J. Muratore

High Energy Accelerator Research Organization, Tsukuba, Ibaraki, Japan

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Publications (96)56.29 Total impact

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    ABSTRACT: 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 commission-ing. We give an overview of head-on beam-beam compen-sation in general and the specific design for RHIC, which is based on electron lenses. The status of installation and commissioning are presented along with plans for the fu-ture.
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    ABSTRACT: In polarized proton operation, the RHIC performance is limited by the head-on beam-beam effect. To overcome these limitations two electron lenses were installed and are under commissioning. One lens uses a newly manufactured superconducting solenoid, in the other lens the spare super-conducting solenoid of the BNL Electron Beam Ion Source (EBIS) is installed to allow for propagation of the electron beam. (This spare magnet will be replaced by the same type of superconducting magnet that is also used in the other lens during the 2013 shut-down.) We give an overview of the commissioning configuration of both lenses, and report on first results in commissioning the hardware. We also re-port on lattice modifications needed to adjust the phase ad-vance between the beam-beam interactions and the electron lenses, as well as upgrades to the RHIC instrumentation for the commissioning.
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    ABSTRACT: BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.
    IEEE Transactions on Applied Superconductivity 01/2012; 22(3):4101604-4101604. · 1.20 Impact Factor
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    ABSTRACT: The superconducting magnet system for the J-PARC neutrino beam line for the T2K experiment has been served for the beam operation without serious disturbance since April 2009. Present most concern of the system is the operational current limit of superconducting corrector magnets for beam steering due to systematic quenches at lower currents. Operational experience of the magnet system and examples of troubleshoot including countermeasures against the corrector magnet quenches are presented.
    IEEE Transactions on Applied Superconductivity 07/2011; · 1.20 Impact Factor
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    ABSTRACT: In December 2009 during its first cold test, LQS01, the first Long Nb<sub>3</sub>Sn Quadrupole made by LARP (LHC Accelerator Research Program, a collaboration of BNL, FNAL, LBNL and SLAC), reached its target field gradient of 200 T/m. This target was set in 2005 by the US Department of Energy, CERN and LARP, as a significant milestone toward the development of Nb<sub>3</sub>Sn quadrupoles for possible use in LHC luminosity upgrades. LQS01 is a 90 mm aperture, 3.7 m long quadrupole using Nb<sub>3</sub>Sn coils. The coil layout is equal to the layout used in the LARP Technological Quadrupoles (TQC and TQS models). Pre-stress and support are provided by a segmented aluminum shell pre-loaded using bladders and keys, similarly to the TQS models. After the first test the magnet was disassembled, reassembled with an optimized pre-stress, and reached 222 T/m at 4.5 K. In this paper we present the results of both tests and the next steps of the Long Quadrupole R&D.
    IEEE Transactions on Applied Superconductivity 07/2011; · 1.20 Impact Factor
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    ABSTRACT: A copper coil dipole magnet from the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) has been retrofitted by HTS-110 Ltd with coils made from Bi-2223 wire and a self-contained cryogenic cooling system, while keeping the magnet's original iron yoke. This modified bending dipole, which is the first such known retrofit HTS-based accelerator magnet, provides the benefits of a compact coil design to accommodate space-limited experimental issues and a significant reduction in power costs as compared to the original copper magnet. In order to validate this modified design for use in the synchrotron, a detailed magnetic field map has been measured using a multiple-Hall probe assembly and transporter system. The results are discussed in this paper, along with the performance of the closed circuit cryogenics system in keeping the coils below 45 K.
    IEEE Transactions on Applied Superconductivity 07/2011; · 1.20 Impact Factor
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    ABSTRACT: An innovative feature of the proposed Energy Recovery Linac (ERL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS allows solenoid to be placed in close proximity to the cavity and thus provides early focusing of the electron beam. In addition, cryogenic testing at 77 K is simpler and cheaper than 4 K testing. This paper will present the design, construction and test results of this HTS solenoid. The HTS solenoid in the proposed ERL will be situated in the transition region between the superconducting cavity at 4 K and the cryostat at the room temperature. Solenoid inside the cryogenic structure provides an early focusing and hence low emittance beam. The temperature in the transition region will be too high for a conventional low temperature superconductor and resistive heat load from copper coils will be too high on cryogenic system. HTS coils also allow much higher current density and significant reduction in size as compared to copper coils. Hence HTS solenoid provide a unique and technically superior solution. The use of a HTS solenoid with superconducting cavity offers a unique option as it can be placed in a cold to warm transition region to provide early focussing without using additional space. Construction and test results so far are very encouraging for its use in the ERL project.
    01/2011;
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    ABSTRACT: The test of the first LARP (LHC Accelerator Research Program) Long Quadrupole is a significant milestone toward the development of Nb<sub>3</sub>Sn quadrupoles for LHC (Large Hadron Collider) Luminosity Upgrades. These 3.7-m long magnets, scaled from the 1-m long Technological Quadrupoles, are used to develop our capabilities to fabricate and assemble Nb<sub>3</sub>Sn coils and structures with lengths comparable to accelerator magnet dimensions. The long quadruples have a target gradient of 200 T/m in a 90-mm aperture. Pre-stress and support are provided by an Al-shell-based structure pre-loaded using bladders and keys. The coils were fabricated at BNL and FNAL, the shell-based structure was designed and assembled at LBNL, the test is performed at FNAL. In this paper we present the final steps of the development of the first model (LQS01), several upgrades to the test facility, the test results of witness cables, and the short sample limit.
    IEEE Transactions on Applied Superconductivity 07/2010; · 1.20 Impact Factor
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    ABSTRACT: Following success of a prototype R&D, construction of a superconducting magnet system for J-PARC neutrino beam line has been carried out since 2005. A new conceptual beam line with the superconducting combined function magnets demonstrated the successful beam transport to the neutrino production target.
    IEEE Transactions on Applied Superconductivity 07/2010; · 1.20 Impact Factor
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    ABSTRACT: 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.
    01/2010;
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    ABSTRACT: The LHC accelerator research program (LARP) is currently developing 4 m long Nb<sub>3</sub>Sn quadrupole magnets for a possible upgrade of the LHC Interaction Regions (IR). In order to provide a reliable test bed for the fabrication and test of long Nb<sub>3</sub> Sn coils, LARP has started the development of the long racetrack magnet LRS01. The magnet is composed of two 3.6 m long racetrack coils contained in a support structure based on an aluminum shell pre-tensioned with water-pressurized bladders and interference keys. For the phase-one test of the assembly procedure and loading operation, the structure was pre-stressed at room temperature and cooled down to 77 K with instrumented, solid aluminum "dummy coils". Mechanical behavior and stress homogeneity were monitored with strain gauges mounted on the shell and the dummy coils. The dummy coils were replaced with reacted and impregnated Nb<sub>3</sub>Sn coils in a second assembly procedure, followed by cool-down to 4.5 K and powered magnet test. This paper reports on the assembly and loading procedures of the support structure as well as the comparison between strain gauge data and 3-D model predictions.
    IEEE Transactions on Applied Superconductivity 07/2008; · 1.20 Impact Factor
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    ABSTRACT: Development of high-performance Nb<sub>3</sub>Sn quadrupoles is one of the major goals of the LHC Accelerator Research Program (LARP). As part of this program, long racetrack magnets were made in order to check the fabrication steps for long Nb<sub>3</sub>Sn coils, that the changes in coil length that take place during reaction and cooldown are correctly accounted for in the quadrupole design, and the use of a long aluminum shell for the support structure. This paper reports the construction of the first long Nb<sub>3</sub>Sn magnet with racetrack coils 3.6 m long. The magnet reached a nominal "plateau" at 9596 A after five quenches. This is about 90% of the estimated conductor limit. The peak field in the coils at this current was 11 T.
    IEEE Transactions on Applied Superconductivity 07/2008; · 1.20 Impact Factor
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    ABSTRACT: A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4 m-long quadrupole magnets (LQ) wound with Nb<sub>3</sub>Sn conductor. The goal of these magnets is to be a proof of principle that Nb<sub>3</sub>Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on the design of the LARP Technological Quadrupoles, presently under development at FNAL and LBNL, with 90-mm aperture and gradient higher than 200 T/m. The design of the first LQ model will be completed by the end of 2007 with the selection of a mechanical design. In this paper we present the coil design addressing some fabrication technology issues, the quench protection study, and three designs of the support structure.
    IEEE Transactions on Applied Superconductivity 07/2008; · 1.20 Impact Factor
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    ABSTRACT: The LHC Accelerator Research Program (LARP) is currently developing 4 m long NbSn quadrupole magnets for a possible upgrade of the LHC Interaction Regions (IR). In order to provide a reliable test bed for the fabrication and test of long NbSn coils, LARP has started the development of the long racetrack magnet LRS01. The magnet is composed of two 3.6 m long racetrack coils contained in a support structure based on an aluminum shell pre-tensioned with water-pressurized bladders and interference keys. For the phase-one test of the assembly procedure and loading operation, the structure was pre-stressed at room temperature and cooled down to 77 K with instrumented, solid aluminum 'dummy coils'. Mechanical behavior and stress homogeneity were monitored with strain gauges mounted on the shell and the dummy coils. The dummy coils were replaced with reacted and impregnated NbSn coils in a second assembly procedure, followed by cool-down to 4.5 K and powered magnet test. This paper report on the assembly and loading procedures of the support structure as well as the comparison between strain gauge data and D model predictions.
    IEEE Transactions on Applied Superconductivity - IEEE TRANS APPL SUPERCONDUCT. 01/2008; 18(2).
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    ABSTRACT: At present, functional NMR studies of metabolic processes, which require repeated images taken over a period of time, are only performed on sedated animals. This is because the axes defined by the main NMR solenoid field and the time varying gradient magnets used for spatial encoding are fixed and cannot follow the motion of an awake animal. Construction and test results will be presented for a pair of superconducting dipole coils built to make possible NMR studies of animals that are awake by providing a dynamically variable orientation of the NMR field. Each dipole coil was wound from a single cylindrical layer of Nb-Ti cable with a cos-theta distribution. One coil was wound over the other and oriented so that the fields are perpendicular. The coil pair can then produce fields in any direction perpendicular to that of the main solenoid. When powered together, the dipole and solenoid fields would allow the NMR axis to vary with time and, thus, track the motion of an awake animal. A 1 m-long pair of coils was successfully ramped to the design field, 0.08 T, at the high rate (~25 T/s) needed to track the motion. Measurements of the field quality were made during the ramping. The ramp rate studies and the magnetic field measurements are reported.
    IEEE Transactions on Applied Superconductivity 07/2007; · 1.20 Impact Factor
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    ABSTRACT: Development of high-performance Nb<sub>3</sub>Sn quadrupoles is one of the major goals of the LHC Accelerator Research Program (LARP). As part of this program, long racetrack magnets are being made in order to check that the change in coil length that takes place during reaction is correctly accounted for in the quadrupole design and to check for length effects in implementing the "shell" method of coil support. To check the racetrack magnet manufacturing plan, a short racetrack magnet is being made. This magnet will be the first to use restack-rod process Nb<sub>3</sub>Sn, making it a "long sample" test vehicle for this new material. The paper reports the reaction and characterization of the Nb<sub>3</sub>Sn, and construction features and test results from the short racetrack magnet. The paper also reports on the status of the construction of the first long racetrack magnet.
    IEEE Transactions on Applied Superconductivity 07/2007; · 1.20 Impact Factor
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    ABSTRACT: This paper presents a summary of the design, construction and test results of a common coil dipole DCC017 made using ldquoreact & windrdquo Nb<sub>3</sub>Sn technology. It reached the computed short sample field of 10.2 T at 10.8 kA after a number of quenches. In order to build high field magnets with brittle pre-reacted superconductors one must develop magnet designs, tooling and construction techniques that keep conductor degradation due to bending and handling to a tolerable level. The successful construction and test of this magnet demonstrates that it is possible to design and build magnets in the 10 (plus) T range using ldquoreact & windrdquo technology. The magnet is based on a 2-layer common coil design with a clear horizontal space of 31 mm. A unique feature of the design is a tall 338 mm clear vertical open space that can facilitate possible flat racetrack coil testing in a high background field without dis-assembling the magnet.
    IEEE Transactions on Applied Superconductivity 07/2007; · 1.20 Impact Factor
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    ABSTRACT: The LHC Accelerator Research Program (LARP) has a primary goal to develop, assemble, and test full size Nb<sub>3</sub>Sn quadrupole magnet models for a luminosity upgrade of the Large Hadron Collider (LHC). A major milestone in this development is to assemble and test, by the end of 2009, two 4 m-long quadrupole cold masses, which will be the first Nb<sub>3</sub>Sn accelerator magnet models approaching the length of real accelerator magnets. The design is based on the LARP Technological Quadrupoles (TQ), under development at FNAL and LBNL, with gradient higher than 200 T/m and aperture of 90 mm. The mechanical design will be chosen between two designs presently explored for the TQs: traditional collars and Al-shell based design (preloaded by bladders and keys). The fabrication of the first long quadrupole model is expected to start in the last quarter of 2007. Meanwhile the fabrication of 4 m-long racetrack coils started this year at BNL. These coils will be tested in an Al-shell based supporting structure developed at LBNL. Several challenges have to be addressed for the successful fabrication of long Nb<sub>3</sub>Sn coils. This paper presents these challenges with comments and solutions adopted or under study for these magnets. The coil design of these magnets, including conductor and insulation features, and quench protection studies are also presented.
    IEEE Transactions on Applied Superconductivity 07/2007; · 1.20 Impact Factor
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    01/2006;
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    ABSTRACT: The J-PARC Neutrino Experiment, the construction of which starts in JFY 2004, will use a superconducting magnet system for its primary proton beam line. The system, which bends the 50 GeV 0.75 MW proton beam by about 80 degrees, consists of 28 superconducting combined function magnets. The magnets utilize single layer left/right asymmetric coils that generate a dipole field of 2.6 T and a quadrupole field of 18.6 T/m with the operation current of about 7.35 kA. The system also contains a few conduction cooled superconducting corrector magnets that serve as vertical and horizontal steering magnets. All the magnets are designed to provide a physical beam aperture of 130 mm in order to achieve a large beam acceptance. Extensive care is also required to achieve safe operation with the high power proton beam. The paper summarizes the system design as well as some safety analysis results.
    IEEE Transactions on Applied Superconductivity 07/2005; · 1.20 Impact Factor

Publication Stats

318 Citations
206 Downloads
56.29 Total Impact Points

Institutions

  • 2004–2011
    • High Energy Accelerator Research Organization
      • Institute of Materials Structure Science
      Tsukuba, Ibaraki, Japan
  • 1992–2011
    • Fermi National Accelerator Laboratory (Fermilab)
      • Technical Division
      Batavia, Illinois, United States
  • 1989–2011
    • Brookhaven National Laboratory
      • Superconducting Magnet Division
      New York City, NY, United States
  • 2001
    • Cornell University
      • Laboratory for Elementary Particle Physics
      Ithaca, NY, United States