07 Accelerator Technology Main Systems

T10 Superconducting Magnets

Paper Title Page
MOPAN021 Magnetic Field Calculations of the Superconducting Dipole Magnets for the High- Energy Storage Ring at FAIR 194
  • H. Soltner, M. Pabst, R. Tolle
    FZJ, Julich
  For the High-Energy Storage Ring (HESR) to be established for the FAIR facility, magnetic field calculations have been carried out for the layout of the superconducting dipole magnets. Four configurations have been considered for the 2.72 m long magnets, straight ones and bent ones with a bending radius of 13,889 m, respectively, both for the cos(Θ) layout and for the double helix dipole layout. This contribution will focus particularly on the advantages and disadvantages of the individual configurations in terms of field quality in the diopole regions.  
MOPAN023 Superconductive Damping Wigglers for the CLIC Project 200
  • R. Rossmanith, S. Casalbuoni, A. W. Grau, M. Hagelstein, B. K. Kostka
    FZK, Karlsruhe
  • T. Baumbach, A. Bernhard, A.-S. Muller, D. Wollmann
    University of Karlsruhe, Karlsruhe
  • H.-H. Braun, M. Korostelev, Y. Papaphilippou, F. Zimmermann
    CERN, Geneva
  • E. M. Mashkina, E. Steffens
    University of Erlangen-Nurnberg, Physikalisches Institut II, Erlangen
  The CLIC damping ring requires wigglers with both high on-axis fields and short periods. The present design foresees a superconductive wiggler with a period length of 5 cm, a peak on-axis field of 2.5 T and a full width aperture of 12 mm. In this paper we explore the performance improvements of the damping ring when these parameters are pushed to 2.7 T at a period length of 2 cm with the expense of a reduced aperture of 5 mm. A design for a prototype for testing the field quality of such a wiggler is presented in this paper and the possibility to test this wiggler with beam in the storage ring ANKA is described.  
MOPAN073 Parametric Study of Heat Deposition from Collision Debris into the Insertion Superconducting Magnets for the LHC Luminosity Upgrade 323
  • C. Hoa, F. Cerutti, J.-P. Koutchouk, G. Sterbini, E. Y. Wildner
    CERN, Geneva
  • F. Broggi
    INFN/LASA, Segrate (MI)
  With a new geometry in a higher luminosity environment, the power deposition in the superconducting magnets becomes a critical aspect to analyze and to integrate in the insertion design. In this paper, we quantify the power deposited in magnets insertion at variable positions from the interaction point (IP). A fine characterization of the debris due to the proton-proton collisions at 7 TeV, shows that the energetic particles in the very forward direction give rise to non intuitive dependences of the impacting energy on the magnet front face and inner surface. The power deposition does not vary significantly with the distance to the interaction point, because of counterbalancing effects of different contributions to power deposition. We have found out that peak power density in the magnet insertion does not vary significantly with or without the Target Absorber Secondaries (TAS) protection.  
MOPAN077 Geometry of the LHC Short Straight Sections Before Installation in the Tunnel: Resulting Aperture, Axis and BPM Positioning 335
  • D. P. Missiaen, P. Bestmann, M. C.L. Buzio, S. D. Fartoukh, M. Giovannozzi, J. B. Jeanneret, A. M. Lombardi, Y. Papaphilippou, S. Pauletta, J. C. Perez, H. Prin, E. Y. Wildner
    CERN, Geneva
  The Large Hadron Collider Short Straight Sections (SSS) are currently being installed in their final position in the accelerator tunnel. For all the SSSs, both those in the regular arcs as well as those in the insertion regions, magnetic and geometric measurements are made at different steps of their assembly. These stages range from production in the industry to the cryostating at CERN, as well as during and after cold tests or during installation of the BPM and the cold warm transition for the stand alone magnets. The results of the geometry at the various production stages by means of different procedures and analysis tools are reported and discussed in details in this paper.  
MOPAN079 Assembly and Quality Control of the LHC Cryostats at CERN. Motivations, Means, Results and Lessons Learned 338
  • A. Poncet, P. Cruikshank, V. Parma, P. M. Strubin, J.-P. G. Tock, D. Tommasini
    CERN, Geneva
  In 2001 the project management decided to perform at CERN the final assembly of the LHC superconducting magnets,with cryostat parts and cold masses produced by European Industry in large series. This industrial-like production has required a very significant investment in tooling,production facilities,engineering and quality control efforts, in contractual partnership with a consortium of firms. This unusual endeavour of a limited lifetime represented more than 800'000 working hours spanning over four years,the work being done on a result oriented basis by the contractor. This paper presents the reasons for having insourced this project at CERN,describes the work breakdown structure,the production means and methods,the infrastructure specially developed,the tooling,logistics and quality control aspects of the work performed,and the results achieved, in analytical form. Finally the lessons learned are outlined.  
MOPAN080 Modeling of Flexible Components for Asserting the Stability of Superconducting Magnets 341
  • A. Kumar, S. C. Bapna, S. Dutta, K. Swarna
    RRCAT, Indore (M. P.)
  • A. Poncet
    CERN, Geneva
  Funding: Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, INDIA European Organisation for Nuclear Research (CERN), Geneva, Switzerland

Superconducting magnets are subjected to various forces during their cool down and alignment. Their construction invariably includes bellows, gimbals, hoses and composite supports. A good estimate of the deformations arising out of the cool down and alignment operations is necessary as these induce relative displacements between the fiducialised external vessel and hidden cold mass of the magnet. The nonlinear and orthotropic behaviour of these elements may make the model complicated and if solved as a nonlinear problem, would entail a large solution time as the overall model size runs into million nodes. Authors developed a unified Finite Element Model of the LHC Short Straight Section and during this process many innovative modeling techniques evolved. The developed model uses isotropic material constitutive laws with linear material properties. The paper is presenting some of the salient features of these modeling techniques.

MOPAN083 130 mm Aperture Quadrupoles for the LHC Luminosity Upgrade 350
  • E. Todesco, F. Borgnolutti
    CERN, Geneva
  • A. Mailfert
    ENSEM, Vandoeuvre les Nancy
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, contract number RII3-CT-2003-506395)

Studies for the LHC luminosity upgrade showed the need for quadrupoles with apertures much larger than the present baseline (70 mm). In this paper we focus on the design issues of a 130 mm aperture quadrupole. We first consider the Nb-Ti option, presenting the magnetic design with the LHC dipole cable. We study the Lorentz forces and we discuss the field quality constraints. For the Nb3Sn option we sketch two designs, the first based on the LARP 10 mm cable, and the second one on a 15 mm cable. The issue of the stress induced by the Lorentz forces, which is critical for the Nb3Sn, is discussed using both scaling laws and finite element models.

MOPAN084 Estimating Field Quality in Low-beta Superconducting Quadrupoles and its Impact on Beam Stability 353
  • E. Todesco, B. Bellesia, J.-P. Koutchouk
    CERN, Geneva
  • C. Santoni
    Universite Blaise Pascal, Clermont-Ferrand
  Funding: We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, contract number RII3-CT-2003-506395)

The aim of this analysis is to study if the field quality in a large aperture low-beta superconducting quadrupole for the LHC upgrade limits the beam performances due to increased geometric aberrations. Random field errors in superconducting quadrupoles are usually estimated by computing the effect of a random positioning of the coil blocks around the nominal position with an r.m.s. of 0.05 mm. Here, we review the experience acquired in the construction of 7 superconducting quadrupoles in the RHIC and in the LHC projects to estimate the precision in the block positioning, showing that there is no visible dependence on the magnet aperture. Different magnet models are then used to estimate the expected field quality in quadrupoles with apertures ranging from 50 to 200 mm. The impact on geometrical aberrations and scaling laws for their dependence on the aperture are finally evaluated.

MOPAN085 Completion of the Series Fabrication of the Main Superconducting Quadrupole Magnets of LHC 356
  • T. Tortschanoff, M. Modena, Y. Papaphilippou, L. Rossi, K. M. Schirm
    CERN, Geneva
  • R. Burgmer, H.-U. Klein, D. Krischel, B. Schellong, P. Schmidt
    ACCEL, Bergisch Gladbach
  • M. Durante, A. Payn, J.-M. Rifflet, F. Simon
    CEA, Gif-sur-Yvette
  By end of November 2006, the last cold mass of the main superconducting quadrupole cold masses were delivered by ACCEL Instruments to CERN. This comprised 360 cold masses for the arc regions of the machine and 32 special units dedicated to the dispersion suppressor regions. The latter ones contain the same main magnet but different types of correctors and are of increased length with respect to the regular arc ones. The end of the fabrication of these magnets coincided with the end of the main dipole deliveries allowing a parallel assembly into their cryostats and installation into the LHC tunnel. The positioning into the tunnel was optimized using the warm field measurements performed in the factory. On the other hand the correct slotting of the quadrupoles was complicated due to the multitude of variants and by the fact that a number of units needed to be replaced by spares which in some cases required a reshuffling of the positioning. The paper gives some final data about the successful fabrication at ACCEL Instruments and explains the issue of their best positions in the machine.  
MOPAN086 Final Geometry of 1232 LHC Dipoles 359
  • E. Y. Wildner, M. Bajko, P. Bestmann, S. D. Fartoukh, J. B. Jeanneret, D. P. Missiaen, D. Tommasini
    CERN, Geneva
  The 15 m long main dipoles for the Large Hadron Collider are now being installed in their final positions in the accelerator tunnel. Geometric measurements of the magnets after many of the production steps from industry to the cryostating, after cold tests and after preparation of the magnets for installation, have been made, permitting careful control of the shape of the magnet, the positioning of the field correctors, and the final positioning in the tunnel. The result of the geometry control at the different production stages, from industry to CERN, using different kinds of control procedures and analysis, will be reported.  
MOPAN088 A Large Aperture Superconducting Dipole for Beta Beams to Minimize Heat Deposition in the Coil 365
  • E. Y. Wildner, C. Vollinger
    CERN, Geneva
  The aim of "beta beams" in a decay ring is to produce highly energetic pure electron neutrino and anti-neutrino beams coming from b-decay of 18Ne10+ and 6He2+ ion beams. The decay products, having different magnetic rigidities than the ion beam, are deviated inside the dipole. The aperture and the length of the magnet have to be optimized to avoid that the decay products hit the coil. The decay products are intercepted by absorber blocks inside the beam pipe between the dipoles to protect the following dipole. A first design of a 6T arc dipole using a cosine theta layout of the coil with an aperture of 80 mm fulfils the optics requirements. Heat deposition in the coil has been calculated using different absorber materials to find a solution to efficiently protect the coil. Aspects of impedance minimization for the case of having the absorbers inside the beam pipe have also been addressed.  
MOPAN091 Design of Mechanical Structure and Cryostat for IASW Superconducting Wiggler at NSRRC 374
  • H.-H. Chen, C.-H. Chang, T.-C. Fan, M.-H. Huang, C.-S. Hwang, J. C. Jan, F.-Y. Lin
    NSRRC, Hsinchu
  An in-achromatic superconducting wiggler (IASW) was successfully constructed and installed at the Taiwan Light Source (TLS) in January 2006. The cryostat with a 30 L liquid nitrogen aluminum reservoir shielding surrounds the helium vessel, which comprises the cold mass and 100 L liquid helium. The helium vessel is suspended by eight suspension links, which are thermally intercepted at 80 K and can be adjusted by applying tension, such that the center of the cold mass does not move during cooled to 4.2 K. A three-layered stainless tube was designed to prevent the transfer port from freezing and the steam- electricity separation system is designed to supply electricity and return the helium gas to prevent freezing of the power feedthrough.  
MOPAN117 Magnet System for Helical Muon Cooling Channels 443
  • S. A. Kahn, M. Alsharo'a, R. P. Johnson
    Muons, Inc, Batavia
  • V. Kashikhin, V. S. Kashikhin, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  Funding: Supported in part by STTR Grant DE-FG02-04ER86191.

A helical cooling channel consisting of a pressurized gas absorber imbedded in a magnetic channel that provides superimposed solenoidal, helical dipole and helical quadrupole fields has shown considerable promise in providing six-dimensional cooling of muon beams. The analysis of this muon cooling technique with both analytic and simulation studies has shown significant reduction of muon phase space. A particular channel that has been simulated is divided into four segments each with progressively stronger fields and smaller apertures to reduce the equilibrium emittance so that more cooling can occur. The fields in the helical channel are sufficiently large that the conductor for segments 1 and 2 can be Nb3Sn and the conductor for segments 3 and 4 may need to be high temperature superconductor. This paper will describe the magnetic specifications for the channel and two conceptual designs on how to implement the magnetic channel.

MOPAN118 High Field HTS Solenoid for Muon Cooling 446
  • S. A. Kahn, M. Alsharo'a, R. P. Johnson, M. Kuchnir
    Muons, Inc, Batavia
  • R. C. Gupta, R. B. Palmer, P. Wanderer, E. Willen
    BNL, Upton, Long Island, New York
  • D. J. Summers
    UMiss, University, Mississippi
  Funding: Work supported by U. S. Department of Energy under Contract DE-AC02-98CH1088 and SBIR Grant DE-FG02-04ER86191

The ability of high temperature superconducting (HTS) conductor to carry high currents at low temperatures makes feasible the development of very high field magnets for uses in accelerators and beam-lines. A specific application of a very high field solenoid is to provide a very small beta region for the final cooling stages for a muon collider. This paper will describe a conceptual design of a 50 Tesla solenoid based on Bi-2223 HTS tape, where the magnet will be operated at 4.2 K to take advantage of the high current carrying capacity at that temperature. A 25 Tesla solenoid has been run using a 5 Tesla Bi-2212 insert. The current carrying capacity of the BSCCO wire has been measured to be 266 Amps/mm2 at 4.2 K at the NHFML. This paper will describe the technical issues associated with building this 50 Tesla magnet. In particular it will address how to mitigate the large Lorentz stresses associated with the high field magnet and how to design the magnet to reduce the compressive end forces.

MOPAS012 Magnets for the MANX 6-D Muon Cooling Demonstration Experiment 461
  • V. S. Kashikhin, V. Kashikhin, M. J. Lamm, G. Romanov, K. Yonehara, A. V. Zlobin
    Fermilab, Batavia, Illinois
  • R. P. Johnson, S. A. Kahn, T. J. Roberts
    Muons, Inc, Batavia
  Funding: Supported in part by DOE STTR grant DE-FG02-04ER86191

MANX is a 6-dimensional muon ionization-cooling experiment that has been proposed to Fermilab to demonstrate the use of a Helical Cooling Channel (HCC) for future muon colliders and neutrino factories. The HCC for MANX has solenoidal, helical dipole, and helical quadrupole magnetic components which diminish as the beam loses energy as it slows down in a liquid helium absorber inside the magnets. Two superconducting magnet system designs are described which use quite different approaches to providing the needed fields. Additional magnets that provide emittance matching between the HCC and upstream and downstream spectrometers are also described as are the results of G4Beamline simulations of the beam cooling behaviour of the complete magnet and absorber system.

MOPAS013 Design Study of a 2-in-1 Large-aperture IR Dipole (D2) for the LHC Luminosity Upgrade 464
  • V. Kashikhin, A. V. Zlobin
    Fermilab, Batavia, Illinois
  Funding: This work was supported by the U. S. Department of Energy.

After LHC operates for several years at nominal parameters it will need an upgrade to higher luminosity. Replacing the low-beta insertions with a higher performance design based on advanced superconducting magnets is a straightforward step in this direction. One of the approaches being considered for the new LHC IRs is a "dipole-first: option with two separation dipoles placed in front of the focusing quadrupoles. It reduces the number of parasitic collisions with respect to the "quadrupole-first" option and allows independent field error corrections for each beam. Most of key magnet designs for the "dipole-first" option including high-field large-aperture dipoles (D1) and 2-in-1 quadrupoles have already been studied and reported. This paper focuses on design studies of the 2-in-1 separation dipole (D2) located between D1 and the quadrupoles. High operation field of the same polarity in large adjacent apertures imposes limitations on the maximum field, field quality and mechanics for this magnet. This paper analyses possible D2 magnet designs based on Nb3Sn superconductor and compares them in terms of the aperture size, maximum field, field quality and Lorents forces in the coil.

MOPAS019 Focusing Solenoid for the Front End of a Linear RF Accelerator 473
  • I. Terechkine, V. Kashikhin, T. M. Page, M. Tartaglia, J. C. Tompkins
    Fermilab, Batavia, Illinois
  Following a design study, a prototype of a focusing solenoid for use in a superconducting RF linac has been built and is being tested at FNAL. The solenoid cold mass is comprised of the main coil, two bucking coils, and a soft steel flux return. It is mounted inside a dedicated cryostat with a 20 mm diameter warm bore. At the maximum current of 250 A, the magnetic field reaches 7.2 T in the center of the solenoid and is less than 0.01 T at a distance of 200 mm from the center. The flange-to-flange length of the system is 270 mm. This report discusses the main design features of the solenoid and first test results.  
MOPAS023 Nb3Sn Accelerator Magnet Technology R&D at Fermilab 482
  • A. V. Zlobin, G. Ambrosio, N. Andreev, E. Barzi, R. Bossert, R. H. Carcagno, G. Chlachidze, J. DiMarco, SF. Feher, V. Kashikhin, V. S. Kashikhin, M. J. Lamm, A. Nobrega, I. Novitski, D. F. Orris, Y. M. Pischalnikov, P. Schlabach, C. Sylvester, M. Tartaglia, J. C. Tompkins, D. Turrioni, G. Velev, R. Yamada
    Fermilab, Batavia, Illinois
  Funding: This work was supported by the U. S. Department of Energy

Accelerator magnets based on Nb3Sn superconductor advances magnet operation fields above 10T and increases the coil temperature margin. Development of a new accelerator magnet technology includes the demonstration of main magnet parameters (maximum field, quench performance, field quality, etc.) and their reproducibility using short models, and then the demonstration of technology scale up using long coils. Fermilab is working on the development of Nb3Sn accelerator magnets using shell-type dipole coils and react-and-wind method. As a part of the first phase of technology development Fermilab built and tested six 1-m long dipole models and several dipole mirror configurations. The last three dipoles and two mirrors reached their design fields of 10-11 T. Reproducibility of magnet field quality was demonstrated by all six short models. The technology scale up phase has started by building 2m and 4m dipole coils and testing them in a mirror configuration. This effort complements the Nb3Sn scale up work being performed in the framework of US LHC Accelerator Research Program (LARP). The status and main results of the Nb3Sn accelerator magnet development at Fermilab are reported.

MOPAS027 Energy Deposition Studies of Block-Coil Quadrupoles for the LHC Luminosity Upgrade 491
  • N. V. Mokhov, V. Kashikhin, M. Monville
    Fermilab, Batavia, Illinois
  • P. Ferracin, G. L. Sabbi
    LBNL, Berkeley, California
  Funding: Work supported by the Director, Office of Science, U. S. Department of Energy under Contract DE-AC02-05CH11231.

At the LHC upgrade luminosity of 1035 cm-2 s-1, collision product power in excess of a kW is deposited in the inner triplet quadrupoles. The quadrupole field sweeps secondary particles from pp-collisions into the superconducting coils, concentrating the power deposition at the magnetic mid-planes. The local peak power density can substantially exceed the conductor quench limits and reduce component lifetime. Under these conditions, block-coil geometries may result in overall improved performance by removing the superconductor from the magnetic mid-planes and/or allowing increased shielding at such locations. First realistic energy deposition simulations are performed for an interaction region based on block-coil quadrupoles with parameters suitable for the LHC upgrade. Results are presented on 3-D distributions of power density and accumulated dose in the inner triplet components as well as on dynamic heat loads on the cryogenic system. Optimization studies are performed on configuration and parameters of the beam pipe, cold bore and cooling channels. The feasibility of the proposed design is discussed.

MOPAS029 Progress on the Design and Fabrication of the MICE Spectrometer Solenoids 497
  • S. P. Virostek, M. A. Green, D. Li, M. S. Zisman
    LBNL, Berkeley, California
  Funding: This work was supported by the U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling in a short section of a realistic cooling channel using a muon beam at Rutherford Appleton Laboratory (RAL) in the UK. A five-coil, superconducting spectrometer solenoid magnet at each end of the cooling channel will provide a 4 T uniform field region for the scintillating fiber tracker within the magnet bore tubes. The tracker modules are used to measure the muon beam emittance as it enters and exits the cooling channel. The cold mass for the 400 mm warm bore magnet consists of two sections: a three-coil spectrometer magnet and a two-coil matching section that matches the uniform field of the solenoid into the MICE cooling channel. The detailed design and analysis of the two spectrometer solenoids has been completed, and the fabrication of the magnets is in its final stages. The primary features of the spectrometer solenoid magnetic and mechanical designs are presented along with a summary of key fabrication issues and photos of the fabrication process.

MOPAS030 Progress on the Design of the Coupling Coils for Mice and Mucool 500
  • M. A. Green, S. P. Virostek
    LBNL, Berkeley, California
  • X. L. Guo, G. Han, L. Jia, L. K. Li, S. Y. Li, C. S. Liu, X. K. Liu, L. Wang, H. Wu, F. Y. Xu
    ICST, Harbin
  Funding: This work was supported by the U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling in a short section of a realistic cooling channel using a muon beam at Rutherford Appleton Laboratory (RAL) in the UK. The MICE RF and Coupling Coil Module comprises a superconducting solenoid mounted around four normal conducting 201.25-MHz RF cavities. Each cavity has a pair of thin curved beryllium windows to close the conventional open beam irises. The coil package that surrounds the RF cavities is to be mounted on the outside of a 1.4 m diameter vacuum vessel. The coupling coil confines the beam in the cavity module and, in particular, within the radius of the cavity beam windows. The two MICE coupling solenoids will be operated in series using a 300 A, 10 V power supply. The maximum longitudinal force that will be carried by the cold mass support system is 0.5 MN during the expected operating and failure modes of the experiment. The detailed design and analysis of the two coupling coils has been completed, and the fabrication of the magnets is under way. The primary magnetic and mechanical design features of the coils are presented along with a summary of key fabrication issues.

MOPAS035 Rapid-Cycling Dipole using Block-Coil Geometry and Bronze-Process Nb3Sn Superconductor 512
  • P. M. McIntyre, A. D. McInturff, A. Sattarov
    Texas A&M University, College Station, Texas
  Funding: Doe gratn #DE-FG02-06ER41405

The block coil geometry utilized in recent high-field dipole development has significant benefit for applications requiring rapid cycling, since it intrinsically suppresses coupling currents between strands. A conceptual design for a 6 Tesla dipole has been studied for such applications, in which the intra-strand losses are minimized by using bronze-process Nb3Sn superconducting wire developed for ITER. That conductor provides isolated fine filaments and optimum matrix resistance between filaments. The block-coil geometry further accommodates placement of He cooling channels inside the coil, so that heat from radiation and from AC losses can be removed with minimum temperature rise in the coil. The design could be operated with supercritical helium cooling, and should make it possible to operate with a continuous ramp rate of 5-10 T/s.

MOPAS055 Combined Function Magnets Using Double-Helix Coils 560
  • C. Goodzeit, M. J. Ball, R. B. Meinke
    Advanced Magnet Lab., Inc, Melbourne, Florida
  We describe a technology for creating easy-to-manufacture combined function magnets. The field is produced by double-helix coils in which the axial path of the windings is defined by a sinusoidal function containing the superposition of the desired multipoles. The magnitude of the superimposed multipoles relative to the main field can be easily controlled to any level. For example, the combined function winding can contain a quadrupole magnet along with the dipole in an easily manufactured, low cost configuration. An example of a 5 T magnet with a main dipole field and a superimposed quadrupole is shown. We discuss the amplitude of the quadruple component and how it effects the maximum dipole field that can be obtained in the coil. We also show how low level (i.e. 0.1% - 1%) modulation amplitudes of superimposed multipoles can be used as built-in or "free" correction coils to compensate for iron saturation effects or geometrically-induced multipoles. An example is shown for a small bend radius (i.e. 718 mm), 100 mm aperture bent dipole in which the bent-yoke-induced quadrupole harmonic is completely corrected by the modulation function of the double helix turns.

This work is partially supported under U. S. Department of Energy grant : DoE SBIR DE-FG02-06ER 84492

MOPAS093 Vibration Measurements to Study the Effect of Cryogen Flow in a Superconducting Quadrupole 643
  • P. He, M. Anerella, S. Aydin, G. Ganetis, M. Harrison, A. K. Jain, B. Parker
    BNL, Upton, Long Island, New York
  Funding: Work supported by the US Department of Energy under contract DE-AC02-98CH10886.

The conceptual design of compact superconducting magnets for the International Linear Collider final focus is presently under development at BNL. A primary concern in using superconducting quadrupoles is the potential for inducing additional vibrations from cryogenic operation. We have employed a Laser Doppler Vibrometer system to measure the vibrations at resolutions ~1 nm (at frequencies above ~8 Hz) in a spare RHIC quadrupole coldmass under cryogenic conditions. Some preliminary results of these studies were presented at the Nanobeam 2005 workshop*. These results were limited in resolution due to a rather large motion of the laser head itself. As a first step towards improving the measurement quality, an actively stabilized isolation table was used to reduce the motion of the laser holder. The improved set-up will be described, and vibration spectra measured at cryogenic temperatures, both with and without helium flow, will be presented.

*A. Jain, et al., Nanobeam 2005, Kyoto, Japan, Oct.17-21, 2005; paper WG2d-05; available at http://wwwal.kuicr.kyoto-u.ac.jp/NanoBM .

FRXKI01 Superconducting Magnet Needs for the ILC 3732
  • J. C. Tompkins, V. S. Kashikhin
    Fermilab, Batavia, Illinois
  • J. A. Clarke
    Cockcroft Institute, Warrington, Cheshire
  • M. A. Palmer
    CLASSE, Ithaca
  • B. Parker
    BNL, Upton, Long Island, New York
  The ILC Reference Design Report will be completed early in 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the ILC will have more than 11,000 magnetic elements of which more than 1200 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Magnet Systems Group and the leaders of the Area Systems Groups, responsible for beamline design. The superconducting magnet components include the Main Linac quadrupoles, the Positron Source undulators, the Damping Ring wigglers, and the complex array of Final Focus superconducting elements in the Beam Delivery System.  
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FRXKI02 Magnet Development for LARP 3737
  • G. L. Sabbi
    LBNL, Berkeley, California
  The talk will cover progress and prospects for developing Nb3Sn quadrupoles for the eventual upgrade of the LHC IR's. The talk should also cover developments in cabling, but not R&D on the Nb3Sn strand.  
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FRXKI03 Magnets for Upgrade of the Accelerator Complex at CERN 3738
  • L. Rossi
    CERN, Geneva
  While the LHC is approaching commissioning phase, a global plan with different options for the consolidation and upgrade of the accelerator complex is under discussion at CERN. In one option the change of the interaction region (IR) magnets, in order to increase the luminosity of the LHC, is considered. This measure may be accompanied or not by an increase of the beam current. In any case the needs of new more performing Nb-Ti based magnets and/or Nb3Sn magnets is established. The choice of Nb3Sn based magnets with13-15 T peak field on the coil seems mandatory for the low-beta triplet quadrupoles in case a factor two or more in luminosity is envisaged. In another option the improvement of the injector chain is considered. For the moment the first priority is the design of a new PS of energy about 50 GeV, with duty cycle less than 1 Hz. In this paper a comparison among the option based on normal conducting magnets (today baseline) and superconducting magnets of various types will be presented. In the frame of the longer-term scenario, magnets envisaged for an upgrade of the present SPS (from 450 to 1 TeV) and for neutrino production facilities will be discussed as well.  
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FROAKI01 Magnet Acceptance and Allocation at the LHC Magnet Evaluation Board 3739
  • L. Bottura, P. Bestmann, N. Catalan-Lasheras, S. D. Fartoukh, S. S. Gilardoni, M. Giovannozzi, J. B. Jeanneret, M. Karppinen, A. M. Lombardi, K. H. Mess, D. P. Missiaen, M. Modena, R. Ostojic, Y. Papaphilippou, P. Pugnat, S. Ramberger, S. Sanfilippo, W. Scandale, F. Schmidt, N. Siegel, A. P. Siemko, D. Tommasini, T. Tortschanoff, E. Y. Wildner
    CERN, Geneva
  The normal- and superconducting magnets for the LHC ring have been carefully examined to insure that each of the more than 1800 assemblies is suitable for the operation in the accelerator. Magnet coordinators, hardware experts and accelerator physicists, joined in the LHC Magnet Evaluation Board, have contributed to this work that consists in the magnet acceptance, and the optimisation achieved by sorting magnets according to their geometry, field quality and quench level. This paper gives a description of the magnet approval mechanism that has been running since four years, reporting in a concise summary on the main results achieved. We take as specific indicators the computed mechanical aperture, the sorting efficiency with respect to systematic and random field errors in the magnets, and the case-by-case analysis necessary to accommodate hardware limitations such as quench limits and training.  
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FROAKI02 LHC Magnet Tests: Operational Techniques and Empowerment for Successful Completion 3742
  • V. Chohan, G. H. Hemelsoet, F. Pirotte, K. Priestnall, E. Veyrunes
    CERN, Geneva
  • N. Ali, P. Awale, S. Bahuguna, V. Chauhan, M. Y. Dixit, J. A. Gore, J. John, E. Kandaswamy, A. Kasbekar, P. Kashyap, C. P. Kulkarni, A. Laddha, S. Malhotra, M. Mascarenhas, J. K. Mishra, P. Motiwala, K. Nair, R. Narayanan, S. Padmakumar, A. Pagare, D. Peruppayikkad, S. Raghunathan, S. Rao, D. Roy, S. Sethumadhavan, S. Sharma, S. Shimjith, S. Singh, S. T. Sonnis, P. Surendran, A. Tikaria
    BARC, Mumbai
  • U. Bhunia
    DAE/VECC, Calcutta
  • A. Kasliwal
    RRCAT, Indore (M. P.)
  The LHC magnet tests operation team* developed various innovative techniques, particularly since early 2004, to complete the superconductor magnet testing by end 2006. Overall and cryogenic priority handling, rapid on-bench thermal cycling, rule-based goodness evaluation on round-the-clock basis, multiple, mashed web systems are some of these techniques applied with rigour for successful tests completion in time. This paper highlights these operation empowerment tools which had a pivotal role for success. A priority handling method was put in place to enable maximum throughput from twelve test benches, having many different constraints. For the cryogenics infrastructure, it implied judicious allocation of limited resources to the benches. Rapid On-Bench Thermal Cycle was a key strategy to accelerate magnets tests throughput, saving time and simplifying logistics. First level magnet appraisal was developed for 24 hr decision making so as to prepare a magnet further for LHC or keep it on standby. Web based systems (Tests Management and E-Traveller) were other essential ideas to track & coordinate various stages of tests handled by different teams.  
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FRYKI01 Radidly-Cyling Superconducting Accelerator Magnets for FAIR at GSI 3745
  • G. Moritz
    GSI, Darmstadt
  The demand for high beam intensities leads to the requirement of rapidly cycling cycling magnets for synchrotrons. An example is FAIR (Facility for Antiproton and Ion Research) at GSI, which will consist of two synchrotrons (SIS 100 and SIS 300) in one tunnel and several storage rings. The high field ramp rate (up to 1 T/s) and the repetition frequency of up to 1 Hz require R&D for the superconducting magnets of these rings. Persistent currents in the superconductor and eddy currents in wire, cable, iron and vacuum chamber reduce the field quality and generate cryogenic losses. A magnet lifetime of 20 years is desired, resulting in up to 108 magnet cycles. Therefore, special attention has to be paid to magnet material fatigue problems. R&D work is being done, in collaboration with many institutions, to reach the requirements mentioned above. Model dipoles were built and tested. The results of the R&D are reported. Full length dipoles for SIS 100 are under construction.  
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FRYKI02 Next Generation Superconductors for Accelerator Magnets 3750
  • J. Schwartz
    NHMFL, Tallahassee, Florida
  The talk should cover progress and prospects for Nb3Sn, Nb3Al, varieties of HTS, and MgB2. The talk should discuss these items in relation to the performance requirements and cost of accelerator magnets.  
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