse beam transfer function measurement with head-on electron-proton beam are presented.

  11. NUMERICAL STUDIES OF THE FRICTION FORCE FOR THE RHIC ELECTRON COOLER.

    SciTech Connect

    FEDOTOV,A.V.; BEN-ZVI,I.; LITVINENKO, V.

    2005-05-16

    Accurate calculation of electron cooling times requires an accurate description of the dynamical friction force. The proposed RHIC cooler will require {approx}55 MeV electrons, which must be obtained from an RF linac, leading to very high transverse electron temperatures. A strong solenoid will be used to magnetize the electrons and suppress the transverse temperature, but the achievable magnetized cooling logarithm will not be large. In this paper, we explore the magnetized friction force for parameters of the RHIC cooler, using the VORPAL code [l]. VORPAL can simulate dynamical friction and diffusion coefficients directly from first principles [2]. Various aspects of the fiction force are addressed for the problem of high-energy electron cooling in the RHIC regime.

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

    SciTech Connect

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

    2007-06-25

    The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

  13. Design aspects of an electrostatic electron cooler for low-energy RHIC operation

    SciTech Connect

    Fedotov, A.; Ben-Zvi, I.; Brodowski, J.; Chang, X.Y.; Gassner, D.; Hoff, L.; Kayran, D.; Kewisch, J.; Oerter, B.; Pendzick, A.; Tepikian, S.; Thieberger, P.; Prost, L.; Shemyakin, A.

    2011-03-28

    Electron cooling was proposed to increase the luminosity of the Relativistic Heavy Ion Collider (RHIC) operation for heavy ion beam energies below 10 GeV/nucleon. The electron cooling system needed should be able to deliver an electron beam of adequate quality in a wide range of electron beam energies (0.9-5 MeV). An option of using an electrostatic accelerator to produce electrons for cooling heavy ions in RHIC was evaluated in detail. In this paper, we describe the requirements and options which were considered in the design of such a cooler for RHIC, as well as the associated challenges. The expected luminosity improvement and limitations with such an electron cooling system are also discussed.

  14. The effects of the RHIC E-lenses magnetic structure layout on the proton beam trajectory

    SciTech Connect

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

    2011-03-28

    We are designing two electron lenses (E-lens) to compensate for the large beam-beam tune spread from proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). They will be installed in RHIC IR10. First, the layout of these two E-lenses is introduced. Then the effects of e-lenses on proton beam are discussed. For example, the transverse fields of the e-lens bending solenoids and the fringe field of the main solenoids will shift the proton beam. For the effects of the e-lens on proton beam trajectory, we calculate the transverse kicks that the proton beam receives in the electron lens via Opera at first. Then, after incorporating the simplified E-lens lattice in the RHIC lattice, we obtain the closed orbit effect with the Simtrack Code.

  15. Optimization of dynamic aperture for hadron lattices in eRHIC

    SciTech Connect

    Jing, Yichao; Litvinenko, Vladimir; Trbojevic, Dejan

    2015-05-03

    The potential upgrade of the Relativistic Heavy Ion Collider (RHIC) to an electron ion collider (eRHIC) involves numerous extensive changes to the existing collider complex. The expected very high luminosity is planned to be achieved at eRHIC with the help of squeezing the beta function of the hadron ring at the IP to a few cm, causing a large rise of the natural chromaticities and thus bringing with it challenges for the beam long term stability (Dynamic aperture). We present our effort to expand the DA by carefully tuning the nonlinear magnets thus controlling the size of the footprints in tune space and all lower order resonance driving terms. We show a reasonably large DA through particle tracking over millions of turns of beam revolution.

  16. Mimicking bipolar sextupole power supplies for low-energy operations at RHIC

    SciTech Connect

    Montag, C.; Bruno, D.; Jain, A.; Robert-Demolaize, G.; Satogata, T.; Tepikian, S.

    2011-03-28

    RHIC operated at energies below the nominal ion injection energy of E=9.8 GeV/u in 2010. Earlier test runs and magnet measurements indicated that all defocusing sextupole unipolar power supplies should be reversed to provide the proper sign of chromaticity. However, vertical chromaticity at E=3.85 GeV/u with this power supply configuration was still not optimal. This uncertainty inspired a new machine configuration where only half of the defocusing sextupole power supplies were reversed, taking advantage of the flexibility of the RHIC nonlinear chromaticity correction system to mimic bipolar sextupoles. This configuration resulted in a 30 percent luminosity gain and eliminated the need for further polarity changes for later 2010 low energy physics operations. Here we describe the background to this problem, operational experience, and RHIC online model changes to implement this solution.

  17. Measuring two-particle Bose-Einstein correlations with PHOBOS@RHIC

    SciTech Connect

    Betts, R.; Barton, D.; Carroll, A.

    1995-07-15

    The authors present results of a simulation of the measurement of two-particle Bose-Einstein correlations in central Au-Au collisions with the PHOBOS detector at RHIC. This measurement is expected to yield information on the relevant time and distance scales in these collisions. As the space-time scale is directly connected with the equation of state governing the evolution of the particle source, this information will be essential in understanding the physics of nucleus-nucleus collisions at RHIC energies. The authors demonstrate that the PHOBOS detector has sufficient resolution and acceptance to distinguish a variety of physics scenarios.

  18. Measuring two-particle Bose-Einstein correlations with PHOBOS@RHIC

    SciTech Connect

    Betts, R.; Barton, D.; Carroll, A.

    1995-12-31

    We present results of a simulation of the measurement of two-particle Bose-Einstein correlations in central Au-Au collisions with the PHOBOS detector at RHIC. This measurement is expected to yield information on the relevant time and distance scales in these collisions. As the space-time scale is directly connected with the equation of state governing the evolution of the particle source, this information will be essential in understanding the physics of nucleus-nucleus collisions at RHIC energies. We demonstrate that the PHOBOS detector has sufficient resolution and acceptance to distinguish a variety of physics scenarios.

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

    SciTech Connect

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

    2010-03-17

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

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

    SciTech Connect

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

    2007-04-26

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

  1. Twist-3 predictions for single spin asymmetry for light-hadron productions at RHIC

    SciTech Connect

    Kanazawa, Koichi

    2011-12-14

    We present several predictions for the single spin asymmetry for the {pi}, K, and {eta}-meson productions at RHIC kinematics using the twist-3 quark-gluon correlation functions determined from our analysis of RHIC data. After discussing the P{sub T}-dependence of A{sub N}, we give predictions for A{sub N} for pions and kaons at {radical}(S) = 500 GeV and A{sub N} for the {eta}-meson at {radical}(S) = 200 GeV.

  2. Off-momentum beta-beat correction in the RHIC proton run

    SciTech Connect

    Luo Y.; Bai, M.; Fischer, W.; Marusic, A.; Mernick, K.; White, S.

    2012-05-20

    In this article, we will review the techniques to measure the off-momentum {beta}-beat and the correction algorithms with the chromatic arc sextupoles in RHIC. We will focus on the measurement and correction of the off-momentum {beta}*-beat at the interaction points. The off-momentum {beta}* is measured with the quadrupole strength change and a high resolution phase lock loop tune meter. The results of off-momentum {beta}* correction performed in a dedicated beam experiment in the 2012 RHIC 250 GeV polarized proton run are presented.

  3. Linear optics measurements and corrections using an AC dipole in RHIC

    SciTech Connect

    Wang, G.; Bai, M.; Yang, L.

    2010-05-23

    We report recent experimental results on linear optics measurements and corrections using ac dipole. In RHIC 2009 run, the concept of the SVD correction algorithm is tested at injection energy for both identifying the artificial gradient errors and correcting it using the trim quadrupoles. The measured phase beatings were reduced by 30% and 40% respectively for two dedicated experiments. In RHIC 2010 run, ac dipole is used to measure {beta}* and chromatic {beta} function. For the 0.65m {beta}* lattice, we observed a factor of 3 discrepancy between model and measured chromatic {beta} function in the yellow ring.

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

    SciTech Connect

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

    2001-06-18

    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.

  5. eRHIC ring-ring design with head-on beam-beam compensation

    SciTech Connect

    Montag,C.; Blaskiewicz, M.; Pozdeyev, E.; Fischer, W.; MacKay, W. W.

    2009-05-04

    The luminosity of the eRHIC ring-ring design is limited by the beam-beam effect exerted on the electron beam. Recent simulation studies have shown that the beam-beam limit can be increased by means of an electron lens that compensates the beam-beam effect experienced by the electron beam. This scheme requires proper design of the electron ring, providing the correct betatron phase advance between interaction point and electron lens. We review the performance of the eRHIC ring-ring version and discuss various parameter sets, based on different cooling schemes for the proton/ion beam.

  6. Optics measurement and correction during acceleration with beta-squeeze in RHIC

    SciTech Connect

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

    2015-05-03

    In the past, beam optics correction at RHIC has only taken place at injection and at final energy, with interpolation of corrections partially into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats that, if corrected, could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoiding the high-order multipole fields sampled by particles within the bunch. We recently demonstrated successful beam optics corrections during acceleration at RHIC. We verified conclusively the superior control of the beam realized via these corrections

  7. Research and development of RHIC injection kicker upgrade with nano second FID pulse generator

    SciTech Connect

    Zhang W.; Sandberg, J.; Hahn, H.; Fischer, W.; Liaw, C.J.; Pai, C.; Tuozzolo, J.

    2012-05-20

    Our recent effort to test a 50 kV, 1 kA, 50 ns pulse width, 10 ns pulse rise time FID pulse generator with a 250 ft transmission cable, resistive load, and existing RHIC injection kicker magnet has produced unparalleled results. This is the very first attempt to drive a high strength fast kicker magnet with a nano second high pulsed power (50 MVA) generator for large accelerator and colliders. The technology is impressive. We report here the result and future plan of RHIC Injection kicker upgrade.

  8. γ production as a probe for early state dynamics in high energy nuclear collisions at RHIC

    DOE PAGES

    Liu, Yunpeng; Chen, Baoyi; Xu, Nu; ...

    2011-02-01

    γ production in heavy ion collisions at RHIC energy is investigated. While the transverse momentum spectra of the ground state γ(1s) are controlled by the initial state Cronin effect, the excited bb⁻ states are characterized by the competition between the cold and hot nuclear matter effects and sensitive to the dissociation temperatures determined by the heavy quark potential. We emphasize that it is necessary to measure the excited heavy quark states in order to extract the early stage information in high energy nuclear collisions at RHIC.

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

    SciTech Connect

    Zeno, K.

    2014-08-18

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

  10. An orbit fit program for localizing errors in RHIC

    SciTech Connect

    Liu, C.; Minty, M.; Ptitsyn, V.

    2011-11-01

    Many errors in an accelerator are evidenced as transverse kicks to the beam which distort the beam trajectory. Therefore, the information of the errors are imprinted in the distorted orbits, which are different from what would be predicted by the optics model. In this note, we introduce an algorithm for fitting the orbit based on an on-line optics model. By comparing the measured and fitted orbits, we first present results validating the algorithm. We then apply the algorithm and localize the location of the elusive source of vertical diurnal variations observed in RHIC. The difference of two trajectories (linear accelerator) or closed orbits (storage ring) should match exactly a betatron oscillation, which is predictable by the optics model, in an ideal machine. However, in the presence of errors, the measured trajectory deviates from prediction since the model is imperfect. Comparison of measurement to model can be used to detect such errors. To do so the initial conditions (phase space parameters at any point) must be determined which can be done by comparing the difference orbit to prediction using only a few beam position monitors (BPMs). The fitted orbit can be propagated along the beam line based on the optics model. Measurement and model will agree up to the point of an error. The error source can be better localized by additionally fitting the difference orbit using downstream BPMs and back-propagating the solution. If one dominating error source exist in the machine, the fitted orbit will deviate from the difference orbit at the same point.

  11. Reflections on the Gordon Commission

    ERIC Educational Resources Information Center

    Haertel, Edward

    2014-01-01

    Background:This brief reflection on the work of the Gordon Commission calls out significant themes and implications found in the various papers authored by the commissioners and other scholars, especially those included in this special issue of Teachers College Record. Purpose: The forward-looking vision of the Gordon Commission is contrasted with…

  12. Vermont Technical Education Commission Report.

    ERIC Educational Resources Information Center

    Vermont State Technical Education Commission, Montpelier.

    A 1968 New England Regional Commission grant to the Vermont Department of Administration financed a feasibility study for a technical college at the postsecondary level. The commission undertook two specific studies: an examination of ultimate career destinations of Vermont secondary students and a survey of Vermont industry to determine immediate…

  13. Commission 31: Time

    NASA Astrophysics Data System (ADS)

    Matsakis, Demetrios; Defraigne, Pascale; Hosokawa, M.; Leschiutta, S.; Petit, G.; Zhai, Z.-C.

    2007-03-01

    The most intensely discussed and controversial issue in time keeping has been the proposal before the International Telecommunications Union (ITU) to redefine Coordinated Universal Time (UTC) so as to replace leap seconds by leap hours. Should this proposal be adopted, the practice of inserting leap seconds would cease after a specific date. Should the Earth's rotation continue to de-accelerate at its historical rate, the next discontinuity in UTC would be an hour inserted several centuries from now. Advocates of this proposal cite the need to synchronize satellite and other systems, such as GPS, Galileo, and GLONASS, which did not exist and were not envisioned when the current system was adopted. They note that leap second insertions can be and have been incorrectly implemented or accounted for. Such errors have to date had localized impact, but they could cause serious mishaps involving loss of life. For example, some GPS receivers have been known to fail simply because there was no leap second after a long enough interval, other GPS receivers failed because the leap second information was broadcast more than three months in advance, and some commercial software used for internet time-transfer Network Time Protocol (NTP) could either discard all data received after a leap second or interpret it as a frequency change. The ambiguity associated with the extra second could also disrupt financial accounting and certain forms of encryption. Those opposed to the proposal question the need for a change, and also point out the costs of adjusting to the proposed change and its inconvenience to amateur astronomers and others who rely upon astronomical calculations published in advance. Reports have been circulated that the cost of checking and correcting software to accommodate the new definition of UTC would be many millions of dollars for some systems. In October 2005 American Astronomical Society asked the ITU for a year's time to study the issue. This commission has

  14. DESIGN CONSIDERATIONS FOR THE MECHANICAL TUNER OF THE RHIC ELECTRON COOLER RF CAVITY.

    SciTech Connect

    RANK, J.; BEN-ZVI,I.; HAHN,G.; MCINTYRE,G.; DALY,E.; PREBLE,J.

    2005-05-16

    The ECX Project, Brookhaven Lab's predecessor to the RHIC e-Cooler, includes a prototype RF tuner mechanism capable of both coarse and fast tuning. This tuner concept, adapted originally from a DESY design, has longer stroke and significantly higher loads attributable to the very stiff ECX cavity shape. Structural design, kinematics, controls, thermal and RF issues are discussed and certain improvements are proposed.

  15. A new detector at RHIC, sPHENIX goals and status

    NASA Astrophysics Data System (ADS)

    Reed, Rosi; sPHENIX Collaboration

    2017-01-01

    The study of heavy-ion collisions, which can create a new form matter, a nearly ideal strongly interacting fluid where quarks and gluons are no longer confined into nucleons, called Quark Gluon Plasma (QGP), is on the frontier of QCD studies. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab (BNL) has had a long and successful program of QGP study since 2000, with many upgrades that have increased the delivered luminosity considerably in the last decade. The sPHENIX proposal is for a second generation experiment at RHIC, which will take advantage of the increased luminosity, and allow measurements of jets, jet correlations and Upsilons (ϒs), with a kinematic reach that will overlap with measurements made at the Large Hadron Collider (LHC). Complementary measurements at RHIC and at the LHC probe the QGP at different temperatures and densities, which are necessary to determine the temperature dependence of transport coefficients of the QGP. The sPHENIX detector will have large acceptance electromagnetic and hadronic calorimetry, as well as precision tracking, and high rate capability which are necessary for precision jet and ϒ observables. The experiment will enable a program of systematic measurements at RHIC, with a detector capable of acquiring a large sample of events in p+p, p+A, and A+A collisions. This proceedings outlines the key measurements enabled by the new detector, and status of the project itself.

  16. Beam experiments related to the head-on beam-beam compensation project at RHIC

    SciTech Connect

    Montag, C.; Bai, M.; Drees, A.; Fischer, W.; Marusic, A.; Wang, G.

    2011-03-28

    Beam experiments have been performed in RHIC to determine some key parameters of the RHIC electron lenses, and to test the capability of verifying lattice modifications by beam measurements. We report the status and recent results of these experiments. The Relativistic Heavy Ion Collider (RHIC) consists of two superconducting storage rings that intersect at six locations around its circumference. Beams collide in interaction points (IPs) 6 and 8, which are equipped with the detectors STAR and PHENIX, respectively (Fig. 1). With the polarized proton working point constrained between 2/3 and 7/10 to achieve good luminosity lifetime and maintain polarization, the proton bunch intensity is limited to 2 {center_dot} 10{sup 11} protons per bunch by the resulting beam-beam tuneshift. To overcome this limitation, installation of an electron lens in IP 10 is foreseen to partially compensate the beam-beam effect and reduce the beam-beam tuneshift parameter. As part of this project, beam experiments are being performed at RHIC to determine key parameters of the electron lens as well as to verify lattice modifications.

  17. Combined element magnet production for the relativistic heavy ion collider (RHIC) at BNL

    SciTech Connect

    Mulhall, S.; Foelsche, H.; Ganetis, G.

    1995-05-01

    The production of 432 combined element magnets for RHIC is well underway. These magnets consist of a superconducting corrector, a quadrupole, and a sextupole combined into an integrated cold mass which is inserted into a cryostat. Production experiences as well as test results are reported.

  18. Setup and performance of RHIC for the 2008 run with deuteron-gold collisions.

    SciTech Connect

    Gardner,C.; Abreu, N.P.; Ahren, L.; Alessi, J.; Bai, M.; et al.

    2008-06-23

    This year (2008) deuterons and gold ions were collided in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) for the first time since 2003. The setup and performance of the collider for the 2008 run is reviewed with a focus on improvements that have led to an order of magnitude increase in luminosity over that achieved in the 2003 run.

  19. Wake fields and energy spread for the eRHIC ERL

    SciTech Connect

    Fedotov, A.; Kayran, D.

    2011-10-16

    Wake fields in high-current ERLs can cause significant beam quality degradations. Here we summarize effects of coherent synchrotron radiation, resistive wall, accelerating cavities and wall roughness for ERL parameters of the eRHIC project. A possibility of compensation of such correlated energy spread is also presented. An emphasis in the discussion is made on the suppression of coherent synchrotron radiation due to shielding and a possible reduction of wall roughness effects for realistic surfaces. In this report we discuss the wake fields with a focus on their effect on the energy spread of the beam. Other effects of wake fields are addressed elsewhere. An energy spread builds up during a pass though a very long beam transport in the eRHIC ERL under design. Such energy spread become important when beam is decelerated to low energy, and needs to be corrected. Several effects, such as Coherent Synchrotron Radiation (CSR), Resistive Wall (RW), accelerating RF cavities (RF) and Wall Roughness (WR) were considered. In this paper, we briefly summarize major contributions to energy spread from the wake fields for eRHIC parameters, and present possible energy spread compensation for decelerated beam. In the rest of the report we discuss effects which we believe are suppressed for the eRHIC parameters.

  20. CHARGED PARTICLE PRODUCTION AT HIGH RAPIDITY IN p+p COLLISIONS AT RHIC.

    SciTech Connect

    DEBBE,R.

    2006-05-30

    This report describes the recent analysis of identified charged particle production at high rapidity performed on data collected from p+p collisions at RHIC ({radical}s = 200 GeV). The extracted invariant cross-sections compare well to NLO pQCD calculations. However, a puzzling high yield of protons at high rapidity and p{sub T} has been found.