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RF TECHNIQUES FOR IMPROVED LUMINOSITY IN RHIC.

Description: The luminosity of the Relativistic Heavy Ion Collider has improved significantly [1] over the first three physics runs. A number of special rf techniques have been developed to facilitate higher luminosity. The techniques described herein include: an ultra low-noise rf source for the 197 MHz storage rf system, a frequency shift switch-on technique for transferring bunches from the acceleration to the storage system, synchronizing the rings during the energy ramp (including crossing the transiti… more
Date: July 5, 2004
Creator: BRENNAN,J. M. BLASKIEWICZ,J. BUTLER,J. DELONG,J. FISCHER,W. HAYES,T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A Low Noise RF Source for RHIC

Description: 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 provide… more
Date: July 5, 2004
Creator: Hayes, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Investigating the Heating of a Potassium-Doped Aluminosilicate Ion Source Using a 1 Micron Laser

Description: The heavy ion fusion (HIF) program is interested in developing a high brightness ion source for high energy density physics (HEDP) experiments. One possible approach to obtaining higher brightness may be to raise the surface temperature of the ion source just prior to extraction. The current ion source material being studied is a layer of potassium-doped aluminosilicate bonded to a tungsten substrate. It is speculated that if the surface temperature of the source is raised above 1200 C (from a … more
Date: December 14, 2004
Creator: Schmitt, R. C.; Meier, W. R.; Kwan, J. W.; Abbott, R. P. & Latkowski, J. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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PROPOSAL FOR A SILICON VERTEX TRACKER (VTX) FOR THE PHENIX EXPERIMENT.

Description: We propose the construction of a Silicon Vertex Tracker (VTX) for the PHENIX experiment at RHIC. The VTX will substantially enhance the physics capabilities of the PHENIX central arm spectrometers. Our prime motivation is to provide precision measurements of heavy-quark production (charm and beauty) in A+A, p(d)+A, and polarized p+p collisions. These are key measurements for the future RHIC program, both for the heavy ion program as it moves from the discovery phase towards detailed investigati… more
Date: March 30, 2004
Creator: AKIBA,Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Cable Design for Fast Ramped Superconducting Magnets (Cos-θ Design).

Description: The new heavy ion synchrotron facility proposed by GSI will have two superconducting magnet rings in the same tunnel, with rigidities of 300 T-m and 100 T-m. Fast ramp times are needed, which can cause significant problems for the magnets, particularly in the areas of ac loss and magnetic field distortion. The development of the low loss Rutherford cable that can be used is described, together with a novel insulation scheme designed to promote efficient cooling. Measurements of contact resistan… more
Date: March 22, 2004
Creator: Ghosh, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electron-Cloud Simulation and Theory for High-Current Heavy-Ion Beams

Description: Stray electrons can arise in positive-ion accelerators for heavy ion fusion or other applications as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary- electron emission. We summarize the distinguishing features of electron cloud issues in heavy-ion-fusion accelerators and a plan for developing a self-consistent simulation capability for heavy-ion beams and electron clouds. We also present results from several ingredients in thi… more
Date: July 26, 2004
Creator: Cohen, R; Friedman, A; Lund, S; Molvik, A; Lee, E; Azevedo, T et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High pT hadron spectra at RHIC: an overview

Description: Recent results on high transverse momentum (p{sub T}) hadron production in p+p, d+Au and Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) are reviewed. Comparison of the nuclear modification factors, R{sub dAu}(p{sub T}) and R{sub AA}(p{sub T}), demonstrates that the large suppression in central Au+Au collisions is due to strong final-state effects. Theoretical models which incorporate jet quenching via gluon Bremsstrahlung in the dense partonic medium that is expected in central … more
Date: October 11, 2004
Creator: Klay, J L
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A METHOD TO MEASURE THE FOCUSING PROPERTIES (R-MATRIX) OF A MAGNET.

Description: In this paper we discuss, and study the feasibility of a method that may be used to measure the focusing properties of a magnet. This method may prove valuable when applied to ''non-conventional'' magnets that deviate from the usual dipole magnets or other multipole magnets (quadrupoles/sextupoles etc.) which are commonly used in a synchrotron or a beam line. In this category of ''non-conventional'' magnets, fall special magnets, which come under the name ''Snakes'', which are being used in syn… more
Date: July 5, 2004
Creator: TSOUPAS,N. THIEBERGER,P. BROWN,K. GASSNER,D. GLENN,W. AHRENS,L. ROSER,T. LEE,Y. Y. WEI,J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Compensation for Bunch Emittance in a Magnetization and Space Charge Dominated Beam.

Description: In order to obtain sufficient cooling rates for the Relativistic Heavy Ion Collider (RHIC) electron cooling, a bunched beam with high bunch charge, high repetition frequency and high energy is required and it is necessary to use a ''magnetized'' beam, i.e., an electron beam with non-negligible angular momentum. Applying a longitudinal solenoid field on the cathode can generate such a beam, which rotates around its longitudinal axis in a field-free region. This paper suggests how a magnetized be… more
Date: June 21, 2004
Creator: Chang, X.; Ben-Zvi, Ilan & Kewisch, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Minijet Deformation and Charge-independent Two-particleCorrelations on Momentum Subspace (eta,phi) In Au-Au Collisions atsqrt(sNN) = 130 GeV

Description: We present first measurements of charge-independent correlations on momentum-space difference variables {eta}{sub 1}-{eta}{sub 2} (pseudorapidity) and {phi}{sub 1}-{phi}{sub 2} (azimuth) for charged primary hadrons with transverse momentum within 0.15 {le} p{sub t} {le} 2 GeV/c and |{eta}| {le} 1.3 from Au-Au collisions at {radical}s{sub NN} = 130 GeV. We observe strong charge-independent correlations associated with minijets and elliptic flow. The width of the minijet peak on {eta}{sub 1}-{eta… more
Date: November 4, 2004
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Overview of US heavy-ion fusion progress and plans

Description: Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, transport, final focusing, chambers and targets for inertial fusion energy (IFE) driven by induction linac accelerators seek to provide the scientific and technical basis for the Integrated Beam Experiment (IBX), an integrated source-to-target physics experiment recently included in the list of future facilities planned by the U.S. Department of Energy. To optimize the d… more
Date: June 1, 2004
Creator: Logan, B. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Status report on the 'Merging' of the Electron-Cloud Code POSINST with the 3-D Accelerator PIC CODE WARP

Description: We have integrated the electron-cloud code POSINST [1] with WARP [2]--a 3-D parallel Particle-In-Cell accelerator code developed for Heavy Ion Inertial Fusion--so that the two can interoperate. Both codes are run in the same process, communicate through a Python interpreter (already used in WARP), and share certain key arrays (so far, particle positions and velocities). Currently, POSINST provides primary and secondary sources of electrons, beam bunch kicks, a particle mover, and diagnostics. W… more
Date: April 19, 2004
Creator: Vay, J. L.; Furman, M. A.; Azevedo, A. W.; Cohen, R. H.; Friedman, A.; Grote, D. P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The Modular Point Design for Heavy Ion Fusion

Description: We report on an ongoing study on modular Heavy Ion Fusion drivers. The modular driver is characterized by 10 to 20 nearly identical induction linacs, each carrying a single high current beam. In this scheme, the Integrated Research Experiment (IRE) can be one of the full size induction linacs. Hence, this approach offers significant advantages in terms of driver development path. For beam transport, these modules use solenoids which are capable of carrying high line charge densities, even at lo… more
Date: September 17, 2004
Creator: Yu, S. S.; Barnard, J. J.; Briggs, R. J.; Callahan, D.; Celata, C. M.; Chao, L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Recent enhancements to the MARS15 code

Description: The MARS code is under continuous development and has recently undergone substantial improvements that further increase its reliability and predictive power in numerous shielding, accelerator, detector and space applications. The major developments and new features of the MARS15 (2004) version described in this paper concern an extended list of elementary particles and arbitrary heavy ions and their interaction cross-sections, inclusive and exclusive nuclear event generators, module for modelin… more
Date: May 12, 2004
Creator: al., Nikolai V. Mokhov et
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electron beam diagnostic for space charge measurement of an ion beam

Description: A non-perturbing electron beam diagnostic system for measuring the charge distribution of an ion beam is developed for Heavy Ion Fusion (HIF) beam physics studies. Conventional diagnostics require temporary insertion of sensors into the beam, but such diagnostics stop the beam, or significantly alter its properties. In this diagnostic a low energy, low current electron beam is swept transversely across the ion beam; the measured electron beam deflection is used to infer the charge density profi… more
Date: September 25, 2004
Creator: Roy, Prabir K.; Yu, Simon S.; Henestroza, Enrique; Eylon, Shmuel; Shuman, Derek B.; Ludvig, Jozsef et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design and characterization of a neutralized-transport experiment for heavy-ion fusion

Description: In heavy-ion inertial-confinement fusion systems, intense beams of ions must be transported from the exit of the final focus magnet system through the fusion chamber to hit millimeter-sized spots on the target. Effective plasma neutralization of intense ion beams in this final transport is essential for a heavy-ion fusion power plant to be economically competitive. The physics of neutralized drift has been studied extensively with particle-in-cell simulations. To provide quantitative comparison… more
Date: March 14, 2004
Creator: Henestroza, E.; Eylon, S.; Roy, P. K.; Yu, S. S.; Anders, A.; Bieniosek, F. M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Studies in ion source development for application in heavy ion fusion

Description: The overall purpose of these experiments is to contribute to the development of ion injector technology in order to produce a driver for use in a heavy-ion-fusion (HIF) power generating facility. The overall beam requirements for HIF are quite demanding; a short list of the constraints is the following: (1) Low cost (a large portion of overall cost will come from the beam system); (2) Bright, low emittance beam; (3) Total beam energy 5MJ; (4) Spot size 3mm (radius); (5) Pulse Duration 10ns; (6)… more
Date: May 30, 2004
Creator: Kapica, Jonathan G.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Scientific issues in future induction linac accelerators for heavy ion fusion

Description: Achievement of atomic-resolution electron-beam tomography will allow determination of the three-dimensional structure of nanoparticles (and other suitable specimens) at atomic resolution. Three-dimensional reconstructions will yield ''section'' images that resolve atoms overlapped in normal electron microscope images (projections), resolving lighter atoms such as oxygen in the presence of heavier atoms, and atoms that lie on non-lattice sites such as those in non-periodic defect structures. Our… more
Date: June 7, 2004
Creator: Celata, C. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Diagnostics for intense heavy ion beams in the HIF-VNL

Description: Modern diagnostic techniques provide detailed information on beam conditions in injector, transport, and final focus experiments in the HIF-VNL. Parameters of interest include beam current, beam energy, transverse and longitudinal distributions, emittance, and space charge neutralization. Imaging techniques, based on kapton films and optical scintillators, complement and in some cases, may replace conventional techniques based on slit scans. Time-resolved optical diagnostics that provide 4-D tr… more
Date: June 11, 2004
Creator: Bieniosek, F. M.; Eylon, S.; Faltens, A.; Friedman, A.; Kwan, J. W.; Leitner, M. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Extractor Configurations for a Heavy Ion Fusion Volume Source

Description: In order for volume sources to deliver the current (e.g., 0.8 A of Ar{sup +} per module) and brightness necessary for heavy ion fusion (HIF), they must operate at high current density. Conventional extractor designs for 1 to 2 MeV run into voltage breakdown limitations and cannot easily produce the required current rise time (about one microsecond). We discuss two systems that can overcome these volume-extraction problems. Each uses multichannel preaccelerators followed by a single channel main… more
Date: August 30, 2004
Creator: Anderson, O. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Production of e+e- Pairs Accompanied by Nuclear Dissociation in Ultra-peripheral Heavy Ion Collisions

Description: We present the first data on e{sup +}e{sup -} pair production accompanied by nuclear breakup in ultra-peripheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order corrections to the pair production cross section should be enhanced. We compare the pair kinematic distributions with two calculations: one based on the equivalent photon approximation, and the other using lowest-or… more
Date: April 7, 2004
Creator: Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Allgower, C.; Amonett, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Simulating Electron Cloud Effects in Heavy-Ion Beams

Description: Stray electrons can be introduced in heavy ion fusion accelerators as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. We summarize here results from several studies of electron-cloud accumulation and effects: (1) Calculation of the electron cloud produced by electron desorption from computed beam ion loss; the importance of ion scattering is shown; (2) Simulation of the effect of specified electron cloud dis… more
Date: August 4, 2004
Creator: Cohen, R. H.; Friedman, A.; Lund, S. W.; Molvik, A. W.; Azevedo, T.; Vay, J. L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Matter in extremis: Ultrarelativistic nuclear collisions at RHIC

Description: 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 me… more
Date: August 20, 2004
Creator: Jacobs, Peter & Wang, Xin-Nian
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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