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Sample records for superconducting magnet beam

  1. Testing beam-induced quench levels of LHC superconducting magnets

    Science.gov (United States)

    Auchmann, B.; Baer, T.; Bednarek, M.; Bellodi, G.; Bracco, C.; Bruce, R.; Cerutti, F.; Chetvertkova, V.; Dehning, B.; Granieri, P. P.; Hofle, W.; Holzer, E. B.; Lechner, A.; Nebot Del Busto, E.; Priebe, A.; Redaelli, S.; Salvachua, B.; Sapinski, M.; Schmidt, R.; Shetty, N.; Skordis, E.; Solfaroli, M.; Steckert, J.; Valuch, D.; Verweij, A.; Wenninger, J.; Wollmann, D.; Zerlauth, M.

    2015-06-01

    In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with the top beam energies of 3.5 and 4 TeV per proton (from 2012) instead of the nominal 7 TeV. The currents in the superconducting magnets were reduced accordingly. To date only seventeen beam-induced quenches have occurred; eight of them during specially designed quench tests, the others during injection. There has not been a single beam-induced quench during normal collider operation with stored beam. The conditions, however, are expected to become much more challenging after the long LHC shutdown. The magnets will be operating at near nominal currents, and in the presence of high energy and high intensity beams with a stored energy of up to 362 MJ per beam. In this paper we summarize our efforts to understand the quench levels of LHC superconducting magnets. We describe beam-loss events and dedicated experiments with beam, as well as the simulation methods used to reproduce the observable signals. The simulated energy deposition in the coils is compared to the quench levels predicted by electrothermal models, thus allowing one to validate and improve the models which are used to set beam-dump thresholds on beam-loss monitors for run 2.

  2. Testing beam-induced quench levels of LHC superconducting magnets

    CERN Document Server

    Auchmann, B; Bednarek, M; Bellodi, G; Bracco, C; Bruce, R; Cerutti, F; Chetvertkova, V; Dehning, B; Granieri, P P; Hofle, W; Holzer, E B; Lechner, A; Del Busto, E Nebot; Priebe, A; Redaelli, S; Salvachua, B; Sapinski, M; Schmidt, R; Shetty, N; Skordis, E; Solfaroli, M; Steckert, J; Valuch, D; Verweij, A; Wenninger, J; Wollmann, D; Zerlauth, M

    2015-01-01

    In the years 2009-2013 the Large Hadron Collider (LHC) has been operated with the top beam energies of 3.5 TeV and 4 TeV per proton (from 2012) instead of the nominal 7 TeV. The currents in the superconducting magnets were reduced accordingly. To date only seventeen beam-induced quenches have occurred; eight of them during specially designed quench tests, the others during injection. There has not been a single beam- induced quench during normal collider operation with stored beam. The conditions, however, are expected to become much more challenging after the long LHC shutdown. The magnets will be operating at near nominal currents, and in the presence of high energy and high intensity beams with a stored energy of up to 362 MJ per beam. In this paper we summarize our efforts to understand the quench levels of LHC superconducting magnets. We describe beam-loss events and dedicated experiments with beam, as well as the simulation methods used to reproduce the observable signals. The simulated energy depositio...

  3. Cryogenic Beam Loss Monitors for the Superconducting Magnets of the LHC

    CERN Document Server

    Bartosik, MR; Sapinski, M; Kurfuerst, C; Griesmayer, E; Eremin, V; Verbitskaya, E

    2014-01-01

    The Beam Loss Monitor detectors close to the interaction points of the Large Hadron Collider are currently located outside the cryostat, far from the superconducting coils of the magnets. In addition to their sensitivity to lost beam particles, they also detect particles coming from the experimental collisions, which do not contribute significantly to the heat deposition in the superconducting coils. In the future, with beams of higher energy and brightness resulting in higher luminosity, distinguishing between these interaction products and dangerous quench-provoking beam losses from the primary proton beams will be challenging. The system can be optimised by locating beam loss monitors as close as possible to the superconducting coils, inside the cold mass in a superfluid helium environment, at 1.9 K. The dose then measured by such Cryogenic Beam Loss Monitors would more precisely correspond to the real dose deposited in the coil. The candidates under investigation for such detectors are based on p+-n-n+ si...

  4. Superconducting wiggler magnets for beam-emittance damping rings

    CERN Document Server

    Schoerling, Daniel

    2012-01-01

    Ultra-low emittance beams with a high bunch charge are necessary for the luminosity performance of linear electron-positron colliders, such as the Compact Linear Collider (CLIC). An effective way to create ultra-low emittance beams with a high bunch charge is to use damping rings, or storage rings equipped with strong damping wiggler magnets. The remanent field of the permanent magnet materials and the ohmic losses in normal conductors limit the economically achievable pole field in accelerator magnets operated at around room temperature to below the magnetic saturation induction, which is 2.15 T for iron. In wiggler magnets, the pole field in the center of the gap is reduced further like the hyperbolic cosine of the ratio of the gap size and the period length multiplied by pi. Moreover, damping wiggler magnets require relatively large gaps because they have to accept the un-damped beam and to generate, at a small period length, a large magnetic flux density amplitude to effectively damp the beam emittance....

  5. A novel beam optics concept in a particle therapy gantry utilizing the advantages of superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Gerbershagen, Alexander; Meer, David; Schippers, Jacobus Maarten; Seidel, Mike [Paul Scherrer Institut (PSI), Villigen (Switzerland)

    2016-11-01

    A first order design of the beam optics of a superconducting proton therapy gantry beam is presented. The possibilities of superconducting magnets with respect to the beam optics such as strong fields, large apertures and superposition of different multipole fields have been exploited for novel concepts in a gantry. Since various techniques used in existing gantries have been used in our first design steps, some examples of the existing superconducting gantry designs are described and the necessary requirements of such a gantry are explained. The study of a gantry beam optics design is based on superconducting combined function magnets. The simulations have been performed in first order with the conventional beam transport codes. The superposition of strong dipole and quadrupole fields generated by superconducting magnets enables the introduction of locally achromatic bending sections without increasing the gantry size. A rigorous implementation of such beam optics concepts into the proposed gantry design dramatically increases the momentum acceptance compared to gantries with normal conducting magnets. In our design this large acceptance has been exploited by the implementation of a degrader within the gantry and a potential possibility to use the same magnetic field for all energies used in a treatment, so that the superconducting magnets do not have to vary their fields during a treatment. This also enables very fast beam energy changes, which is beneficial for spreading the Bragg peak over the thickness of the tumor. The results show an improvement of its momentum acceptance. Large momentum acceptance in the gantry creates a possibility to implement faster dose application techniques.

  6. A novel beam optics concept in a particle therapy gantry utilizing the advantages of superconducting magnets.

    Science.gov (United States)

    Gerbershagen, Alexander; Meer, David; Schippers, Jacobus Maarten; Seidel, Mike

    2016-09-01

    A first order design of the beam optics of a superconducting proton therapy gantry beam is presented. The possibilities of superconducting magnets with respect to the beam optics such as strong fields, large apertures and superposition of different multipole fields have been exploited for novel concepts in a gantry. Since various techniques used in existing gantries have been used in our first design steps, some examples of the existing superconducting gantry designs are described and the necessary requirements of such a gantry are explained. The study of a gantry beam optics design is based on superconducting combined function magnets. The simulations have been performed in first order with the conventional beam transport codes. The superposition of strong dipole and quadrupole fields generated by superconducting magnets enables the introduction of locally achromatic bending sections without increasing the gantry size. A rigorous implementation of such beam optics concepts into the proposed gantry design dramatically increases the momentum acceptance compared to gantries with normal conducting magnets. In our design this large acceptance has been exploited by the implementation of a degrader within the gantry and a potential possibility to use the same magnetic field for all energies used in a treatment, so that the superconducting magnets do not have to vary their fields during a treatment. This also enables very fast beam energy changes, which is beneficial for spreading the Bragg peak over the thickness of the tumor. The results show an improvement of its momentum acceptance. Large momentum acceptance in the gantry creates a possibility to implement faster dose application techniques. Copyright © 2016. Published by Elsevier GmbH.

  7. Canted-Cosine-Theta Superconducting Accelerator Magnets for High Energy Physics and Ion Beam Cancer Therapy

    Science.gov (United States)

    Brouwer, Lucas Nathan

    Advances in superconducting magnet technology have historically enabled the construction of new, higher energy hadron colliders. Looking forward to the needs of a potential future collider, a significant increase in magnet field and performance is required. Such a task requires an open mind to the investigation of new design concepts for high field magnets. Part I of this thesis will present an investigation of the Canted-Cosine-Theta (CCT) design for high field Nb3Sn magnets. New analytic and finite element methods for analysis of CCT magnets will be given, along with a discussion on optimization of the design for high field. The design, fabrication, and successful test of the 2.5 T NbTi dipole CCT1 will be presented as a proof-of-principle step towards a high field Nb3Sn magnet. Finally, the design and initial steps in the fabrication of the 16 T Nb3Sn dipole CCT2 will be described. Part II of this thesis will investigate the CCT concept extended to a curved magnet for use in an ion beam therapy gantry. The introduction of superconducting technology in this field shows promise to reduce the weight and cost of gantries, as well as open the door to new beam optics solutions with high energy acceptance. An analytic approach developed for modeling curved CCT magnets will be presented, followed by a design study of a superconducting magnet for a proton therapy gantry. Finally, a new magnet concept called the "Alternating Gradient CCT" (AG-CCT) will be introduced. This concept will be shown to be a practical magnet solution for achieving the alternating quadrupole fields desired for an achromatic gantry, allowing for the consideration of treatment with minimal field changes in the superconducting magnets. The primary motivation of this thesis is to share new developments for Canted-Cosine-Theta superconducting magnets, with the hope this design will improve technology for high energy physics and ion beam cancer therapy.

  8. Experiments on the margin of beam induced quenches a superconducting quadrupole magnet in the LHC

    CERN Document Server

    Bracco, C; Bednarek, M J; Nebot Del Busto, E; Goddard, B; Holzer, E B; Nordt, A; Sapinski, M; Schmidt, R; Solfaroli Camillocci, M; Zerlauth, M

    2012-01-01

    Protection of LHC equipment relies on a complex system of collimators to capture injected and circulating beam in case of LHC kicker magnet failures. However, for specific failures of the injection kickers, the beam can graze the injection protection collimators and induce quenches of downstream superconducting magnets. This occurred twice during 2011 operation and cannot be excluded during future operation. Tests were performed during Machine Development periods of the LHC to assess the quench margin of the quadrupole located just downstream of the last injection protection collimator in point 8. In addition to the existing Quench Protection System, a special monitoring instrumentation was installed at this magnet to detect any resistance increase below the quench limit. The correlation between the magnet and Beam Loss Monitor signals was analysed for different beam intensities and magnet currents. The results of the experiments are presented.

  9. Beta Beams for Neutrino Production Heat Deposition from Decaying Ions in Superconducting Magnets

    CERN Document Server

    Wildner, Elena; Cerutti, F

    2008-01-01

    This report describes studies of energy deposition in superconducting magnets from secondary ions in the "beta beam" decay ring as described in the base-line scenario of the EURISOL Beta Beam Design Study. The lattice structure proposed in the Design Study has absorber elements inserted between the superconducting magnets to protect the magnet coils. We describe an efficient and small model made to carry out the study. The specially developed options in the beam code "ACCSIM" to track largely off-momentum particles has permitted to extract the necessary information to interface the transport and interaction code "FLUKA" with the aim to calculate the heat deposition in the magnets and the absorbers. The two beta emitters 18Ne10+ and 6He2+ used for neutrino and anti-neutrino production and their daughter ions have been tracked. The absorber system proposed in the Design Study is efficient to intercept the ions decayed in the arc straight sections as foreseen, however, the continuous decay in the dipoles induce ...

  10. Beam Halo on the LHC TCDQ Diluter System and Thermal Load on the Downstream Superconducting Magnets

    CERN Document Server

    Goddard, B; Presland, A; Redaelli, S; Robert-Démolaize, G; Sarchiapone, L; Weiler, T; Weterings, W

    2006-01-01

    The moveable single-jawed graphite TCDQ diluter must be positioned very close to the circulating LHC beam in order to prevent damage to downstream components in the event of an unsynchronised beam abort. A two-jawed graphite TCS.IR6 collimator forms part of the TCDQ system. The requirement to place the jaws close to the beam means that the system can intercept a substantial beam halo load. Initial investigations indicated a worryingly high heat load on the Q4 coils. This paper presents the updated load cases, shielding and simulation geometry, and the results of simulations of the energy deposition in the TCDQ system and in the downstream superconducting Q4 magnet. The implications for the operation of the LHC are discussed.

  11. Beta Beams for neutrino production: Heat deposition from decaying ions in superconducting magnets

    CERN Document Server

    Wildner, Elena; Cerutti, Francesco

    This note describes studies of energy deposition in superconducting magnets from secondary ions in the “beta beam” decay ring as described in the base-line scenario of the EURISOL Beta Beam Design Study. The lattice structure proposed in the Design Study has absorber elements inserted between the superconducting magnets to protect the magnet coils. We describe an efficient and small model made to carry out the study. The specially developed options in the beam code “ACCSIM” to track largely off-momentum particles has permitted to extract the necessary information to interface the transport and interaction code “FLUKA” with the aim to calculate the heat deposition in the magnets and the absorbers. The two beta emitters 18Ne10+ and 6He2+ used for neutrino and anti-neutrino production and their daughter ions have been tracked. The absorber system proposed in the Design Study is efficient to intercept the ions decayed in the arc straight sections as foreseen, however, the continuous decay in the dipol...

  12. Magnetic fields and beam optics studies of a 250 MeV superconducting proton radiotherapy cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Won [Research Institute and Hospital, National Cancer Center, 809 Madu-dong, Koyang, Kyonggi (Korea, Republic of)], E-mail: jwkim@ncc.re.kr

    2007-11-21

    A 250 MeV superconducting cyclotron for the proton radiation therapy was designed at the Michigan State University (MSU) for use at the Paul Scherrer Institut. This work was based on the conceptual design carried out at the MSU in 1994. The previous design was refined to finalize the magnet configuration and to optimally arrange cyclotron elements for the actual construction. The spiral angle of the pole was reduced, the new hill-edges and valley shims being introduced. The magnetic fields were highly isochronized using a least square fitting routine involving a schematic shimming scheme. The resulting reference field was adequate for the elaborate study of beam optics. The optics simulation predicted that extraction efficiency of above 80% was achievable for a beam with the initial phase width of 20{sup o}. The vertical deflector was investigated located in the central region to control the beam intensity with tracking of beam phase spaces. Some measurement results for the constructed cyclotron were found in a good agreement with those of the optics study.

  13. High field superconducting magnets

    Science.gov (United States)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  14. Model of an LHC superconducting quadrupole magnet

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Model of a superconducting quadrupole magnet for the LHC project. These magnets are used to focus the beam by squeezing it into a smaller cross-section, a similar effect to a lens focusing light. However, each magnet only focuses the beam in one direction so alternating magnet arrangements are required to produce a fully focused beam.

  15. Results of the studies on energy deposition in IR6 superconducting magnets from continuous beam loss on the TCDQ system

    CERN Document Server

    Bracco, C; Presland, A; Redaelli, S; Sarchiapone, L; Weiler, T

    2007-01-01

    A single sided mobile graphite diluter block TCDQ, in combination with a two-sided secondary collimator TCS and an iron shield TCDQM, will be installed in front of the superconducting quadrupole Q4 magnets in IR6, in order to protect it and other downstream LHC machine elements from destruction in the event of a beam dump that is not synchronised with the abort gap. The TCDQ will be positioned close to the beam, and will intercept the particles from the secondary halo during low beam lifetime. Previous studies (1-4) have shown that the energy deposited in the Q4 magnet coils can be close to or above the quench limit. In this note the results of the latest FLUKA energy deposition simulations for Beam 2 are described, including an upgrade possibility for the TCDQ system with an additional shielding device. The results are discussed in the context of the expected performance levels for the different phases of LHC operation.

  16. The superconducting bending magnets 'CESAR'

    CERN Document Server

    Pérot, J

    1978-01-01

    In 1975, CERN decided to build two high precision superconducting dipoles for a beam line in the SPS north experimental area. The aim was to determine whether superconducting magnets of the required accuracy and reliability can be built and what their economies and performances in operation will be. Collaboration between CERN and CAE /SACLAY was established in order to make use of the knowledge and experience already acquired in the two laboratories. (0 refs).

  17. Performance of a superconducting magnet system operated in the Super Omega Muon beam line at J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    Makida, Yasuhiro; Ikedo, Yutaka; Ogitsu, Toru; Shimomura, Koichiro; Miyake, Yasuhiro; Yoshida, Makoto; Adachi, Taihei; Kadono, Ryosuke; Kawamura, Naritoshi; Strasser, Patric; Koda, Akihiro; Fujimori, Hiroshi; Nishiyama, Kusuo; Ohhata, Hirokatsu; Okamura, Takahiro; Okada, Ryutaro [J-PARC, KEK, Shirakata 203-1, Tokai, Naka, Ibaraki (Japan); Orikasa, Tomofumi [Keihin Product Operations, Toshiba, Suehiro 2-4, Tsurumi, Yokohama (Japan)

    2014-01-29

    A superconducting magnet system, which is composed of an 8 m long solenoid for transportation and 12 short solenoids for focusing, has been developed for Muon Science Establishment facility of J-PARC. The transport solenoid is composed of a 6 m straight section connected to a 45 degree curved section at each end. Muons of various momenta and of both electric charges are transported through the solenoid inner bore with an effective diameter of 0.3 m, where 2 T magnetic field is induced. There are 12 focusing solenoids with an effective bore diameter of 0.6 m and a length of 0.35 m arranged on a straight line at suitable intervals. The maximum central field of each focusing solenoid is 0.66 T. All solenoid coils are cooled by GM cryocoolers through their own conductions. The magnet system has been installed into the beam line in the summer of 2012, and its performance has been checked. Beam commissioning has been carried out since October 2012. During beam operation, temperature rise over 6 K in the transport solenoid due to a nuclear heating from the muon production target is observed at beam intensity of about 300 kW.

  18. The first LHC superconducting magnet is unloaded

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The first superconducting magnet is moved into position using a transfer table. This must be performed with great precision so that the LHC ring is correctly aligned, allowing the beams to travel along the correct paths.

  19. Magnetic and superconducting nanowires

    DEFF Research Database (Denmark)

    Piraux, L.; Encinas, A.; Vila, L.

    2005-01-01

    magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also...

  20. Large Superconducting Magnet Systems

    CERN Document Server

    Védrine, P.

    2014-07-17

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  1. Checking BEBC superconducting magnet

    CERN Multimedia

    1974-01-01

    The superconducting coils of the magnet for the 3.7 m Big European Bubble Chamber (BEBC) had to be checked, see Annual Report 1974, p. 60. The photo shows a dismantled pancake. By December 1974 the magnet reached again the field design value of 3.5 T.

  2. Superconducting Accelerator Magnets

    CERN Document Server

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  3. LHC Superconducting Magnets

    CERN Document Server

    Jean Leyder

    2000-01-01

    The LHC is the next step in CERN's quest to unravel the mysteries of the Universe. It will accelerate protons to energies never before achieved in laboratories, and to hold them on course it will use powerful superconducting magnets on an unprecedented scale.

  4. Superconducting Materials, Magnets and Electric Power Applications

    Science.gov (United States)

    Crabtree, George

    2011-03-01

    The surprising discovery of superconductivity a century ago launched a chain of convention-shattering innovations and discoveries in superconducting materials and applications that continues to this day. The range of large-scale applications grows with new materials discoveries - low temperature NbTi and Nb3 Sn for liquid helium cooled superconducting magnets, intermediate temperature MgB2 for inexpensive cryocooled applications including MRI magnets, and high temperature YBCO and BSSCO for high current applications cooled with inexpensive liquid nitrogen. Applications based on YBCO address critical emerging challenges for the electricity grid, including high capacity superconducting cables to distribute power in urban areas; transmission of renewable electricity over long distances from source to load; high capacity DC interconnections among the three US grids; fast, self-healing fault current limiters to increase reliability; low-weight, high capacity generators enabling off-shore wind turbines; and superconducting magnetic energy storage for smoothing the variability of renewable sources. In addition to these grid applications, coated conductors based on YBCO deposited on strong Hastelloy substrates enable a new generation of all superconducting high field magnets capable of producing fields above 30 T, approximately 50% higher than the existing all superconducting limit based on Nb3 Sn . The high fields, low power cost and the quiet electromagnetic and mechanical operation of such magnets could change the character of high field basic research on materials, enable a new generation of high-energy colliding beam experiments and extend the reach of high density superconducting magnetic energy storage.

  5. Superconducting magnetic quadrupole

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.W.; Shepard, K.W.; Nolen, J.A.

    1995-08-01

    A design was developed for a 350 T/m, 2.6-cm clear aperture superconducting quadrupole focussing element for use in a very low q/m superconducting linac as discussed below. The quadrupole incorporates holmium pole tips, and a rectangular-section winding using standard commercially-available Nb-Ti wire. The magnet was modeled numerically using both 2D and 3D codes, as a basis for numerical ray tracing using the quadrupole as a linac element. Components for a prototype singlet are being procured during FY 1995.

  6. Superconducting magnets for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.E.

    1984-08-01

    Three types of magnets are currently used to provide the background field required for magnet resonance imaging (MRI). (i) Permanent magnets produce fields of up to 0.3 T in volumes sufficient for imaging the head or up to 0.15 T for whole body imaging. Cost and simplicity of operation are advantages, but relatively low field, weight (up to 100 tonnes) and, to a small extent, instability are limitations. (ii) Water-cooled magnets provide fields of up to 0.25 T in volumes suitable for whole body imaging, but at the expense of power (up to 150 kW for 0.25 T) and water-cooling. Thermal stability of the field requires the maintenance of constant temperature through periods both of use and of quiescence. (iii) Because of the limitations imposed by permanent and resistive magnets, particularly on field strength, the superconducting magnet is now most widely used to provide background fields of up to 2 T for whole body MRI. It requires very low operating power and that only for refrigeration. Because of the constant low temperature, 4.2 K, at which its stressed structure operates, its field is stable. The following review deals principally with superconducting magnets for MRI. However, the sections on field analysis apply to all types of magnet and the description of the source terms of circular coils and of the principals of design of solenoids apply equally to resistive solenoidal magnets.

  7. Superconducting pulsed magnets

    CERN Document Server

    CERN. Geneva

    2006-01-01

    Lecture 1. Introduction to Superconducting Materials Type 1,2 and high temperature superconductors; their critical temperature, field & current density. Persistent screening currents and the critical state model. Lecture 2. Magnetization and AC Loss How screening currents cause irreversible magnetization and hysteresis loops. Field errors caused by screening currents. Flux jumping. The general formulation of ac loss in terms of magnetization. AC losses caused by screening currents. Lecture 3. Twisted Wires and Cables Filamentary composite wires and the losses caused by coupling currents between filaments, the need for twisting. Why we need cables and how the coupling currents in cables contribute more ac loss. Field errors caused by coupling currents. Lecture 4. AC Losses in Magnets, Cooling and Measurement Summary of all loss mechanisms and calculation of total losses in the magnet. The need for cooling to minimize temperature rise in a magnet. Measuring ac losses in wires and in magnets. Lecture 5. Stab...

  8. A superconducting magnetic gear

    Science.gov (United States)

    Campbell, A. M.

    2016-05-01

    A comparison is made between a magnetic gear using permanent magnets and superconductors. The objective is to see if there are any fundamental reasons why superconducting magnets should not provide higher power densities than permanent magnets. The gear is based on the variable permeability design of Attilah and Howe (2001 IEEE Trans. Magn. 37 2844-46) in which a ring of permanent magnets surrounding a ring of permeable pole pieces with a different spacing gives an internal field component at the beat frequency. Superconductors can provide much larger fields and forces but will saturate the pole pieces. However the gear mechanism still operates, but in a different way. The magnetisation of the pole pieces is now constant but rotates with angle at the beat frequency. The result is a cylindrical Halbach array which produces an internal field with the same symmetry as in the linear regime, but has an analytic solution. In this paper a typical gear system is analysed with finite elements using FlexPDE. It is shown that the gear can work well into the saturation regime and that the Halbach array gives a good approximation to the results. Replacing the permanent magnets with superconducting tapes can give large increases in torque density, and for something like a wind turbine a combined gear and generator is possible. However there are major practical problems. Perhaps the most fundamental is the large high frequency field which is inevitably present and which will cause AC losses. Also large magnetic fields are required, with all the practical problems of high field superconducting magnets in rotating machines. Nevertheless there are ways of mitigating these difficulties and it seems worthwhile to explore the possibilities of this technology further.

  9. Superconducting Magnets for Particle Accelerators

    CERN Document Server

    Rossi, L

    2012-01-01

    Superconductivity has been the most influential technology in the field of accelerators in the last 30 years. Since the commissioning of the Tevatron, which demonstrated the use and operability of superconductivity on a large scale, superconducting magnets and rf cavities have been at the heart of all new large accelerators. Superconducting magnets have been the invariable choice for large colliders, as well as cyclotrons and large synchrotrons. In spite of the long history of success, superconductivity remains a difficult technology, requires adequate R&D and suitable preparation, and has a relatively high cost. Hence, it is not surprising that the development has also been marked by a few setbacks. This article is a review of the main superconducting accelerator magnet projects; it highlights the main characteristics and main achievements, and gives a perspective on the development of superconducting magnets for the future generation of very high energy colliders.

  10. Design of MgB2 superconducting dipole magnet for particle beam transport in accelerators

    DEFF Research Database (Denmark)

    Abrahamsen, A.B.; Zangenberg, N.; Baurichter, A.

    2006-01-01

    A comprehensive analysis of the innovation potential of superconductivity at Risø was performed in February 2004 by the main author of this report [1]. Several suggestions for new products and new markets were formulated by the superconductivity group andexamined by the innovation staff at Risø. ...... accelerator, B = 4:4 Tesla and coil aperture D = 76 mm [6], which has been identified by Danfysik A/S as interesting. It isconcluded that MgB2 is useful for the dipole application and construction of a small test coil of one half of the magnet is planned in 2007....

  11. Feeding helium to superconducting magnets

    CERN Multimedia

    1979-01-01

    The photo shows two of the 3 superconducting magnets (two MBS dipoles (CESAR) of 150 mm bore and 4.5 T, and one quadrupole (CASTOR) of 90 mm bore and 54 T/m) which were installed in the hall EHN1 (Annual Report 1978 p. 134) and ran until 1985. They formed a section of the beam H6 travelling from target T4 (down the bottom of the photo) towards the NA30 setup followed by the NA11 setup. The two big transversal pipelines are the quench lines of the two magnets (on the right, one quadrupole and one dipole, the other dipole lays down the photo and is not visible). The Jura side of the hall is on the right.

  12. Superconductivity

    CERN Document Server

    Thomas, D B

    1974-01-01

    A short general review is presented of the progress made in applied superconductivity as a result of work performed in connection with the high-energy physics program in Europe. The phenomenon of superconductivity and properties of superconductors of Types I and II are outlined. The main body of the paper deals with the development of niobium-titanium superconducting magnets and of radio-frequency superconducting cavities and accelerating structures. Examples of applications in and for high-energy physics experiments are given, including the large superconducting magnet for the Big European Bubble Chamber, prototype synchrotron magnets for the Super Proton Synchrotron, superconducting d.c. beam line magnets, and superconducting RF cavities for use in various laboratories. (0 refs).

  13. Thickness-modulated tungsten–carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields

    Directory of Open Access Journals (Sweden)

    Ismael García Serrano

    2016-11-01

    Full Text Available We report efficient vortex pinning in thickness-modulated tungsten–carbon-based (W–C nanostructures grown by focused ion beam induced deposition (FIBID. By using FIBID, W–C superconducting films have been created with thickness modulation properties exhibiting periodicity from 60 to 140 nm, leading to a strong pinning potential for the vortex lattice. This produces local minima in the resistivity up to high magnetic fields (2.2 T in a broad temperature range due to commensurability effects between the pinning potential and the vortex lattice. The results show that the combination of single-step FIBID fabrication of superconducting nanostructures with built-in artificial pinning landscapes and the small intrinsic random pinning potential of this material produces strong periodic pinning potentials, maximizing the opportunities for the investigation of fundamental aspects in vortex science under changing external stimuli (e.g., temperature, magnetic field, electrical current.

  14. SUPERCONDUCTING QUADRUPOLE ARRAYS FOR MULTIPLE BEAM TRANSPORT

    Energy Technology Data Exchange (ETDEWEB)

    Rainer Meinke

    2003-10-01

    The goal of this research was to develop concepts for affordable, fully functional arrays of superconducting quadrupoles for multi-beam transport and focusing in heavy ion fusion (HIF)accelerators. Previous studies by the Virtual National Laboratory (VNL) collaboration have shown that the multi-beam transport system (consisting of alternating gradient quadrupole magnets, a beam vacuum system, and the beam monitor and control system) will likely be one of the most expensive and critical parts of such an accelerator. This statement is true for near-term fusion research accelerators as well as accelerators for the ultimate goal of power production via inertial fusion. For this reason, research on superconducting quadrupole arrays is both timely and important for the inertial fusion energy (IFE) research program. This research will also benefit near-term heavy ion fusion facilities such as the Integrated Research Experiment (IRE)and/or the Integrated Beam Experiment (IBX). We considered a 2-prong approach that addresses the needs of both the nearer and longer term requirements of the inertial fusion program. First, we studied the flat coil quadrupole design that was developed by LLNL; this magnet is 150 mm long with a 50 mm aperture and thus is suitable for near term experiments that require magnets of a small length to aperture ratio. Secondly, we studied the novel double-helix quadrupole (DHQ) design in a small (3 x 3) array configuration; this design can provide an important step to the longer term solution of low-cost, easy to manufacture array constructions. Our Phase I studies were performed using the AMPERES magnetostatic analysis software. Consideration of these results led to plans for future magnet R&D construction projects. The first objective of Phase I was to develop the concept of a superconducting focusing array that meets the specific requirements of a heavy ion fusion accelerator. Detailed parameter studies for such quadrupole arrays were performed

  15. Novel Approach to Linear Accelerator Superconducting Magnet System

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, Vladimir; /Fermilab

    2011-11-28

    Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.

  16. High Temperature Superconducting Magnets for Efficient Low Energy Beam Transport Systems

    CERN Document Server

    Popovic, M; Johnson, R P; Nipper, J H

    2013-01-01

    Modern ion accelerators and ion implantation systems need very short, highly versatile, Low Energy Beam Transport (LEBT) systems. The need for reliable and continuous operation requires LEBT designs to be simple and robust. The energy efficiency of available high temperature superconductors (HTS), with efficient and simple cryocooler refrigeration, is an additional attraction. Innovative, compact LEBT systems based on solenoids designed and built with high-temperature superconductor will be developed using computer models and prototyped. The parameters will be chosen to make this type of LEBT useful in a variety of ion accelerators, ion implantation systems, cancer therapy synchrotrons, and research accelerators, including the ORNL SNS. The benefits of solenoids made with HTS will be evaluated with analytical and numerical calculations for a two-solenoid configuration, as will be used in the SNS prototype LEBT that will replace the electrostatic one at SNS, and a single solenoid configuration, as was proposed...

  17. Quench thresholds in operational superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Allinger, J; Danby, G; Foelsche, H; Jackson, J; Lowenstein, D; Prodell, A; Weng, W

    1978-01-01

    Superconducting magnets exposed to intense primary proton beams in high energy physics applications are subject to potentially extreme heat deposition. The beam power density, its duration and spatial distribution, the current density in the superconductor and, potentially, in the normal metal substrate, as well as the construction and cooling details of the magnet, are all relevant parameters. An extension of some earlier work is discussed in which 28.5 GeV/c proton beams with up to 50 k joules of energy were targeted upstream from a 4 m long, 4 T dipole magnet used to deflect the protons through an angle of 8/sup 0/. Quench thresholds much greater than the enthalpy limit of the magnet materials were observed. In the beam exposure experiment described, intense beams of 1.5 GeV/c protons have been deflected directly into the magnet coil at relatively steep angles of incidence. The magnet quench threshold was studied by varying the beam currents and beam sizes.

  18. Magnetic and Superconducting Materials at High Pressures

    Energy Technology Data Exchange (ETDEWEB)

    Struzhkin, Viktor V. [Carnegie Inst. of Washington, Washington, DC (United States)

    2015-03-24

    transitions from magnetic to nonmagnetic phases in a broad pressure-temperature range; using X-ray methods including the newly developed RIXS high-pressure technique to explore pressure-tuned electronic excitations in strongly correlated 3d-materials; and advancing transport and magnetic techniques for measurements on small samples at very high pressures in a wide temperature range, with the application of focused ion beam technology and photolithography tailored to the design of microcircuits down to a nanoscale size, thus expanding the horizon in the search for novel physical phenomena at ultrahigh pressures. Apply new optical magnetic sensing techniques with NV- centers in diamond to detect superconductivity and magnetic transitions with unprecedented spatial resolution.

  19. Tutorial on Superconducting Accelerator Magnets

    Science.gov (United States)

    Ball, M. J. Penny; Goodzeit, Carl L.

    1997-05-01

    A multimedia CD-ROM tutorial on the physics and engineering concepts of superconducting magnets for particle accelerators is being developed under a U.S. Dept. of Energy SBIR grant. The tutorial, scheduled for distribution this summer, is targeted to undergraduate junior or senior level science students. However, its unified presentation of the broad range of issues involved in the design of superconducting magnets for accelerators and the extensive detail about the construction process (including animations and video clips) will also be of value to staff of research institutes and industrial concerns with an interest in applied superconductivity or magnet development. The source material, which is based on the world-wide R and D programs to develop superconducting accelerator magnets, is organized in five units with the following themes: Introduction to magnets and accelerators; (2) Superconductors for accelerator magnets; (3) Magnetic design methods for accelerator magnets; (4) Electrical, mechanical, and cryogenic considerations for the final magnet package; (5) Performance characteristics and measurement methods. A detailed outline and examples will be shown.

  20. Compact superconducting coplanar microwave beam splitters

    Energy Technology Data Exchange (ETDEWEB)

    Baust, Alexander; Haeberlein, Max; Goetz, Jan; Hoffmann, Elisabeth; Menzel, Edwin P.; Schwarz, Manuel J.; Wulschner, Friedrich; Zhong, Ling; Deppe, Frank; Marx, Achim; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TUM, Garching (Germany); Kalb, Norbert; Losinger, Thomas [Physik-Department, TUM, Garching (Germany)

    2012-07-01

    The recent evolution of circuit quantum electrodynamics systems making use of standing-wave microwave modes towards setups for propagating quantum microwaves has triggered the need for low-loss superconducting microwave beam splitters. Such a device should have ports compatible with the coplanar geometry relevant for circuit QED and, at the same time, be compact allowing for scalability. This combination presents fundamental and technological challenges. In this work, we present the fabrication and characterization of various compact superconducting coplanar microwave beam splitters. In addition, we discuss efforts towards a tunable beam splitter.

  1. LLNL superconducting magnets test facility

    Energy Technology Data Exchange (ETDEWEB)

    Manahan, R; Martovetsky, N; Moller, J; Zbasnik, J

    1999-09-16

    The FENIX facility at Lawrence Livermore National Laboratory was upgraded and refurbished in 1996-1998 for testing CICC superconducting magnets. The FENIX facility was used for superconducting high current, short sample tests for fusion programs in the late 1980s--early 1990s. The new facility includes a 4-m diameter vacuum vessel, two refrigerators, a 40 kA, 42 V computer controlled power supply, a new switchyard with a dump resistor, a new helium distribution valve box, several sets of power leads, data acquisition system and other auxiliary systems, which provide a lot of flexibility in testing of a wide variety of superconducting magnets in a wide range of parameters. The detailed parameters and capabilities of this test facility and its systems are described in the paper.

  2. SUPERCONDUCTING HELICAL SNAKE MAGNET FOR THE AGS.

    Energy Technology Data Exchange (ETDEWEB)

    WILLEN, E.; ANERELLA, M.; ESCALLIER, G.; GANETIS, G.; GHOSH, A.; GUPTA, R.; HARRISON, M.; JAIN, A.; LUCCIO, A.; MACKAY, W.; MARONE, A.; MURATORE, J.; PLATE, S.; ET AL.

    2005-05-16

    A superconducting helical magnet has been built for polarized proton acceleration in the Brookhaven AGS. This ''partial Snake'' magnet will help to reduce the loss of polarization of the beam due to machine resonances. It is a 3 T magnet some 1940 mm in magnetic length in which the dipole field rotates with a pitch of 0.2053 degrees/mm for 1154 mm in the center and a pitch of 0.3920 degrees/mm for 393 mm in each end. The coil cross-section is made of two slotted cylinders containing superconductor. In order to minimize residual offsets and deflections of the beam on its orbit through the Snake, a careful balancing of the coil parameters was necessary. In addition to the main helical coils, a solenoid winding was built on the cold bore tube inside the main coils to compensate for the axial component of the field that is experienced by the beam when it is off-axis in this helical magnet. Also, two dipole corrector magnets were placed on the same tube with the solenoid. A low heat leak cryostat was built so that the magnet can operate in the AGS cooled by several cryocoolers. The design, construction and performance of this unique magnet will be summarized.

  3. Superconductivity basics and applications to magnets

    CERN Document Server

    Sharma, R G

    2015-01-01

    This book presents the basics and applications of superconducting magnets. It explains the phenomenon of superconductivity, theories of superconductivity, type II superconductors and high-temperature cuprate superconductors. The main focus of the book is on the application to superconducting magnets to accelerators and fusion reactors and other applications of superconducting magnets. The thermal and electromagnetic stability criteria of the conductors and the present status of the fabrication techniques for future magnet applications are addressed. The book is based on the long experience of the author in studying superconducting materials, building magnets and numerous lectures delivered to scholars. A researcher and graduate student will enjoy reading the book to learn various aspects of magnet applications of superconductivity. The book provides the knowledge in the field of applied superconductivity in a comprehensive way.

  4. Superconducting Helical Snake Magnet for the AGS

    CERN Document Server

    Willen, Erich; Escallier, John; Ganetis, George; Ghosh, Arup; Gupta, Ramesh C; Harrison, Michael; Jain, Animesh K; Luccio, Alfredo U; MacKay, William W; Marone, Andrew; Muratore, Joseph F; Okamura, Masahiro; Plate, Stephen R; Roser, Thomas; Tsoupas, Nicholaos; Wanderer, Peter

    2005-01-01

    A superconducting helical magnet has been built for polarized proton acceleration in the Brookhaven AGS. This "partial Snake" magnet will help to reduce the loss of polarization of the beam due to machine resonances. It is a 3 T magnet some 1940 mm in magnetic length in which the dipole field rotates with a pitch of 0.2053 degrees/mm for 1154 mm in the center and a pitch of 0.3920 degrees/mm for 393 mm in each end. The coil cross-section is made of two slotted cylinders containing superconductor. In order to minimize residual offsets and deflections of the beam on its orbit through the Snake, a careful balancing of the coil parameters was necessary. In addition to the main helical coils, a solenoid winding was built on the cold bore tube inside the main coils to compensate for the axial component of the field that is experienced by the beam when it is off-axis in this helical magnet. Also, two dipole corrector magnets were placed on the same tube with the solenoid. A low heat leak cryostat was built so that t...

  5. Design Study of a Superconducting Gantry for Carbon Beam Therapy

    CERN Document Server

    Kim, J

    2016-01-01

    This paper describes the design study of a gantry for a carbon beam. The designed gantry is compact such that its size is comparable to the size of the proton gantry. This is possible by introducing superconducting double helical coils for dipole magnets. The gantry optics is designed in such a way that it provides rotation-invariant optics and variable beam size as well as point-to-parallel scanning of a beam. For large-aperture magnet, three-dimensional magnetic field distribution is obtained by invoking a computer code, and a number of particles are tracked by integrating equations of motion numerically together with three-dimensional interpolation. The beam-shape distortion due to the fringe field is reduced to an acceptable level by optimizing the coil windings with the help of genetic algorithm. Higher-order transfer coefficients are calculated and shown to be reduced greatly with appropriate optimization of the coil windings.

  6. Superconducting Ring Cyclotron for Riken RI Beam Factory in Japan

    Science.gov (United States)

    Okuno, H.; Dantsuka, T.; Yamada, K.; Kase, M.; Maie, T.; Kamigaito, O.

    2010-04-01

    Since 1997, RIKEN Nishina Center has been constructing the Radioactive Isotope Beam Factory (RIBF) and succeeded in beam commissioning of its accelerator complex at the end of 2006. The world's first superconducting ring cyclotron (SRC) is the final booster in the RIBF accelerator complex which is able to accelerate all-element heavy ions to a speed of about 70% of the velocity of light. The ring cyclotron consists of 6 major superconducting sector magnets with a maximum field of 3.8 T. The total stored energy is 235 MJ, and its overall sizes are 19 m diameter, 8 m height and 8,300 tons. The magnet system assembly was completed in August 2005, and successfully reached the maximum field in November 2005. The first beam was extracted at the end of 2006 and the first uranium beam was extracted in March 2007. However operation of the helium refrigerator was not satisfactory although the commissioning of SRC was successful. Operation was stopped every two month due to degradation of its cooling power. In February 2008 the reason of the degradation was revealed to be oil contamination. Operation of the cryogenic system was restarted from August 2008 after hard task to clean up the helium refrigerator and to add oil separators to the compressor. After restoration long-term steady operation to keep the magnet superconducting continued for about 8 months with no sign of degradation of cooling capacity.

  7. Superconducting bulk magnets for magnetic levitation systems

    Science.gov (United States)

    Fujimoto, H.; Kamijo, H.

    2000-06-01

    The major applications of high-temperature superconductors have mostly been confined to products in the form of wires and thin films. However, recent developments show that rare-earth REBa 2Cu 3O 7- x and light rare-earth LREBa 2Cu 3O 7- x superconductors prepared by melt processes have a high critical-current density at 77 K and high magnetic fields. These superconductors will promote the application of bulk high-temperature superconductors in high magnetic fields; the superconducting bulk magnet for the Maglev train is one possible application. We investigated the possibility of using bulk magnets in the Maglev system, and examined flux-trapping characteristics of multi-superconducting bulks arranged in array.

  8. Beam commissioning for a superconducting proton linac

    Science.gov (United States)

    Wang, Zhi-Jun; He, Yuan; Jia, Huan; Dou, Wei-ping; Chen, Wei-long; Zhang, X. L.; Liu, Shu-hui; Feng, Chi; Tao, Yue; Wang, Wang-sheng; Wu, Jian-qiang; Zhang, Sheng-hu; Zhao, Hong-Wei

    2016-12-01

    To develop the next generation of safe and cleaner nuclear energy, the accelerator-driven subcritical (ADS) system emerges as one of the most attractive technologies. It will be able to transmute the long-lived transuranic radionuclides produced in the reactors of today's nuclear power plants into shorter-lived ones, and also it will provide positive energy output at the same time. The prototype of the Chinese ADS (C-ADS) proton accelerator comprises two injectors and a 1.5 GeV, 10 mA continuous wave (CW) superconducting main linac. The injector scheme II at the C-ADS demo facility inside the Institute of Modern Physics is a 10 MeV CW superconducting linac with a designed beam current of 10 mA, which includes an ECR ion source, a low-energy beam transport line, a 162.5 MHz radio frequency quadrupole accelerator, a medium-energy beam transport line, and a superconducting half wave resonator accelerator section. This demo facility has been successfully operating with an 11 mA, 2.7 MeV CW beam and a 3.9 mA, 4.3 MeV CW beam at different times and conditions since June 2014. The beam power has reached 28 kW, which is the highest record for the same type of linear accelerators. In this paper, the parameters of the test injector II and the progress of the beam commissioning are reported.

  9. Compact Superconducting Final Focus Magnet Options for the ILC

    CERN Document Server

    Parker, Brett; Escallier, John; Harrison, Michael; He, Ping; Jain, Animesh K; Markiewicz, Thomas W; Marone, Andrew; Maruyama, Takashi; Nosochkov, Yuri; Seryi, Andrei; Wu, Kuo-Chen

    2005-01-01

    We present a compact superconducting final focus (FF) magnet system for the ILC based on recent BNL direct wind technology developments. Direct wind gives an integrated coil prestress solution for small transverse size coils. With beam crossing angles more than 15 mr, disrupted beam from the IP passes outside the coil while incoming beam is strongly focused. A superconducting FF magnet is adjustable to accommodate collision energy changes, i.e. energy scans and low energy calibration runs. A separate extraction line permits optimization of post IP beam diagnostics. Direct wind construction allows adding separate coils of arbitrary multipolarity (such as sextupole coils for local chromaticity correction). In our simplest coil geometry extracted beam sees significant fringe field. Since the fringe field affects the extracted beam, we also study advanced configurations that give either dramatic fringe field reduction (especially critical for gamma-gamma colliders) or useful quadrupole focusing on the outgoing be...

  10. Superconductivity for Magnets

    CERN Document Server

    Flükiger, R

    2014-01-01

    The present state of development of a series of industrial superconductors is reviewed in consideration of their future applications in high field accelerator magnets, with particular attention on the material aspect. The discussion is centred on Nb3Sn and MgB2, which are industrially available in a round wire configuration in kilometre lengths and are already envisaged for use in the LHC Upgrade (HL-LHC). The two systems Bi-2212 and R.E.123 may be used in magnets with even higher fields in future accelerators: they are briefly described.

  11. Superconducting magnets and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.E.C. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Francis Bitter National Magnet Lab.)

    1989-08-01

    Superconducting magnets are now being used in applications as diverse as medical imaging, fusion research, and power conditioning. The steady improvement in the understanding of instability and quenching has allowed increases in current density and compactness of winding. The reduction in winding size that has thus followed has allowed the construction of economic magnets for imaging, for acceleration, and for high-resolution spectrometers. Large magnets for fusion and energy applications have been made possible by composite conductors containing large fractions of copper or aluminum. The advent of high-temperature superconductors may hold the promise, eventually, of very-high-field magnets. Meanwhile low-temperature superconductors capable of generating fields up to 30 T have been developed.

  12. Nanostructuring superconducting vortex matter with focused ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Guillamón, I. [Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Unidad Asociada de Bajas Temperaturas y Altos Campos Magnéticos, UAM, CSIC, Cantoblanco, E-28049 Madrid (Spain); Suderow, H., E-mail: hermann.suderow@uam.es [Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Unidad Asociada de Bajas Temperaturas y Altos Campos Magnéticos, UAM, CSIC, Cantoblanco, E-28049 Madrid (Spain); Kulkarni, P.; Vieira, S. [Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Unidad Asociada de Bajas Temperaturas y Altos Campos Magnéticos, UAM, CSIC, Cantoblanco, E-28049 Madrid (Spain); Córdoba, R.; Sesé, J. [Laboratorio de Microscopías Avanzadas (LMA) – Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza 50009 (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); and others

    2014-08-15

    Highlights: • Nanostructuring vortex matter with focused ion beams. • Nanofabrication produces high vortex density gradients. • Patterning gives nanocrystalline vortex lattice. - Abstract: Focused ion beams provide new opportunities to create small nanofabricated structures. Materials where this technique is successfully applied are different from those that are widely used in e-beam or photolithography processes. Arrays of holes have been fabricated in several layered superconductors, such as the transition metal dichalcogenides. A focused ion beam system can be also used to deposit superconducting material. A Ga beam is used to decompose a precusor W(CO){sub 6} molecule, giving an amorphous mixture of W–C–Ga–O which is superconducting below liquid helium temperatures. The amorphous nature of the deposit gives isotropic superconducting features, and vortex pinning is determined by the surface topography (or film thickness). Here we present vortex lattice images in an amorphous thin film with a nanofabricated array of dots. We find vortex confinement within the dots and inhomogeneous vortex distributions with large magnetic field gradients (around a Tesla in 10–20 nm). We discuss scaling behavior of the vortex lattice after nanofabrication.

  13. EBIT装置零蒸发低温超导磁体系统的研制%Development of the superconducting magnet system with zero evaporation for Electron Beam Ion Trap ( EBIT )

    Institute of Scientific and Technical Information of China (English)

    张敏; 付云清; 陈文革; 王福堂; 陈治友; 何鹏; 朱加伍; 黄鹏程; 王超; 路迪

    2011-01-01

    Development of the superconducting magnet system with zero evaporation for Electron Beam Ion Trap (EBIT) was almost completed. The superconducting magnet of EBIT was arranged by a pair of split coils up and down, and the peak of magnetic field strength of superconducting magnet was up to 4.5 T, the uniformity was better than 2×10 in the range of ± 10mm on the central axis of magnet, and the time decaying ratio of magnet was better than 1 ×10-4 in 8h with closed - loop current. In order to reduce the consumption of liquid helium, the cryogenic system included two cooling - shields cooled by two stage G - M refrigerator. At present, the performance test results show the superconducting magnet of EBIT can meet that user's basic demands.%介绍了EBIT( Electron Beam Ion Trap,电子束离子阱)装置零蒸发低温超导磁体系统的研制过程与超导磁体的性能测试结果.该系统中超导磁体由一对上下布置的分离线圈组成,中心最大磁场强度可达4.5T,在中心轴线上±10mm内磁场均匀度优于2×10-4,磁场衰减系数在8h小于1×10-4;同时其低温杜瓦系统采用双冷屏结构,并通过二级G-M制冷机冷却冷屏来降低液氦的蒸发量.超导磁体的性能测试结果表明满足用户基本要求.

  14. Superconducting magnetic energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.D.

    1976-01-01

    Fusion power production requires energy storage and transfer on short time scales to create confining magnetic fields and for heating plasmas. The theta-pinch Scyllac Fusion Test Reactor (SFTR) requires 480 MJ of energy to drive the 5-T compression field with a 0.7-ms rise time. Tokamak Experimental Power Reactors (EPR) require 1 to 2 GJ of energy with a 1 to 2-s rise time for plasma ohmic heating. The design, development, and testing of four 300-kJ energy storage coils to satisfy the SFTR needs are described. Potential rotating machinery and homopolar energy systems for both the Reference Theta-Pinch Reactor (RTPR) and tokamak ohmic-heating are presented.

  15. Development of superconducting magnet systems for HIFExperiments

    Energy Technology Data Exchange (ETDEWEB)

    Sabbi, Gian Luca; Faltens, A.; Leitzke, A.; Seidl, P.; Lund, S.; Martovets ky, N.; Chiesa, L.; Gung, C.; Minervini, J.; Schultz, J.; Goodzeit, C.; Hwang, P.; Hinson, W.; Meinke, R.

    2004-07-27

    The U.S. Heavy Ion Fusion program is developing superconducting focusing quadrupoles for near-term experiments and future driver accelerators. Following the fabrication and testing of several models, a baseline quadrupole design was selected and further optimized. The first prototype of the optimized design achieved a conductor-limited gradient of 132 T/m in a 70 mm bore, with measured field harmonics within 10 parts in 10{sup 4}. In parallel, a compact focusing doublet was fabricated and tested using two of the first-generation quadrupoles. After assembly in the cryostat, both magnets reached their conductor-limited quench current. Further optimization steps are currently underway to improve the performance of the magnet system and reduce its cost. They include the fabrication and testing of a new prototype quadrupole with reduced field errors as well as improvements of the cryostat design for the focusing doublet. The prototype units will be installed in the HCX beamline at LBNL, to perform accelerator physics experiments and gain operational experience. Successful results in the present phase will make superconducting magnets a viable option for the next generation of integrated beam experiments.

  16. Superconducting magnets. Citations from NTIS data base

    Science.gov (United States)

    Reimherr, G. W.

    1980-10-01

    The cited reports discuss research on materials studies, theory, design and applications of superconducting magnets. Examples of applications include particle accelerators, MHD power generation, superconducting generators, nuclear fusion research devices, energy storage systems, and magnetic levitation. This updated bibliography contains 218 citations, 88 of which are new entries to the previous edition.

  17. Superconducting magnets in physics: problems and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Bronca, G.; Parain, J.

    1974-10-01

    The present status of solutions for the construction of magnets using superconducting windings is given. A review is given of achievements and projects using superconductors for the production of magnetic fields.

  18. Advanced Manufacturing of Superconducting Magnets

    Science.gov (United States)

    Senti, Mark W.

    1996-01-01

    The development of specialized materials, processes, and robotics technology allows for the rapid prototype and manufacture of superconducting and normal magnets which can be used for magnetic suspension applications. Presented are highlights of the Direct Conductor Placement System (DCPS) which enables automatic design and assembly of 3-dimensional coils and conductor patterns using LTS and HTS conductors. The system enables engineers to place conductors in complex patterns with greater efficiency and accuracy, and without the need for hard tooling. It may also allow researchers to create new types of coils and patterns which were never practical before the development of DCPS. The DCPS includes a custom designed eight-axis robot, patented end effector, CoilCAD(trademark) design software, RoboWire(trademark) control software, and automatic inspection.

  19. Superconducting magnet system for PERC

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, Carmen [Physikalisches Institut, Universitaet Heidelberg (Germany); Collaboration: PERC-Collaboration

    2012-07-01

    The new PERC (Proton Electron Radiation Channel) instrument will be an extremely bright and versatile source of neutron decay products. It will feed several novel precision experiments of spectra and correlation measurements in neutron decay. Its main component is a more than 11 m long superconducting magnet system. The neutron decay volume is located inside an 8 m long neutron guide in a strong longitudinal magnetic field of 1.5 T. A variable magnetic barrier of 3 T to 6 T serves to precisely limit the phase space of the emerging electrons and protons to control systematic errors on the 10{sup -4}level. The instrument is currently under development and will be installed at the neutron-beamline Mephisto at the FRM II, Garching. In this talk we give an overview on the special characteristics and advantages of PERC's field design. We show that with our design we can prevent magnetic traps in magnetic field and achieve a clean separation of neutrons and decay-products.

  20. Safety and reliability in superconducting MHD magnets

    Energy Technology Data Exchange (ETDEWEB)

    Laverick, C.; Powell, J.; Hsieh, S.; Reich, M.; Botts, T.; Prodell, A.

    1979-07-01

    This compilation adapts studies on safety and reliability in fusion magnets to similar problems in superconducting MHD magnets. MHD base load magnet requirements have been identified from recent Francis Bitter National Laboratory reports and that of other contracts. Information relevant to this subject in recent base load magnet design reports for AVCO - Everett Research Laboratories and Magnetic Corporation of America is included together with some viewpoints from a BNL workshop on structural analysis needed for superconducting coils in magnetic fusion energy. A summary of design codes used in large bubble chamber magnet design is also included.

  1. Superconducting materials suitable for magnets

    CERN Document Server

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    The range of materials available for superconducting magnets is steadily expanding, even as the choice of material becomes potentially more complex. When virtually all magnets were cooled by helium at ~2-5 K it was easy to separate the domain of Nb-Ti from those of Nb3Sn applications and very little surprise that more than 90% of all magnets are still made from Nb-Ti. But the development of useful conductors of the Bi-Sr-Ca-Cu-O and YBa2Cu3Ox high temperature superconductors, coupled to the recent discovery of the 39 K superconductor MgB2 and the developing availability of cryocoolers suggests that new classes of higher temperature, medium field magnets based on other than Nb-based conductors could become available in the next 5-10 years. My talks will discuss the essential physics and materials science of these 5 classes of material - Nb-Ti, Nb3Sn, MgB2, Bi-Sr-Ca-Cu-O and YBa2Cu3Ox - in the context of those aspects of their science, properties and fabrication properties, which circumscribe their applications...

  2. Accelerator Technology: Magnets, Normal and Superconducting

    CERN Document Server

    Bottura, L

    2013-01-01

    This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '8.1 Magnets, Normal and Superconducting' of the Chapter '8 Accelerator Technology' with the content: 8.1 Magnets, Normal and Superconducting 8.1.1 Introduction 8.1.2 Normal Conducting Magnets 8.1.2.1 Magnetic Design 8.1.2.2 Coils 8.1.2.3 Yoke 8.1.2.4 Costs 8.1.2.5 Undulators, Wigglers, Permanent Magnets 8.1.2.6 Solenoids 8.1.3 Superconducting Magnets 8.1.3.1 Superconducting Materials 8.1.3.2 Superconducting Cables 8.1.3.3 Stability and Margins, Quench and Protection 8.1.3.4 Magnetization, Coupling and AC Loss 8.1.3.5 Magnetic Design of Superconducting Accelerator Magnets 8.1.3.6 Current Leads 8.1.3.7 Mechanics, Insulation, Cooling and Manufacturing Aspects

  3. Durability Evaluation of Superconducting Magnets

    Science.gov (United States)

    Inoue, Akihiko; Ogata, Masafumi; Nakauchi, Masahiko; Asahara, Tetsuo; Herai, Toshiki; Nishikawa, Yoichi

    2006-06-01

    It is one of the most essential things to verify the durability of devices and components of JR-Maglev system to realize the system into the future inauguration. Since the load requirements were insufficient in terms of the durability under vibrations under mere running tests carried out on Yamanashi Maglev Test Line hereinafter referred to YMTL, we have developed supplemental method with bench tests. Superconducting magnets hereinafter referred to SCM as used in the experimental running for the last seven years on the YMTL were brought to Kunitachi Technical Research Institute; we conducted tests to evaluate the durability of SCM up to a period of the service life in commercial use. The test results have indicated that no irregularity in each part of SCM proving that SCM are sufficiently durable for the practical application.

  4. Progress on Superconducting Magnets for the MICE Cooling Channel

    Energy Technology Data Exchange (ETDEWEB)

    Green, Michael A; Virostek, Steve P.; Li, Derun; Zisman, Michael S.; Wang, Li; Pan, Heng; Wu, Hong; Guo, XingLong; Xu, FengYu; Liu, X. K.; Zheng, S. X.; Bradshaw, Thomas; Baynham, Elwyn; Cobb, John; Lau, Wing; Lau, Peter; Yang, Stephanie Q.

    2009-09-09

    The muon ionization cooling experiment (MICE) consists of a target, a beam line, a pion decay channel, the MICE cooling channel. Superconducting magnets are used in the pion decay channel and the MICE cooling channel. This report describes the MICE cooling channel magnets and the progress in the design and fabrication of these magnets. The MICE cooling channel consists of three types of superconducting solenoids; the spectrometer solenoids, the coupling solenoids and the focusing solenoids. The three types of magnets are being fabricated in he United States, China, and the United Kingdom respectively. The spectrometer magnets are used to analyze the muon beam before and after muon cooling. The coupling magnets couple the focusing sections and keep the muon beam contained within the iris of the RF cavities that re used to recover the muon momentum lost during ionization cooling. The focusing magnets focus the muon beam in the center of a liquid hydrogen absorber. The first of the cooling channel magnets will be operational in MICE in the spring of 2010.

  5. Optimized Superconducting Quadrupole Arrays for Multiple Beam Transport

    Energy Technology Data Exchange (ETDEWEB)

    Meinke, Rainer, B.; Goodzeit, Carl, L.; Ball, Millicent, J.

    2005-09-20

    This research project advanced the development of reliable, cost-effective arrays of superconducting quadrupole magnets for use in multi-beam inertial fusion accelerators. The field in each array cell must be identical and meet stringent requirements for field quality and strength. An optimized compact array design using flat double-layer pancake coils was developed. Analytical studies of edge termination methods showed that it is feasible to meet the requirements for field uniformity in all cells and elimination of stray external field in several ways: active methods that involve placement of field compensating coils on the periphery of the array or a passive method that involves use of iron shielding.

  6. Downsized superconducting magnetic energy storage systems

    Science.gov (United States)

    Palmer, David N.

    Scaled-down superconductive magnetic energy storage systems (DSMES) and superconductive magnetic energy power sources (SMEPS) are proposed for residential, commercial/retail, industrial off-peak and critical services, telephone and other communication systems, computer operations, power back-up/energy storages, power sources for space stations, and in-field military logistics/communication systems. Recent advances in high-Tc superconducting materials technology are analyzed. DSMES/SMEPS concepts are presented, and design, materials, and systems requirements are discussed. Problems ar identified, and possible solutions are offered. Comparisons are made with mechanical and primary and secondary energy storage and conversion systems.

  7. Design study of a superconducting gantry for carbon beam therapy

    Science.gov (United States)

    Kim, J.; Yoon, M.

    2016-09-01

    This paper describes beam-optics design of a gantry for carbon ions in cancer therapy accelerators. A compact design is important for such a gantry. The designed gantry is compact such that its size is comparable to the size of the existing proton gantries. This is made possible by introducing superconducting double helical coils for dipole magnets. The gantry optics is designed in such a way that it provides rotation-invariant optics, a variable beam size, and point-to-parallel scanning of a beam. For large-aperture magnet, a three-dimensional magnetic field distribution is obtained by invoking a computer code, and a number of particles are tracked by integrating equations of motion numerically together with a three-dimensional interpolation. The beam-shape distortion due to the fringe field is reduced to an acceptable level by optimizing the coil windings with the help of a genetic algorithm. Higher-order transfer coefficients are calculated and shown to be reduced greatly with appropriate optimization of the coil windings.

  8. Induced Magnetism in Color-Superconducting Media

    CERN Document Server

    Ferrer, Efrain J

    2009-01-01

    The dense core of compact stars is the natural medium for the realization of color superconductivity. A common characteristic of such astrophysical objects is their strong magnetic fields, especially those of the so called magnetars. In this talk, I discuss how a color superconducting core can generate or/and enhance the stellar magnetic field independently of a magnetohydrodynamic dynamo mechanism. The magnetic field generator is in this case a gluonic current which circulates to stabilize the color superconductor in the presence of a strong magnetic field or under the pairing stress produced in the medium by the neutrality and $\\beta$-equilibrium constraints.

  9. Calibration beams at the SSC (Superconducting Super Collider)

    Energy Technology Data Exchange (ETDEWEB)

    Autin, A.; Edwards, H. (Superconducting Super Collider Lab., Dallas, TX (USA)); Bensinger, J.R. (Superconducting Super Collider Lab., Dallas, TX (USA) Brandeis Univ., Waltham, MA (USA)); Baller, B.; Browning, F.; Coleman, R.; Cooper, J.; Cossairt, D.; Kula, L.; Malensek, A.; Stefanski, R.; Stutte, L. (Fermi National Accelerator Lab., Batavia, IL (USA))

    1989-04-30

    This paper discusses the following topics on the Superconducting Super Collider: beam specification at calibration halls; high energy booster options with tunnels to surface; switchyard; six beams with high and low power options; switchyard optics for both high and low energy transport; secondary beams; wide band beams; radiation shielding; tagging system; and test and calibration halls.

  10. Superconductive silicon nanowires using gallium beam lithography.

    Energy Technology Data Exchange (ETDEWEB)

    Henry, Michael David; Jarecki, Robert Leo,

    2014-01-01

    This work was an early career LDRD investigating the idea of using a focused ion beam (FIB) to implant Ga into silicon to create embedded nanowires and/or fully suspended nanowires. The embedded Ga nanowires demonstrated electrical resistivity of 5 m-cm, conductivity down to 4 K, and acts as an Ohmic silicon contact. The suspended nanowires achieved dimensions down to 20 nm x 30 nm x 10 m with large sensitivity to pressure. These structures then performed well as Pirani gauges. Sputtered niobium was also developed in this research for use as a superconductive coating on the nanowire. Oxidation characteristics of Nb were detailed and a technique to place the Nb under tensile stress resulted in the Nb resisting bulk atmospheric oxidation for up to years.

  11. Integrated design of superconducting accelerator magnets

    CERN Document Server

    Russenschuck, Stephan; Ramberger, S; Rodríguez-Mateos, F; Wolf, R

    1999-01-01

    This chapter introduces the main features of the ROXIE program which has been developed for the design of the superconducting magnets for the Large Hadron Collider (LHC) at CERN. The program combines numerical field calculation with a reduced vector-potential formulation, the application of vector-optimization methods, and the use of genetic as well as deterministic minimization algorithms. Together with the applied concept of features, the software is used as an approach towards integrated design of superconducting magnets. The main quadrupole magnet for the LHC, was chosen as an example for the integrated design process. (17 refs).

  12. Magnetism and superconductivity in heavy fermion systems

    Energy Technology Data Exchange (ETDEWEB)

    Flouquet, J. (DRFMC, C.E.N.G., 38 - Grenoble (France)); Brison, J.P.; Hasselbach, K.; Taillefer, L. (C.N.R.S., 38 - Grenoble (France)); Behnia, K.; Jaccard, D. (DPMC, Geneva Univ. (Switzerland)); Visser, A. de (Natuurkundig Lab., Univ. van Amsterdam (Netherlands))

    1991-12-01

    The normal and superconducting properties of heavy fermion compounds are reviewed. The discussion is focus on the three uranium compounds: UBe{sub 13}, UPt{sub 3} and URu{sub 2}Si{sub 2}. Special attention is given: 1) to unusual (H.T) superconducting phase diagram as discovered in UPt{sub 3} where two successive superconducting phases seem to occur in zero magnetic field; 2) to the role of long range ordering as found in URu{sub 2}Si{sub 2} and UPt{sub 3}. (orig.).

  13. Comparing superconducting and permanent magnets for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Nielsen, Kaspar Kirstein; Bahl, C. R. H.

    2016-01-01

    We compare the cost of a high temperature superconducting (SC) tape-based solenoidwith a permanent magnet (PM) Halbach cylinder for magnetic refrigeration.Assuming a five liter active magnetic regenerator volume, the price of each type ofmagnet is determined as a function of aspect ratio of the r......We compare the cost of a high temperature superconducting (SC) tape-based solenoidwith a permanent magnet (PM) Halbach cylinder for magnetic refrigeration.Assuming a five liter active magnetic regenerator volume, the price of each type ofmagnet is determined as a function of aspect ratio...

  14. Magnetic Flux Dynamics in Horizontally Cooled Superconducting Cavities

    CERN Document Server

    Martinello, M; Grassellino, A; Crawford, A C; Melnychuk, O; Romanenko, A; Sergatkov, D A

    2015-01-01

    Previous studies on magnetic flux expulsion as a function of cooling details have been performed for superconducting niobium cavities with the cavity beam axis placed parallel respect to the helium cooling flow, and findings showed that for sufficient cooling thermogradients all magnetic flux could be expelled and very low residual resistance could be achieved. In this paper we investigate the flux trapping and its impact on radio frequency surface resistance when the resonators are positioned perpendicularly to the helium cooling flow, which is representative of how superconducting radio-frequency (SRF) cavities are cooled in an accelerator. We also extend the studies to different directions of applied magnetic field surrounding the resonator. Results show that in the cavity horizontal configuration there is a different impact of the various field components on the final surface resistance, and that several parameters have to be considered to understand flux dynamics. A newly discovered phenomenon of concent...

  15. Design of a superconducting beam transport channel and beam dynamics for a strong-focusing cyclotron

    Science.gov (United States)

    Badgley, Karie Elizabeth

    There is an increasing interest in high power proton accelerators for use as neutron and muon sources, accelerator driven systems (ADS) for nuclear waste transmutation, high energy physics, medical physics, nuclear physics, and medical isotope production. Accelerating high current beams has a number of challenges; including avoiding harmful resonance crossing, space charge effects and, specific to cyclotrons, sufficient turn separation at injection and extraction. The Accelerator Research Laboratory at Texas A&M University is developing a high-power strong-focusing cyclotron with two main technologies to overcome these challenges. The first is a superconducting RF cavity to provide the energy gain required for fully separated turns. The second is the use of superconducting beam transport channels within the sectors of the cyclotron to provide strong-focusing with alternating focusing and defocusing quadrupoles. A method has been developed to find the equilibrium spiral orbit through the cyclotron which maintains isochronicity. The isochronous spiral orbit was then used to perform full linear optics calculations. The strengths of the quadrupoles were adjusted to hold the horizontal and vertical betatron tunes constant per turn to avoid resonance crossing. Particle tracking was performed with a modified MAD-X-PTC code and Synergia to provide a framework for future space charge studies. Magnetic modeling was performed on a 2D cross section of the beam transport channel. The wire locations were adjusted to reduce the higher order multipoles and a good field region was obtained at 70% of the beam pipe aperture with multipoles less than 10-4 . The 2D model was also used to determine the required current density needed to produce the quadrupole gradients. MgB2 superconducting wire was chosen as it meets all the field and current requirements and can operate at a reduced cryogenic cost. A winding mandrel was also designed and fabricated which minimized the bend radius for

  16. Superconducting wiggler with semi-cold beam duct at Taiwan light source

    Science.gov (United States)

    Hwang, C.-S.; Chang, C.-H.; Chen, H.-H.; Lin, F.-Y.; Fan, T.-C.; Huang, M.-H.; Jan, J.-C.; Hsu, K.-T.; Chen, J.; Hsu, S.-N.; Hsiung, G.-Y.; Chang, H.-P.; Kuo, C.-C.; Chien, Y.-C.; Hsiao, F.-Z.; Chen, J.-R.; Chen, C.-T.

    2006-01-01

    A 3.2 T superconducting wiggler with a periodic length of 6 cm and 32 poles was designed and fabricated as an X-ray source. The beam duct of this magnet is a semi-cold, ultra-high vacuum chamber that consists of an aluminum and stainless steel taper. The number of poles in this magnet design is even, to minimize the integral strengths of the multipole components. Two measurement systems—involving room-temperature and cryogenic Hall probes—were set up to measure the field of the superconducting wiggler. A cryogenic plant that supplied liquid helium and nitrogen to the superconducting wiggler has already been established. The performance of magnet construction is good and the commissioning of the superconducting wiggler in the storage ring has been successful. No trim coil compensation on the magnet is required to adjust the electron beam orbit. Furthermore, the electron beams exhibit no loss and remain highly stable after the superconducting wiggler has been quenched.

  17. Po Superconducting Magnet:detail of the windings

    CERN Multimedia

    1982-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam Po. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8307552X.

  18. Superconductivity and magnetism: Materials properties and developments

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, N.H.; Bay, N.; Grivel, J.C. (eds.) [and others

    2003-07-01

    The 24th Risoe International Symposium on Materials Science focuses on development of new materials, devices and applications, as well as experimental and theoretical studies of novel and unexplained phenomena in superconductivity and magnetism, e.g. within high.T{sub c} superconductivity, magnetic superconductors, MgB{sub 2}, CMR materials, nanomagnetism and spin-tronics. The aim is to stimulate exchange of ideas and establish new collaborations between leading Danish and international scientists. The topics are addressed by presentations from 24 invited speakers and by 41 contributed papers. (ln)

  19. Manufacturing and Testing of Accelerator Superconducting Magnets

    CERN Document Server

    Rossi, L

    2014-01-01

    Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of the accelerator magnets having an impact on the construction technology. We put in evidence how the design and component quality impact on construction and why the final product calls for a total-quality approach. LHC experience is widely discussed and main lessons are spelled out. Then the new Nb3Sn technology, under development for the next generation magnet construction, is outlined. Finally, we briefly review the testing procedure of accelerator superconducting magnets, underlining the close connection with the design validation and with the manufacturing process.

  20. Superconducting resonators as beam splitters for linear-optics quantum computation.

    Science.gov (United States)

    Chirolli, Luca; Burkard, Guido; Kumar, Shwetank; Divincenzo, David P

    2010-06-11

    We propose and analyze a technique for producing a beam-splitting quantum gate between two modes of a ring-resonator superconducting cavity. The cavity has two integrated superconducting quantum interference devices (SQUIDs) that are modulated by applying an external magnetic field. The gate is accomplished by applying a radio frequency pulse to one of the SQUIDs at the difference of the two mode frequencies. Departures from perfect beam splitting only arise from corrections to the rotating wave approximation; an exact calculation gives a fidelity of >0.9992. Our construction completes the toolkit for linear-optics quantum computing in circuit quantum electrodynamics.

  1. Performance of Superconducting Magnet Prototypes for LCLS-II Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, Vladimir [Fermilab; Andreev, Nikolai [Fermilab; DiMarco, Joseph [Fermilab; Makarov, Alexander [Fermilab; Tartaglia, Michael [Fermilab; Velev, George [Fermilab

    2016-12-30

    The new LCLS-II Linear Superconducting Accelerator at SLAC needs superconducting magnet packages installed inside SCRF Cryomodules to focus and steer an electron beam. Two magnet prototypes were built and successfully tested at Fermilab. Magnets have an iron dominated configuration, quadrupole and dipole NbTi superconducting coils, and splittable in the vertical plane configuration. Magnets inside the Cryomodule are conductively cooled through pure Al heat sinks. Both magnets performance was verified by magnetic measurements at room temperature, and during cold tests in liquid helium. Test results including magnetic measurements are discussed. Special attention was given to the magnet performance at low currents where the iron yoke and the superconductor hysteresis effects have large influence. Both magnet prototypes were accepted for the installation in FNAL and JLAB prototype Cryomodules.

  2. 6 June 2012 - British Member of Parliament for Bromsgrove Parliamentary Private Secretary to George Osborne, Chancellor of the Exchequer S. Javid MP signing the guest book with Adviser E. Tsesmelis and visiting the LHC superconducting magnet test hall with Beams Department Head P. Collier, Head of Operations M. Lamont and Adviser E. Tsesmelis.

    CERN Document Server

    Maximilien Brice

    2012-01-01

    6 June 2012 - British Member of Parliament for Bromsgrove Parliamentary Private Secretary to George Osborne, Chancellor of the Exchequer S. Javid MP signing the guest book with Adviser E. Tsesmelis and visiting the LHC superconducting magnet test hall with Beams Department Head P. Collier, Head of Operations M. Lamont and Adviser E. Tsesmelis.

  3. 23rd June 2010 - University of Bristol Head of the Aerospace Engineering Department and Professor of Aerospace Dynamics N. Lieven visiting CERN control centre with Beams Department Head P. Collier, visiting the LHC superconducting magnet test hall with R. Veness and CMS control centre with Collaboration Spokesperson G. Tonelli and CMS User J. Goldstein.

    CERN Multimedia

    Jean-Claude Gadmer

    2010-01-01

    23rd June 2010 - University of Bristol Head of the Aerospace Engineering Department and Professor of Aerospace Dynamics N. Lieven visiting CERN control centre with Beams Department Head P. Collier, visiting the LHC superconducting magnet test hall with R. Veness and CMS control centre with Collaboration Spokesperson G. Tonelli and CMS User J. Goldstein.

  4. 18 January 2011 - The British Royal Academy of Engineering in the LHC tunnel with CMS Collaboration Spokesperson G. Tonelli and Beams Department Head P. Collier; in the CERN Control Centre with P. Collier and LHC superconducting magnet test hall with Technology Department Head F. Bordry.

    CERN Multimedia

    Jean-Claude Gadmer

    2011-01-01

    18 January 2011 - The British Royal Academy of Engineering in the LHC tunnel with CMS Collaboration Spokesperson G. Tonelli and Beams Department Head P. Collier; in the CERN Control Centre with P. Collier and LHC superconducting magnet test hall with Technology Department Head F. Bordry.

  5. 1st September 2010 - British Vice-Chancellor, Liverpool University Sir Newby and Lady Newby signing the Guest Book with Head of International Relations F. Pauss; visiting the LHC superconducting magnet test hall with P. Cruikshank; accompanied by Beams Department Head P. Collier and Liverpool University T. Bowcock and P. Allport.

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    1st September 2010 - British Vice-Chancellor, Liverpool University Sir Newby and Lady Newby signing the Guest Book with Head of International Relations F. Pauss; visiting the LHC superconducting magnet test hall with P. Cruikshank; accompanied by Beams Department Head P. Collier and Liverpool University T. Bowcock and P. Allport.

  6. CERN tests largest superconducting solenoid magnet

    CERN Multimedia

    2006-01-01

    "CERN's Compacts Muon Solenoid (CMS) - the world's largest superconducting solenoid magnet - has reached full field in testing. The instrument is part of the proton-proton Large Hadron Collider (LHC) project, located in a giant subterranean chamber at Cessy on the Franco-Swiss border." (1 page)

  7. Superconducting vortex pinning with artificial magnetic nanostructures.

    Energy Technology Data Exchange (ETDEWEB)

    Velez, M.; Martin, J. I.; Villegas, J. E.; Hoffmann, A.; Gonzalez, E. M.; Vicent, J. L.; Schuller, I. K.; Univ. de Oviedo-CINN; Unite Mixte de Physique CNRS/Thales; Univ. Paris-Sud; Univ.Complutense de Madrid; Univ. California at San Diego

    2008-11-01

    This review is dedicated to summarizing the recent research on vortex dynamics and pinning effects in superconducting films with artificial magnetic structures. The fabrication of hybrid superconducting/magnetic systems is presented together with the wide variety of properties that arise from the interaction between the superconducting vortex lattice and the artificial magnetic nanostructures. Specifically, we review the role that the most important parameters in the vortex dynamics of films with regular array of dots play. In particular, we discuss the phenomena that appear when the symmetry of a regular dot array is distorted from regularity towards complete disorder including rectangular, asymmetric, and aperiodic arrays. The interesting phenomena that appear include vortex-lattice reconfigurations, anisotropic dynamics, channeling, and guided motion as well as ratchet effects. The different regimes are summarized in a phase diagram indicating the transitions that take place as the characteristic distances of the array are modified respect to the superconducting coherence length. Future directions are sketched out indicating the vast open area of research in this field.

  8. Technical issues of a high-Tc superconducting bulk magnet

    Science.gov (United States)

    Fujimoto, Hiroyuki

    2000-06-01

    Superconducting magnets made of high-Tc superconductors are promising for industrial applications. It is well known that REBa2Cu3O7-x superconductors prepared by melt processes have a high critical current density, Jc, at 77 K and high magnetic fields. The materials are very promising for high magnetic field applications as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. Light rare-earth (LRE) BaCuO bulks, compared with REBaCuO bulks, exhibit a larger Jc in high magnetic fields and a much improved irreversibility field, Hirr, at 77 K. In this study, we discuss technical issues of a high-Tc superconducting bulk magnet, namely the aspects of the melt processing for bulk superconductors, their characteristic superconducting properties and mechanical properties, and trapped field properties of a superconducting bulk magnet. One of the possible applications is a superconducting bulk magnet for the magnetically levitated (Maglev) train in the future.

  9. Magnetic shielding for superconducting RF cavities

    Science.gov (United States)

    Masuzawa, M.; Terashima, A.; Tsuchiya, K.; Ueki, R.

    2017-03-01

    Magnetic shielding is a key technology for superconducting radio frequency (RF) cavities. There are basically two approaches for shielding: (1) surround the cavity of interest with high permeability material and divert magnetic flux around it (passive shielding); and (2) create a magnetic field using coils that cancels the ambient magnetic field in the area of interest (active shielding). The choice of approach depends on the magnitude of the ambient magnetic field, residual magnetic field tolerance, shape of the magnetic shield, usage, cost, etc. However, passive shielding is more commonly used for superconducting RF cavities. The issue with passive shielding is that as the volume to be shielded increases, the size of the shielding material increases, thereby leading to cost increase. A recent trend is to place a magnetic shield in a cryogenic environment inside a cryostat, very close to the cavities, reducing the size and volume of the magnetic shield. In this case, the shielding effectiveness at cryogenic temperatures becomes important. We measured the permeabilities of various shielding materials at both room temperature and cryogenic temperature (4 K) and studied shielding degradation at that cryogenic temperature.

  10. The advantages and challenges of superconducting magnets in particle therapy

    Science.gov (United States)

    Gerbershagen, Alexander; Calzolaio, Ciro; Meer, David; Sanfilippo, Stéphane; Schippers, Marco

    2016-08-01

    This paper provides an overview of the current developments in superconducting magnets for applications in proton and ion therapy. It summarizes the benefits and challenges regarding the utilization of these magnets in accelerating systems (e.g. superconducting cyclotrons) and gantries. The paper also provides examples of currently used superconducting particle therapy systems and proposed designs.

  11. Design of a superconducting magnet for CADS

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-Liang; MA Li-Zhen; WU Vei; ZHENG Shi-Jun; DU Jun-Jie; HAN Shao-Fei; GUAN Ming-Zhi; HE Yuan

    2012-01-01

    This paper describes a superconducting magnet system for the China Accelerator Driven System (CADS).The magnetic field is provided hy one main,two bucking and four racetrack coils.The main coil produces a central field of up to 7 T and the effective length is more than 140 mm,the two bucking coils can shield most of the fringe field,and the four racetrack superconducting coils produce the steering magnetic field.Its leakage field in the cavity zone is about 5 × 10-5 T when the shielding material Niobium and cryogenic permalloy are used as the Meissner shielding and passive shielding respectively.The quench calculations and protection system are also discussed.

  12. A current limiter with superconducting coil for magnetic field shielding

    Science.gov (United States)

    Kaiho, K.; Yamaguchi, H.; Arai, K.; Umeda, M.; Yamaguchi, M.; Kataoka, T.

    2001-05-01

    The magnetic shield type superconducting fault current limiter have been built and successfully tested in ABB corporate research and so on. The device is essentially a transformer in which the secondary winding is the superconducting tube. However, due to the large AC losses and brittleness of the superconducting bulk tube, they have not yet entered market. A current limiter with superconducting coil for the magnetic field shielding is considered. By using the superconducting coil made by the multi-filamentary high Tc superconductor instead of the superconducting bulk tube, the AC losses can be reduced due to the reduced superconductor thickness and the brittleness of the bulk tube can be avoidable. This paper presents a preliminary consideration of the magnetic shield type superconducting fault current limiter with superconducting coil as secondary winding and their AC losses in comparison to that of superconducting bulk in 50 Hz operation.

  13. Comparing superconducting and permanent magnets for magnetic refrigeration

    Directory of Open Access Journals (Sweden)

    R. Bjørk

    2016-05-01

    Full Text Available We compare the cost of a high temperature superconducting (SC tape-based solenoid with a permanent magnet (PM Halbach cylinder for magnetic refrigeration. Assuming a five liter active magnetic regenerator volume, the price of each type of magnet is determined as a function of aspect ratio of the regenerator and desired internal magnetic field. It is shown that to produce a 1 T internal field in the regenerator a permanent magnet of hundreds of kilograms is needed or an area of superconducting tape of tens of square meters. The cost of cooling the SC solenoid is shown to be a small fraction of the cost of the SC tape. Assuming a cost of the SC tape of 6000 $/m2 and a price of the permanent magnet of 100 $/kg, the superconducting solenoid is shown to be a factor of 0.3-3 times more expensive than the permanent magnet, for a desired field from 0.5-1.75 T and the geometrical aspect ratio of the regenerator. This factor decreases for increasing field strength, indicating that the superconducting solenoid could be suitable for high field, large cooling power applications.

  14. A superconducting large-angle magnetic suspension

    Science.gov (United States)

    Downer, James R.; Anastas, George V., Jr.; Bushko, Dariusz A.; Flynn, Frederick J.; Goldie, James H.; Gondhalekar, Vijay; Hawkey, Timothy J.; Hockney, Richard L.; Torti, Richard P.

    1992-01-01

    SatCon Technology Corporation has completed a Small Business Innovation Research (SBIR) Phase 2 program to develop a Superconducting Large-Angle Magnetic Suspension (LAMS) for the NASA Langley Research Center. The Superconducting LAMS was a hardware demonstration of the control technology required to develop an advanced momentum exchange effector. The Phase 2 research was directed toward the demonstration for the key technology required for the advanced concept CMG, the controller. The Phase 2 hardware consists of a superconducting solenoid ('source coils') suspended within an array of nonsuperconducting coils ('control coils'), a five-degree-of-freedom positioning sensing system, switching power amplifiers, and a digital control system. The results demonstrated the feasibility of suspending the source coil. Gimballing (pointing the axis of the source coil) was demonstrated over a limited range. With further development of the rotation sensing system, enhanced angular freedom should be possible.

  15. Development of superconducting quadrupole magnets for beam-interaction region at CERN-LHC (11). Field quality of the third 1m model magnets with new design; CERN-LHC bimu sonyuyo shikyoku chodendo magunetto no kaihatsu (11). Shin dezain 1m moderu magunetto ni okeru jiba tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, N.; Ajima, Y.; Ogitsu, T.; Roger, R.; Tsuchiya, K.; Yamamoto, A.; Shintomi, T. [High Energy Accelerator Research Organization, Tsukuba (Japan)

    2000-05-29

    In the high-energy accelerator research aircraft construction, it develops beam last convergence superconductivity quadrupoles electromagnet used by the CERN-LHC accelerator in CERN and cooperation. It requires the thing that the magnetic field gradient in the operation of this electromagnet is very high with 215T/m and that the accuracy is also high on the uniformity of the magnetic field. It had manufactured 2 magnets until now, and it carried out the magnetic field measurement. From this result, it was confirmed that there was the necessity of the improvement in the 20 pole components, and it designed the new magnet cross-sectional shape, and it manufactured the No.3 machine. In this report, magnetic field measurement result of this No.3 machine is reported. (NEDO)

  16. Preliminary study of superconducting bulk magnets for Maglev

    Science.gov (United States)

    Fujimoto, Hiroyuki; Kamijo, Hiroki

    Recent development shows that melt-processed YBaCuO (Y123) or Rare Earth (RE)123 superconductors have a high Jc at 77 K and high magnetic field, leading to high field application as a superconducting quasi-permanent bulk magnet with the liquid nitrogen refrigeration. One of the promising applications is a superconducting magnet for the magnetically levitated (Maglev) train. We discuss a superconducting bulk magnet for the Maglev train in the aspect of a preliminary design of the bulk magnet and also processing for (L)REBaCuO bulk superconductors and their characteristic superconducting properties.

  17. Superconducting dipole magnet for the CBM experiment at FAIR

    Directory of Open Access Journals (Sweden)

    Kurilkin P.

    2017-01-01

    Full Text Available The scientific goal of the CBM (Compressed Baryonic Matter experiment at FAIR (Darmstadt is to explore the phase diagram of strongly interacting matter at highest baryon densities. The physics program of the CBM experiment is complimentary to the programs to be realized at MPD and BMN facilities at NICA and will start with beam derived by the SIS100 synchrotron. The 5.15 MJ superconducting dipole magnet will be used in the silicon tracking system of the CBM detector. The magnet will provide a magnetic field integral of 1 Tm which is required to obtain a momentum resolution of 1% for the track reconstruction. The results of the development of dipole magnet of the CBM experiment are presented.

  18. A superconducting magnet upgrade of the ATF2 final focus

    CERN Document Server

    Parker, B; Escallier, J; He, P; Jain, P; Marone, A; Wanderer, P; Wu, KC; Hauviller, C; Marin, E; Tomas, R; Zimmermann, F; Bolzon, B; Jeremie, A; Kimura, N; Kubo, K; Kume, T; Kuroda, S; Okugi, T; Tauchi, T; Terunuma, N; Tomaru, T; Tsuchiya, K; Urakawa, J; Yamamoto, A; Bambade, P; Coe, P; Urner, D; Seryi, A; Spencer, C; White, G

    2010-01-01

    The ATF2 facility at KEK is a proving ground for linear collider technology with a well instrumented extracted beam line and Final Focus (FF). The primary ATF2 goal is to demonstrate the extreme beam demagnification and spot stability needed for a linear collider FF [1]. But the ATF2 FF uses water cooled magnets and the ILC baseline has a superconducting (SC) FF [2]. We plan to upgrade ATF2 and replace some of the warm FF magnets with SC FF magnets. The ATF2 SC magnets, like the ILC FF, will made via direct wind construction [3]. ATF2 coil winding is in progress at BNL and warm magnetic measurements indicate we have achieved good field quality. Studies indicate that having ATF2 FF magnets with larger aperture and better field quality should allow reducing the ATF2 FF beta function for study of focusing regimes relevant to CLIC [4]. The ATF2 magnet cryostat will have laser view ports for directly monitoring cold mass movement. We plan to make stability measurements at BNL and KEK to relate ATF2 FF magnet perfo...

  19. A Superconducting Magnet Upgrade of the ATF2 Final Focus

    Energy Technology Data Exchange (ETDEWEB)

    Parker B.; Anerella M.; Escallier J.; He P.; Jain A.; Marone A.; Wanderer P.; Wu K.C.; Hauviller C.; Marin E.; Tomas R.; Zimmermann F.; Bolzon B.; Jeremie A.; Kimura N.; Kubo K.; Kume T.; Kuroda S.; Okugi T.; Tauchi T.; Terunuma N.; Tomaru T.; Tsuchiya K.; Urakawa J.; Yamamoto A.; Bambabe P.; Coe P.; Urner D.; Seryi A.; Spencer C.; White G.

    2010-05-23

    The ATF2 facility at KEK is a proving ground for linear collider technology with a well instrumented extracted beam line and Final Focus (FF). The primary ATF2 goal is to demonstrate the extreme beam demagnification and spot stability needed for a linear collider FF. But the ATF2 FF uses water cooled magnets and the ILC baseline has a superconducting (SC) FF. We plan to upgrade ATF2 and replace some of the warm FF magnets with SC FF magnets. The ATF2 SC magnets, like the ILC FF, will made via direct wind construction. ATF2 coil winding is in progress at BNL and warm magnetic measurements indicate we have achieved good field quality. Studies indicate that having ATF2 FF magnets with larger aperture and better field quality should allow reducing the ATF2 FF beta function for study of focusing regimes relevant to CLIC. The ATF2 magnet cryostat will have laser view ports for directly monitoring cold mass movement. We plan to make stability measurements at BNL and KEK to relate ATF2 FF magnet performance to that of a full length ILC QD0 R and D FF prototype under construction at BNL.

  20. A Superconducting Magnet Upgrade of the ATF2 Final Focus

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Brett; /Brookhaven; Anerella, Michael; /Brookhaven; Escallier, John; /Brookhaven; He, Ping; /Brookhaven; Jain, Animesh; /Brookhaven; Marone, Andrew; /Brookhaven; Wanderer, Peter; /Brookhaven; Wu, Kuo-Chen; /Brookhaven; Bambade, Philip; /Orsay, LAL; Bolzon, Benoit; /Annecy, LAPP; Jeremie, Andrea; /Annecy, LAPP; Coe, Paul; /Oxford U.; Urner, David /Oxford U.; Hauviller, Claude; /CERN; Marin, Eduardo; /CERN; Tomas, Rogelio; /CERN; Zimmermann, Frank; /CERN; Kimura, Nobuhiro; /KEK, Tsukuba; Kubo, Kiyoshi; /KEK, Tsukuba; Kume, Tatsuya /KEK, Tsukuba; Kuroda, Shigeru; /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /SLAC /SLAC /SLAC

    2012-07-05

    The ATF2 facility at KEK is a proving ground for linear collider technology with a well instrumented extracted beam line and Final Focus (FF). The primary ATF2 goal is to demonstrate the extreme beam demagnification and spot stability needed for a linear collider FF. But the ATF2 FF uses water cooled magnets and the ILC baseline has a superconducting (SC) FF. We plan to upgrade ATF2 and replace some of the warm FF magnets with SC FF magnets. The ATF2 SC magnets, like the ILC FF, will made via direct wind construction. ATF2 coil winding is in progress at BNL and warm magnetic measurements indicate we have achieved good field quality. Studies indicate that having ATF2 FF magnets with larger aperture and better field quality should allow reducing the ATF2 FF beta function for study of focusing regimes relevant to CLIC. The ATF2 magnet cryostat will have laser view ports for directly monitoring cold mass movement. We plan to make stability measurements at BNL and KEK to relate ATF2 FF magnet performance to that of a full length ILC QD0 R&D FF prototype under construction at BNL.

  1. Permanent magnet design for high-speed superconducting bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (5519 S. Bruner, Hinsdale, IL 60521); Uherka, Kenneth L. (830 Ironwood, Frankfort, IL 60423); Abdoud, Robert G. (13 Country Oaks La., Barrington Hills, IL 60010)

    1996-01-01

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing.

  2. Magnetic Field Reentrant Superconductivity in Aluminum Nanowires

    Science.gov (United States)

    Bretz-Sullivan, Terence; Goldman, Allen

    Reentrance to the superconducting state through the application of a magnetic field to quasi-one dimensional superconductors driven resistive by current, is counter to the expected properties of superconductors. It was not until recently that a microscopic mechanism explaining the phenomenon was proposed in which superconductivity and phase slip driven dissipation coexist in a non-equilibrium state. Here we present additional results of magnetic field induced reentrance into the superconducting state in quasi-one-dimensional aluminum nanowires with an in-plane magnetic field both transverse to, and along the wire axis. The reentrant behavior is seen in the magnetic field dependence of the I-V characteristic and resistance vs. temperature, and in the wire's magnetoresistance at 450mK. This work was supported by DOE Basic Energy Sciences Grant DE-FG02-02ER46004. Samples were fabricated at the Minnesota Nanofabrication Center. Parts of this work were carried out in the University of Minnesota Characterization Facility, a member of the Materials Research Facilities Network (www.mrfn.org) funded via the NSF MRSEC program.

  3. Measurement and Modeling of Magnetic Hysteresis in the LHC Superconducting Correctors

    CERN Document Server

    Venturini-Delsolaro, W; Chaudhari, Y; Karppinen, M; Sammut, N

    2006-01-01

    The Large Hadron Collider, now under construction at CERN, relies heavily on superconducting magnets for its optics layout: besides the main magnets, almost all the correcting magnets are superconducting. Along with clear advantages, this brings about complications due to the effects of persistent currents in the superconducting filaments. Corrector magnets that trim key beam parameters or compensate field errors of the main magnets (among others those due to hysteresis), are in their turn hysteretic. In this paper we present the measured magnetic hysteresis and its possible influence on accelerator operation, with particular reference to realtime compensation of dynamic effects in the main magnets, and reproducibility issues between runs. The modeling strategy as a function of the required accuracy is discussed, and two examples are presented.

  4. High-temperature superconducting undulator magnets

    Science.gov (United States)

    Kesgin, Ibrahim; Kasa, Matthew; Ivanyushenkov, Yury; Welp, Ulrich

    2017-04-01

    This paper presents test results on a prototype superconducting undulator magnet fabricated using 15% Zr-doped rare-earth barium copper oxide high temperature superconducting (HTS) tapes. On an 11-pole magnet we demonstrate an engineering current density, J e, of more than 2.1 kA mm‑2 at 4.2 K, a value that is 40% higher than reached in comparable devices wound with NbTi-wire, which is used in all currently operating superconducting undulators. A novel winding scheme enabling the continuous winding of tape-shaped conductors into the intricate undulator magnets as well as a partial interlayer insulation procedure were essential in reaching this advance in performance. Currently, there are rapid advances in the performance of HTS; therefore, achieving even higher current densities in an undulator structure or/and operating it at temperatures higher than 4.2 K will be possible, which would substantially simplify the cryogenic design and reduce overall costs.

  5. Evidence for spin-triplet superconducting correlations in metal-oxide heterostructures with noncollinear magnetization

    Science.gov (United States)

    Khaydukov, Yu. N.; Ovsyannikov, G. A.; Sheyerman, A. E.; Constantinian, K. Y.; Mustafa, L.; Keller, T.; Uribe-Laverde, M. A.; Kislinskii, Yu. V.; Shadrin, A. V.; Kalaboukhov, A.; Keimer, B.; Winkler, D.

    2014-07-01

    Heterostructures composed of ferromagnetic La0.7Sr0.3MnO3, ferromagnetic SrRuO3, and superconducting YBa2Cu3O6+x were studied experimentally. Structures of composition Au /La0.7Sr0.3MnO3/SrRuO3/YBa2Cu3O6+x were prepared by pulsed laser deposition, and their high quality was confirmed by x-ray diffraction and reflectometry. A noncollinear magnetic state of the heterostructures was revealed by means of superconducting quantum interference device magnetometry and polarized neutron reflectometry. We have further observed superconducting currents in mesa structures fabricated by deposition of a second superconducting Nb layer on top of the heterostructure, followed by patterning with photolithography and ion-beam etching. Josephson effects observed in these mesa structures can be explained by the penetration of a triplet component of the superconducting order parameter into the magnetic layers.

  6. A Scaling Law for the Snapback in Superconducting Accelerator Magnets

    CERN Document Server

    Bottura, L; Bauer, P; Haverkamp, M; Pieloni, T; Sanfilippo, S; Velev, G

    2005-01-01

    The decay of the sextupole component in the bending dipoles during injection and the subsequent snapback at the start of beam acceleration are issues of common concern for all superconducting colliders built or in construction. Recent studies performed on LHC and Tevatron dipole magnets revealed many similarities in the snapback characteristics. Some are expected, e.g. the effect of operational history. One particular similarity, however, is striking and is the subject of this paper. It appears that there is a simple linear relation between the amount of sextupole drift during the decay and the magnet current (or field) change during the ramp required to resolve the snapback. It is surprising that the linear correlation between snapback amplitude and snapback field holds very well for all magnets of the same family (e.g. Tevatron or LHC dipoles). In this paper we present the data collected to date and discuss a simple theory that explains the scaling found.

  7. SMES: Superconducting Magnetic Energy Storage

    Science.gov (United States)

    1993-01-01

    power to magnetically levitated trains . A very small size SMES can poten- tially be part of a hybrid propul- sion system on large transit buses...potentially lead to the increased use of urban transit, maglev and electric vehicles, thereby re- ducing air pollution. Illustration courtesy of

  8. Superconducting Sphere in an External Magnetic Field Revisited

    Science.gov (United States)

    Sazonov, Sergey N.

    2013-01-01

    The purpose of this article is to give the intelligible procedure for undergraduate students to grasp proof of the fact that the magnetic field outside the hollow superconducting sphere (superconducting shell) coincides with the field of a point magnetic dipole both when an uniform external magnetic field is applied as when a ferromagnetic sphere…

  9. Torus CLAS12-Superconducting Magnet Quench Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V S; Elouadhiri, L; Ghoshal, P K; Kashy, D; Makarov, A; Pastor, O; Quettier, L; Velev, G; Wiseman, M

    2014-06-01

    The JLAB Torus magnet system consists of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration. These coils are wound with SSC-36 Nb-Ti superconductor and have the peak magnetic field of 3.6 T. The first coil manufacturing based on the JLAB design began at FNAL. The large magnet system dimensions (8 m diameter and 14 MJ of stored energy) dictate the need for quench protection. Each coil is placed in an aluminum case mounted inside a cryostat and cooled by 4.6 K supercritical helium gas flowing through a copper tube attached to the coil ID. The large coil dimensions and small cryostat thickness drove the design to challenging technical solutions, suggesting that Lorentz forces due to transport currents and eddy currents during quench and various failure scenarios are analyzed. The paper covers the magnet system quench analysis using the OPERA3d Quench code.

  10. Superconducting magnets for the LHC main lattice

    CERN Document Server

    Rossi, L

    2004-01-01

    The main lattice of the Large Hadron Collider (LHC) will employ about 1600 main magnets and more than 4000 corrector magnets. All superconducting and working in pressurized superfluid helium bath, these impressive line of magnets will fill more than 20 km of the underground tunnel. With almost 70 main dipoles already delivered and 10 main quadrupoles almost completed, we passed the 5% of the production and now all manufacturers have fully entered into series production. In this paper the most critical issues encountered in the ramping up in such a real large scale fabrication will be addressed: uniformity of the coil size and of prestress, special welding technique, tolerances on curvature (dipoles) or straightness (quadrupoles) and of the cold mass extremities, harmonic content and, most important, the integrated field uniformity among magnets. The actual limits and the solution for improvements will be discussed. Finally a realistic schedule based on actual achievements is presented.

  11. Permanent superconducting magnets for space applications

    Science.gov (United States)

    Weinstein, Roy

    1994-01-01

    Work has been done to develop superconducting trapped field magnets (TFM's) and to apply them to a bumper-tether device for magnetic docking of spacecraft. The quality parameters for TFM's are J(c), the critical current of the superconductor, and d, the diameter of the superconducting tile. During this year we have doubled d, for production models, from 1 cm to 2 cm. This was done by means of seeding, an improved temperature profile in processing, and the addition of 1 percent Pt to the superconductor chemistry. Using these tiles we have set increasing records for the fields' permanent magnets. Magnets fabricated from old 1 cm tiles trapped 1.52 Tesla at 77K, 4.0T at 65K and 7.0T at 55K. The second of these fields broke a 17 year old record set at Stanford. The third field broke our own record. More recently using 2 cm tiles, we have trapped 2.3T at 77K, and 5.3T at 65K. We expect to trap lOT at 55K in this magnet in the near future. We have also achieved increases in J(c) using a method we developed for seeding U-235, and subsequently bombarding with neutrons. This method doubles J(c). We have not yet fabricated magnets from these tiles. During this year we have increased production yields from 15 percent to 95 percent. We have explored the properties of a magnetic bumper-tether for spacecraft. We have measured the bumper forces, and their dependence on time, distance, and the field of the ordinary ferromagnet (used together with a TFM). We have accounted for 85 percent of the collision energy, and its transformation to magnetic energy and heat energy. We have learned to control the relative bumper and tether forces by controlling TFM and ferromagnetic field strengths.

  12. Low Loss and Magnetic Field-tuned Superconducting THz Metamaterial

    CERN Document Server

    Jin, Biaobing; Engelbrecht, Sebastian; Pimenov, Andrei; Wu, Jingbo; Xu, Qinyin; Cao, Chunhai; Chen, Jian; Xu, Weiwei; Kang, Lin; Wu, Peiheng

    2010-01-01

    Superconducting terahertz (THz) metamaterial (MM) made from superconducting Nb film has been investigated using a continuous-wave THz spectroscopy with a superconducting split-coil magnet. The obtained quality factors of the resonant modes at 132 GHz and 450 GHz are about three times as large as those calculated for a metal THz MM operating at 1 K, which indicates that superconducting THz MM is a very nice candidate to achieve low loss performance. In addition, the magnetic field-tuning on superconducting THz MM is also demonstrated, which offer an alternative tuning method apart from the existed electric, optical and thermal tuning on THz MM.

  13. Ruthenocuprats: Playground for superconductivity and magnetism

    Directory of Open Access Journals (Sweden)

    A. Khajehnezhad

    2008-03-01

    Full Text Available  We have compared the structural, electrical, and magnetic properties of Ru(Gd1.5-xPrxCe0.5Sr2Cu2O10-δ (Pr/Gd samples with x = 0.0, 0.01, 0.03, 0.033, 0.035, 0.04, 0.05, 0.06, 0.1 and RuGd1.5(Ce0.5-xPrxSr2Cu2O10-δ (Pr/Ce samples with x = 0.0, 0.01, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2 prepared by the standard solid-state reaction technique with RuGd1.5(GdxCe0.5-x Sr2Cu2O10-δ (Gd/Ce samples with x= 0.0, 0.1, 0.2, 0.3. We obtained the XRD patterns for different samples with various x. The lattice parameters versus x for different substitutions have been obtained from the Rietveld analysis. To determine how the magnetic and superconducting properties of these layered cuprate systems can be affected by Pr substitution, the resistivity and magnetoresistivity, with Hext varying from 0.0 to 15 kOe, have been measured at various temperatures. Superconducting transition temperature Tc and magnetic transition Tirr have been obtained through resistivity and ac susceptibility measurements. The Tc suppression due to Gd/Ce, Pr/Gd and Pr/Ce substitutions show competition between pair breaking by magnetic impurity, hole doping due to different ionic valences, difference in ionic radii, and oxygen stoichiometry. Pr/Gd substitution suppresses superconductivity more rapidly than for Pr/Ce or Gd/Ce, showing that the effect of hole doping and pair breaking by magnetic impurity is stronger than the difference in ionic radii. In Pr/Gd substitution, the small difference between the ionic radii of Pr and Gd, and absorption of more oxygen due to higher valence of Pr with respect to Gd, decrease the mean Ru-Ru distance, and as a result, the magnetic exchange interaction becomes stronger with the increase of x. But, Pr/Ce and Gd/Ce substitutions have a reverse effect. The magnetic properties such as Hc, obtained through magnetization measurements versus applied magnetic field isoterm at 77K and room temperatures, become stronger with x in Pr/Gd and weaker with x in Pr

  14. Ion beam measurements at the superconducting ECR ion source SECRAL

    Energy Technology Data Exchange (ETDEWEB)

    Maeder, Jan; Rossbach, Jon; Lang, Ralf; Maimone, Fabio; Spaedtke, Peter; Tinschert, Klaus [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Sun, Liangting; Cao, Yun; Zhao, Hongwei [Institute of Modern Physics, Lanzhou, GS (China)

    2009-08-15

    Measurement of the charge-state distribution, the beam profile, the beam emittance of the named ion source are presented. Furthermore computer simulations of the magnetic flux-density distribution in this source are described. (HSI)

  15. Improving the design and analysis of superconducting magnets for particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ramesh Chandra [Univ. of Rajasthan, Jaipur (India). Dept. of Physics

    1996-11-01

    High energy particle accelerators are now the primary means of discovering the basic building blocks of matter and understanding the forces between them. In order to minimize the cost of building these machines, superconducting magnets are used in essentially all present day high energy proton and heavy ion colliders. The cost of superconducting magnets is typically in the range of 20--30% of the total cost of building such machines. The circulating particle beam goes through these magnets a large number of times (over hundreds of millions). The luminosity performance and life time of the beam in these machines depends significantly on the field quality in these magnets. Therefore, even a small error in the magnetic field shape may create a large cumulative effect in the beam trajectory to throw the particles of the magnet aperture. The superconducting accelerator magnets must, therefore, be designed and constructed so that these errors are small. In this thesis the research and development work will be described 3which has resulted in significant improvements in the field quality of the superconducting magnets for the Relativistic Heavy Ion Collider (RHIC). The design and the field quality improvements in the prototype of the main collider dipole magnet for the Superconducting Super Collider (SSC) will also be presented. RHIC will accelerate and collide two counter rotating beams of heavy ions up to 100 GeV/u and protons up to 250 GeV. It is expected that RHIC will create a hot, dense quark-gluon plasma and the conditions which, according to the Big Bang theory, existed in the early universe.

  16. Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

    Science.gov (United States)

    Zhao, H. W.; Sun, L. T.; Guo, J. W.; Lu, W.; Xie, D. Z.; Hitz, D.; Zhang, X. Z.; Yang, Y.

    2017-09-01

    The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24-28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of 40Ar+ and 129Xe26+ have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL), China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24 +18 GHz ) heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

  17. Anisotropy of superconductivity of as-grown MgB$_2$ thin films by molecular beam epitaxy

    OpenAIRE

    Harada, Y.; Udsuka, M.; Nakanishi, Y.; Yoshizawa, M.

    2004-01-01

    Superconducting thin films of magnesium diboride (MgB$_2$) were prepared on MgO (001) substrate by a molecular beam epitaxy (MBE) method with the co-evaporation conditions of low deposition rate in ultra-high vacuum. The structural and physical properties of the films were studied by RHEED, XRD, XPS, resistivity and magnetization measurements.All films demonstrated superconductivity without use of any post-annealing process.The highest {\\it T}$_{c,onset}$ determined by resistivity measurement...

  18. Critical Magnetic Field Determination of Superconducting Materials

    Energy Technology Data Exchange (ETDEWEB)

    Canabal, A.; Tajima, T.; /Los Alamos; Dolgashev, V.A.; Tantawi, S.G.; /SLAC; Yamamoto, T.; /Tsukuba, Natl. Res. Lab. Metrol.

    2011-11-04

    Superconducting RF technology is becoming more and more important. With some recent cavity test results showing close to or even higher than the critical magnetic field of 170-180 mT that had been considered a limit, it is very important to develop a way to correctly measure the critical magnetic field (H{sup RF}{sub c}) of superconductors in the RF regime. Using a 11.4 GHz, 50-MW, <1 {mu}s, pulsed power source and a TE013-like mode copper cavity, we have been measuring critical magnetic fields of superconductors for accelerator cavity applications. This device can eliminate both thermal and field emission effects due to a short pulse and no electric field at the sample surface. A model of the system is presented in this paper along with a discussion of preliminary experimental data.

  19. Transformer current sensor for superconducting magnetic coils

    Science.gov (United States)

    Shen, Stewart S.; Wilson, C. Thomas

    1988-01-01

    A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.

  20. High-Field Superconducting Magnets Supporting PTOLEMY

    Science.gov (United States)

    Hopkins, Ann; Luo, Audrey; Osherson, Benjamin; Gentile, Charles; Tully, Chris; Cohen, Adam

    2013-10-01

    The Princeton Tritium Observatory for Light, Early Universe, Massive Neutrino Yield (PTOLEMY) is an experiment planned to collect data on Big Bang relic neutrinos, which are predicted to be amongst the oldest and smallest particles in the universe. Currently, a proof-of-principle prototype is being developed at Princeton Plasma Physics Laboratory to test key technologies associated with the experiment. A prominent technology in the experiment is the Magnetic Adiabatic Collimation with an Electrostatic Filter (MAC-E filter), which guides tritium betas along magnetic field lines generated by superconducting magnets while deflecting those of lower energies. B field mapping is performed to ensure the magnets produce a minimum field at the midpoint of the configuration of the magnets and to verify accuracy of existing models. Preliminary tests indicate the required rapid decrease in B field strength from the bore of the more powerful 3.35 T magnet, with the field dropping to 0.18 T approximately 0.5 feet from the outermost surface of the magnet.

  1. Time Transient Effects in Superconducting Magnets

    CERN Document Server

    AUTHOR|(CDS)2051280; Russenschuck, Stephan; Palumbo, Luigi

    2004-01-01

    The subject of this thesis is the study of time transient effects in super- conducting cables, with applications to accelerator magnets, and the development of a simulation code. The superconducting cables are modeled at the strand level as a lumped resistor, inductor generator circuit. The analysis in time domain of the circuit currents discloses the transient effects. The code developed can solve Rutherford type cable of any size, shape geometry under any exciting external field. The code has been implemented in Roxie where it is used to compute ramp dependent field error and heat losses.

  2. Magnetic interaction between spatially extended superconducting tunnel junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    2002-01-01

    A general description of magnetic interactions between superconducting tunnel junctions is given. The description covers a wide range of possible experimental systems, and we explicitly explore two experimentally relevant limits of coupled junctions. One is the limit of junctions with tunneling...... been considered through arrays of superconducting weak links based on semiconductor quantum wells with superconducting electrodes. We use the model to make direct interpretations of the published experiments and thereby propose that long-range magnetic interactions are responsible for the reported...

  3. Ultralow Friction in a Superconducting Magnetic Bearing

    Science.gov (United States)

    Bornemann, Hans J.; Siegel, Michael; Zaitsev, Oleg; Bareiss, Martin; Laschuetza, Helmut

    1996-01-01

    Passive levitation by superconducting magnetic bearings can be utilized in flywheels for energy storage. Basic design criteria of such a bearing are high levitation force, sufficient vertical and horizontal stability and low friction. A test facility was built for the measurement and evaluation of friction in a superconducting magnetic bearing as a function of operating temperature and pressure in the vacuum vessel. The bearing consists of a commercial disk shaped magnet levitated above single grain, melt-textured YBCO high-temperature superconductor material. The superconductor was conduction cooled by an integrated AEG tactical cryocooler. The temperature could be varied from 50 K to 80 K. The pressure in the vacuum chamber was varied from 1 bar to 10(exp -5) mbar. At the lowest pressure setting, the drag torque shows a linear frequency dependence over the entire range investigated (0 less than f less than 40 Hz). Magnetic friction, the frequency independent contribution, is very low. The frequency dependent drag torque is generated by molecular friction from molecule-surface collisions and by eddy currents. Given the specific geometry of the set-up and gas pressure, the molecular drag torque can be estimated. At a speed of 40 Hz, the coefficient of friction (drag-to-lift ratio) was measured to be mu = 1.6 x 10(exp -7) at 10(exp -5) mbar and T = 60 K. This is equivalent to a drag torque of 7.6 x 10(exp -10) Nm. Magnetic friction causes approx. 1% of the total losses. Molecular friction accounts for about 13% of the frequency dependent drag torque, the remaining 87% being due to eddy currents and losses from rotor unbalance. The specific energy loss is only 0.3% per hour.

  4. On the interplay of superconductivity and magnetism

    CERN Document Server

    Powell, B J

    2002-01-01

    We explore the exchange field dependence of the Hubbard model with a attractive, effective, pairwise, nearest neighbour interaction via the Hartree-Fock-Gorkov approximation. We derive a Ginzburg-Landau theory of spin triplet superconductivity in an exchange field. For microscopic parameters which lead to ABM phase superconductivity in zero field, the Ginzburg-Landau theory allows both an axial (A, A sub 1 or A sub 2) solution with the vector order parameter, d(k), perpendicular to the field, H, and an A phase solution with d(k) parallel to H. We study the spin-generalised Bogoliubov-de Gennes (BdG) equations for this model with parameters suitable for strontium ruthenate (Sr sub 2 RuO sub 4). The A sub 2 phase is found to be stable in a magnetic field. However, in the real material, spin-orbit coupling could pin the order parameter to the crystallographic c-axis which would favour the A phase for fields parallel to the c-axis. We show that the low temperature thermodynamic behaviour in a magnetic field could...

  5. Method for obtaining large levitation pressure in superconducting magnetic bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    1996-01-01

    A method and apparatus for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap.

  6. Method for obtaining large levitation pressure in superconducting magnetic bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    1997-01-01

    A method and apparatus for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap.

  7. Operational experience with forced cooled superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, D.P., E-mail: denis.ivanov30@mail.ru [National Research Center “Kurchatov Institute”, Moscow 123182 (Russian Federation); Kolbasov, B.N., E-mail: kolbasov@nfi.kiae.ru [National Research Center “Kurchatov Institute”, Moscow 123182 (Russian Federation); Anashkin, I.O.; Khvostenko, P.P. [National Research Center “Kurchatov Institute”, Moscow 123182 (Russian Federation); Pan, W.J. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China); Pradhan, S.; Sharma, A.N. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Song, Y.T.; Weng, P.D. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031 (China)

    2013-10-15

    Highlights: ► Seventeen breakdowns happened in the fusion facilities with forced cooled superconducting magnets (FCSMs). ► The breakdowns always began on the electric, cryogenic and diagnostic communications (ECDCs) and never on the coils. ► In all the FCSMs the ECDCs were always insulated worse than the coils. ► For reliable operation of ITER organization team should essentially improve the ECDC insulation. ► Use of stainless steel grounded casings filled up with solid insulation over all the ECDCs is the best way to get reliable insulation. -- Abstract: Force-cooled concept has been chosen for ITER superconducting magnet to get reliable coil insulation using vacuum-pressure impregnation (VPI) technology. However 17 breakdowns occurred during operation of six magnets of this type or their single coil tests at operating voltage < 3 kV, while ITER needs 12 kV. All the breakdowns started on electric, cryogenic and diagnostic communications (ECDCs) by the high voltage induced at fast current variations in magnets concurrently with vacuum deterioration, but never on the coils, though sometimes the latter were damaged too. It suggests that simple wrap insulation currently employed on ECDCs and planned to be used in ITER is unacceptable. Upgrade of the ECDC insulation to the same level as on the coils is evidently needed. This could be done by covering each one from ECDCs with vacuum-tight grounded stainless steel casings filled up with solid insulator using VPI-technology. Such an insulation will be insensitive to in-cryostat conditions, excluding helium leaks and considerably simplifying the tests thus allowing saving time and cost. However it is not accepted in ITER design yet. So guarantee of breakdown prevention is not available.

  8. Electrical joints in the CMS superconducting magnet

    CERN Document Server

    Farinon, S; Curé, B; Fabbricatore, P; Greco, Michela; Musenich, R

    2002-01-01

    The Compact Muon Solenoid (CMS) is one of the general-purpose detectors to be provided for the LHC project at CERN. The design field of the CMS superconducting magnet is 4 T, the magnetic length is 12.5 m and the free bore is 6 m. The CMS coil consists of five independent modules each containing four winding layers. Each winding layer is composed of a single length of aluminum stabilized and aluminum alloy reinforced conductor. Each of the four conductor lengths within a module will be electrically joined after winding is completed, and each of the five modules will be connected to the magnet bus bars during module assembly. Due to the large dimensions of the conductor and to the high current it carries, the conductor joints are sources of substantial and nontrivial joule heating during nonsteady state operation of the magnet. In addition to steady-state conditions, three transient conditions have been analyzed. The first is related to the current diffusion during a magnet transient that results in a time dep...

  9. Magnetization measurements on LHC superconducting strands

    CERN Document Server

    Le Naour, S; Wolf, R; Puzniak, R; Szewczyk, A; Wisniewski, A; Fikis, H; Foitl, M; Kirchmayr, H

    1999-01-01

    When using superconducting magnets in particle accelerators like the LHC, persistent currents in the superconductor often determine the field quality at injection, where the magnetic field is low. This paper describes magnetization measurements made on LHC cable strands at the Technical University of Vienna and the Institute of Physics of the Polish Academy of Sciences in collaboration with CERN. Measurements were performed at T=2 K and T=4.2 K on more than 50 strands of 7 different manufacturers with NbTi filament diameter between 5 and 7 micrometer. Two different measurement set-ups were used: vibrating sample magnetometer, with a sample length of about 8 mm, and an integrating coil magnetometer, with sample length of about 1 m. The two methods were compared by measuring the same sample. Low field evidence of proximity effect is discussed. Statistics like ratio of the width of the magnetization loop at 4.2 K 2 K, and the initial slope dM/dB after cooldown are presented. Decrease of the magnetization with ti...

  10. Magnetic-field-induced superconducting state in Zn nanowires driven in the normal state by an electric current.

    Science.gov (United States)

    Chen, Yu; Snyder, S D; Goldman, A M

    2009-09-18

    Four-terminal resistance measurements have been carried out on Zn nanowires formed using electron-beam lithography. When driven resistive by current, these wires reenter the superconducting state upon application of small magnetic fields. The data are qualitatively different from those of previous experiments on superconducting nanowires, which revealed either negative magnetoresistance near T_{c} or high-magnetic-field-enhanced critical currents.

  11. Electromagnetic superconductivity of vacuum induced by strong magnetic field

    CERN Document Server

    Chernodub, M N

    2012-01-01

    The quantum vacuum may become an electromagnetic superconductor in the presence of a strong external magnetic field of the order of 10^{16} Tesla. The magnetic field of the required strength (and even stronger) is expected to be generated for a short time in ultraperipheral collisions of heavy ions at the Large Hadron Collider. The superconducting properties of the new phase appear as a result of a magnetic-field-assisted condensation of quark-antiquark pairs with quantum numbers of electrically charged rho mesons. We discuss similarities and differences between the suggested superconducting state of the quantum vacuum, a conventional superconductivity and the Schwinger pair creation. We argue qualitatively and quantitatively why the superconducting state should be a natural ground state of the vacuum at the sufficiently strong magnetic field. We demonstrate the existence of the superconducting phase using both the Nambu-Jona-Lasinio model and an effective bosonic model based on the vector meson dominance (th...

  12. Reliability of large superconducting magnets through design

    Energy Technology Data Exchange (ETDEWEB)

    Henning, C.D.

    1980-09-05

    As superconducting magnet systems grow larger and become the central component of major systems involving fusion, magnetohydrodynamics, and high-energy physics, their reliability must be commensurate with the enormous capital investment in the projects. Although the magnet may represent only 15% of the cost of a large system such as the Mirror Fusion Test Facility, its failure would be catastrophic to the entire investment. Effective quality control during construction is one method of ensuring success. However, if the design is unforgiving, even an inordinate amount of effort expended on quality control may be inadequate. Creative design is the most effective way of ensuring magnet reliability and providing a reasonable limit on the amount of quality control needed. For example, by subjecting the last drawing operation is superconductor manufacture to a stress larger than the magnet design stress, a 100% proof test is achieved; cabled conductors offer mechanical redundancy, as do some methods of conductor joining; ground-plane insulation should be multilayered to prevent arcs, and interturn and interlayer insulation spaced to be compatible with the self-extinguishing of arcs during quench voltages; electrical leads should be thermally protected; and guard vacuum spaces can be incorporated to control helium leaks. Many reliable design options are known to magnet designers. These options need to be documented and organized to produce a design guide. Eventually, standard procedures, safety factors, and design codes can lead to reliability in magnets comparable to that obtained in pressure vessels and other structures. Wihout such reliability, large-scale applications in major systems employing magnetic fusion energy, magnetohydrodynamics, or high-energy physics would present unacceptable economic risks.

  13. High temperature superconductivity induced by incipient magnetism

    Science.gov (United States)

    Weger, M.; Pereg, Y.

    1990-10-01

    We consider the BCS gap equation, with an attractive interaction λ with an upper cutoff ω 0 and lower cutoff ω 1, and a repulsive interaction μ with cutoffΓ. We consider parameters such that a superconducting solution does not exist. We add a repulsive interaction ν eith cutoff ω1 ( ω1 < ω0), and show that this repulsive interaction (that we attribute to incipient magnetism) induces a superconducting state possessing a high transition temperature. In this state, the gap function Δ(ɛ) oscillates as function of ɛ, with a period of order ω 0. We also find solutions antisymmetric in energy [ Δ( ɛ) = - Δ(- ɛ) ], which turn out to be almost degenerate with the normal, symmetric ones. We discuss the physical implications of this model. Our model thus combines a low frequency repulsion due to antiferromagnetic interactions, with excitonic attraction at intermediate frequencies, and ordinary Coulomb repulsion above that. All frequency ranges, and coupling strengths, are comparable with the bandwidth.

  14. Superconducting accelerating structures for very low velocity ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Shepard, K.W.; Ostroumov, P.N.; Fuerst, J.D.; Waldschmidt, G.; /Argonne; Gonin, I.V.; /Fermilab

    2008-01-01

    This paper presents designs for four types of very-low-velocity superconducting accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006 < v/c < 0.06. Superconducting TEM-class cavities have been widely applied to CW acceleration of ion beams. SC linacs can be formed as an array of independently-phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the US and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front-end of such linacs, particularly for the post-acceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008 < {beta} = v/c < 0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  15. Superconducting accelerating structures for very low velocity ion beams

    Directory of Open Access Journals (Sweden)

    J. Xu

    2008-03-01

    Full Text Available This paper presents designs for four types of very-low-velocity superconducting (SC accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006Superconducting TEM-class cavities have been widely applied to cw acceleration of ion beams. SC linacs can be formed as an array of independently phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the U.S. and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front end of such linacs, particularly for the postacceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008<β=v/c<0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication, and processing have increased SC cavity gradients by a factor of 3–4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  16. Low cost composite structures for superconducting magnetic energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Rix, C. (General Dynamics Space Magnetics, San Diego, CA (United States)); McColskey, D. (National Inst. of Standards and Technology, Boulder, CO (United States)); Acree, R. (Phillips Lab., Edwards Air Force Base, CA (United States))

    1994-07-01

    As part of the Superconducting Magnetic Energy Storage/Engineering Test Model (SMES-ETM) programs, design, analysis, fabrication and test programs were conducted to evaluate the low cost manufacturing of Fiberglass Reinforced Plastic (FRP) beams for usage as major components of the structural and electrical insulation systems. These studies utilized pultrusion process technologies and vinylester resins to produce large net sections at costs significantly below that of conventional materials. Demonstration articles incorporating laminate architectures and design details representative of SMES-ETM components were fabricated using the pultrusion process and epoxy, vinylester, and polyester resin systems. The mechanical and thermal properties of these articles were measured over the temperature range from 4 K to 300 K. The results of these tests showed that the pultruded, vinylester components have properties comparable to those of currently used materials, such as G-10, and are capable of meeting the design requirements for the SMES-ETM system.

  17. Magnetism in structures with ferromagnetic and superconducting layers

    Energy Technology Data Exchange (ETDEWEB)

    Zhaketov, V. D.; Nikitenko, Yu. V., E-mail: nikiten@nf.jinr.ru [Joint Institute for Nuclear Research (Russian Federation); Radu, F. [Helmholtz-Zentrum Berlin für Materialen un Energie (Germany); Petrenko, A. V. [Joint Institute for Nuclear Research (Russian Federation); Csik, A. [MTA Atomki, Institute for Nuclear Research (Hungary); Borisov, M. M.; Mukhamedzhanov, E. Kh. [Russian Research Centre Kurchatov Institute (Russian Federation); Aksenov, V. L. [Russian Research Centre Kurchatov Institute, Konstantinov St. Petersburg Nuclear Physics Institute (Russian Federation)

    2017-01-15

    The influence of superconductivity on ferromagnetism in the layered Ta/V/Fe{sub 1–x}V{sub x}/V/Fe{sub 1–x}V{sub x}/Nb/Si structures consisting of ferromagnetic and superconducting layers is studied using polarized neutron reflection and scattering. It is experimentally shown that magnetic structures with linear sizes from 5 nm to 30 μm are formed in these layered structures at low temperatures. The magnetization of the magnetic structures is suppressed by superconductivity at temperatures below the superconducting transition temperatures in the V and Nb layers. The magnetic states of the structures are shown to undergo relaxation over a wide magnetic-field range, which is caused by changes in the states of clusters, domains, and Abrikosov vortices.

  18. Development of superconducting magnetic bearing with superconducting coil and bulk superconductor for flywheel energy storage system

    Science.gov (United States)

    Arai, Y.; Seino, H.; Yoshizawa, K.; Nagashima, K.

    2013-11-01

    We have been developing superconducting magnetic bearing for flywheel energy storage system to be applied to the railway system. The bearing consists of a superconducting coil as a stator and bulk superconductors as a rotor. A flywheel disk connected to the bulk superconductors is suspended contactless by superconducting magnetic bearings (SMBs). We have manufactured a small scale device equipped with the SMB. The flywheel was rotated contactless over 2000 rpm which was a frequency between its rigid body mode and elastic mode. The feasibility of this SMB structure was demonstrated.

  19. Design and test of a superconducting magnet in a linear accelerator for an Accelerator Driven Subcritical System

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Quanling, E-mail: pengql@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Xu, Fengyu [Harbin Institute of Technology, Heilongjiang 150006 (China); Wang, Ting [Beijing Huantong Special Equipment Co., LTD, Beijing 100192 (China); Yang, Xiangchen [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, Anbin [Harbin Institute of Technology, Heilongjiang 150006 (China); Wei, Xiaotao [Beijing Huantong Special Equipment Co., LTD, Beijing 100192 (China); Gao, Yao; Hou, Zhenhua; Wang, Bing; Chen, Yuan; Chen, Haoshu [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2014-11-11

    A batch superconducting solenoid magnet for the ADS proton linear accelerator has been designed, fabricated, and tested in a vertical dewar in Sept. 2013. A total of ten superconducting magnets will be installed into two separate cryomodules. Each cryomodule contains six superconducting spoke RF cavities for beam acceleration and five solenoid magnets for beam focusing. The multifunction superconducting magnet contains a solenoid for beam focusing and two correctors for orbit correction. The design current for the solenoid magnet is 182 A. A quench performance test shows that the operating current of the solenoid magnet can reach above 300 A after natural quenching on three occasions during current ramping (260 A, 268 A, 308 A). The integrated field strength and leakage field at the nearby superconducting spoke cavities all meet the design requirements. The vertical test checked the reliability of the test dewar and the quench detection system. This paper presents the physical and mechanical design of the batch magnets, the quench detection technique, field measurements, and a discussion of the residual field resulting from persistent current effects.

  20. Development of large bore superconducting magnet for wastewater treatment application

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui Ming; Xu, Dong; Shen, Fuzhi; Zhang, Hengcheng; Li, Lafeng [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing (China)

    2017-03-15

    Water issue, especially water pollution, is a serious issue of 21st century. Being an significant technique for securing water resources, superconducting magnetic separation wastewater system was indispensable. A large bore conduction-cooled magnet was custom-tailored for wastewater treatment. The superconducting magnet has been designed, fabricated and tested. The superconducting magnet was composed of NbTi solenoid coils with an effective horizontal warm bore of 400 mm and a maximum central field of 2.56T. The superconducting magnet system was cooled by a two-stage 1.5W 4K GM cryocooler. The NbTi solenoid coils were wound around an aluminum former that is thermally connected to the second stage cold head of the cryocooler through a conductive copper link. The temperature distribution along the conductive link was measured during the cool-down process as well as at steady state. The magnet was cooled down to 4.8K in approximately 65 hours. The test of the magnetic field and quench analysis has been performed to verify the safe operation for the magnet system. Experimental results show that the superconducting magnet reached the designed magnetic performance.

  1. Superconducting Magnets for the 12 GeV Upgrade at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Fair, Ruben J. [JLAB; Young, Glenn R. [JLAB

    2015-06-01

    Jefferson Laboratory is embarked on an energy upgrade to its flagship continuous electron beam accelerator in order to expand the scope of its research capabilities and probe further into the structure of nuclear particles. The 12 GeV upgrade includes the design, manufacture, integration, installation and commissioning of eight different superconducting magnets in three separate experimental halls. The effort involves other national laboratories, universities and industry spanning three countries. This paper will summarize the key characteristics of these magnets, ranging in size from 0.2 to 23 MJ in stored energy, and featuring many different types and configurations. The paper will also give an overview of the specific technical challenges for each magnet, and a status report on magnet manufacture and expected delivery dates. The 12GeV upgrade at J-Lab represents the largest superconducting magnet fabrication and installation program currently ongoing in the United States and this paper will present the breadth of collaborations supporting it.

  2. Constructing a Superconducting Corrector Magnet for the LHC

    CERN Multimedia

    CERN Audiovisual Unit

    1998-01-01

    1. Construction principles : development at CERN shown on a decapolar (MCD) superconducting corrector magnet.2. Computer controlled automatic winding : development with Ferrara University, Italy.3. Electro-mechanically controlled automatic winding : development with CAT-Patel, India

  3. Radiation Shielding Utilizing A High Temperature Superconducting Magnet Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project aims to leverage near-term high-temperature superconducting technologies to assess applicability of magnetic shielding for protecting against exposure...

  4. Low temperature magnetic force microscopy on ferromagnetic and superconducting oxides

    Science.gov (United States)

    Sirohi, Anshu; Sheet, Goutam

    2016-05-01

    We report the observation of complex ferromagnetic domain structures on thin films of SrRuO3 and superconducting vortices in high temperature superconductors through low temperature magnetic force microscopy. Here we summarize the experimental details and results of magnetic imaging at low temperatures and high magnetic fields. We discuss these data in the light of existing theoretical concepts.

  5. Superconducting and hybrid systems for magnetic field shielding

    Science.gov (United States)

    Gozzelino, L.; Gerbaldo, R.; Ghigo, G.; Laviano, F.; Truccato, M.; Agostino, A.

    2016-03-01

    In this paper we investigate and compare the shielding properties of superconducting and hybrid superconducting/ferromagnetic systems, consisting of cylindrical cups with an aspect ratio of height/radius close to unity. First, we reproduced, by finite-element calculations, the induction magnetic field values measured along the symmetry axis in a superconducting (MgB2) and in a hybrid configuration (MgB2/Fe) as a function of the applied magnetic field and of the position. The calculations are carried out using the vector potential formalism, taking into account simultaneously the non-linear properties of both the superconducting and the ferromagnetic material. On the basis of the good agreement between the experimental and the computed data we apply the same model to study the influence of the geometric parameters of the ferromagnetic cup as well as of the thickness of the lateral gap between the two cups on the shielding properties of the superconducting cup. The results show that in the considered non-ideal geometry, where the edge effect in the flux penetration cannot be disregarded, the superconducting shield is always the most efficient solution at low magnetic fields. However, a partial recovery of the shielding capability of the hybrid configuration occurs if a mismatch in the open edges of the two cups is considered. In contrast, at high magnetic fields the hybrid configurations are always the most effective. In particular, the highest shielding factor was found for solutions with the ferromagnetic cup protruding over the superconducting one.

  6. Safety aspects of superconducting magnets for Super-FRS

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The Super Fragment Separator (Super FRS) is a two-stage in flight separator to be built next to the site of GSI, Darmstadt, Germany as part of FAIR (Facility for Anti-proton and Ion Research). Its purpose is to create and separate rare isotope beams and to enable the mass measurement also for very short lived nuclei. A superferric design with superconducting coils and standard iron yoke shaping the magnetic field was chosen for the magnets. The cooling will be by a liquid Helium bath. For the main dipoles only the coil is at cold for the multiplets (asemblies of quadrupoles and hgher order correctors) also the iron yoke will be in the bath. From a safety point of view the large He-volumes of more than 1000 l of the multiplets, the high design pressure of 20 bar, as well as the high inductances of the magnets up to 30 H are challenges to be considered in the design and definition of the testing procedures.

  7. Imprinting superconducting vortex footsteps in a magnetic layer.

    Science.gov (United States)

    Brisbois, Jérémy; Motta, Maycon; Avila, Jonathan I; Shaw, Gorky; Devillers, Thibaut; Dempsey, Nora M; Veerapandian, Savita K P; Colson, Pierre; Vanderheyden, Benoît; Vanderbemden, Philippe; Ortiz, Wilson A; Nguyen, Ngoc Duy; Kramer, Roman B G; Silhanek, Alejandro V

    2016-06-06

    Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit cards and computer hard drives. Here we experimentally show that a similar principle can be applied for imprinting the trajectory of quantum units of flux (vortices), travelling in a superconducting film (Nb), into a soft magnetic layer of permalloy (Py). In full analogy with the magnetic drawing board, vortices act as tiny magnetic scribers leaving a wake of polarized magnetic media in the Py board. The mutual interaction between superconducting vortices and ferromagnetic domains has been investigated by the magneto-optical imaging technique. For thick Py layers, the stripe magnetic domain pattern guides both the smooth magnetic flux penetration as well as the abrupt vortex avalanches in the Nb film. It is however in thin Py layers without stripe domains where superconducting vortices leave the clearest imprints of locally polarized magnetic moment along their paths. In all cases, we observe that the flux is delayed at the border of the magnetic layer. Our findings open the quest for optimizing magnetic recording of superconducting vortex trajectories.

  8. Magnetism and superconductivity in neodymium/lanthanum superlattices

    DEFF Research Database (Denmark)

    Goff, J.P.; Sarthour, R.S.; McMorrow, Desmond Francis

    1997-01-01

    bilayers. Magnetization studies reveal the onset of superconductivity at a temperature comparable to bulk DHCP La, and the results suggest coupling across the antiferromagnetic Nd layers. The magnetic structures, investigated using neutron diffraction techniques, resemble those found in bulk Nd....... For the cubic sites of the DHCP structure the magnetic order is confined to individual Nd blocks. However, the magnetic order on the Nd hexagonal sites propagates coherently through the La, even when it becomes superconducting. (C) 1998 Elsevier Science B.V. All rights reserved....

  9. Magnetic response of superconducting mesoscopic-size YBCO powder

    Energy Technology Data Exchange (ETDEWEB)

    Deimling, C.V. [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil)], E-mail: cesard@df.ufscar.br; Motta, M.; Lisboa-Filho, P.N. [Laboratorio de Materiais Supercondutores, Departamento de Fisica, Universidade Estadual Paulista, Bauru, SP Brazil (Brazil); Ortiz, W.A. [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil)

    2008-07-15

    In this work it is reported the magnetic behavior of submicron and mesoscopic-size superconducting YBCO powders, prepared by a modified polymeric precursors method. The grain size and microstructure were analyzed using scanning electron microscopy (SEM). Measurements of magnetization and AC-susceptibility as a function of temperature were performed with a quantum design SQUID magnetometer. Our results indicated significant differences on the magnetic propreties, in connection with the calcination temperature and the pressure used to pelletize the samples. This contribution is part of an effort to study vortex dynamics and magnetic properties of submicron and mesoscopic-size superconducting samples.

  10. Study on industrial wastewater treatment using superconducting magnetic separation

    Science.gov (United States)

    Zhang, Hao; Zhao, Zhengquan; Xu, Xiangdong; Li, Laifeng

    2011-06-01

    The mechanism of industrial wastewater treatment using superconducting magnetic separation is investigated. Fe 3O 4 nanoparticles were prepared by liquid precipitation and characterized by X-ray diffraction (XRD). Polyacrylic acid (PAA) film was coated on the magnetic particles using plasma coating technique. Transmission electron microscope (TEM) observation and infrared spectrum measurement indicate that the particle surface is well coated with PAA, and the film thickness is around 1 nm. Practical paper factory wastewater treatment using the modified magnetic seeds in a superconducting magnet (SCM) was carried out. The results show that the maximum removal rate of chemical oxygen demand (COD) by SCM method can reach 76%.

  11. Vibration-induced field fluctuations in a superconducting magnet

    Science.gov (United States)

    Britton, J. W.; Bohnet, J. G.; Sawyer, B. C.; Uys, H.; Biercuk, M. J.; Bollinger, J. J.

    2016-06-01

    Superconducting magnets enable precise control of nuclear and electron spins, and are used in experiments that explore biological and condensed-matter systems, and fundamental atomic particles. In high-precision applications, a common view is that slow (Be+9 electron-spin qubits in the 4.46 -T field of a superconducting magnet. We measure a spin-echo T2 coherence time of ˜6 ms for the Be+9 electron-spin resonance at 124 GHz , limited by part-per-billion fractional fluctuations in the magnet's homogeneous field. Vibration isolation of the magnet improved T2 to ˜50 ms.

  12. Superconductivity in Strong Magnetic Field (Greater Than Upper Critical Field)

    Energy Technology Data Exchange (ETDEWEB)

    Tessema, G.X.; Gamble, B.K.; Skove, M.J.; Lacerda, A.H.; Mielke, C.H.

    1998-08-22

    The National High Magnetic Field Laboratory, funded by the National Science Foundation and other US federal Agencies, has in recent years built a wide range of magnetic fields, DC 25 to 35 Tesla, short pulse 50 - 60 Tesla, and quasi-continuous 60 Tesla. Future plans are to push the frontiers to 45 Tesla DC and 70 to 100 Tesla pulse. This user facility, is open for national and international users, and creates an excellent tool for materials research (metals, semiconductors, superconductors, biological systems ..., etc). Here we present results of a systematic study of the upper critical field of a novel superconducting material which is considered a promising candidate for the search for superconductivity beyond H{sub c2} as proposed by several new theories. These theories predict that superconductors with low carrier density can reenter the superconducting phase beyond the conventional upper critical field H{sub c2}. This negates the conventional thinking that superconductivity and magnetic fields are antagonistic.

  13. Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator

    CERN Document Server

    Fraser, M A; Jones, R M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering...

  14. The effects of magnetization process on levitation characteristics of a superconducting bulk magnet

    Science.gov (United States)

    Jiang, J.; Gong, Y. M.; Li, Y. H.; Liang, G.; Yang, X. S.; Cheng, C. H.; Zhao, Y.

    2015-09-01

    In this paper, a bulk YBCO superconductor was magnetized in a chosen magnetic field generated from a superconducting magnet (SM) after field cooling process. The effects of magnetization process with different magnetization intensities on levitation forces and relaxation characteristics were investigated. From the results, it can be confirmed that the superconducting bulk magnet (SBM) magnetized with proper magnetization intensity was beneficial to improve the levitation characteristics of the magnetic levitation system. Nevertheless, when the magnetization intensity exceeded 0.85T, the levitation forces and the relaxation characteristics of the SBM attained saturation.

  15. MTN magnet for the SPS extracted beam.

    CERN Multimedia

    1976-01-01

    This type of dipole magnet was used in the extracted beam lines of the North Area. It shows an opening for three different proton beam lines: a primary extracted proton beam, split by an upstream magnetic beam splitter (see photo 7612017) into three separated beams passes through different parts of its aperture: right, left up, left down. These magnets were designed to be concrete-insulated for radiation resistance. F. Streun stands on the right.

  16. Evaluation of superconducting magnetic energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Little, A. D.

    1979-11-01

    Superconducting magnetic energy storage (SMES) systems differ from other storage systems presently in use, or considered for use, by the electric utility industry, principally because of the radically different technology involved. SMES also has certain unique advantages: it appears to be able to store and deliver energy at very high efficiency, and it can switch from the charge to discharge mode in a few tens of milliseconds. The combination of these two desirable characteristics distinguishes SMES from almost all other energy storage systems. This investigation was undertaken to discover if the nation and the electric utility industry might benefit sufficiently from the use of SMES systems to justify continued research and development support by DOE. At present, systems development is in a relatively early stage, and much component development for many of the major subsystems remains to be performed. It appears each SMES unit will be large and therefore expensive; also that the investment in research and development required to achieve final commercial success may be substantial.

  17. Electromagnetic, stress and thermal analysis of the Superconducting Magnet

    CERN Document Server

    Ren, Yong

    2015-01-01

    Within the framework of the National Special Project for Magnetic Confined Nuclear Fusion Energy of China, the design of a superconducting magnet project as a test facility of the Nb3Sn coil or NbTi coil for the Chinese Fusion Engineering Test Reactor (CFETR) has been carried out not only to estimate the relevant conductor performance but also to implement a background magnetic field for CFETR CS insert and toroidal field (TF) insert coils. The superconducting magnet is composed of two parts: the inner part with Nb3Sn cable-in-conduit conductor (CICC) and the outer part with NbTi CICC. Both parts are connected in series and powered by a single DC power supply. The superconducting magnet can be cooled with supercritical helium at inlet temperature of 4.5 K. The total inductance and stored energy of the superconducting magnet are about 0.278 H and 436.6 MJ at an operating current of 56 kA respectively. An active quench protection circuit was adopted to transfer the stored magnetic energy of the superconducting ...

  18. Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films

    Science.gov (United States)

    Schoenhuber, P.; Moon, F. C.

    1995-01-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation

  19. Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films

    Science.gov (United States)

    Schoenhuber, P.; Moon, F. C.

    1995-04-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation

  20. Beam imaging in the injection line of the INFN-LNS superconducting cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Nicolosi, Dario, E-mail: dario.nicolosi@lns.infn.it; Cosentino, Luigi; Mascali, David; Pappalardo, Alfio; Castro, Maurizio; Celona, Luigi; Marchetta, Carmelo; Marletta, Salvatore; Maugeri, Antonio; Rifuggiato, Danilo; Seminara, Angelo; Gammino, Santo [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy)

    2016-02-15

    A cheap and efficient diagnostic system for beam monitoring has been recently developed at INFN-LNS in Catania. It consists of a high sensitivity CCD camera detecting the light produced by an ion beam hitting the surface of a scintillating screen and a frame grabber for image acquisition. A scintillating screen, developed at INFN-LNS and consisting of a 2 μm BaF{sub 2} layer evaporated on an aluminium plate, has been tested by using {sup 20}Ne and {sup 40}Ar beams in the keV energy range. The CAESAR ECR ion source has been used for investigating the influence of the frequency and magnetic field tuning effects, the impact of the microwave injected power, and of the focusing solenoids along the low energy beam transport on the beam shape and current. These tests will allow to better understand the interplay between the plasma and beam dynamics and, moreover, to improve the transport efficiency along the low energy beam line and the matching with the superconducting cyclotron, particularly relevant in view of the expected upgrade of the machine.

  1. Design study of the KIRAMS-430 superconducting cyclotron magnet

    Science.gov (United States)

    Kim, Hyun Wook; Kang, Joonsun; Hong, Bong Hwan; Jung, In Su

    2016-07-01

    Design study of superconducting cyclotron magnet for the carbon therapy was performed at the Korea Institute of Radiological and Medical Science (KIRAMS). The name of this project is The Korea Heavy Ion Medical Accelerator (KHIMA) project and a fixed frequency cyclotron with four spiral sector magnet was one of the candidate for the accelerator type. Basic parameters of the cyclotron magnet and its characteristics were studied. The isochronous magnetic field which can guide the 12C6+ ions up to 430 MeV/u was designed and used for the single particle tracking simulation. The isochronous condition of magnetic field was achieved by optimization of sector gap and width along the radius. Operating range of superconducting coil current was calculated and changing of the magnetic field caused by mechanical deformations of yokes was considered. From the result of magnetic field design, structure of the magnet yoke was planned.

  2. Experimental studies on the thermal properties of fast pulsed superconducting accelerator magnets; Experimentelle Untersuchungen thermischer Eigenschaften schnell gepulster supraleitender Beschleunigermagnete

    Energy Technology Data Exchange (ETDEWEB)

    Bleile, Alexander

    2016-01-06

    The new Facility for Antiproton and Ion Research FAIR is being constructed at the GSI research center in Darmstadt (Germany). This wordwide unique accelerator facility will provide beams of ions and antiprotons at high intensities and high energies for the fundamental research in nuclear, atomic and plasma physics as well as for applied science. The superconducting synchrotron SIS100 with a magnetic rigidity of 100 T/m, the core component of the FAIR facility will provide primary ion beams of all types from hydrogen up to uranium. One of the key technical systems of a new synchrotron are fast ramped electromagnets for the generation of fast ramped magnetic fields for deflecting and focusing of the ion beams. To reduce the energy consumption and to keep the operating costs of the synchrotron as low as possible superconducting magnet technology is applied in the SIS100. Superconducting magnets have been developed at GSI within the scope of the FAIR project. Although the superconducting magnet technology promises high cost saving, the power consumption of the fast ramped superconducting magnets can't be completely neglected. The pulsed operation generates dynamic losses in the iron yokes as well as in the superconducting coils of the magnets. A forced two-phase helium flow provides effective cooling for supercounducting magnets exposed to a continous relative high heat flow. The subject of this PhD thesis is experimental investigations and analysis of the dynamic power losses in fast ramped superconducting magnets and their dependencies on the operation cycles of the synchrotron. This research was conducted on the the first series SIS100 dipole magnet. Based on the experimentally defined dynamic heat loads and helium mass flow rates in the dipole magnet the heat loads and helium consumption for all other types of superconducting magnet modules of the SIS100 have been estimated. These results are essential for the development of the cooling system for the the

  3. Study of flow fractionation characteristics of magnetic chromatography utilizing high-temperature superconducting bulk magnet

    Directory of Open Access Journals (Sweden)

    Satoshi Fukui, Yoshihiro Shoji, Jun Ogawa, Tetsuo Oka, Mitsugi Yamaguchi, Takao Sato, Manabu Ooizumi, Hiroshi Imaizumi and Takeshi Ohara

    2009-01-01

    Full Text Available We present numerical simulation of separating magnetic particles with different magnetic susceptibilities by magnetic chromatography using a high-temperature superconducting bulk magnet. The transient transport is numerically simulated for two kinds of particles having different magnetic susceptibilities. The time evolutions were calculated for the particle concentration in the narrow channel of the spiral arrangement placed in the magnetic field. The field is produced by the highly magnetized high-temperature superconducting bulk magnet. The numerical results show the flow velocity difference of the particle transport corresponding to the difference in the magnetic susceptibility, as well as the possible separation of paramagnetic particles of 20 nm diameter.

  4. Superconductivity in Medicine

    Science.gov (United States)

    Alonso, Jose R.; Antaya, Timothy A.

    2012-01-01

    Superconductivity is playing an increasingly important role in advanced medical technologies. Compact superconducting cyclotrons are emerging as powerful tools for external beam therapy with protons and carbon ions, and offer advantages of cost and size reduction in isotope production as well. Superconducting magnets in isocentric gantries reduce their size and weight to practical proportions. In diagnostic imaging, superconducting magnets have been crucial for the successful clinical implementation of magnetic resonance imaging. This article introduces each of those areas and describes the role which superconductivity is playing in them.

  5. Beam Dynamics Design Studies of a Superconducting Radioactive Ion Beam Post-accelerator

    CERN Document Server

    Fraser, MA; Pasini, M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently post- accelerated by the normal conducting REX linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of trans- verse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wa...

  6. Case Studies on Superconducting Magnets for Particle Accelerators

    CERN Document Server

    Ferracin, P

    2014-01-01

    During the CERN Accelerator School 'Superconductivity for accelerators', the students were divided into 18 groups, and 6 different exercises (case studies), involving the design and analysis of superconducting magnets and RF cavities, were assigned. The problems covered a broad spectrum of topics, from properties of superconducting materials to operation conditions and general dimensions of components. The work carried out by the students turned out to be an extremely useful opportunity to review the material explained during the lectures, to become familiar with the orders of magnitude of the key parameters, and to understand and compare different design options. We provide in this paper a summary of the activities related to the case studies on superconducting magnets and present the main outcomes.

  7. Analytical & Numerical Modelings of Elliptical Superconducting Filament Magnetization

    CERN Document Server

    Bottura, L; Bouillault, F; Devred, Arnaud

    2005-01-01

    This paper deals with the two-dimensional computation of magnetization in an elliptic superconducting filament by using numerical and analytical methods. The numerical results are obtained from the finite element method and by using Bean's model. This model is well adapted for Low Tc superconductor studies. We observe the effect of the axis ratio and of the field angle to the magnetic moment per unit length at saturation, and also to the cycle of magnetization. Moreover, the current density and the distribution of the electromagnetic fields in the superconducting filament are also studied.

  8. CLIQ. A new quench protection technology for superconducting magnets

    CERN Document Server

    Ravaioli, Emmanuele; ten Kate, H H J

    CLIQ, the Coupling-Loss Induced Quench system, is a new method for protecting superconducting magnets after a sudden transition to the normal state. It offers significant advantages over the conventional technology due to its effective mechanism for heating the superconductor relying on coupling loss and its robust electrical design, which makes it more reliable and less interfering with the coil winding process. The analysis of the electro-magnetic and thermal transients during and after a CLIQ discharge allows identifying the system parameters that affect the system performance and defining guidelines for implementing this technology on coils of various characteristics. Most existing superconducting magnets can be protected by CLIQ as convincingly shown by test results performed on magnets of different sizes, superconductor types, geometries, cables and strand parameters. Experimental results are successfully reproduced by means of a novel technique for modeling non-linear dynamic effects in superconducting...

  9. Thermal properties of a large-bore cryocooled 10 T superconducting magnet for a hybrid magnet

    Energy Technology Data Exchange (ETDEWEB)

    Ishizuka, M., E-mail: Mas_Ishizuka@shi.co.j [Graduate School of Engineering, Tohoku University, 6-6 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579 (Japan); Research and Development Center, Sumitomo Heavy Industries, Ltd., 19 Natsushima-chou, Yokosuka, Kanagawa 237-8555 (Japan); Hamajima, T. [Graduate School of Engineering, Tohoku University, 6-6 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579 (Japan); Itou, T. [Ehime Works, Sumitomo Heavy Industries, Ltd., 5-2 Soubiraki-cho, Niihama, Ehime 792-8588 (Japan); Sakuraba, J. [Research and Development Center, Sumitomo Heavy Industries, Ltd., 19 Natsushima-chou, Yokosuka, Kanagawa 237-8555 (Japan); Nishijima, G.; Awaji, S.; Watanabe, K. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2010-11-01

    A cryocooled 10 T superconducting magnet with a 360 mm room temperature bore has been developed for a hybrid magnet. The superconducting magnet cooled by four Gifford-McMahon cryocoolers has been designed to generate a magnetic field of 10 T. Since superconducting wires composed of coils were subjected to large hoop stress over 150 MPa and Nb{sub 3}Sn superconducting wires particularly showed a low mechanical strength due to those brittle property, Nb{sub 3}Sn wires strengthened by NbTi-filaments were developed for the cryocooled superconducting magnet. We have already reported that the hybrid magnet could generate the resultant magnetic field of 27.5 T by adding 8.5 T from the superconducting magnet and 19 T from a water-cooled Bitter resistive magnet, after the water-cooled resistive magnet was inserted into the 360 mm room temperature bore of the cryocooled superconducting magnet. When the hybrid magnet generated the field of 27.5 T, it achieved the high magnetic-force field (B x {partial_derivative}Bz/{partial_derivative}z) of 4500 T{sup 2}/m, which was useful for magneto-science in high fields such as materials levitation research. In this paper, we particularly focus on the cause that the cryocooled superconducting magnet was limited to generate the designed magnetic field of 10 T in the hybrid magnet operation. As a result, it was found that there existed mainly two causes as the limitation of the magnetic field generation. One was a decrease of thermal conductive passes due to exfoliation from the coil bobbin of the cooling flange. The other was large AC loss due to both a thick Nb{sub 3}Sn layer and its large diameter formed on Nb-barrier component in Nb{sub 3}Sn wires.

  10. A FORMULA FOR CALCULATING THE ERRORS OF SUPERCONDUCTING MAGNETIZATION CURVE

    Institute of Scientific and Technical Information of China (English)

    GUO SHU-QUAN; LIU MENG-LIN; ZHENG DONG-NING; ZHAO BAI-RU

    2001-01-01

    Because of field inhomogeneity in the magnetization measurement system, large errors may exist in the decreasing field superconducting magnetization curves, but not in the increasing field curves. The physical origin of the large errors is proposed here. A simple formula for calculating the errors is given. This formula is consistent with the experimental data.

  11. Power Switches Utilizing Superconducting Material for Accelerator Magnets

    CERN Document Server

    March, S A; Yang, Y

    2009-01-01

    Power switches that utilize superconducting material find application in superconducting systems. They can be used for the protection of magnets as a replacement for warm DC breakers, as well as for the replacement of cold diodes. This paper presents a comparison of switches made of various superconducting materials having transport currents of up to 600 A and switching times of the order of milliseconds. The switches operate in the temperature range 4.2-77 K and utilize stainless steel clad YBCO tape and MgB2 tape with a nickel, copper, and iron matrix. Results from simulations and tests are reported.

  12. Mathematical formulation to predict the harmonics of the superconducting Large Hadron Collider magnets

    Directory of Open Access Journals (Sweden)

    Nicholas Sammut

    2006-01-01

    Full Text Available CERN is currently assembling the LHC (Large Hadron Collider that will accelerate and bring in collision 7 TeV protons for high energy physics. Such a superconducting magnet-based accelerator can be controlled only when the field errors of production and installation of all magnetic elements are known to the required accuracy. The ideal way to compensate the field errors obviously is to have direct diagnostics on the beam. For the LHC, however, a system solely based on beam feedback may be too demanding. The present baseline for the LHC control system hence requires an accurate forecast of the magnetic field and the multipole field errors to reduce the burden on the beam-based feedback. The field model is the core of this magnetic prediction system, that we call the field description for the LHC (FIDEL. The model will provide the forecast of the magnetic field at a given time, magnet operating current, magnet ramp rate, magnet temperature, and magnet powering history. The model is based on the identification and physical decomposition of the effects that contribute to the total field in the magnet aperture of the LHC dipoles. Each effect is quantified using data obtained from series measurements, and modeled theoretically or empirically depending on the complexity of the physical phenomena involved. This paper presents the developments of the new finely tuned magnetic field model and, using the data accumulated through series tests to date, evaluates its accuracy and predictive capabilities over a sector of the machine.

  13. Cryocooled superconducting magnets for high magnetic fields at the HFLSM and future collaboration with the TML

    Science.gov (United States)

    Watanabe, K.; Nishijima, G.; Awaji, S.; Koyama, K.; Takahashi, K.; Kobayashi, N.; Kiyoshi, T.

    2006-11-01

    A hybrid magnet needs a large amount of liquid helium for operation. In order to make an easy-to-operate hybrid magnet system, we constructed a cryocooled 28 T hybrid magnet, consisting of an outer cryocooled 10 T superconducting magnet and an inner traditional water-cooled 19 T resistive magnet. As a performance test, the cryocooled hybrid magnet generated 27.5 T in a 32 mm room temperature experimental bore. As long as Nb3Sn superconducting wires are employed, the expected maximum high field generation in the cryocooled superconducting magnet will be 17 T at 5 K. We adopted the high temperature superconducting insert coil, employing Ag-sheathed Bi2Sr2Ca2Cu3O10superconducting tape. In combination with the low temperature 16.5 T back-up coil with a 174 mm cold bore, the cryocooled high temperature superconducting magnet successfully generated the total central field of 18.1 T in a 52 mm room temperature bore. As a next step, we start the collaboration with the National Institute for Materials Science for the new developmental works of a 30 T high temperature superconducting magnet and a 50 T-class hybrid magnet.

  14. Radiation hardness of superconducting magnet insulation materials for FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Seidl, Tim

    2013-03-15

    This thesis focuses on radiation degradation studies of polyimide, polyepoxy/glass-fiber composites and other technical components used, for example, in the superconducting magnets of new ion accelerators such as the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz Center of Heavy Ion Research (GSI) in Darmstadt. As accelerators are becoming more powerful, i.e., providing larger energies and beam intensities, the potential risk of radiation damage to the components increases. Reliable data of the radiation hardness of accelerator materials and components concerning electrical, thermal and other technical relevant properties are of great interest also for other facilities such as the Large Hadron Collider (LHC) of CERN. Dependent on the position of the different components, induced radiation due to beam losses consists of a cocktail of gammas, neutrons, protons, and heavier particles. Although the number of heavy fragments of the initial projectiles is small compared to neutrons, protons, or light fragments (e.g. ? particles), their large energy deposition can induce extensive damage at rather low fluences (dose calculations show that the contribution of heavy ions to the total accumulated dose can reach 80 %). For this reason, defined radiation experiments were conducted using different energetic ion beams (from protons to uranium) and gamma radiation from a Co-60 source. The induced changes were analyzed by means of in-situ and ex-situ analytical methods, e.g. ultraviolet-visible and infrared spectroscopy, residual gas analysis, thermal gravimetric analysis, dielectric strength measurements, measurements of low temperature thermal properties, and performance tests. In all cases, the radiation induces a change in molecular structure as well as loss of functional material properties. The amount of radiation damage is found to be sensitive to the used type of ionizing radiation and the long term stability of the materials is

  15. Tunable strong nonlinearity of a micromechanical beam embedded in a dc-superconducting quantum interference device

    Energy Technology Data Exchange (ETDEWEB)

    Ella, Lior, E-mail: lior.ella@weizmann.ac.il; Yuvaraj, D.; Suchoi, Oren; Shtempluk, Oleg; Buks, Eyal [Faculty of Electrical Engineering, Technion, Haifa 32000 (Israel)

    2015-01-07

    We present a study of the controllable nonlinear dynamics of a micromechanical beam coupled to a dc-SQUID (superconducting quantum interference device). The coupling between these systems places the modes of the beam in a highly nonlinear potential, whose shape can be altered by varying the bias current and applied flux of the SQUID. We detect the position of the beam by placing it in an optical cavity, which sets free the SQUID to be used solely for actuation. This enables us to probe the previously unexplored full parameter space of this device. We measure the frequency response of the beam and find that it displays a Duffing oscillator behavior which is periodic in the applied magnetic flux. To account for this, we develop a model based on the standard theory for SQUID dynamics. In addition, with the aim of understanding if the device can reach nonlinearity at the single phonon level, we use this model to show that the responsivity of the current circulating in the SQUID to the position of the beam can become divergent, with its magnitude limited only by noise. This suggests a direction for the generation of macroscopically distinguishable superposition states of the beam.

  16. Beam steering in superconducting quarter-wave resonators: An analytical approach

    Directory of Open Access Journals (Sweden)

    Alberto Facco

    2011-07-01

    Full Text Available Beam steering in superconducting quarter-wave resonators (QWRs, which is mainly caused by magnetic fields, has been pointed out in 2001 in an early work [A. Facco and V. Zviagintsev, in Proceedings of the Particle Accelerator Conference, Chicago, IL, 2001 (IEEE, New York, 2001, p. 1095], where an analytical formula describing it was proposed and the influence of cavity geometry was discussed. Since then, the importance of this effect was recognized and effective correction techniques have been found [P. N. Ostroumov and K. W. Shepard, Phys. Rev. ST Accel. Beams 4, 110101 (2001PRABFM1098-440210.1103/PhysRevSTAB.4.110101]. This phenomenon was further studied in the following years, mainly with numerical methods. In this paper we intend to go back to the original approach and, using well established approximations, derive a simple analytical expression for QWR steering which includes correction methods and reproduces the data starting from a few calculable geometrical constants which characterize every cavity. This expression, of the type of the Panofski equation, can be a useful tool in the design of superconducting quarter-wave resonators and in the definition of their limits of application with different beams.

  17. 2-D Electromagnetic Model of Fast-Ramping Superconducting Magnets

    CERN Document Server

    Auchmann, B; Kurz, S; Russenschuck, Stephan

    2006-01-01

    Fast-ramping superconducting (SC) accelerator magnets are the subject of R&D efforts by magnet designers at various laboratories. They require modifications of magnet design tools such as the ROXIE program at CERN, i.e. models of dynamic effects in superconductors need to be implemented and validated. In this paper we present the efforts towards a dynamic 2-D simulation of fast-ramping SC magnets with the ROXIE tool. Models are introduced and simulation results are compared to measurements of the GSI001 magnet of a GSI test magnet constructed and measured at BNL.

  18. Numerical calculation of transient field effects in quenching superconducting magnets

    CERN Document Server

    Schwerg, Nikolai; Russenschuck, Stephan

    2009-01-01

    The maximum obtainable magnetic induction of accelerator magnets, relying on normal conducting cables and iron poles, is limited to around 2 T because of ohmic losses and iron saturation. Using superconducting cables, and employing permeable materials merely to reduce the fringe field, this limit can be exceeded and fields of more than 10 T can be obtained. A quench denotes the sudden transition from the superconducting to the normal conducting state. The drastic increase in electrical resistivity causes ohmic heating. The dissipated heat yields a temperature rise in the coil and causes the quench to propagate. The resulting high voltages and excessive temperatures can result in an irreversible damage of the magnet - to the extend of a cable melt-down. The quench behavior of a magnet depends on numerous factors, e.g. the magnet design, the applied magnet protection measures, the external electrical network, electrical and thermal material properties, and induced eddy current losses. The analysis and optimizat...

  19. submitter Thermal, Hydraulic, and Electromagnetic Modeling of Superconducting Magnet Systems

    CERN Document Server

    Bottura, L

    2016-01-01

    Modeling techniques and tailored computational tools are becoming increasingly relevant to the design and analysis of large-scale superconducting magnet systems. Efficient and reliable tools are useful to provide an optimal forecast of the envelope of operating conditions and margins, which are difficult to test even when a prototype is available. This knowledge can be used to considerably reduce the design margins of the system, and thus the overall cost, or increase reliability during operation. An integrated analysis of a superconducting magnet system is, however, a complex matter, governed by very diverse physics. This paper reviews the wide spectrum of phenomena and provides an estimate of the time scales of thermal, hydraulic, and electromagnetic mechanisms affecting the performance of superconducting magnet systems. The analysis is useful to provide guidelines on how to divide the complex problem into building blocks that can be integrated in a design and analysis framework for a consistent multiphysic...

  20. Interplay between superconductivity and magnetism in iron-based superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chubukov, Andrey V [University of Wisconsin

    2015-06-10

    This proposal is for theoretical work on strongly correlated electron systems, which are at the center of experimental and theoretical activities in condensed-matter physics. The interest to this field is driven fascinating variety of observed effects, universality of underlying theoretical ideas, and practical applications. I propose to do research on Iron-based superconductors (FeSCs), which currently attract high attention in the physics community. My goal is to understand superconductivity and magnetism in these materials at various dopings, the interplay between the two, and the physics in the phase in which magnetism and superconductivity co-exist. A related goal is to understand the origin of the observed pseudogap-like behavior in the normal state. My research explores the idea that superconductivity is of electronic origin and is caused by the exchange of spin-fluctuations, enhanced due to close proximity to antiferromagnetism. The multi-orbital/multi-band nature of FeSCs opens routes for qualitatively new superconducting states, particularly the ones which break time-reversal symmetry. By all accounts, the coupling in pnictdes is below the threshold for Mott physics and I intend to analyze these systems within the itinerant approach. My plan is to do research in two stages. I first plan to address several problems within weak-coupling approach. Among them: (i) what sets stripe magnetic order at small doping, (ii) is there a preemptive instability into a spin-nematic state, and how stripe order affects fermions; (iii) is there a co-existence between magnetism and superconductivity and what are the system properties in the co-existence state; (iv) how superconductivity emerges despite strong Coulomb repulsion and can the gap be s-wave but with nodes along electron FSs, (v) are there complex superconducting states, like s+id, which break time reversal symmetry. My second goal is to go beyond weak coupling and derive spin-mediated, dynamic interaction between

  1. Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL.

    Science.gov (United States)

    Zhao, H W; Sun, L T; Zhang, X Z; Guo, X H; Cao, Y; Lu, W; Zhang, Z M; Yuan, P; Song, M T; Zhao, H Y; Jin, T; Shang, Y; Zhan, W L; Wei, B W; Xie, D Z

    2008-02-01

    There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

  2. Design and System Integration of the Superconducting Wiggler Magnets for the Compact Linear Collider Damping Rings

    CERN Document Server

    Schoerling, D; Bernhard, A; Bragin, A; Karppinen, M; Maccaferri, R; Mezentsev, N; Papaphilippou, Y; Peiffer, P; Rossmanith, R; Rumolo, G; Russenschuck, S; Vobly, P; Zolotarev, K

    2012-01-01

    To achieve high luminosity at the collision point of the Compact Linear Collider (CLIC) the normalized horizontal and vertical emittances of the electron and positron beams must be reduced to 500 nm and 4 nm before the beams enter the 1.5TeV linear accelerators. An effective way to accomplish ultra-low emittances with only small effects on the electron polarization is using damping rings operating at 2.86 GeV equipped with superconducting wiggler magnets. This paper describes a technical design concept for the CLIC damping wigglers.

  3. Magnetoelastic instabilities and vibrations of superconducting-magnet systems

    Energy Technology Data Exchange (ETDEWEB)

    Moon, F.C.

    1982-03-01

    This report describes the research accomplished under Depatment of Energy/NSF grants associated with the structural design of superconducting magnets for magnetic fusion reactors. The main results pertain to magnetomechanical instabilities in toroidal and poloidal field magnets for proposed fusion reactors. One major accomplishment was the building and testing of a 1/75th scale superconducting structural model of a 16 coil Tokamak reactor. Using this model the buckling of toroidal and poloidal field coils under different constraints was observed. A series of dynamic tests were performed, including the effect of currents on natural frequencies, poloidal-toroidal coil interaction, and buckling induced superconducting-normal quench of the coils. The stability of poloidal coils in a toroidal magnet field were investigated with the 16 coil torus. A superconducting poloidal coil was observed to become statically unstable or buckle as the current approached a certain value. Magnetoelastic buckling of other magnet systems such as a yin-yang pair of magnets, Ioffe coils, and discrete coil solenoids were also studied.

  4. Coexistence of Incommensurate Magnetism and Superconductivity in the Two-Dimensional Hubbard Model.

    Science.gov (United States)

    Yamase, Hiroyuki; Eberlein, Andreas; Metzner, Walter

    2016-03-04

    We analyze the competition of magnetism and superconductivity in the two-dimensional Hubbard model with a moderate interaction strength, including the possibility of incommensurate spiral magnetic order. Using an unbiased renormalization group approach, we compute magnetic and superconducting order parameters in the ground state. In addition to previously established regions of Néel order coexisting with d-wave superconductivity, the calculations reveal further coexistence regions where superconductivity is accompanied by incommensurate magnetic order.

  5. High Magnetic Field Superconducting Magnets Fabricated In Budker Inp For Sr Generation

    CERN Document Server

    Zolotarev, K V; Khruschev, S V; Krämer, Dietrich; Kulipanov, G N; Lev, V H; Mezentsev, N A; Miginsky, E G; Shkaruba, V A; Syrovatin, V M; Tsukanov, V M; Zjurba, V K

    2004-01-01

    BESSY operates a 3-rd generation synchrotron light source in VUV to XUV region at Berlin-Adlershof. The main radiation sources in storage ring are special magnetic elements as undulators and wigglers. 3 superconducting shifters and one multipole superconducting wiggler are operating giving enhanced photon flux for 10-25 keV X-ray region. As the superconducting elements presently are located in straight sections, BESSY intends to exchange 4 of conventional room-temperature bending magnets by superconducting ones.The report contains brief description of 9 Tesla superbend prototype as a candidate for replacing of conventional magnets of BESSY-2, which was designed, fabricated and tested at Budker INP and was commissioned at BESSY in June 2004.Main parameters of 9 Tesla superconducting bending magnet prototype as well as testing results are presented.

  6. Study of quench propagation velocity in superconducting magnets for UNK

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, I.V.; Sheherbakov, P.A.; Snitko, V.P.; Tkachenko, N.P.; Vasiliev, L.M.; Vybornov, M.G.; Ziobin, A.V.

    1989-03-01

    Two superconducting magnet models, warm-iron and cold-iron designs are studied within the frames of work on UNK. The present note describes the method and results on measuring quench propagation velocity in the superconducting cables with a transport current in external field under the cooling conditions typical for those of the magnet winding. The results on measuring quench propagation velocities in warm-iron and cold-iron designs are presented. The results obtained for short samples and model coils are compared.

  7. A Novel superconducting toroidal field magnet concept using advanced materials

    Science.gov (United States)

    Schwartz, J.

    1992-03-01

    The plasma physics database indicates that two distinct approaches to tokamak design may lead to commercial fusion reactors: low Aspect ratio, high plasma current, relatively low magnetic field devices, and high Aspect ratio, high field devices. The former requires significant enhancements in plasma performance, while the latter depends primarily upon technology development. The key technology for the commercialization of the high-field approach is large, high magnetic field superconducting magnets. In this paper, the physics motivation for the high field approach and key superconducting magnet (SCM) development issues are reviewed. Improved SCM performance may be obtained from improved materials and/or improved engineering. Superconducting materials ranging from NbTi to high- T c oxides are reviewed, demonstrating the broad range of potential superconducting materials. Structural material options are discussed, including cryogenic steel alloys and fiber-reinforced composite materials. Again, the breadth of options is highlighted. The potential for improved magnet engineering is quantified in terms of the Virial Theorem Limit, and two examples of approaches to highly optimized magnet configurations are discussed. The force-reduced concept, which is a finite application of the force-free solutions to Ampere's Law, appear promising for large SCMs but may be limited by the electromagnetics of a fusion plasma. The Solid Superconducting Cylinder (SSC) concept is proposed. This concept combines the unique properties of high- T c superconductors within a low- T c SCM to obtain (1) significant reductions in the structural material volume, (2) a decoupling of the tri-axial (compressive and tensile) stress state, and (3) a demountable TF magnet system. The advantages of this approach are quantified in terms of a 24 T commercial reactor TF magnet system. Significant reductions in the mechanical stress and the TF radial build are demonstrated.

  8. Design and Test Results of Superconducting Magnet for Heavy-Ion Rotating Gantry

    Science.gov (United States)

    Takayama, S.; Koyanagi, K.; Miyazaki, H.; Takami, S.; Orikasa, T.; Ishii, Y.; Kurusu, T.; Iwata, Y.; Noda, K.; Obana, T.; Suzuki, K.; Ogitsu, T.; Amemiya, N.

    2017-07-01

    Heavy-ion radiotherapy has a high curative effect in cancer treatment and also can reduce the burden on patients. These advantages have been generally recognized. Furthermore, a rotating gantry can irradiate a tumor with ions from any direction without changing the position of the patient. This can reduce the physical dose on normal cells, and is thus commonly used in proton radiotherapy. However, because of the high magnetic rigidity of carbon ions, the weight of the rotating gantry for heavy-ion therapy is about three-times heavier than those used for proton cancer therapy, according to our estimation. To overcome this issue, we developed a small and lightweight rotating gantry in collaboration with the National Institute of Radiological Sciences (NIRS). The compact rotating gantry was composed of ten low-temperature superconducting (LTS) magnets that were designed from the viewpoint of beam optics. These LTS magnets have a surface-winding coil-structure and provide both dipole and quadrupole fields. The maximum dipole and quadrupole magnetic field of the magnets were 2.88 T and 9.3 T/m, respectively. The rotating gantry was installed at NIRS, and beam commissioning is in progress to achieve the required beam quality. In the three years since 2013, in a project supported by the Ministry of Economy, Trade and Industry (METI) and the Japan Agency for Medical Research and Development (AMED), we have been developing high-temperature superconducting (HTS) magnets with the aim of a further size reduction of the rotating gantry. To develop fundamental technologies for designing and fabricating HTS magnets, a model magnet was manufactured. The model magnet was composed of 24 saddle-shaped HTS coils and generated a magnetic field of 1.2 T. In the presentation, recent progress in this research will be reported.

  9. A test of a 2 Tesla superconducting transmission line magnet system

    Energy Technology Data Exchange (ETDEWEB)

    Piekarz, Henryk; Carcagno, Ruben; Claypool, Brad; Foster, George W.; Hays, Steven L.; Huang, Yuenian; Kashikhin, Vladimir; Malamud, Ernest; Mazur, Peter O.; Nehring,; Oleck, Andrew; Rabehl, Roger; Schlabach, Phil; Sylvester, Cosmore; Velev, Gueorgui; Volk, James; /Fermilab; Wake, Masayoshi; /KEK, Tsukuba

    2005-09-01

    Superconducting transmission line magnet test system for an injector accelerator of a staged VLHC proton-proton colliding beam accelerator has been built and operated at Fermilab. The 1.5 m long, twin-aperture, combined function dipole magnet of 2 Tesla field is excited by a single turn 100 kA transmission line superconductor. The 100 kA dc current is generated using dc-dc switching converters powered by a bulk 240 kW supply. A pair of horizontally placed conventional leads facilitates transfer of this current to the magnet transmission line superconductor operating at liquid helium temperature. Fabrication of magnet components and magnet assembly work are described. The magnet test system and its operation are presented, and the performance is summarized.

  10. Normal zone propagation in adiabatic superconducting magnets: Pt. 1; Normal zone propagation velocity in superconducting composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Z.P.; Iwasa, Y. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Francis Bitter National Magnet Lab. Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center)

    1991-09-01

    A normal zone propagation model has been developed for superconducting composites under adiabatic conditions. It is based on the Whetstone-Roos model, originally developed for normal zone propagation in adiabatic wires of unclad superconductor. The model takes into account the temperature and magnetic field dependent material properties, for both superconductor and matrix metal. Analytical results agree well with experimental data. (author).

  11. Slice of the LHC prototype beam tubes in dipole magnet

    CERN Multimedia

    1995-01-01

    A slice of the LHC accelerator prototype beam tubes surrounded by magnets. The LHC will accelerate two proton beams in opposite directions. The high bending and accelerating fields needed can only be reached using superconductors. At very low temperatures superconductors have no electrical resistance and therefore no power loss. The LHC will be the largest superconducting installation ever built, a unique challenge for CERN and its industrial partners. About dipole magnets: There will be 1232 dipole magnets in the LHC, used to guide the particles around the 27 km ring. Dipole magnets must have an extremely uniform field, which means the current flowing in the coils has to be very precisely controlled. Nowhere before has such precision been achieved at such high currents. The temperature is measured to five thousandths of a degree, the current to one part in a million. The current creating the magnetic field will pass through superconducting wires at up to 12 500 amps, about 30 000 times the current flowing ...

  12. Hybrid Superconducting Magnetic Bearing (HSMB) for high load devices

    Science.gov (United States)

    McMichael, C. K.; Ma, K. B.; Lamb, M. A.; Lin, M. W.; Chow, L.; Meng, R. L.; Hor, P. H.; Chu, W. K.

    1992-05-01

    Lifting capacities greater than 41 N/cm(exp 2) (60 psi) at 77 K have been achieved with a new type of levitation (hybrid) using a combination of permanent magnets and high quality melt-mixtured YBa2Cu3O(7-delta) (YBCO). The key concept of the hybrid superconducting magnetic bearing (HSMB) is the use of strong magnetic repulsion and attraction from permanent magnets for high levitation or suspension forces in conjunction with a superconductor's flux pinning characteristics to counteract the inherent instabilities in a system consisting of magnets only. To illustrate this concept, radial and axial forces between magnet/superconductor, magnet/magnet, and magnet/superconductor/magnet, were measured and compared for the thrust bearing configuration

  13. Magnet Science and Technology for Basic Research at the High Field Laboratory for Superconducting Materials

    Institute of Scientific and Technical Information of China (English)

    渡辺和雄

    2007-01-01

    Since the first practical cryocooled superconducting magnet using a GM-cryocooler and high temperature superconducting current leads has been demonstrated successfully at the High Field Laboratory for Superconducting Materials (HFLSM), various kinds of cryocooled superconducting magnets in fields up to 15 T have been used to provide access for new research areas in fields of magneto-science. Recently, the HFLSM has succeeded in demonstrating a cryocooed 18 T high temperature superconducting magnet and a high field cryocooled 27.5 T hybrid magnet. Cryocooled magnet technology and basic research using high field magnets at the HFLSM are introduced.

  14. Vibration-induced field fluctuations in a superconducting magnet

    CERN Document Server

    Britton, J W; Bohnet, J G; Uys, H; Biercuk, M J; Bollinger, J J

    2015-01-01

    Superconducting magnets enable precise control of nuclear and electron spins, and are used in experiments that explore biological and condensed matter systems, and fundamental atomic particles. In high-precision applications, a common view is that that slow (<1 Hz) drift of the homogeneous magnetic field limits control and measurement precision. We report on previously undocumented higher-frequency field noise (10 Hz to 200 Hz) that limits the coherence time of 9Be+ electron-spin qubits in the 4.46 T field of a superconducting magnet. We measure a spin-echo T2 coherence time of ~6 ms for the 9Be+ electron-spin resonance at 124 GHz, limited by part-per-billion fractional fluctuations in the magnet's homogeneous field. Vibration isolation of the magnet improved T2 to ~50 ms.

  15. Decoherence in Superconducting Qubits from Surface Magnetic States

    Science.gov (United States)

    Hover, David; Sendelbach, Steven; Kittel, Achim; Mueck, Michael; McDermott, Robert

    2008-03-01

    Unpaired spins in amorphous surface oxides can act as a source of decoherence in superconducting and other solid-state qubits. A density of surface spins can give rise to low-frequency magnetic flux noise, which in turn leads to dephasing of the qubit state. In addition, magnetic surface states can couple to high-frequency resonant magnetic fields, and thereby contribute to energy relaxation of the qubit. We present the results of low-frequency measurements of the nonlinear and imaginary spin susceptibility of surface magnetic states in superconducting devices at millikelvin temperatures. In addition, we describe high-frequency magnetic resonance measurements that directly probe the surface spin density of states. We present calculations that connect the measurement results to qubit energy relaxation and dephasing times.

  16. Application concepts of small regenerative cryocoolers in superconducting magnet systems

    Science.gov (United States)

    van der Laan, M. T. G.; Tax, R. B.; ten Kate, H. H. J.

    Superconducting magnets are in growing use outside laboratories for example MRI scanners in hospitals. Other applications under development are magnet systems for separation, levitated trains and ship propulsion. The application of cryocoolers can make these systems more practical. Interfacing these cryocoolers to the magnets can be designed in several different ways. The four basic methods will be dealt with. Test results of a realized GM cryocooler-SC magnet system will be shown. It handles about a 1:3 scale MRI magnet of which one of the six coils has been successfully tested at temperatures between 10 and 14 K.

  17. Equilibrium of a magnet floating above a superconducting disk

    Science.gov (United States)

    Williams, Richard; Matey, J. R.

    1988-02-01

    A superconducting body will repel a nearby magnet. The repulsion is due to the perfect diamagnetism resulting from the Meissner effect. A small magnet will float above a superconducting disk at an equilibrium position over the disk center, stable against lateral displacements. It is not intuitively obvious why the potential energy of the magnet over a flat disk should have a minimum at the center, rather than a maximum. We have measured the properties of the attractive potential well of a YBa2Cu3O7 disk by two experiments. In the first, we use a low-frequency magnetic field, 0-100 Hz, to excite oscillations of a small, freely levitating bar magnet about its equilibrium position. We find sharp resonances, corresponding to longitudinal, transverse, and torsional modes of oscillation. The frequencies of these resonances define the properties near the bottom of the potential well. In the second experiment, we attach the magnet to a vertical glass fiber of known stiffness. The magnet is suspended horizontally a small known distance, z, above the superconducting disk. By moving the magnet from the center of the disk to the edge and measuring the bending of the support fiber as a function of position we determine the shape of the potential curve for large displacements and the total energy needed to escape from the well.

  18. Superconducting Cable and Magnets for the Large Hadron Collider

    CERN Document Server

    Rossi, L

    2004-01-01

    The Large Hadron Collider (LHC) is a high energy, high luminosity particle accelerator under construction at CERN and it will be the largest application of superconductivity. Most of the existing 27 km underground tunnel will be filled with superconducting magnets, mainly 15 m long dipoles and 3 m long quadrupoles. These 1232 dipole and 400 quadrupole magnets as well as many other magnets, are wound with copper stabilized NbTi Rutherford cables and will be operated at 1.9 K by means of pressurized superfluid helium. The operating dipole field is 8.33 T; however the whole system is designed for possible operation up to 9 T. The coils are powered at about 12 kA and about 12 GJ of magnetic energy will be stored in superconducting devices. After a brief review of the main characteristics of the superconductors and of the magnets, the special measures taken to fulfill the mass production with the necessary accuracy are presented. The results on one third of the superconducting cable production and on the first f...

  19. Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator

    Directory of Open Access Journals (Sweden)

    M. A. Fraser

    2011-02-01

    Full Text Available The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wave resonator and the asymmetry of the rf defocusing forces in the solenoid focusing channel. A racetrack shaped beam port aperture was shown to improve the symmetry of the fields in the high-β quarter-wave resonator and reduce the loss of acceptance under the offset used to compensate the steering force. The methods used to compensate the beam steering are described and an optimization routine written to minimize the steering effect when all cavities of a given family are offset by the same amount, taking into account the different velocity profiles across the range of mass-to-charge states accepted. The assumptions made in the routine were shown to be adequate and the results well correlated with the beam quality simulated in multiparticle beam dynamics simulations. The specification of the design tolerances is outlined based on studies of the sensitivity of the beam to misalignment and errors, with particular

  20. A preliminary study of the feasibility of using superconducting quarter-wave resonators for accelerating high intensity proton beams

    Institute of Scientific and Technical Information of China (English)

    YANG Liu; LU Xiang-Yang; QUAN Sheng-Wen; YAO Zhong-Yuan; LUO Xing; ZHOU Kui

    2012-01-01

    The superconducting (SC) cavities currently used for the acceleration of protons at a low velocity range are based on half-wave resonators.Due to the rising demand on high current,the issue of beam loading and space-charge problems has arisen.Qualities of low cost and high accelerating efficiency are required for SC cavities,which are properly fitted by using SC quarter-wave resonators (QWR).We propose a concept of using QWRs with frequency 162.5 MHz to accelerate high current proton beams.The main factor limiting SC QWRs being applied to high current proton beams is vertical beam steering,which is dominantly caused by the magnetic field on axis.In this paper,we intend to analyze steering and eliminate it to verify the qualification of using QWRs to accelerate high intensity proton beams.

  1. Superconducting high current magnetic Circuit: Design and Parameter Estimation of a Simulation Model

    CERN Document Server

    Kiefer, Alexander; Reich, Werner Dr

    The Large Hadron Collider (LHC) utilizes superconducting main dipole magnets that bend the trajectory of the particle beams. In order to adjust the not completely homogeneous magnetic feld of the main dipole magnets, amongst others, sextupole correctcorrector magnets are used. In one of the 16 corrector magnet circuits placed in the LHC, 154 of these sextupole corrector magnets (MCS) are connected in series. This circuit extends on a 3.35 km tunnel section of the LHC. In 2015, at one of the 16 circuits a fault was detected. The simulation of this circuit is helpful for fnding the fault by applying alternating current at different frequencies. Within this Thesis a PSpice model for the simulation of the superconducting corrector magnet circuit was designed. The physical properties of the circuit and its elements were analyzed and implemented. For the magnets and bus-bars, sub-circuits were created which reflect the parasitic effects of electrodynamics and electrostats. The inductance values and capacitance valu...

  2. Academic Training Lecture Regular Programme: Superconducting Magnets with HTS

    CERN Multimedia

    2012-01-01

    Superconducting Magnets with HTS (1/5), by Justin Schwartz (North Carolina State University).   Monday, June 25, 2012 from 11:00 to 12:00 (Europe/Zurich) at CERN ( 30-7-018 - Kjell Johnsen Auditorium ).   More information here.

  3. Route to topological superconductivity via magnetic field rotation

    Energy Technology Data Exchange (ETDEWEB)

    Loder, Florian; Kampf, Arno P.; Kopp, Thilo [Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg (Germany)

    2015-07-01

    Apart from the very few spin-triplet superconductors with p-wave pairing symmetry, a candidate system for topological superconductivity is a conventional, two-dimensional s-wave superconductor in a magnetic field with a sufficiently strong Rashba spin-orbit coupling. Typically, the required magnetic field to convert the superconductor into a topologically non-trivial state is however by far larger than the upper critical field H{sub c2}, which excludes its realization. Here we argue that this problem is overcome by rotating the magnetic field into the superconducting plane. We explore the topological transitions which occur upon changing the strength and the orientation of the magnetic field and show that an unusual superconducting state with finite-momentum pairing exists, which preserves its topological nature up to an in-plane field orientation. We discuss the realizability of this state at the superconducting interface between LaAlO{sub 3} and SrTiO{sub 3}.

  4. Levitation of Superconductive Cable in Earth Magnetic Field

    Directory of Open Access Journals (Sweden)

    Bohus Ulrych

    2006-01-01

    Full Text Available The paper represents an introductory study about a superconductive cable levitating in Earth’s magnetic field. Built are two mathematical models of the problem providing both the shape of the arc of the cable and forces acting along it. The theoretical analysis is supplemented with an illustrative example.

  5. Survey of high field superconducting material for accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Scahlan, R.; Greene, A.F.; Suenaga, M.

    1986-05-01

    The high field superconductors which could be used in accelerator dipole magnets are surveyed, ranking these candidates with respect to ease of fabrication and cost as well as superconducting properties. Emphasis is on Nb/sub 3/Sn and NbTi. 27 refs., 2 figs. (LEW)

  6. Mirror Fusion Test Facility: Superconducting magnet system cost analysis

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-01

    At the request of Victor Karpenko, Project manager for LLL`s Mirror Fusion Test Facility, EG&G has prepared this independent cost analysis for the proposed MFTF Superconducting Magnet System. The analysis has attempted to show sufficient detail to provide adequate definition for a basis of estimating costs.

  7. Superconductivity and magnetic order in La--Ce alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wollan, J.J.; Finnemore, D.K.

    1971-03-01

    Superconductivity and magnetic order have been studied both above and below the Kondo temperature for the La--Ce system. Electrical resistivity measurements on La 0.2, 1.0, 2.0, 3.2, and 4.0 wt. percent Ce have been made from 0.060 to 20.0K.

  8. Nucleation of bulk superconductivity close to critical magnetic fields

    DEFF Research Database (Denmark)

    Fournais, Søren; Kachmar, Ayman

    2011-01-01

    threshold value of the applied magnetic field for which bulk superconductivity contributes to the leading order of the energy. Furthermore, the energy of the bulk is related to that of the Abrikosov problem in a periodic lattice. A key ingredient of the proof is a novel L∞ -bound which is of independent...

  9. Superconductive combinational logic circuit using magnetically coupled SQUID array

    Energy Technology Data Exchange (ETDEWEB)

    Yamanashi, Y., E-mail: yamanasi@ynu.ac.j [Interdisciplinary Research Center, Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokohama 240-8501 (Japan); Umeda, K.; Sai, K. [Department of Electrical and Computer Engineering, Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokohama 240-8501 (Japan)

    2010-11-01

    In this paper, we propose the development of superconductive combinational logic circuits. One of the difficulties in designing superconductive single-flux-quantum (SFQ) digital circuits can be attributed to the fundamental nature of the SFQ circuits, in which all logic gates have latching functions and are based on sequential logic. The design of ultralow-power superconductive digital circuits can be facilitated by the development of superconductive combinational logic circuits in which the output is a function of only the present input. This is because superconductive combinational logic circuits do not require determination of the timing adjustment and clocking scheme. Moreover, semiconductor design tools can be used to design digital circuits because CMOS logic gates are based on combinational logic. The proposed superconductive combinational logic circuits comprise a magnetically coupled SQUID array. By adjusting the circuit parameters and coupling strengths between neighboring SQUIDs, fundamental combinational logic gates, including the AND, OR, and NOT gates, can be built. We have verified the accuracy of the operations of the fundamental logic gates by analog circuit simulations.

  10. The Darwin-Breit magnetic interaction and superconductivity

    CERN Document Server

    Essen, Hanno

    2013-01-01

    A number of facts indicating the relevance of the Darwin magnetic interaction energy in the superconducting phase are pointed out. The magnetic interaction term derived by Darwin is the same as the, so called, Breit term in relativistic quantum mechanics. While this term always is a small perturbation in few body systems it can be shown to be potentially dominating in systems of large numbers of electrons. It is therefore a natural candidate in the explanation of emergent phenomena---phenomena that only occur in sufficiently large systems. The dimensionless parameter that indicates the importance of the magnetic energy is the number of electrons times the classical electron radius divided by the size of the system. The number of electrons involved are only the electrons at the Fermi surface; electrons with lower energy cannot contribute to current density and thus not to the magnetic field. The conventional understanding of superconductivity has always been problematic and no really reductionistic derivation ...

  11. State-of-the-art of superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Lubell, M. S.

    1972-09-01

    A survey of the most recent developments in superconducting magnet materials is presented, and complete data on the upper critical field and transition temperature for the NbTi alloy system are given. The overall critical current density of compound conductors is shown for both low and high field commercial superconductors. A tabulation is given of high field and large bore solenoids, comparing design and test data. Comparative data are also given for some nonsolenoidal coils, and details are listed for the systems under construction or design. A criterion is derived for the stable current density attainable in extremely large magnet systems such as those envisioned for fusion reactors: j ∝ (stored energy)-1/6 . The review concludes with summaries concerning the structural materials useful in large magnets and the effects of radiation on superconducting magnets.

  12. Scaling of Superconducting Switches for Extraction of Magnetic Energy

    CERN Document Server

    Ballarino, A

    2010-01-01

    In certain cases it is necessary to extract the energy from a superconducting magnet when it quenches, in order to limit the heat generated by the event and thus prevent irreversible damage. This is usually achieved by opening a contact breaker across a resistor in the circuit feeding the magnet. For the heavy currents used to excite large magnets such switches incorporate sophisticated devices to limit arcing during the operation; besides being quite large and expensive, such switches have a limited lifetime. It is therefore interesting to consider the use of superconducting switches to perform this function, the advantage being that such switches would (i) not require maintenance and (ii) would be housed within the cryogenic environment of the magnet, and thus avoid permanent diversion of the current in and out of that environment to the mechanical switch (which operates at room temperature). However, practical switches for such an application are made up of superconductor in a metal matrix, and it is conve...

  13. Field Measurement for Superconducting Magnets of ADS Injector I

    CERN Document Server

    Yang, Xiangchen

    2013-01-01

    The superconducting solenoid magnet prototype for ADS injection-I had been fabricated in Beijing Qihuan Mechanical and Electric Engineer Company and tested in Haerbin Institute of Technology (HIT) in Nov, 2012. Batch magnet production was processed after some major revision from the magnet prototype, they include: removing off the perm-alloy shield, extending the iron yoke, using thin superconducting cable, etc. The first one of the batch magnets was tested in the vertical Dewar in HIT in Sept. 2013. Field measurement was carried out at the same time by the measurement platform that seated on the top of the vertical Dewar. This paper will present the field measurement system design, measurement results and discussion on the residual field from the persistent current effect.

  14. Quench Tests of LHC Magnets with Beam: Studies on Beam Loss development and determination of Quench levels

    CERN Document Server

    Priebe, A; Sapinski, M

    The application of superconducting materials in the field of high energy accelerator physics not only opens the doors to the generation of the magnetic fields unattainable to normal conductors but also demands facing new challenges. A transition fromthe superconducting state, which is characterized by a resistance-free flow of the electric current, to the normal conducting state is called quenching. This process might be extremely dangerous and even lead to destruction of amagnet superconducting coil if no protecting actions are taken. Therefore, the knowledge of a magnet quench level, i.e. amount of energy which causes the transition to the resistive state, is crucial for the safety and operational efficiency of the accelerator. Regarding that, specific thresholds are incorporated to dedicated quench prevention systems in order to suppress the origin of detected energy perturbation, for example beam losses, or mitigate the consequences of the quenching process by dissipating the energy stored in the magnetic...

  15. Experimental evidence for Froehlich superconductivity in high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, N. [National High Magnetic Field Laboratory, LANL, MS-E536, Los Alamos, NM (United States)]. E-mail: nharrison@lanl.gov; Mielke, C.H.; Singleton, J. [National High Magnetic Field Laboratory, LANL, MS-E536, Los Alamos, NM (United States); Brooks, J.S. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL (United States); Tokumoto, M. [Electrotechnical Laboratory, Tsukuba, Ibaraki (Japan)

    2001-05-14

    Resistivity and irreversible magnetization data taken within the high magnetic field CDW{sub x} phase of the quasi-two-dimensional organic metal {alpha}-(BEDT-TTF){sub 2}KHg(SCN){sub 4} are shown to be consistent with a field-induced inhomogeneous superconducting phase. In-plane skin depth measurements show that the resistive transition on entering the CDW{sub x} phase is both isotropic and representative of the bulk. (author). Letter-to-the-editor.

  16. Structural materials for large superconducting magnets for tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Long, C.J.

    1976-12-01

    The selection of structural materials for large superconducting magnets for tokamak-type fusion reactors is considered. The important criteria are working stress, radiation resistance, electromagnetic interaction, and general feasibility. The most advantageous materials appear to be face-centered-cubic alloys in the Fe-Ni-Cr system, but high-modulus composites may be necessary where severe pulsed magnetic fields are present. Special-purpose structural materials are considered briefly.

  17. SERPENTINE COIL TOPOLOGY FOR BNL DIRECT WIND SUPERCONDUCTING MAGNETS.

    Energy Technology Data Exchange (ETDEWEB)

    PARKER, B.; ESCALLIER, J.

    2005-05-16

    Serpentine winding, a recent innovation developed at BNL for direct winding superconducting magnets, allows winding a coil layer of arbitrary multipolarity in one continuous winding process and greatly simplifies magnet design and production compared to the planar patterns used before. Serpentine windings were used for the BEPC-II Upgrade and JPARC magnets and are proposed to make compact final focus magnets for the EC. Serpentine patterns exhibit a direct connection between 2D body harmonics and harmonics derived from the integral fields. Straightforward 2D optimization yields good integral field quality with uniformly spaced (natural) coil ends. This and other surprising features of Serpentine windings are addressed in this paper.

  18. Rotor assembly including superconducting magnetic coil

    Energy Technology Data Exchange (ETDEWEB)

    Snitchler, Gregory L. (Shrewsbury, MA); Gamble, Bruce B. (Wellesley, MA); Voccio, John P. (Somerville, MA)

    2003-01-01

    Superconducting coils and methods of manufacture include a superconductor tape wound concentrically about and disposed along an axis of the coil to define an opening having a dimension which gradually decreases, in the direction along the axis, from a first end to a second end of the coil. Each turn of the superconductor tape has a broad surface maintained substantially parallel to the axis of the coil.

  19. Determination of AC Characteristics of Superconducting Dipole Magnets in the Large Hadron Collider Based on Experimental Results and Simulations

    CERN Document Server

    Ambjørndalen, Sara; Verweij, Arjan

    The Large Hadron Collider (LHC) utilizes high-field superconducting Main Dipole Magnets that bend the trajectory of the beam. The LHC ring is electrically divided into eight octants, each allocating a 7 km chain of 154 Main Dipole Magnets. Dedicated de- tection and protection systems prevent irreversible magnet damage caused by quenches. Quench is a local transition from the superconducting to the normal conducting state. Triggering of such systems, along with other failure scenarios, result in fast transient phenomena. In order to analyze the consequence of such electrical transients and failures in the dipole chain, one needs a circuit model that is validated against measurements. Currently, there exists an equivalent circuit of the Main Dipole Magnet resolved at an aperture level. Each aperture model takes into account the dynamic effects occurring in the magnets, trough a lossy-inductance model and parasitic capacitances to ground. At low frequencies the Main Dipole Magnet behaves as a linear inductor. Ca...

  20. Field Quality and Hysteresis of LHC Superconducting Corrector Magnets

    CERN Document Server

    Allitt, M; Giloux, C; Karppinen, M; Khare, P; Lombardi, A M; Maurya, T; Puntambekar, A; Remondino, Vittorio; Santrich-Badal, A; Venturini-Delsolaro, W; Wolf, R

    2004-01-01

    The Large Hadron Collider (LHC) will use some 7600 superconducting corrector magnets. The magnetic field quality is measured at room temperature by 12 magnetic measurement benches employed by the corrector manufacturers. CERN performs magnetic measurements at 4.2 K and at 1.9 K on a small subset of corrector magnets. The paper discusses the correlation between the warm and cold field measurements. The field quality is compared to the target field quality for LHC. Many corrector circuits will be powered in a way which cannot be predicted before LHC will start operation and which even then may change between physics runs. The measured magnetic hysteresis and its influence on possible setting errors during operation is discussed, in particular for the orbit correctors and the tuning/trim quadrupole magnet circuits.

  1. Magnetic hysteresis effects in superconducting coplanar microwave resonators

    Energy Technology Data Exchange (ETDEWEB)

    Bothner, D.; Gaber, T.; Kemmler, M.; Gruenzweig, M.; Ferdinand, B.; Koelle, D.; Kleiner, R. [Universitaet Tuebingen (Germany); Wuensch, S.; Siegel, M. [Karlsruher Institut fuer Technologie (Germany); Mikheenko, P.; Johansen, T.H. [University of Oslo (Norway)

    2013-07-01

    We present experimental data regarding the impact of external magnetic fields on quality factor and resonance frequency of superconducting microwave resonators in a coplanar waveguide geometry. In particular we focus on the influence of magnetic history and show with the assistance of numerical calculations that the found hysteretic behaviour can be well understood with a highly inhomogeneous microwave current density in combination with established field penetration models for type-II superconducting thin films. Furthermore we have used magneto-optical imaging techniques to check the field distribution which we have assumed in our calculations. Finally, we demonstrate that and how the observed hysteretic behaviour can be used to optimize and tune the resonator performance for possible hybrid quantum sytems in magnetic fields.

  2. Vacuum impregnation with epoxy of large superconducting magnet structures

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.A.; Coyle, D.E.; Miller, P.B.; Wenzel, W.F.

    1978-06-01

    The Lawrence Berkeley Laboratory (LBL) has been developing a new generation of superconducting magnets which have the helium cooling system as an integral part of the magnet structure. The LBL technique calls for large sections of the magnet structure to be vacuum impregnated with epoxy. The epoxy was chosen for its impregnation properties. Epoxies which have good impregnation characteristics are often subject to cracking when they are cooled to cryogenic temperatures. The cracking of such an epoxy can be controlled by: (1) minimizing the amount of epoxy in the structure; (2) reducing the size of unfilled epoxy spaces; and (3) keeping the epoxy in compression. The technique for using the epoxy is often more important than the formulation of the epoxy. The LBL vacuum impregnation and curing technique is described. Experimental measurements on small samples of coil sections are presented. Practical experience with large vacuum impregnation superconducting coils (up to two meters in dia) is also discussed.

  3. A superconducting large-angle magnetic suspension. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Downer, J.R.; Anastas, G.V. Jr.; Bushko, D.A.; Flynn, F.J.; Goldie, J.H.; Gondhalekar, V.; Hawkey, T.J.; Hockney, R.L.; Torti, R.P.

    1992-12-01

    SatCon Technology Corporation has completed a Small Business Innovation Research (SBIR) Phase 2 program to develop a Superconducting Large-Angle Magnetic Suspension (LAMS) for the NASA Langley Research Center. The Superconducting LAMS was a hardware demonstration of the control technology required to develop an advanced momentum exchange effector. The Phase 2 research was directed toward the demonstration for the key technology required for the advanced concept CMG, the controller. The Phase 2 hardware consists of a superconducting solenoid ('source coils') suspended within an array of nonsuperconducting coils ('control coils'), a five-degree-of-freedom positioning sensing system, switching power amplifiers, and a digital control system. The results demonstrated the feasibility of suspending the source coil. Gimballing (pointing the axis of the source coil) was demonstrated over a limited range. With further development of the rotation sensing system, enhanced angular freedom should be possible.

  4. The design considerations for a superconducting magnetic bearing system

    Science.gov (United States)

    Cansiz, Ahmet; Yildizer, Irfan

    2014-09-01

    In this paper a high temperature superconducting magnetic bearing is studied with various design considerations. The design of the bearing consists of a rotor with 7.5 kg mass. The stable levitation of the rotor is provided with the Evershed type and superconducting components. The dynamic stability of the rotor is strengthened with the electromagnetic and electrodynamic levitation techniques. The force on the rotor is predicted in terms of semi-analytical frozen image model. The designed driving system sustains stable levitation during the rotation of the rotor and achieves higher rotational speed than that of the torque driver. The results indicate that the designed rotor and driving system have potential solutions for the development of the superconducting flywheel energy storage.

  5. Development of superconducting magnetic bearing for flywheel energy storage system

    Science.gov (United States)

    Miyazaki, Yoshiki; Mizuno, Katsutoshi; Yamashita, Tomohisa; Ogata, Masafumi; Hasegawa, Hitoshi; Nagashima, Ken; Mukoyama, Shinichi; Matsuoka, Taro; Nakao, Kengo; Horiuch, Shinichi; Maeda, Tadakazu; Shimizu, Hideki

    2016-12-01

    We have been developing a superconducting magnetic bearing (SMB) that has high temperature superconducting (HTS) coils and bulks for a flywheel energy storage system (FESS) that have an output capability of 300 kW and a storage capacity of 100 kW h (Nagashima et al., 2008, Hasegawa et al., 2015) [1,2]. The world largest-class FESS with a SMB has been completed and test operation has started. A CFRP flywheel rotor that had a diameter of 2 m and weight of 4000 kg had a capability to be rotated at a maximum speed of 6000 min-1. The SMB using superconducting material both for its rotor and stator is capable of supporting the flywheel that had the heavy weight and the high seed rotation mentioned above. This paper describes the design of the SMB and results of the cooling test of the SMB.

  6. Fiber Optic Cryogenic Sensors for Superconducting Magnets and Superconducting Power Transmission lines at CERN

    CERN Document Server

    Chiuchiolo, A; Cusano, A; Bajko, M; Perez, J C; Bajas, H; Giordano, M; Breglio, G; Palmieri, L

    2014-01-01

    The design, fabrication and tests of a new generation of superconducting magnets for the upgrade of the LHC require the support of an adequate, robust and reliable sensing technology. The use of Fiber Optic Sensors is becoming particularly challenging for applications in extreme harsh environments such as ultra-low temperatures, high electromagnetic fields and strong mechanical stresses offering perspectives for the development of technological innovations in several applied disciplines.

  7. Superconducting Magnets for Accelerators and Detectors

    CERN Document Server

    Rossi, L

    2003-01-01

    The development of superconductors for magnet applications has received a strong boost from the High Energy Physics (HEP) community, both for detector magnets and for accelerator magnets. The demand for very high current density (both Jc and Jc,overall), for fine filaments, for control of the copper content, for very compact cables with large current capability, the ability to superstabilize large cables at moderate cost, together with necessity of producing hundreds of tons of materials for large projects, have been the main motivation for the continued improvement of practical superconductors. HEP has provided so far, and still does nowadays, a unique forum where material scientists, fabrication engineers and final users, i.e. magnet designers and magnet constructors, gather together and, by sharing their knowledge and their needs, are able to accomplish real progress in the technology. In particular accelerator magnets have reached a point where, in order to go beyond the 9 T limit of the present LHC in co...

  8. Cryogenic Infrastructure for Testing of LHC Series Superconducting Magnets

    CERN Document Server

    Axensalva, J; Herblin, L; Lamboy, J P; Tovar-Gonzalez, A; Vuillerme, B

    2005-01-01

    The ~1800 superconducting magnets for the LHC machine shall be entirely tested at reception before their installation in the tunnel. For this purpose and in order to reach the reliability and efficiency at the nominal load required for an industrial operation for several years, we have gradually upgraded and retrofitted the cryogenic facilities installed in the early nineties for the testing at CERN of prototypes and preseries magnets. The final infrastructure of the test station, dedicated to check industrially the quality of the series magnets, is now nearly complete. We present the general layout and describe the overall performance of the system.

  9. Superconducting Magnet Technology for the Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Todesco, E. [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TE Dept.; Ambrosio, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Ferracin, P. [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TE Dept.; Rifflet, J. M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TE Dept.; Sabbi, G. L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Segreti, M. [Alternative Energies and Atomic Energy Commission (CEA), Saclay (France); Nakamoto, T. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); van Weelderen, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TE Dept.; Xu, Q. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan)

    2015-10-01

    In this section we present the magnet technology for the High Luminosity LHC. After a short review of the project targets and constraints, we discuss the main guidelines used to determine the technology, the field/gradients, the operational margins, and the choice of the current density for each type of magnet. Then we discuss the peculiar aspects of each class of magnet, with special emphasis on the triplet.

  10. Thermo-magnetic instabilities in Nb3Sn superconducting accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Bordini, Bernardo [Univ. of Pisa (Italy)

    2006-09-01

    The advance of High Energy Physics research using circulating accelerators strongly depends on increasing the magnetic bending field which accelerator magnets provide. To achieve high fields, the most powerful present-day accelerator magnets employ NbTi superconducting technology; however, with the start up of Large Hadron Collider (LHC) in 2007, NbTi magnets will have reached the maximum field allowed by the intrinsic properties of this superconductor. A further increase of the field strength necessarily requires a change in superconductor material; the best candidate is Nb3Sn. Several laboratories in the US and Europe are currently working on developing Nb3Sn accelerator magnets, and although these magnets have great potential, it is suspected that their performance may be fundamentally limited by conductor thermo-magnetic instabilities: an idea first proposed by the Fermilab High Field Magnet group early in 2003. This thesis presents a study of thermo-magnetic instability in high field Nb3Sn accelerator magnets. In this chapter the following topics are described: the role of superconducting magnets in High Energy Physics; the main characteristics of superconductors for accelerator magnets; typical measurements of current capability in superconducting strands; the properties of Nb3Sn; a description of the manufacturing process of Nb3Sn strands; superconducting cables; a typical layout of superconducting accelerator magnets; the current state of the art of Nb3Sn accelerator magnets; the High Field Magnet program at Fermilab; and the scope of the thesis.

  11. Unconventional superconductivity from magnetism in transition-metal dichalcogenides

    Science.gov (United States)

    Rahimi, M. A.; Moghaddam, A. G.; Dykstra, C.; Governale, M.; Zülicke, U.

    2017-03-01

    We investigate proximity-induced superconductivity in monolayers of transition-metal dichalcogenides (TMDs) in the presence of an externally generated exchange field. A variety of superconducting order parameters is found to emerge from the interplay of magnetism and superconductivity, covering the entire spectrum of possibilities to be symmetric or antisymmetric with respect to the valley and spin degrees of freedom, as well as even or odd in frequency. More specifically, when a conventional s -wave superconductor with singlet Cooper pairs is tunnel-coupled to the TMD layer, both spin-singlet and triplet pairings between electrons from the same and opposite valleys arise due to the combined effects of intrinsic spin-orbit coupling and a magnetic-substrate-induced exchange field. As a key finding, we reveal the existence of an exotic even-frequency triplet pairing between equal-spin electrons from different valleys, which arises whenever the spin orientations in the two valleys are noncollinear. All types of superconducting order turn out to be highly tunable via straightforward manipulation of the external exchange field.

  12. Optimum design of flywheel storage system using superconducting magnetic bearings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Hun; Kim, Jong Soo; Kim, Jung Guen [Ajou University, Suwon (Korea)

    1999-03-01

    The flywheel energy storage system using superconducting magnetic bearings is a device to store electrical energy as rotational kinetic energy by motor and to convert it to electrical energy by generator when it is necessary. An analytical model of the SMB-FESS is necessary to identify the system behavior. At first, we have to model the superconducting magnetic bearings that have different characteristics from mechanical and the electric magnetic bearing. Modeling the SMB is same as estimating the bearing parameter. The theoretical modal parameter is calculated through the equation of motion and the experimental modal parameter is estimated through the impact testing (modal testing). The bearing parameter is searched by using the non-linear least square method until the theoretical result corresponds to the experimental result. The suggested modeling method is verified by comparing experimental and analytical frequency response function. The loss mechanisms associated with the combined effects of magnetic unbalance and hysteretic damping in the superconducting flywheel system have been modeled under the assumption that dynamic characteristics of the bearing can be approximated by a linear, elastic anisotropic spring with complex stiffness. Theoretical energy loss model effected by unbalance is derived from generalized rotational model including gyroscopic effect and generalized response. The validity of suggested energy loss model is confirmed by comparing experimental deceleration curve. (author). 12 refs., 28 figs., 10 tabs.

  13. 1999 Review of superconducting dipole and quadrupole magnets for particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Devred, A. [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee (DAPNIA), 91 - Gif-sur-Yvette (France); CERN, Conseil Europeen pour la recherche nucleaire, Laboratoire europeen pour la physique des particules Geneve (Switzerland)

    1999-12-01

    The quest for elementary particles has promoted the development of particle accelerators producing beams of increasingly higher energies. In a synchrotron-type accelerator, the particle energy is directly proportional to the product of the machine's radius times the bending magnets' field strength. Present proton experiments at the TeV scale require facilities with circumferences ranging from a few to tens of kilometers and relying on a large number (several hundreds to several thousands) of high field dipole magnets and high field gradient quadrupole magnets. These electro-magnets use high current density, low critical temperature superconducting cables and are cooled down at liquid helium temperature. They are among the most costly and the most challenging components of the machine. After explaining what are the various types of accelerator magnets and why they are needed (section 1), we present a brief history of large superconducting particle accelerators, and we detail ongoing superconducting accelerator magnet R and D programs around the world (Section 2). Then, we review the superconducting materials that are available at industrial scale (chiefly, NbTi and Nb3Sn), and we describe the manufacturing of NbTi wires and cables (section 3). We also present the difficulties of processing and insulating Nb3Sn conductors which, so far, have limited the use of this material in spite of its superior performances. We continue by presenting the complex formalism used to represent two-dimensional fields (section 4), and we discuss the two-dimensional current distributions that are the most appropriate for generating pure dipole and pure quadrupole fields (section 5). We explain how these ideal distributions can be approximated by so-called cos{theta} and cos{sup 2}{theta} coil designs and we describe the difficulties of realizing coil ends. Next, we present the mechanical design concepts that have been developed to restrain magnet coils and to ensure proper

  14. Modular transportable superconducting magnetic Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lieurance, D.; Kimball, F.; Rix, C. [Martin Marietta Space Magnetics, San Diego, CA (United States)

    1994-12-31

    Design and cost studies were performed for the magnet components of mid-size (1-5 MWh), cold supported SMES systems using alternative configurations. The configurations studied included solenoid magnets, which required onsite assembly of the magnet system, and toroid and racetrack configurations which consisted of factory assembled modules. For each configuration, design concepts and cost information were developed for the major features of the magnet system including the conductor, electrical insulation, and structure. These studies showed that for mid-size systems, the costs of solenoid and toroid magnet configurations are comparable and that the specific configuration to be used for a given application should be based upon customer requirements such as limiting stray fields or minimizing risks in development or construction.

  15. Beam Transport in Toroidal Magnetic Field

    CERN Document Server

    Joshi, N; Meusel, O; Ratzinger, U

    2016-01-01

    The concept of a storage ring with toroidal magnetic field was presented in the two previous EPAC conferences. Here we report the first results of experiments performed with beam transport in toroidal magnetic fields and details of the injection system. The beam transport experiments were carried out with 30 degree toroidal segments with an axial magnetic field of 0.6T. The multi turn injection system relies on a transverse injection coil together with an electric kicker system.

  16. Estimating effects from trapped magnetic fluxes in superconducting magnetic levitation measurement

    Institute of Scientific and Technical Information of China (English)

    Masakazu Nakanishi

    2008-01-01

    Superconducting magnetic levitation measurement is one of the most promising approaches to define mass standard based on the fundamental physical constants. However, the present system has unknown factors causing error larger than 50 ppm. We examined the effects of magnetic fluxes trapped in the superconducting coil and the superconducting floating body. When fluxes were trapped in either coil or floating body, their effects were able to be cancelled by reversing polarities of current and magnetic field, as had been believed. However, fluxes trapped in both coil and body induced an attractive force between them and caused error. In order to reduce the fluxes, the coil and the floating body should be cooled in low magnetic field in magnetic and electromagnetic shields.

  17. Magnetic phenomena in holographic superconductivity with Lifshitz scaling

    Directory of Open Access Journals (Sweden)

    Aldo Dector

    2015-09-01

    Full Text Available We investigate the effects of Lifshitz dynamical critical exponent z on a family of minimal D=4+1 holographic superconducting models, with a particular focus on magnetic phenomena. We see that it is possible to have a consistent Ginzburg–Landau approach to holographic superconductivity in a Lifshitz background. By following this phenomenological approach we are able to compute a wide array of physical quantities. We also calculate the Ginzburg–Landau parameter for different condensates, and conclude that in systems with higher dynamical critical exponent, vortex formation is more strongly unfavored energetically and exhibits a stronger Type I behavior. Finally, following the perturbative approach proposed by Maeda, Natsuume and Okamura, we calculate the critical magnetic field of our models for different values of z.

  18. Power deposition in superconducting magnets of the momentum cleaning insertion

    CERN Document Server

    CERN. Geneva; Baishev, I S; Jeanneret, J B; Kourotchkine, I A

    2002-01-01

    This note describes the calculation of power deposition in the superconducting magnets Q6, Q7 and MB8 downstream of the momentum collimators in IR3. To reduce a relatively high power deposition density of 1.8mW/cm^3 in the coils of Q6, we propose to install some fixed shielding collimators upstream of the warm dogleg dipoles D4.

  19. Zinc contamination from brass upon heat treating a superconducting magnet

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D.W.; Hassenzahl, W.V.

    1994-07-01

    Theoretical calculations predicted that zinc outgassing from brass spacers during a planned heat treatment would likely damage a lab-scale superconducting magnet. This specter was reinforced by a simulated heat treatment, the samples of which were analyzed by gravimetry, metallography, and microprobe chemical analysis. It was found that zinc escaping from the brass could diffuse 80 {mu}m into copper electrical conductors and degrade their conductivity. To avoid this, steel was temporarily substituted for the brass during the heat treatment process.

  20. Beam loss reduction by magnetic shielding using beam pipes and bellows of soft magnetic materials

    Science.gov (United States)

    Kamiya, J.; Ogiwara, N.; Hotchi, H.; Hayashi, N.; Kinsho, M.

    2014-11-01

    One of the main sources of beam loss in high power accelerators is unwanted stray magnetic fields from magnets near the beam line, which can distort the beam orbit. The most effective way to shield such magnetic fields is to perfectly surround the beam region without any gaps with a soft magnetic high permeability material. This leads to the manufacture of vacuum chambers (beam pipes and bellows) with soft magnetic materials. A Ni-Fe alloy (permalloy) was selected for the material of the pipe parts and outer bellows parts, while a ferritic stainless steel was selected for the flanges. An austenitic stainless steel, which is non-magnetic material, was used for the inner bellows for vacuum tightness. To achieve good magnetic shielding and vacuum performances, a heat treatment under high vacuum was applied during the manufacturing process of the vacuum chambers. Using this heat treatment, the ratio of the integrated magnetic flux density along the beam orbit between the inside and outside of the beam pipe and bellows became small enough to suppress beam orbit distortion. The outgassing rate of the materials with this heat treatment was reduced by one order magnitude compared to that without heat treatment. By installing the beam pipes and bellows of soft magnetic materials as part of the Japan Proton Accelerator Research Complex 3 GeV rapid cycling synchrotron beam line, the closed orbit distortion (COD) was reduced by more than 80%. In addition, a 95.5% beam survival ratio was achieved by this COD improvement.

  1. Beam loss reduction by magnetic shielding using beam pipes and bellows of soft magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, J., E-mail: kamiya.junichiro@jaea.go.jp; Ogiwara, N.; Hotchi, H.; Hayashi, N.; Kinsho, M.

    2014-11-01

    One of the main sources of beam loss in high power accelerators is unwanted stray magnetic fields from magnets near the beam line, which can distort the beam orbit. The most effective way to shield such magnetic fields is to perfectly surround the beam region without any gaps with a soft magnetic high permeability material. This leads to the manufacture of vacuum chambers (beam pipes and bellows) with soft magnetic materials. A Ni–Fe alloy (permalloy) was selected for the material of the pipe parts and outer bellows parts, while a ferritic stainless steel was selected for the flanges. An austenitic stainless steel, which is non-magnetic material, was used for the inner bellows for vacuum tightness. To achieve good magnetic shielding and vacuum performances, a heat treatment under high vacuum was applied during the manufacturing process of the vacuum chambers. Using this heat treatment, the ratio of the integrated magnetic flux density along the beam orbit between the inside and outside of the beam pipe and bellows became small enough to suppress beam orbit distortion. The outgassing rate of the materials with this heat treatment was reduced by one order magnitude compared to that without heat treatment. By installing the beam pipes and bellows of soft magnetic materials as part of the Japan Proton Accelerator Research Complex 3 GeV rapid cycling synchrotron beam line, the closed orbit distortion (COD) was reduced by more than 80%. In addition, a 95.5% beam survival ratio was achieved by this COD improvement.

  2. Molecular beam epitaxy and superconductivity of stoichiometric FeSe and KxFe2-ySe2 crystalline films

    Institute of Scientific and Technical Information of China (English)

    Wang Li-Li; Ma Xu-Cun; Chen Xi; Xue Qi-Kun

    2013-01-01

    Our recent progress in the fabrication of FeSe and KxFe2-ySe2 ultra thin films and the understanding of their superconductivity properties is reviewed.The growth of high-quality FeSe and KxFe2-ySe2 films is achieved in a well controlled manner by molecular beam epitaxy.The high-quality stoichiometric and superconducting crystalline thin films allow us to investigate the intrinsic superconductivity properties and the interplay between the superconductivity and the film thickness,the local structure,the substrate,and magnetism.In situ low-temperature scanning tunneling spectra reveal the nodes and the twofold symmetry in FeSe,high-temperature superconductivity at the FeSe/SrTiO3 interface,phase separation and magnetic order in KxFe2-ySe2,and the suppression of superconductivity by twin boundaries and Fe vacancies.Our findings not only provide fundamental information for understanding the mechanism of unconventional superconductivity,but also demonstrate a powerful way of engineering superconductors and raising the transition temperature.

  3. Numerical calculation of transient field effects in quenching superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Schwerg, Juljan Nikolai

    2010-07-01

    The maximum obtainable magnetic induction of accelerator magnets, relying on normal conducting cables and iron poles, is limited to around 2 T because of ohmic losses and iron saturation. Using superconducting cables, and employing permeable materials merely to reduce the fringe field, this limit can be exceeded and fields of more than 10 T can be obtained. A quench denotes the sudden transition from the superconducting to the normal conducting state. The drastic increase in electrical resistivity causes ohmic heating. The dissipated heat yields a temperature rise in the coil and causes the quench to propagate. The resulting high voltages and excessive temperatures can result in an irreversible damage of the magnet - to the extend of a cable melt-down. The quench behavior of a magnet depends on numerous factors, e.g. the magnet design, the applied magnet protection measures, the external electrical network, electrical and thermal material properties, and induced eddy current losses. The analysis and optimization of the quench behavior is an integral part of the construction of any superconducting magnet. The dissertation is divided in three complementary parts, i.e. the thesis, the detailed treatment and the appendix. In the thesis the quench process in superconducting accelerator magnets is studied. At first, we give an overview over features of accelerator magnets and physical phenomena occurring during a quench. For all relevant effects numerical models are introduced and adapted. The different models are weakly coupled in the quench algorithm and solved by means of an adaptive time-stepping method. This allows to resolve the variation of material properties as well as time constants. The quench model is validated by means of measurement data from magnets of the Large Hadron Collider. In a second step, we show results of protection studies for future accelerator magnets. The thesis ends with a summary of the results and a critical outlook on aspects which could

  4. Flywheel energy storage using superconducting magnetic bearings

    Science.gov (United States)

    Abboud, R. G.; Uherka, K.; Hull, J.; Mulcahy, T.

    Storage of electrical energy on a utility scale is currently not practicable for most utilities, preventing the full utilization of existing base-load capacity. A potential solution to this problem is Flywheel Energy Storage (FES), made possible by technological developments in high-temperature superconducting materials. Commonwealth Research Corporation (CRC), the research arm of Commonwealth Edison Company, and Argonne National Laboratory are implementing a demonstration project to advance the state of the art in high temperature superconductor (HTS) bearing performance and the overall demonstration of efficient Flywheel Energy Storage. Currently, electricity must be used simultaneously with its generation as electrical energy storage is not available for most utilities. Existing storage methods either are dependent on special geography, are too expensive, or are too inefficient. Without energy storage, electric utilities, such as Commonwealth Edison Company, are forced to cycle base load power plants to meet load swings in hourly customer demand. Demand can change by as much as 30% over a 12-hour period and result in significant costs to utilities as power plant output is adjusted to meet these changes. HTS FES systems can reduce demand-based power plant cycling by storing unused nighttime capacity until it is needed to meet daytime demand.

  5. Test equipment for a flywheel energy storage system using a magnetic bearing composed of superconducting coils and superconducting bulks

    Science.gov (United States)

    Ogata, M.; Matsue, H.; Yamashita, T.; Hasegawa, H.; Nagashima, K.; Maeda, T.; Matsuoka, T.; Mukoyama, S.; Shimizu, H.; Horiuchi, S.

    2016-05-01

    Energy storage systems are necessary for renewable energy sources such as solar power in order to stabilize their output power, which fluctuates widely depending on the weather. Since ‘flywheel energy storage systems’ (FWSSs) do not use chemical reactions, they do not deteriorate due to charge or discharge. This is an advantage of FWSSs in applications for renewable energy plants. A conventional FWSS has capacity limitation because of the mechanical bearings used to support the flywheel. Therefore, we have designed a superconducting magnetic bearing composed of a superconducting coil stator and a superconducting bulk rotor in order to solve this problem, and have experimentally manufactured a large scale FWSS with a capacity of 100 kWh and an output power of 300 kW. The superconducting magnetic bearing can levitate 4 tons and enables the flywheel to rotate smoothly. A performance confirmation test will be started soon. An overview of the superconducting FWSS is presented in this paper.

  6. Design of the superconducting magnet for 9.4 Tesla whole-body magnetic resonance imaging

    Science.gov (United States)

    Li, Y.; Wang, Q.; Dai, Y.; Ni, Z.; Zhu, X.; Li, L.; Zhao, B.; Chen, S.

    2017-02-01

    A superconducting magnet for 9.4 Tesla whole-body magnetic resonance imaging is designed and fabricated in Institute of Electrical Engineering, Chinese Academy of Sciences. In this paper, the electromagnetic design methods of the main coils and compensating coils are presented. Sensitivity analysis is performed for all superconducting coils. The design of the superconducting shimming coils is also presented and the design of electromagnetic decoupling of the Z2 coils from the main coils is introduced. Stress and strain analysis with both averaged and detailed models is performed with finite element method. A quench simulation code with anisotropic continuum model and control volume method is developed by us and is verified by experimental study. By means of the quench simulation code, the quench protection system for the 9.4 T magnet is designed for the main coils, the compensating coils and the shimming coils. The magnet cryostat design with zero helium boiling-off technology is also introduced.

  7. Genetic Algorithms for the Optimal Design of Superconducting Accelerator Magnets

    CERN Document Server

    Ramberger, S

    1998-01-01

    The paper describes the use of genetic algorithms with the concept of niching for the optimal design of superconducting magnets for the Large Hadron Collider, LHC at CERN. The method provides the designer with a number of local optima which can be further examined with respect to objectives such as ease of coil winding, sensitivity to manufacturing tolerances and local electromagnetic force distribution. A 6 block dipole coil was found to have advantages compared to the standard 5 block version which was previously designed using deterministic optimization methods. Results were proven by a short model magnet recently built and tested at CERN.

  8. Advanced measurement systems based on digital processing techniques for superconducting LHC magnets

    CERN Document Server

    Masi, Alessandro; Cennamo, Felice

    The Large Hadron Collider (LHC), a particle accelerator aimed at exploring deeper into matter than ever before, is currently being constructed at CERN. Beam optics of the LHC, requires stringent control of the field quality of about 8400 superconducting magnets, including 1232 main dipoles and 360 main quadrupoles to assure the correct machine operation. The measurement challenges are various: accuracy on the field strength measurement up to 50 ppm, harmonics in the ppm range, measurement equipment robustness, low measurement times to characterize fast field phenomena. New magnetic measurement systems, principally based on analog solutions, have been developed at CERN to achieve these goals. This work proposes the introduction of digital technologies to improve measurement performance of three systems, aimed at different measurement target and characterized by different accuracy levels. The high accuracy measurement systems, based on rotating coils, exhibit high performance in static magnetic field. With vary...

  9. Precision transport of LHC superconducting magnet

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    These photos show tests of the first convoy with a prototype short straight section (SSS) quadrupole in the LHC tunnel. There is little free space in the tunnel as the SSS convoy passes alongside a dipole vacuum vessel. These convoys feature infrared guidance, which offsets the minimal clearance in the tunnel and limits vibration, both of which could damage the fragile magnets.

  10. Ultra-high-field superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Hoard, R.W.; Cornish, D.N.; Scanlan, R.M.; Zbasnik, J.P.; Leber, R.L.; Hickman, R.B.; Lee, J.D.

    1983-08-01

    The following topics are considered: (1) superfluid helium for advanced magnets, (2) conductor reinforcement, (3) designing a 20-T, 2-m bore solenoidal coil, (4) coil size and conductor properties, (5) axial forces on the coil, (6) effect of radiation on the coil systems, and (7) helium-II transient heat transfer and coil protection. (MOW)

  11. Precise Thermometry for Next Generation LHC Superconducting Magnet Prototypes

    CERN Document Server

    Datskov, V; Bottura, L; Perez, J C; Borgnolutti, F; Jenninger, B; Ryan, P

    2013-01-01

    The next generation of LHC superconducting magnets is very challenging and must operate in harsh conditions: high radiation doses in a range between 10 and 50 MGy, high voltage environment of 1 to 5 kV during the quench, dynamic high magnetic field up to 12 T, dynamic temperature range 1.8 K to 300 K in 0.6 sec. For magnet performance and long term reliability it is important to study dynamic thermal effects, such as the heat flux through the magnet structure, or measuring hot spot in conductors during a magnet quench with high sampling rates above 200 Hz. Available on the market cryogenic temperature sensors comparison is given. An analytical model for special electrically insulating thermal anchor (Kapton pad) with high voltage insulation is described. A set of instrumentation is proposed for fast monitoring of thermal processes during normal operation, quenches and failure situations. This paper presents the technology applicable for mounting temperature sensors on high voltage superconducting (SC) cables....

  12. A superconducting magnet mandrel with minimum symmetry laminations for proton therapy

    Science.gov (United States)

    Caspi, S.; Arbelaez, D.; Brouwer, L.; Dietderich, D. R.; Felice, H.; Hafalia, R.; Prestemon, S.; Robin, D.; Sun, C.; Wan, W.

    2013-08-01

    The size and weight of ion-beam cancer therapy gantries are frequently determined by a large aperture, curved, ninety degree, dipole magnet. The higher fields achievable with superconducting technology promise to greatly reduce the size and weight of this magnet and therefore also the gantry as a whole. This paper reports advances in the design of winding mandrels for curved, canted cosine-theta (CCT) magnets in the context of a preliminary magnet design for a proton gantry. The winding mandrel is integral to the CCT design and significantly affects the construction cost, stress management, winding feasibility, eddy current power losses, and field quality of the magnet. A laminated mandrel design using a minimum symmetry in the winding path is introduced and its feasibility demonstrated by a rapid prototype model. Piecewise construction of the mandrel using this laminated approach allows for increased manufacturing techniques and material choices. Sectioning the mandrel also reduces eddy currents produced during field changes accommodating the scan of beam energies during treatment. This symmetry concept can also greatly reduce the computational resources needed for 3D finite element calculations. It is shown that the small region of symmetry forming the laminations combined with periodic boundary conditions can model the entire magnet geometry disregarding the ends.

  13. Tunnel-diode resonator and nuclear magnetic resonance studies of low-dimensional magnetic and superconducting systems

    Energy Technology Data Exchange (ETDEWEB)

    Yeninas, Steven Lee [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    This thesis emphasizes two frequency-domain techniques which uniquely employ radio frequency (RF) excitations to investigate the static and dynamic properties of novel magnetic and superconducting materials.

  14. MEASUREMENT OF THE TRANSVERSE BEAM DYNAMICS IN A TESLA-TYPE SUPERCONDUCTING CAVITY

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [NICADD, DeKalb; Eddy, N. [Fermilab; Edstrom, D. [Fermilab; Lunin, A. [Fermilab; Piot, P. [NICADD, DeKalb; Ruan, J. [Fermilab; Solyak, N. [Fermilab

    2016-09-26

    Superconducting linacs are capable of producing intense, ultra-stable, high-quality electron beams that have widespread applications in Science and Industry. Many project are based on the 1.3-GHz TESLA-type superconducting cavity. In this paper we provide an update on a recent experiment aimed at measuring the transfer matrix of a TESLA cavity at the Fermilab Accelerator Science and Technology (FAST) facility. The results are discussed and compared with analytical and numerical simulations.

  15. Phase boundary of the hexagonal-prism superconducting network in a magnetic field

    Institute of Scientific and Technical Information of China (English)

    金绍维; 李伟; 易佑民; 甄胜来; 缪胜清

    2002-01-01

    In this paper, we systematically study the phase boundary Tc(H ) of a hexagonal-prism superconducting network inan external magnetic field H of arbitrary magnitude and direction. The result indicates that the phase boundary of thehexagonal-prism superconducting circuit varies more sharply than that of the cubic circuit. The potential applicationsof the hexagonal-prism superconducting circuit are also discussed.

  16. Magnetic trapping of superconducting submicron particles produced by laser ablation in superfluid helium

    Science.gov (United States)

    Takahashi, Yuta; Suzuki, Junpei; Yoneyama, Naoya; Tokawa, Yurina; Suzuki, Nobuaki; Matsushima, Fusakazu; Kumakura, Mitsutaka; Ashida, Masaaki; Moriwaki, Yoshiki

    2017-02-01

    We produced spherical superconducting submicron particles by laser ablation of their base metal tips in superfluid helium, and trapped them using a quadrupole magnetic field owing to the diamagnetism caused by the Meissner effect. We also measured their critical temperatures of superconductivity, by observing the threshold temperatures for the confinement of superconducting submicron particles in the trap.

  17. The helium cryogenic plant for the CMS superconducting magnet

    CERN Document Server

    Perinic, G; Dagut, F; Dauguet, P; Hirel, P

    2002-01-01

    A new helium refrigeration plant with a cooling capacity of 800 W at 4.45 K, 4500 W between 60 K and 80 K, and 4 g/s liquefaction simultaneously has been designed and is presently being constructed by Air Liquide for CERN. The refrigeration plant will provide the cooling power for the cool down and the operation of the CMS (Compact Muon Solenoid) superconducting coil whose cold mass weighs 225 t. The refrigeration plant will at first be installed in a surface building for the tests of the superconducting magnet. On completion of the tests the cold box will be moved to its final underground position next to the CMS experimental cavern. This paper presents the process design, describes the main components and explains their selection. (4 refs).

  18. Magnetic design of a 14 mm period prototype superconducting undulator

    Science.gov (United States)

    Gehlot, Mona; Mishra, G.; Trillaud, Frederic; Sharma, Geetanjali

    2017-02-01

    In this paper we report the design of a 14 mm period prototype superconducting undulator that is under fabrication at Insertion Device Development Laboratory (IDDL) at Devi Ahilya Vishwavidyalaya, Indore, India. The field computations are made in RADIA and results are presented in an analytical form for computation of the on axis field and the field on the surface of the coil. On the basis of the findings, a best fit is presented for the model to calculate the field dependence on the gap and the current density. The fit is compared with Moser-Rossmanith formula proposed earlier to predict the magnetic flux density of a superconducting undulator. The field mapping is used to calculate the field integrals and its dependence on gap and current densities as well.

  19. Pareto optimal design of sectored toroidal superconducting magnet for SMES

    Science.gov (United States)

    Bhunia, Uttam; Saha, Subimal; Chakrabarti, Alok

    2014-10-01

    A novel multi-objective optimization design approach for sectored toroidal superconducting magnetic energy storage coil has been developed considering the practical engineering constraints. The objectives include the minimization of necessary superconductor length and torus overall size or volume, which determines a significant part of cost towards realization of SMES. The best trade-off between the necessary conductor length for winding and magnet overall size is achieved in the Pareto-optimal solutions, the compact magnet size leads to increase in required superconducting cable length or vice versa The final choice among Pareto optimal configurations can be done in relation to other issues such as AC loss during transient operation, stray magnetic field at outside the coil assembly, and available discharge period, which is not considered in the optimization process. The proposed design approach is adapted for a 4.5 MJ/1 MW SMES system using low temperature niobium-titanium based Rutherford type cable. Furthermore, the validity of the representative Pareto solutions is confirmed by finite-element analysis (FEA) with a reasonably acceptable accuracy.

  20. Fundamental study of cesium decontamination from soil by superconducting magnet

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, Susumu, E-mail: igarashi@qb.see.eng.osaka-u.ac.jp; Mishima, Fumihito; Akiyama, Yoko, E-mail: yoko-ak@see.eng.osaka-u.ac.jp; Nishijima, Shigehiro

    2013-11-15

    Highlights: •The method for the soil decontamination by the superconducting magnet is proposed. •Cesium ion can be absorbed by Prussian blue in potassium iodide wash fluid. •It is possible to recover Cs{sup +} ion-adsorbing Prussian blue with a high rate by HGMS. •It is expected that HGMS can be applied to the actual soil decontamination. -- Abstract: The radioactive substances have been spread out all over the surrounding area of Fukushima Daiichi Nuclear Power Plant caused by the accident in March 2011. Decontamination and volume reduction of radioactive substances, especially cesium ion, are desired issue. This study proposed a decontamination method of the soil by the magnetic separation using superconducting magnet. Cesium ion was adsorbed by Prussian blue in the potassium iodide solution. We succeeded in separating selectively the cesium ion-adsorbed Prussian blue out of the liquid phase by high gradient magnetic separation. High recovery ratio of the Prussian blue was achieved by this method.

  1. Superconductivity

    CERN Document Server

    Poole, Charles P; Farach, Horacio A

    1995-01-01

    Superconductivity covers the nature of the phenomenon of superconductivity. The book discusses the fundamental principles of superconductivity; the essential features of the superconducting state-the phenomena of zero resistance and perfect diamagnetism; and the properties of the various classes of superconductors, including the organics, the buckministerfullerenes, and the precursors to the cuprates. The text also describes superconductivity from the viewpoint of thermodynamics and provides expressions for the free energy; the Ginzburg-Landau and BCS theories; and the structures of the high

  2. New power-conditioning systems for superconducting magnetic energy storage

    Science.gov (United States)

    Han, Byung Moon

    1992-06-01

    This dissertation presents the development of new power-conditioning systems for superconducting magnetic energy storage (SMES), which can regulate fast and independently the active and reactive powers demanded in the ac network. Three new power-conditioning systems were developed through a systematic approach to match the requirements of the superconducting coil and the ac power network. Each of these new systems is composed of ten 100-MW modules connected in parallel to handle the large current through the superconducting coil. The first system, which was published in the IEEE Transactions on Energy Conversion, consists of line-commutated 24-pulse converter, a thyristor-switched tap-changing transformer, and a thyristor-switched capacitor bank. The second system, which was accepted for publication in the IEEE Transactions on Energy Conversion, consists of a 12-pulse GTO (gate turn-off thyristor) converter and a thyristor-switched tap-changing transformer. The third system, which was submitted to the International Journal of Energy System, consists of a dc chopper and a voltage-source PWM (pulse width modulation) converter. The operational concept of each new system is verified through mathematical analyses and computer simulations. The dynamic interaction of each new system with the ac network and the superconducting coil is analyzed using a simulation model with EMTP (electro-magnetic transients program). The analysis results prove that each new system is feasible and realizable. Each system can regulate the active and reactive powers of the utility network rapidly and independently, and each offer a significant reduction of the system rating by reducing the reactive power demand in the converter. Feasible design for each new system was introduced using a modular design approach based on the 1000 MW/5000 MWH plant, incorporating commercially available components and proven technologies.

  3. Recent developments in superconducting materials including ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Tachikawa, Kyoji

    1987-06-01

    This report describes the history of superconduction starting in 1911, when the superconducting phenomenon was first observed in murcury, until the recent discovery of superconducting materials with high critical temperatures. After outlining the BCS theory, basic characteristics are discussed including the critical temperature, magnetic field and current density to be reached for realizing the superconducting state. Various techniques for practical superconducting materials are discussed, including methods for producing extra fine multiconductor wires from such superconducting alloys as Nb-Ti, intermetallic Nb/sub 3/Sn compound and V/sub 3/Ga, as well as methods for producing wires of Nb/sub 3/Al, Nb/sub 3/(Al, Ge) and Nb/sub 3/Ge such as continuous melt quenching, electron beam irradiation, laser beam irradiation and chemical evaporation. Characteristics of superconducting ceramics are described, along with their applications including superconducting magnets and superconducting elements. (15 figs, 1 tab, 19 refs)

  4. Influence of higher order modes on the beam stability in the high power superconducting proton linac

    CERN Document Server

    Schuh, M; Gerigk, F; Tuckmantel, J

    2011-01-01

    Higher order modes (HOMs) can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor, and complex pulse structure. The full HOM spectrum has to be analyzed in order to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam simulation code simulation of higher order mode dynamics (SMD) focused on beam-HOM interaction was developed, taking into account important effects like the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. Here, SMD is used to investigate the influence of HOMs in detail in the superconducting proton linac at CERN and their potential to drive beam instabilities in the longitudinal and transverse plane.

  5. Influence of higher order modes on the beam stability in the high power superconducting proton linac

    Directory of Open Access Journals (Sweden)

    Marcel Schuh

    2011-05-01

    Full Text Available Higher order modes (HOMs can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor, and complex pulse structure. The full HOM spectrum has to be analyzed in order to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam simulation code simulation of higher order mode dynamics (SMD focused on beam-HOM interaction was developed, taking into account important effects like the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. Here, SMD is used to investigate the influence of HOMs in detail in the superconducting proton linac at CERN and their potential to drive beam instabilities in the longitudinal and transverse plane.

  6. Magnetized and Flat Beam Experiment at FAST

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [Fermilab; Hyun, J. [Sokendai, Tsukuba; Mihalcea, D. [NIU, DeKalb; Piot, P. [NICADD, DeKalb; Sen, T. [Fermilab; Thangaraj, C. [Fermilab

    2017-05-22

    A photocathode, immersed in solenoidal magnetic field, can produce canonical-angular-momentum (CAM) dominated or “magnetized” electron beams. Such beams have an application in electron cooling of hadron beams and can also be uncoupled to yield asymmetric-emittance (“flat”) beams. In the present paper we explore the possibilities of the flat beam generation at Fermilab’s Accelerator Science and Technology (FAST) facility. We present optimization of the beam flatness and four-dimensional transverse emittance and investigate the mapping and its limitations of the produced eigen-emittances to conventional emittances using a skew-quadrupole channel. Possible application of flat beams at the FAST facility are also discussed.

  7. Focused electron beam induced deposition of magnetic nanostructures

    Science.gov (United States)

    de Teresa, Jose M.

    2011-03-01

    Nanopatterning strategies of magnetic materials normally rely on standard techniques such as electron-beam lithography using electron-sensitive resists. Focused electron beam induced deposition (FEBID) is currently being investigated as an alternative single-step route to produce functional magnetic nanostructures. Thus, Co-based and Fe-based precursors have been recently investigated for the growth of magnetic nanostructures by FEBID. In the present contribution, I will give an overview of the existing literature on magnetic nanostructures by FEBID and I will focus on the growth of Co nanostructures by FEBID using Co 2 (CO)8 as precursor gas. The Co content in the nanostructures can reach 95%. Magnetotransport experiments indicate that full metallic behaviour is displayed with relatively low residual resistivity and standard anisotropic magnetoresistance (0.8%). The coercive field of nanowires with changing aspect ratio has been determined in nanowires with width down to 150 nm by means of Magneto-optical Kerr Effect and the magnetization reversal has been imaged by means of Magnetic Force Microscopy, Scanning Transmission X-ray Microscopy as well as Lorentz Microscopy experiments. Nano-Hall probes have been grown with remarkable minimum detectable magnetic flux. Noticeably, it has been found that the domain-wall propagation field is lower than the domain-wall nucleation field in L-shaped nanowires, with potential applications in magnetic logic, sensing and storage. The spin polarization of these Co nanodeposits has been determined through Andreev-Reflection experiments in ferromagnetic-superconducting nanocontacts and amounts to 35%. Recent results obtained in Fe-based nanostructures by FEBID using Fe 2 (CO)9 precursor will be also presented. I acknowledge the collaboration in this field with A. Fernandez-Pacheco, R. Cordoba, L. Serrano, S. Sangiao, L.A. Rodriguez, C. Magen, E. Snoeck, L. Morellon, M.R. Ibarra.

  8. Effects of α-particle beam irradiation on superconducting properties of thin film MgB2 superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Bum; Duong, Pham van; Ha, Dong Hyup; Oh, Young Hoon; Kang, Won Nam; Chai, Jong Seo [Sungkunkwan Univeversity, Suwon (Korea, Republic of); Hong, Seung Pyo; Kim, Ran Young [Kore Institute of Radiological and Medical Science, Seoul (Korea, Republic of)

    2016-06-15

    Superconducting properties of thin film MgB2 superconductors irradiated with 45 MeV α-particle beam were studied. After the irradiation, enhancement of the critical current density and pinning force was observed, scaling close to strong pinning formula. Double logarithmic plots of the maximum pinning force density with irreversible magnetic field show a power law behavior close to carbon-doped MgB2 film or polycrystals. Variation of normalized pinning force density in the reduced magnetic field suggests scaling formulas for strong pinning mechanism like planar defects. We also observed a rapid decay of critical current density as the vortex lattice constant decreases, due to the strong interaction between vortices and increasing magnetic field.

  9. Local magnetization fluctuations in superconducting glasses resolved by Hall sensors

    Science.gov (United States)

    Lefebvre, J.; Hilke, M.; Altounian, Z.; West, K. W.; Pfeiffer, L. N.

    2009-05-01

    We report on magnetization measurements performed on a series of FexNi1-xZr2 superconducting metallic glasses with 0≤x≤0.5 using the Hall effect of a nearby two-dimensional electron gas (2DEG) in a GaAs/Al0.33Ga0.67As heterostructure as a local probe. The great sensitivity of the Hall effect of the 2DEG in such heterostructure is exploited to determine the magnetization of the superconductor due to the Meissner effect and flux trapping. The data are used to determine the lower critical-field Bc1 of the superconductors as a function of temperature. Surprisingly large fluctuations in the magnetization are also observed and attributed to the presence of large flux clusters in the superconductor.

  10. The superconducting magnet system for the Wendelstein7-X stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Sapper, J. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, D-17489 Greifswald (Germany)

    2000-05-01

    The superconducting magnet system for the new stellarator Wendelstein7-X, to be located at Greifswald, Germany, consists of 50 non-planar and 20 planar large magnet coils. The conductor used is a cable-in-conduit type, composed of copper stabilized NbTi strands and enveloped by an aluminium alloy jacket (CICC). The individual winding packs are built up from six (three) double layers, glass insulated and resin impregnated. A cast steel casing encapsulates each winding pack to achieve sufficient mechanical stiffness. The toroidal set-up of the coil system weighs 400 tons and has a diameter of 11 metres. Operation will be at 6 T and a coil current of 1.75 MA. Cooling is provided by supercritical helium. A fast de-energizing system protects the magnet from overheating in the case of a quench. (author)

  11. A novel rotating experimental platform in a superconducting magnet

    Science.gov (United States)

    Chen, Da; Cao, Hui-Ling; Ye, Ya-Jing; Dong, Chen; Liu, Yong-Ming; Shang, Peng; Yin, Da-Chuan

    2016-08-01

    This paper introduces a novel platform designed to be used in a strong static magnetic field (in a superconducting magnet). The platform is a sample holder that rotates in the strong magnetic field. Any samples placed in the platform will rotate due to the rotation of the sample holder. With this platform, a number of experiments such as material processing, culture of biological systems, chemical reactions, or other processes can be carried out. In this report, we present some preliminary experiments (protein crystallization, cell culture, and seed germination) conducted using this platform. The experimental results showed that the platform can affect the processes, indicating that it provides a novel environment that has not been investigated before and that the effects of such an environment on many different physical, chemical, or biological processes can be potentially useful for applications in many fields.

  12. Low-noise nano superconducting quantum interference device operating in Tesla magnetic fields.

    Science.gov (United States)

    Schwarz, Tobias; Nagel, Joachim; Wölbing, Roman; Kemmler, Matthias; Kleiner, Reinhold; Koelle, Dieter

    2013-01-22

    Superconductivity in the cuprate YBa(2)Cu(3)O(7) (YBCO) persists up to huge magnetic fields (B) up to several tens of Teslas, and sensitive direct current (dc) superconducting quantum interference devices (SQUIDs) can be realized in epitaxially grown YBCO films by using grain boundary Josephson junctions (GBJs). Here we present the realization of high-quality YBCO nanoSQUIDs, patterned by focused ion beam milling. We demonstrate low-noise performance of such a SQUID up to B = 1 T applied parallel to the plane of the SQUID loop at the temperature T = 4.2 K. The GBJs are shunted by a thin Au layer to provide nonhysteretic current voltage characteristics, and the SQUID incorporates a 90 nm wide constriction which is used for on-chip modulation of the magnetic flux through the SQUID loop. The white flux noise of the device increases only slightly from 1.3 μΦ(0)/(Hz)(1/2) at B = 0 to 2.3 μΦ(0)/(Hz))(1/2) at 1 T. Assuming that a point-like magnetic particle with magnetization in the plane of the SQUID loop is placed directly on top of the constriction and taking into account the geometry of the SQUID, we calculate a spin sensitivity S(μ)(1/2) = 62 μ(B)/(Hz))(1/2) at B = 0 and 110 μ(B)/(Hz))(1/2) at 1 T. The demonstration of low noise of such a SQUID in Tesla fields is a decisive step toward utilizing the full potential of ultrasensitive nanoSQUIDs for direct measurements of magnetic hysteresis curves of magnetic nanoparticles and molecular magnets.

  13. Cryogenic Characteristics of the ATLAS Barrel Toroid Superconducting Magnet

    CERN Document Server

    Pengo, R; Delruelle, N; Pezzetti, M; Pirotte, O; Passardi, Giorgio; Dudarev, A; ten Kate, H

    2008-01-01

    ATLAS, one of the experiments of the LHC accelerator under commissioning at CERN, is equipped with a large superconducting magnet the Barrel Toroid (BT) that has been tested at nominal current (20500 A). The BT is composed of eight race-track superconducting coils (each one weights about 45 tons) forming the biggest air core toroidal magnet ever built. By means of a large throughput centrifugal pump, a forced flow (about 10 liter/second at 4.5 K) provides the indirect cooling of the coils in parallel. The paper describes the results of the measurements carried out on the complete cryogenic system assembled in the ATLAS cavern situated 100 m below the ground level. The measurements include, among other ones, the static heat loads, i.e., with no or constant current in the magnet, and the dynamic ones, since additional heat losses are produced, during the current ramp-up or slow dump, by eddy currents induced on the coil casing.

  14. Superconducting Magnetic Energy Storage:. Conventional and Trapped Field

    Science.gov (United States)

    Rabinowitz, Mario

    Superconducting magnetic energy storage (SMES) is a most efficient system for energy storage because it stores energy directly in electrical form. The SMES concept is described and analyzed with an examination of its economic viability. The impact of high-temperature supeconductivity on SMES is explored, and a trapped energy storage (TES) innovation that may have beneficial technical and economic ramifications is introduced. In addition to presenting a broad overview, this paper may be of help to those making an evaluation of the potential impact of SMES/TES on the development of new energy sources, and to determine for which energy sources it is most appropriate.

  15. Applied superconductivity

    CERN Document Server

    Newhouse, Vernon L

    1975-01-01

    Applied Superconductivity, Volume II, is part of a two-volume series on applied superconductivity. The first volume dealt with electronic applications and radiation detection, and contains a chapter on liquid helium refrigeration. The present volume discusses magnets, electromechanical applications, accelerators, and microwave and rf devices. The book opens with a chapter on high-field superconducting magnets, covering applications and magnet design. Subsequent chapters discuss superconductive machinery such as superconductive bearings and motors; rf superconducting devices; and future prospec

  16. Production of a highly charged uranium ion beam with RIKEN superconducting electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Higurashi, Y.; Ohnishi, J.; Nakagawa, T.; Haba, H.; Fujimaki, M.; Komiyama, M.; Kamigaito, O. [RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Tamura, M.; Aihara, T.; Uchiyama, A. [SHI Accelerator Service Ltd., 1-17-6 Osaki, Shinagawa, Tokyo 141-0032 (Japan)

    2012-02-15

    A highly charged uranium (U) ion beam is produced from the RIKEN superconducting electron cyclotron resonance ion source using 18 and 28 GHz microwaves. The sputtering method is used to produce this U ion beam. The beam intensity is strongly dependent on the rod position and sputtering voltage. We observe that the emittance of U{sup 35+} for 28 GHz microwaves is almost the same as that for 18 GHz microwaves. It seems that the beam intensity of U ions produced using 28 GHz microwaves is higher than that produced using 18 GHz microwaves at the same Radio Frequency (RF) power.

  17. Magnetism and Superconductivity in Iron-based Superconductors as Probed by Nuclear Magnetic Resonance

    CERN Document Server

    Hammerath, Franziska

    2012-01-01

    Nuclear Magnetic Resonance (NMR) has been a fundamental player in the studies of superconducting materials for many decades. This local probe technique allows for the study of the static electronic properties as well as of the low energy excitations of the electrons in the normal and the superconducting state. On that account it has also been widely applied to Fe-based superconductors from the very beginning of their discovery in February 2008. This dissertation comprises some of these very first NMR results, reflecting the unconventional nature of superconductivity and its strong link to magnetism in the investigated compounds LaO1–xFxFeAs and LiFeAs.

  18. Simulation of ion beam losses in LHC magnets

    CERN Document Server

    AUTHOR|(CDS)2068843; Jowett, John M; Riklund, R

    2005-01-01

    At the particle physics laboratory CERN, the largest accelerator ever, the Large Hadron Collider (LHC), is under construction. In the LHC ultra relativistic particles, mainly protons but also lead ions, will be brought into collision. One problem that arises in the operation is that colliding ion beams in the machine have a very large cross section for electromagnetic interactions, in particular Bound Free Pair Production (BFPP). An electron-positron pair is created by the electromagnetic field between two colliding particles and the electron is created in a bound state of one of the ions. Because of this reaction the ion changes its charge and therefore leaves the wanted trajectory and crashes in a superconducting magnet, depositing heat. The impact of the wrongly charged ions on the inside of the vacuum pipe was simulated with the simulation program FLUKA. It was concluded that it is not likely that enough heat is deposited in the coils of the superconducting magnet to induce a quench, although some uncerta...

  19. Surface field in an ensemble of superconducting spheres under external magnetic field

    CERN Document Server

    Peñaranda, A; Ramírez-Piscina, L

    1999-01-01

    We perform calculations of the magnetic field on the surface of an ensemble of superconducting spheres when placed into an external magnetic field, which is the configuration employed in superheated superconducting granule detectors. The Laplace equation is numerically solved with appropriate boundary conditions by means of an iterative procedure and a multipole expansion.

  20. Beating liquid helium: the technologies of cryogen-free superconducting magnets

    Science.gov (United States)

    Burgoyne, John

    2015-03-01

    Cryogen-free superconducting magnets have been available now for almost 15 years, but have only become standard commercial products in more recent years. In this review we will consider the pros and cons of ``dry'' design including superconducting wire development and selection, thermal budgeting, and the alternative methods for achieving magnet cooling.

  1. Flow Cooling of Superconducting Magnets for Spacecraft Applications

    Science.gov (United States)

    Dietz, A. J.; Audette, W. E.; Barton, M. D.; Hilderbrand, J. K.; Marshall, W. S.; Rey, C. M.; Winter, D. S.; Petro, A. J.

    2008-03-01

    The development and testing of a flow cooling system for high-temperature superconducting (HTS) magnets is described. The system includes a turbo-Brayton cryocooler, a magnet thermal interface, and a magnet thermal isolation and support system. The target application is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). Turbo-Brayton coolers are well suited to such spacecraft applications, as they are compact, modular, lightweight, and efficient, with long maintenance-free lifetimes. Furthermore, the technology scales well to high-cooling capacities. The feasibility of using turbo-Brayton coolers in this application was proven in a design exercise in which existing cooler designs were scaled to provide cooling for the magnet sets required by 200 kW and 1 MW VASIMR engines. The performance of the concepts for the thermal interface and the thermal isolation and support system were measured in separate laboratory tests with a demonstration system built about a representative HTS magnet. Cooling for these tests was provided by a flow cooling loop comprising a compressor, recuperator and GM cryocooler, with the flow pressure, temperature, and mass flow rate selected to effectively simulate the turbo-Brayton operating condition. During system testing, the magnet was cooled below its design operating temperature of 35 K, and good thermal uniformity (<0.4 K) and low thermal loads (<0.5 W) were demonstrated.

  2. PREFACE: International Conference on Superconductivity and Magnetism-ICSM2008

    Science.gov (United States)

    Gencer, Ali; Grasso, Gianni

    2009-03-01

    The International Conference on Superconductivity and Magnetism (ICSM2008) was held at the congress centre of Ankara University in Side, Antalya, between 25-29 August 2008. The conference was the first conference on the combined fields of superconductivity and magnetism organized in Turkey at international level, and it had broad international participation from 42 countries, with registered delegates numbering over 400. A quarter of the attendees were research students. The conference attracted many of the best known leading scientists and experts in the field of superconductivity and magnetism from all over the world. The scientific program involved the presentation and discussion of 336 papers, classified as 65 invited, 81 oral and 190 posters. Submission of papers for the proceedings was on a volunteer basis and we therefore had nearly half of the presented papers, i.e. 30 submitted invited papers, peer-reviewed by Superconductor Science and Technology, and 85 submitted contributing papers, peer-reviewed by the organizers through processes administered by the Editorial Board and Scientific Committee. Reviews were conducted by expert referees at professional level and with the scientific standards expected of a proceedings journal issue published by IOP Publishing. The invited papers on superconductivity and magnetism with superconductivity were considered and processed for Superconductor Science and Technology by IOP itself. Although there are missing papers from some of the plenary speakers, we believe that this special issue of Superconductor Science and Technology (SUST) and the corresponding issue of Journal of Physics: Conference Series (JPCS) reflect most of the booming research in the fields of superconductivity and magnetism. We are very pleased to have worked with IOP on the conference proceedings, with special thanks to Dr Tom Miller and Dr Graham Douglas. Based on a refereed evaluation of all the papers and posters submitted, about 93 papers were

  3. Design of a Superconducting Magnet System for the AEGIS Experiment at CERN

    CERN Document Server

    Dudarev, A; ten Kate, H; Perini, D

    2011-01-01

    The new AEGIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) Experiment will be installed in the Antiproton Decelerator hall at CERN. The main goal is to measure the Earth's gravitational acceleration of antihydrogen atoms. The experiment consists of two high-homogeneity solenoids placed on the same axis. The 5 T magnet is part of a cylindrical Penning trap to catch and to accumulate antiprotons delivered by the decelerator. The antihydrogen is then produced in the 1 T region where sub-kelvin antiproton temperatures provided by the dilution refrigerator are required to form a slowly-moving beam of antihydrogen. The helium bath cooled superconducting magnets; the different traps and the dilution refrigerator are integrated in a common cryostat with an internal vacuum barrier between the insulating cryogenic vacuum and the very high beam vacuum. In addition, the magnet system has to guarantee a smooth transition between the 5 T and the 1 T magnetic field areas required for a loss-free transfer o...

  4. Tunability of the superconductivity of tungsten films grown by focused-ion-beam direct writing

    Science.gov (United States)

    Li, Wuxia; Fenton, J. C.; Wang, Yiqian; McComb, D. W.; Warburton, P. A.

    2008-11-01

    We have grown tungsten-containing films by focused-ion-beam (FIB)-induced chemical vapor deposition. The films lie close to the metal-insulator transition with an electrical conductivity which changes by less than 5% between room temperature and 7 K. The superconducting transition temperature Tc of the films can be controlled between 5.0 and 6.2 K by varying the ion-beam deposition current. The Tc can be correlated with how far the films are from the metal-insulator transition, showing a nonmonotonic dependence, which is well described by the heuristic model of [Osofsky et al., Phys. Rev. Lett. 87, 197004 (2001)]. Our results suggest that FIB direct-writing of W composites might be a potential approach to fabricate mask-free superconducting devices as well as to explore the role of reduced dimensionality on superconductivity.

  5. Superconducting linac beam dynamics with high-order maps for RF resonators

    CERN Document Server

    Geraci, A A; Pardo, R C; 10.1016/j.nima.2003.11.177

    2004-01-01

    The arbitrary-order map beam optics code COSY Infinity has recently been adapted to calculate accurate high-order ion-optical maps for electrostatic and radio-frequency accelerating structures. The beam dynamics of the superconducting low-velocity positive-ion injector linac for the ATLAS accelerator at Argonne National Lab is used to demonstrate some advantages of the new simulation capability. The injector linac involves four different types of superconducting accelerating structures and has a total of 18 resonators. The detailed geometry for each of the accelerating cavities is included, allowing an accurate representation of the on- and off-axis electric fields. The fields are obtained within the code from a Poisson-solver for cylindrically symmetric electrodes of arbitrary geometry. The transverse focusing is done with superconducting solenoids. A detailed comparison of the transverse and longitudinal phase space is made with the conventional ray-tracing code LINRAY. The two codes are evaluated for ease ...

  6. A helium based pulsating heat pipe for superconducting magnets

    Science.gov (United States)

    Fonseca, Luis Diego; Miller, Franklin; Pfotenhauer, John

    2014-01-01

    This study was inspired to investigate an alternative cooling system using a helium-based pulsating heat pipes (PHP), for low temperature superconducting magnets. In addition, the same approach can be used for exploring other low temperature applications. The advantages of PHP for transferring heat and smoothing temperature profiles in various room temperature applications have been explored for the past 20 years. An experimental apparatus has been designed, fabricated and operated and is primarily composed of an evaporator and a condenser; in which both are thermally connected by a closed loop capillary tubing. The main goal is to measure the heat transfer properties of this device using helium as the working fluid. The evaporator end of the PHP is comprised of a copper winding in which heat loads up to 10 watts are generated, while the condenser is isothermal and can reach 4.2 K via a two stage Sumitomo RDK408A2 GM cryocooler. Various experimental design features are highlighted. Additionally, performance results in the form of heat transfer and temperature characteristics are provided as a function of average condenser temperature, PHP fill ratio, and evaporator heat load. Results are summarized in the form of a dimensionless correlation and compared to room temperature systems. Implications for superconducting magnet stability are highlighted.

  7. Quench Simulation of Superconducting Magnets with Commercial Multiphysics Software

    CERN Document Server

    AUTHOR|(SzGeCERN)751171; Auchmann, Bernhard; Jarkko, Niiranen; Maciejewski, Michal

    The simulation of quenches in superconducting magnets is a multiphysics problem of highest complexity. Operated at 1.9 K above absolute zero, the material properties of superconductors and superfluid helium vary by several orders of magnitude over a range of only 10 K. The heat transfer from metal to helium goes through different transfer and boiling regimes as a function of temperature, heat flux, and transferred energy. Electrical, magnetic, thermal, and fluid dynamic effects are intimately coupled, yet live on vastly different time and spatial scales. While the physical models may be the same in all cases, it is an open debate whether the user should opt for commercial multiphysics software like ANSYS or COMSOL, write customized models based on general purpose network solvers like SPICE, or implement the physics models and numerical solvers entirely in custom software like the QP3, THEA, and ROXIE codes currently in use at the European Organisation for Nuclear Research (CERN). Each approach has its strengt...

  8. The contrasting magnetic fields of superconducting pulsars and magnetars

    CERN Document Server

    Lander, S K

    2013-01-01

    We study equilibrium magnetic field configurations in a neutron star whose core has type-II superconducting protons. Unlike normal matter, whose equations do not involve any special field strength, those for superconductors contain the lower critical field, of order 10^{15} G. We find that the ratio between this critical field and the smooth-averaged stellar magnetic field at the crust-core boundary is the key feature dictating the field geometry. Our results suggest that pulsar and magnetar-strength fields have notably different configurations. Field decay for neutron stars with B_{pole}\\sim 10^{14} G could thus result in substantial internal rearrangements, with the toroidal field component being pushed out of the core; this may be related to observed magnetar activity.

  9. An ion-optical design study of a carbon-ion rotating gantry with a superconducting final bending magnet

    Energy Technology Data Exchange (ETDEWEB)

    Bokor, J., E-mail: jozef.bokor@stuba.sk; Pavlovič, M.

    2016-03-11

    Ion-optical designs of an isocentric ion gantry with a compact curved superconducting final bending magnet are presented. The gantry is designed for transporting carbon-therapy beams with nominal kinetic energy of 400 MeV/u, which corresponds to the penetration range of C{sup 6+} beam in water of about 28 cm. In contrast to other existing designs, we present a “hybrid” beam transport system containing a single superconducting element – the last bending magnet. All other elements are based on conventional warm technology. Ion-optical properties of such a hybrid system are investigated in case of transporting non-symmetric (i.e. different emittance patterns in the horizontal and vertical plane) beams. Different conditions for transporting the non-symmetric beams are analyzed aiming at finding the optimal, i.e. the most compact, gantry version. The final gantry layout is presented including a 2D parallel scanning. The ion-optical and scanning properties of the final gantry design are described, discussed and illustrated by computer simulations performed by WinAGILE.

  10. An ion-optical design study of a carbon-ion rotating gantry with a superconducting final bending magnet

    Science.gov (United States)

    Bokor, J.; Pavlovič, M.

    2016-03-01

    Ion-optical designs of an isocentric ion gantry with a compact curved superconducting final bending magnet are presented. The gantry is designed for transporting carbon-therapy beams with nominal kinetic energy of 400 MeV/u, which corresponds to the penetration range of C6+ beam in water of about 28 cm. In contrast to other existing designs, we present a ;hybrid; beam transport system containing a single superconducting element - the last bending magnet. All other elements are based on conventional warm technology. Ion-optical properties of such a hybrid system are investigated in case of transporting non-symmetric (i.e. different emittance patterns in the horizontal and vertical plane) beams. Different conditions for transporting the non-symmetric beams are analyzed aiming at finding the optimal, i.e. the most compact, gantry version. The final gantry layout is presented including a 2D parallel scanning. The ion-optical and scanning properties of the final gantry design are described, discussed and illustrated by computer simulations performed by WinAGILE.

  11. Magnetism and superconductivity of some Tl-Cu oxides

    Science.gov (United States)

    Datta, Timir

    1991-01-01

    Many copper oxide based Thallium compounds are now known. In comparison to the Bi-compounds, the Tl-system shows a richer diversity; i.e., High Temperature Superconductors (HTSC) can be obtained with either one or two Tl-0 layers (m = 1,2); also, the triple-digit phases are easier to synthesize. The value of d, oxygen stoichiometry, is critical to achieving superconductivity. The Tl system is robust to oxygen loss; Tl may be lost or incorporated by diffusion. A diffusion coefficient equal to 10 ms at 900 C was determined. Both ortho-rhombic and tetragonal structures are found, but HTSC behavior is indifferent to the crystal symmetry. This system has the highest T(sub c) confirmed. T(sub c) generally increases with p, the number of CuO layers, but tends to saturate at p = 3. Zero resistance was observed at temperatures as great as 125 K. Most of these HTSC's are hole type, but the Ce-doped specimens may be electronic. The magnetic aspects were studied; because in addition to defining the perfectly diamagnetic ground state as in conventional superconductors, magnetism of the copper oxides show a surprising variety. This is true of both the normal and the superconducting states. Also, due to the large phonon contribution to the specific heat at the high T(sub c) jump, electronic density of states, D(Ef), and coherence length are uncertain, and thus, are estimated from the magnetic results. Results from the Tl-system CuO, LaBaCuO,120 and the Bi-CuO compounds are discussed. The emphasis is on the role of magnetism in the Tl-CuO HTSC, but technological aspects are also pointed out.

  12. High temperature superconducting axial field magnetic coupler: realization and test

    Science.gov (United States)

    Belguerras, L.; Mezani, S.; Lubin, T.; Lévêque, J.; Rezzoug, A.

    2015-09-01

    Contactless torque transmission through a large airgap is required in some industrial applications in which hermetic isolation is necessary. This torque transmission usually uses magnetic couplers, whose dimension strongly depends on the airgap flux density. The use of high temperature superconducting (HTS) coils to create a strong magnetic field may constitute a solution to reduce the size of the coupler. It is also possible to use this coupler to replace a torque tube in transmitting the torque produced by a HTS motor to its load. This paper presents the detailed construction and tests of an axial field HTS magnetic coupler. Pancake coils have been manufactured from BSCCO tape and used in one rotor of the coupler. The second rotor is mainly composed of NdFeB permanent magnets. Several tests have been carried out showing that the constructed coupler is working properly. A 3D finite element (FE) model of the studied coupler has been developed. Airgap magnetic field and torque measurements have been carried out and compared to the FE results. It has been shown that the measured and the computed quantities are in satisfactory agreement.

  13. First Cryogenic Testing of the ATLAS Superconducting Prototype Magnets

    CERN Document Server

    Delruelle, N; Haug, F; Mayri, C; Orlic, J P; Passardi, Giorgio; Pirotte, O; ten Kate, H H J

    2002-01-01

    The superconducting magnet system of the ATLAS detector will consist of a central solenoid, two end-cap toroids and the barrel toroid made of eight coils (BT) symmetrically placed around the central axis of the detector. All these magnets will be individually tested in an experimental area prior to their final installation in the underground cavern of the LHC collider. A dedicated cryogenic test facility has been designed and built for this purpose. It mainly consists of a 1'200 W at 4.5 K refrigerator, a 10 kW liquid nitrogen pre-cooling unit, a cryostat housing liquid helium centrifugal pumps, a distribution valve box and transfer lines. Prior to the start of the series tests of the BT magnets, two model coils are used at this facility. The first one, the so-called B00 of comparatively small size, contains the three different types of superconductors used for the ATLAS magnets which are wound on a cylindrical mandrel. The second magnet, the B0, is a reduced model of basically identical design concept as the...

  14. Superconductivity-like phenomena in an ferrimagnetic endohedral fullerene with diluted magnetic surface

    Science.gov (United States)

    Kantar, Ersin

    2017-09-01

    The hysteretic properties of a Ising-type endohedral fullerene (EF) with a doped magnetic spin-1/2 particle confined within a spherical cage (by diluted magnetic spin-1 particles) are investigated by using the effective-field theory with correlations. The extrinsic and intrinsic parameters dependencies of the magnetic hysteresis curves and superconductivity-like phenomena in the Ising-type EF system have investigated. We have reported that doped magnetic core atom is chiefly responsible of the occurrence of the superconductivity-like phenomena in the system. Moreover, three superconductivity series have been presented by the temperature, surface composition and crystal field.

  15. Electromagnetic characteristics of a superconducting magnet for the 28 GHz ECR ion source according to the series resistance of the protection circuit

    Science.gov (United States)

    Lee, Hongseok; Mo, Young Kyu; Kang, Jong O.; Bang, Seungmin; Kim, Junil; Lee, Onyou; Kang, Hyoungku; Hong, Jonggi; Choi, Sukjin; Hong, In Seok; Nam, Seokho; Ahn, Min Chul

    2015-10-01

    A linear accelerator, called RAON, is being developed as a part of the Rare Isotope Science Project (RISP) at the Institute for Basic Science (IBS). The linear accelerator utilizes an electron cyclotron resonance (ECR) ion source for providing intense highly-charged ion beams to the linear accelerator. The 28-GHz ECR ion source can extract heavy-ion beams from protons to uranium. The superconducting magnet system for the 28-GHz ECR ion source is composed of hexapole coils and four solenoid coils made with low-Tc superconducting wires of NbTi. An electromagnetic force acts on the superconducting magnets due to the magnetic field and flowing current in the case of not only the normal state but also the quench state. In the case of quench on hexapole coils, an unbalanced flowing current among the hexapole coils is generated and causes an unbalanced electromagnetic force. Coil motions and coil strains in the quench state are larger than those in the normal state due to the unbalanced electromagnetic force among hexapole coils. Therefore, an analysis of the electromagnetic characteristics of the superconducting magnet for the 28-GHz ECR ion source on series resistance of the protection circuit in the case of quench should be conducted. In this paper, an analysis of electromagnetic characteristics of Superconducting hexapole coils for the 28-GHz ECR ion source according to the series resistance of the protection circuit in the case of quench performed by using finite-elements-method (FEM) simulations is reported.

  16. Suite of three protein crystallography beamlines with single superconducting bend magnet as the source

    Energy Technology Data Exchange (ETDEWEB)

    MacDowell, Alastair A.; Celestre, Richard S.; Howells, Malcolm; McKinney, Wayne; Krupnick, James; Cambie, Daniella; Domning, Edward E; Duarte, Robert M.; Kelez, Nicholas; Plate, David W.; Cork, Carl W.; Earnest, Thomas N.; Dickert, Jeffery; Meigs, George; Ralston, Corie; Holton, James M.; Alber, Thomas; Berger, James M.; Agard, David A.; Padmore, Howard A.

    2004-08-01

    At the Advanced Light Source (ALS), three protein crystallography (PX) beamlines have been built that use as a source one of the three 6 Tesla single pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single pole superconducting bend magnets enables the development of a hard x-ray program on a relatively low energy 1.9 GeV ring without taking up insertion device straight sections. The source is of relatively low power, but due to the small electron beam emittance, it has high brightness. X-ray optics are required to preserve the brightness and to match the illumination requirements for protein crystallography. This was achieved by means of a collimating premirror bent to a plane parabola, a double crystal monochromator followed by a toroidal mirror that focuses in the horizontal direction with a 2:1 demagnification. This optical arrangement partially balances aberrations from the collimating and toroidal mirrors such that a tight focused spot size is achieved. The optical properties of the beamline are an excellent match to those required by the small protein crystals that are typically measured. The design and performance of these new beamlines are described.

  17. Design and Fabrication Study on the TESLA500 Superconducting Magnet Package

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Tabares, L.; Toral, F.; Calero, J.; Abramian, P.; Iturbe, R.; Etxeandia, J.; Lucia, C.; Landete, R.; Gomez, J.

    2001-07-01

    An international collaboration at DESY is currently studying the possibilities of a new type of particle accelerator: the superconducting linear collider (1). Developed under the project name TESLA, which stands for TeV Energy Superconducting Linear Accelerator, the facility would be placed in a 33 km long tunnel and would work at the energy range of 0.5 to 0.8 TeV. TESLA opens up new horizons not only as a particle accelerator because it can be also used to generate laser-type X-ray beams: the accelerated electrons would be guided through a refined system of magnetic fields to form a Free Electron Laser (FEL). This study is about one of the components of the accelerator: the magnet package. A technical design of this device and a cost estimate of the series production have been performed. The present report should be understood as a Spanish contribution to the TESLA project. The study has been lead by CIEMAT (Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas) [2], and several Spanish companies have also been involved: ANTEC, JEMA and INGOVI. Special thanks are given to the Oficina de Ciencia y Tecnologia, which has granted this work. (Author) 16 refs.

  18. Pressure-induced electronic phase separation of magnetism and superconductivity in CrAs.

    Science.gov (United States)

    Khasanov, Rustem; Guguchia, Zurab; Eremin, Ilya; Luetkens, Hubertus; Amato, Alex; Biswas, Pabitra K; Rüegg, Christian; Susner, Michael A; Sefat, Athena S; Zhigadlo, Nikolai D; Morenzoni, Elvezio

    2015-09-08

    The recent discovery of pressure (p) induced superconductivity in the binary helimagnet CrAs has raised questions on how superconductivity emerges from the magnetic state and on the mechanism of the superconducting pairing. In the present work the suppression of magnetism and the occurrence of superconductivity in CrAs were studied by means of muon spin rotation. The magnetism remains bulk up to p ≃ 3.5 kbar while its volume fraction gradually decreases with increasing pressure until it vanishes at p ≃ 7 kbar. At 3.5 kbar superconductivity abruptly appears with its maximum Tc ≃ 1.2 K which decreases upon increasing the pressure. In the intermediate pressure region (3.5 superconducting and the magnetic volume fractions are spatially phase separated and compete for phase volume. Our results indicate that the less conductive magnetic phase provides additional carriers (doping) to the superconducting parts of the CrAs sample thus leading to an increase of the transition temperature (Tc) and of the superfluid density (ρs). A scaling of ρs with Tc(3.2) as well as the phase separation between magnetism and superconductivity point to a conventional mechanism of the Cooper-pairing in CrAs.

  19. Superconducting magnetic bearings for machine tools. Phase 1, SBIR program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Anastas, G.; Bennett, A.; Downer, J.; Hockney, R.

    1988-01-01

    The research was directed toward investigating the role of superconducting materials in a magnetic bearing system. Superconducting magnetic bearings are shown to offer the potential for vastly improved performance. These bearings are expected to be especially applicable to rotors which have extremely tight position tolerances. The development of superconducting magnetic bearing technology is also expected to allow a number of novel approaches in the development of machinery and systems. Researchers studied an alternative bearing design which employs a superconducting coil and eliminates all conventional magnetic structures. The study has resulted in a design definition and detailed analysis for a superconducting bearing system which is sized to roughly duplicate the air bearing system of an existing air-bearing spindle.

  20. Beam simulations with initial bunch noise in superconducting RF proton linacs

    CERN Document Server

    Tückmantel, J

    2010-01-01

    Circular machines are plagued by coupled bunch instabilities (CBI), driven by impedance peaks, where then all cavity higher order modes (HOMs) are possible drivers. Limiting the CBI growth rate is the fundamental reason that all superconducting rf cavities in circular machines are equipped with HOM dampers. The question arises if for similar reasons HOM damping would not be imperative also in high current superconducting rf proton linacs. Therefore we have simulated the longitudinal bunched beam dynamics in such machines, also including charge and position noise on the injected bunches. Simulations were executed for a generic linac with properties close to the planned SPL at CERN, SNS, or Project X at FNAL. It was found that with strong bunch noise and monopole HOMs with high Qext large beam scatter, possibly exceeding the admittance of a receiving machine, cannot be excluded. A transverse simulation shows similar requirements. Therefore including initial bunch noise in any beam dynamic study on superconducti...

  1. OPERATIONAL EXPERIENCE WITH FAST FIBER-OPTIC BEAM LOSS MONITORS FOR THE ADVANCED PHOTON SOURCE STORAGE RING SUPERCONDUCTING UNDULATORS

    Energy Technology Data Exchange (ETDEWEB)

    Dooling, J.; Harkay, K.; Sajaev, V.; Shang, H.

    2017-06-25

    Fast fiber-optic (FFO) beam loss monitors (BLMs) installed with the first two superconducting undulators (SCUs) in the Advanced Photon Source storage ring have proven to be a useful diagnostic for measuring deposited charge (energy) during rapid beam loss events. The first set of FFOBLMs were installed outside the cryostat of the short SCU, a 0.33-m long device, above and below the beam centerline. The second set are mounted with the first 1.1-mlong SCU within the cryostat, on the outboard and inboard sides of the vacuum chamber. The next 1.1-m-long SCU is scheduled to replace the short SCU later in 2016 and will be fitted with FFOBLMs in a manner similar to original 1.1-m device. The FFOBLMs were employed to set timing and voltage for the abort kicker (AK) system. The AK helps to prevent quenching of the SCUs during beam dumps [1] by directing the beam away from the SC magnet windings. The AK is triggered by the Machine Protection System (MPS). In cases when the AK fails to prevent quenching, the FFOBLMs show that losses often begin before detection by the MPS.

  2. Magnetic phase diagrams based on static and dynamic magnetic behaviour in Ru-based superconducting ferromagnets.

    Science.gov (United States)

    Nigam, R; Pan, A V; Dou, S X

    2011-11-02

    In this work, we present magnetic phase diagrams of a RuSr(2)Eu(1.5)Ce(0.5)Cu(2)O(10-δ) (Ru-1222) superconducting ferromagnet derived from its static and dynamic magnetic responses, measured by temperature and field dependences of dc magnetization and nonlinear ac susceptibility in both low and high magnetic fields. Comparison of magnetic phase diagrams of phase pure and impure samples singles out the intrinsic and extrinsic magnetic features, naturally proposing a unified model of Ru-1222 magnetic behaviour. The results considered within the proposed interpretation indicate full agreement between static and dynamic properties which, if measured in combination, effectively complement each other, uncovering existing ambiguities.

  3. Superconducting Solenoid and Press for Permanent Magnet Fabrication

    Science.gov (United States)

    Mulcahy, T. M.; Hull, J. R.

    2002-08-01

    For the first time, a superconducting solenoid (SCM) was used to increase the remnant magnetization of sintered NdFeB permanent magnets (PMs). In particular, improved magnetic alignment of commercial-grade PM powder was achieved, as it was axial die pressed into 12.7-mm diameter cylindrical compacts in the 76.2-mm warm bore of a 9-T SCM. The press used to compact the powder is unique and was specifically designed for use with the SCM. Although the press was operated in the batch mode for this proof of concept study, its design is intended to enable automated production. In operation, a simple die and punch set made of nonmagnetic materials was filled with powder and loaded into a nonmagnetic press tube. The cantilevered press tube was inserted horizontally, on a carrier manually advanced along a track, into the SCM. The robustness of the mechanical components and the SCM, in its liquid helium dewar, were specifically designed to allow for insertion and extraction of the magnetic powder and compacts, while operating at 9 T.

  4. The Test Facility for the EAST Superconducting Magnets

    Institute of Scientific and Technical Information of China (English)

    Wu Yu; Weng Peide

    2005-01-01

    A large facility for testing superconducting magnets has been in operation at the Institute of Plasma Physics of the Chinese Academy of Sciences since the completion of its construction that began in 1999. A helium refrigerator is used to cool the magnets and liquefy helium which can provide 3.8 K ~ 4.5 K, 1.8 bar ~ 5 bar, 20 g/s ~ 40 g/s supercritical helium for the coils or a 150 L/h liquefying helium capacity. Other major parts include a large vacuum vessel (3.5 m in diameter and 6.1 m in height) with a liquid nitrogen temperature shield, two pairs of current lead,three sets of 14.5 kA~ 50 kA power supply with a fast dump quench protection circuitry, a data acquisition and control system, a vacuum pumping system, and a gas tightness inspecting devise.The primary goal of the test facility is to test the EAST TF and PF magnets in relation to their electromagnetic, stability, thermal, hydraulic, and mechanical performance. The construction of this facility was completed in 2002, followed by a series of systematic coil testing. By now ten TF magnets, a central solenoid model coil, a central solenoid prototype coil, and a model coil of the PF large coil have been successfully tested in the facility.

  5. Analysis of magnetization loops of electrospun nonwoven superconducting fabrics

    Science.gov (United States)

    Zeng, Xian Lin; Karwoth, Thomas; Koblischka, Michael R.; Hartmann, Uwe; Gokhfeld, Denis; Chang, Crosby; Hauet, Thomas

    2017-09-01

    Networks of superconducting Bi2Sr2CaCu2O8 (Bi-2212) nanowires were fabricated by the electrospinning technique. The nanowires have a diameter of the order of 150-200 nm and lengths up to the micrometer range and form a nonwoven, fabric-like network with numerous interconnections enabling a current flow between the nanowires. The porosity of this nanowire network is 0.9928. Therefore, this material represents a novel class of ultraporous high-temperature superconductors. The magnetizations of the nanowire networks [M (T ) and M (H )] were recorded by SQUID magnetometry. The magnetic properties were analyzed using the extended critical state model (ECSM). It is supposed that the averaged diameter of the nanowires rules the magnetic field dependence of the critical current density of the nanowire network. Single nanowires have remarkably high values of the critical current density of 1.04 ×107A /cm2 at 5 K. The macroscopic critical current density less than ˜0.05 A /cm2 at 5 K is fine for this lightweight material. Using ECSM, several important magnetic parameters could be determined including the penetration field Hp, the irreversibility fields Hirr, the upper critical field Hc 2, and the flux pinning forces. Applications for this material class may be found in the direction of sensors, thin shielding layers, or nanoporous bulks.

  6. Commissioning of the Cryogenic System for the ATLAS Superconducting Magnets

    CERN Document Server

    Delruelle, N; Bradshaw, T; Haug, F; ten Kate, H H J; Passardi, Giorgio; Pengo, R; Pezzetti, M; Pirotte, O; Rochford, J

    2006-01-01

    The paper describes the test results of the helium cryoplant for the superconducting magnets of the ATLAS particle detector at CERN. It consists of two refrigerators used in common by all the magnets and of two proximity cryogenic systems (PCS) interfacing respectively the toroids and the central solenoid. Emphasis is given to the commissioning of the refrigerators: the main unit of 6 kW equivalent capacity at 4.5 K and the thermal shield refrigerator providing 20 kW between 40 K and 80 K. The first unit is used for refrigeration at 4.5 K and for the cooling of three sets of 20 kA current leads, while the second one provides, in addition to the 20 kW refrigeration of the thermal shields, 60 kW for the cool-down to 100 K of the 660 ton cold mass of the magnets. The tests, carried out with the equipment in the final underground configuration, are extended to the PCS that includes the large liquid helium centrifugal pumps (each providing 1.2 kg/s) for forced-flow cooling of the magnets and the complex distributi...

  7. The Test Facility for the EAST Superconducting Magnets

    Science.gov (United States)

    Wu, Yu; Weng, Peide

    2005-08-01

    A large facility for testing superconducting magnets has been in operation at the Institute of Plasma Physics of the Chinese Academy of Sciences since the completion of its construction that began in 1999. A helium refrigerator is used to cool the magnets and liquefy helium which can provide 3.8 K-4.5 K, 1.8 bar-5 bar, 20 g/s-40 g/s supercritical helium for the coils or a 150 L/h liquefying helium capacity. Other major parts include a large vacuum vessel (3.5 m in diameter and 6.1 m in height) with a liquid nitrogen temperature shield, two pairs of current lead, three sets of 14.5 kA-50 kA power supply with a fast dump quench protection circuitry, a data acquisition and control system, a vacuum pumping system, and a gas tightness inspecting devise. The primary goal of the test facility is to test the EAST TF and PF magnets in relation to their electromagnetic, stability, thermal, hydraulic, and mechanical performance. The construction of this facility was completed in 2002, followed by a series of systematic coil testing. By now ten TF magnets, a central solenoid model coil, a central solenoid prototype coil, and a model coil of the PF large coil have been successfully tested in the facility.

  8. Superconductivity

    Science.gov (United States)

    1989-07-01

    SUPERCONDUCTIVITY HIGH-POWER APPLICATIONS Electric power generation/transmission Energy storage Acoustic projectors Weapon launchers Catapult Ship propulsion • • • Stabilized...temperature superconductive shields could be substantially enhanced by use of high-Tc materials. 27 28 NRAC SUPERCONDUCTIVITY SHIP PROPULSION APPLICATIONS...motor shown in the photograph. As a next step in the evolution of electric-drive ship propulsion technology, DTRC has proposed to scale up the design

  9. Levitation performance of the magnetized bulk high- Tc superconducting magnet with different trapped fields

    Science.gov (United States)

    Liu, W.; Wang, J. S.; Liao, X. L.; Zheng, S. J.; Ma, G. T.; Zheng, J.; Wang, S. Y.

    2011-03-01

    To a high- Tc superconducting (HTS) maglev system which needs large levitation force density, the magnetized bulk high- Tc superconductor (HTSC) magnet is a good candidate because it can supply additional repulsive or attractive force above a permanent magnet guideway (PMG). Because the induced supercurrent within a magnetized bulk HTSC is the key parameter for the levitation performance, and it is sensitive to the magnetizing process and field, so the magnetized bulk HTSC magnets with different magnetizing processes had various levitation performances, not only the force magnitude, but also its force relaxation characteristics. Furthermore, the distribution and configuration of the induced supercurrent are also important factor to decide the levitation performance, especially the force relaxation characteristics. This article experimentally investigates the influences of different magnetizing processes and trapped fields on the levitation performance of a magnetized bulk HTSC magnet with smaller size than the magnetic inter-pole distance of PMG, and the obtained results are qualitatively analyzed by the Critical State Model. The test results and analyses of this article are useful for the suitable choice and optimal design of magnetized bulk HTSC magnets.

  10. Effect of Anti-dots on the Magnetic Susceptibility in a Superconducting Long Prism

    Science.gov (United States)

    Aguirre, C. A.; Joya, Miryam R.; Barba-Ortega, J.

    2017-02-01

    The magnetic susceptibility of a long mesoscopic superconducting square prism containing one/two (dot) anti-dots is calculated in the framework of the Ginzburg-Landau theoretical model. This magnetic susceptibility shows jumps at each of the vortex transition fields. We studied the influence of the number, size and geometry of the anti-dots on the magnetic susceptibility in a superconducting sample. We found interesting physical behavior when several kinds of materials filled into the anti-dot are considered.

  11. Reinvestigation of superconducting phase diagram of UGe{sub 2} by AC magnetic susceptibility experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ban, S. [Deptartment of Physics, University of Nagoya, Nagoya, 464-8602 (Japan)]. E-mail: f060214d@mbox.nagoya-u.ac.jp; Deguchi, K. [Deptartment of Physics, University of Nagoya, Nagoya, 464-8602 (Japan); Aso, N. [Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581 (Japan); Homma, Y. [Oarai Branch, Inst. for Mater. Research, University of Tohoku, Ibaraki 311-1313 (Japan); Shiokawa, Y. [Oarai Branch, Inst. for Mater. Research, University of Tohoku, Ibaraki 311-1313 (Japan); Sato, N.K. [Deptartment of Physics, University of Nagoya, Nagoya, 464-8602 (Japan)

    2007-03-15

    We report a superconducting phase diagram of the ferromagnetic superconductor UGe{sub 2} investigated by AC magnetic susceptibility measurements. In contrast to previous phase diagrams, we found that the superconducting transition temperature and volume fraction show a 'M-shaped' structure as a function of pressure. From this observation, we suggest that both of two critical points will play a crucial role in the occurrence of superconductivity in UGe{sub 2}.

  12. Superconducting FCL using a combined inducted magnetic field trigger and shunt coil

    Science.gov (United States)

    Tekletsadik, Kasegn D.

    2007-10-16

    A single trigger/shunt coil is utilized for combined induced magnetic field triggering and shunt impedance. The single coil connected in parallel with the high temperature superconducting element, is designed to generate a circulating current in the parallel circuit during normal operation to aid triggering the high temperature superconducting element to quench in the event of a fault. The circulating current is generated by an induced voltage in the coil, when the system current flows through the high temperature superconducting element.

  13. Incommensurate magnetism in non-superconducting PrBa2Cu3O6.92

    DEFF Research Database (Denmark)

    Boothroyd, A.T.; Hill, J.P.; McMorrow, D.F.

    1999-01-01

    We report the discovery of incommensurate magnetic order in non-superconducting single crystals PrBa2Cu3O6.92. Resonant X-ray magnetic scattering at the Pr L-II and L-III edges and high resolution neutron diffraction were used to characterise the magnetic order on the different magnetic sublattices...

  14. A 1 T, 0.33 m bore superconducting magnet operating with cryocoolers at 12 K

    NARCIS (Netherlands)

    Laan, van der M.T.G.; Tax, R.B.; Kate, ten H.H.J.; Klundert, van de L.J.M.

    1992-01-01

    The application of small cryocoolers to cooling a superconducting magnet at 12 K has important advantages, especially for small and medium-size magnets. Simple construction and a helium-free magnet system were obtained. The demonstration magnet developed is a six-coil system with a volume of 75 L an

  15. Protection of Hardware: Powering Systems (Power Converter, Normal Conducting, and Superconducting Magnets)

    CERN Document Server

    Pfeffer, H; Wolff, D

    2016-01-01

    Along with the protection of magnets and power converters, we have added a section on personnel protection because this is our highest priority in the design and operation of power systems. Thus, our topics are the protection of people, power converters, and magnet loads (protected from the powering equipment), including normal conducting magnets and superconducting magnets.

  16. Comparison of Achievable Magnetic Fields with Superconducting and Cryogenic Permanent Magnet Undulators – A Comprehensive Study of Computed and Measured Values

    Energy Technology Data Exchange (ETDEWEB)

    Moog, E. R. [Argonne National Lab. (ANL), Argonne, IL (United States); Dejus, R. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sasaki, S. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-01

    Magnetic modeling was performed to estimate achievable magnetic field strengths of superconducting undulators (SCUs) and to compare them with those of cryogenically cooled permanent magnet undulators (CPMUs). Starting with vacuum (beam stay-clear) gaps of 4.0 and 6.0 mm, realistic allowances for beam chambers (in the SCU case) and beam liners (in the CPMU case) were added. (A 6.0-mm vacuum gap is planned for the upgraded APS). The CPMU magnetic models consider both CPMUs that use NdFeB magnets at ~150 K and PrFeB magnets at 77 K. Parameters of the magnetic models are presented along with fitted coefficients of a Halbach-type expression for the field dependence on the gap-to-period ratio. Field strengths for SCUs are estimated using a scaling law for planar SCUs; an equation for that is given. The SCUs provide higher magnetic fields than the highest-field CPMUs – those using PrFeB at 77 K – for period lengths longer than ~14 mm for NbTi-based SCUs and ~10 mm for Nb3Sn-based SCUs. To show that the model calculations and scaling law results are realistic, they are compared to CPMUs that have been built and NbTi-based SCUs that have been built. Brightness tuning curves of CPMUs (PrFeB) and SCUs (NbTi) for the upgraded APS lattice are also provided for realistic period lengths.

  17. Technical issues of a high-T{sub c} superconducting bulk magnet

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Hiroyuki [Railway Technical Research Institute, 2-8-38 Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan). E-mail: fujimoto at rtri.or.jp

    2000-06-01

    Superconducting magnets made of high-T{sub c} superconductors are promising for industrial applications. It is well known that REBa{sub 2}Cu{sub 3}O{sub 7-}x superconductors prepared by melt processes have a high critical current density, J{sub c}, at 77 K and hig{sub h} magnetic fields. The materials are very promising for high magnetic field applications as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. Light rare-earth (LRE) BaCuO bulks, compared with REBaCuO bulks, exhibit a larger J{sub c} in high magnetic fields and a much improved irreversibility field, H{sub irr}, at 77 K. In this study, we discuss technical issues of a high-T{sub c} superconducting bulk magnet, namely the aspects of the melt processing for bulk superconductors, their characteristic superconducting properties and mechanical properties, and trapped field properties of a superconducting bulk magnet. One of the possible applications is a superconducting bulk magnet for the magnetically levitated (Maglev) train in the future. (author)

  18. Compensation of the magnetization current induced sextupole error at LHC injection field by short lumped permanent sextupole magnets, incorporated into the end configuration of superconducting dipoles

    CERN Document Server

    Asner, A

    1985-01-01

    Compensation of the magnetization current induced sextupole error at LHC injection field by short lumped permanent sextupole magnets, incorporated into the end configuration of superconducting dipoles

  19. Epoxy resin developments for large superconducting magnets impregnation

    Science.gov (United States)

    Rey, J. M.; Gallet, B.; Kircher, F.; Lottin, J. C.

    The future detectors ATLAS and CMS of the Large Hadron Collider at CERN will use two huge superconducting magnets. Both are now under design, and their electrical insulation could be realized using epoxy resin and a wet impregnation technique. Because of their large dimensions, and the indirect cooling of the superconductor, the strengths of the resin and of the resin/conductor interface are of major importance. A new generation of epoxy resins for vacuum/pressure impregnation methods has been tested, and compared with some classical and well-known epoxy resins used in impregnation techniques. In order to understand the mechanical behaviour at 4 K, the complete evolution from liquid state to low temperature service condition is considered. The paper will present some results on the mechanical properties, the density and the chemical shrinkage occurring during the polymerization and the thermal contraction between room temperature and 4 K for these different types of epoxy resins.

  20. Using fiberglass volumes for VPI of superconductive magnetic systems’ insulation

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, I. S.; Bezrukov, A. A.; Pischugin, A. B. [Sredne-Nevskiy Shipyard (SNSZ), 10 Zavodskaya str., c. Pontonniy, Saint-Petersburg (Russian Federation); Bursikov, A. S.; Klimchenko, Y. A.; Marushin, E. L.; Mednikov, A. A.; Rodin, I. Y.; Stepanov, D. B. [The D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), 3 Doroga na Metallostroy, Metallostroy, Saint-Petersburg (Russian Federation)

    2014-01-29

    The paper describes the method of manufacturing fiberglass molds for vacuum pressure impregnation (VPI) of high-voltage insulation of superconductive magnetic systems (SMS) with epoxidian hot-setting compounds. The basic advantages of using such vacuum volumes are improved quality of insulation impregnation in complex-shaped areas, and considerable cost-saving of preparing VPI of large-sized components due to dispensing with the stage of fabricating a metal impregnating volume. Such fiberglass vacuum molds were used for VPI of high-voltage insulation samples of an ITER reactor’s PF1 poloidal coil. Electric insulation of these samples has successfully undergone a wide range of high-voltage and mechanical tests at room and cryogenic temperatures. Some results of the tests are also given in this paper.

  1. Local imaging of magnetic flux in superconducting thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shapoval, Tetyana

    2010-01-26

    Local studies of magnetic flux line (vortex) distribution in superconducting thin films and their pinning by natural and artificial defects have been performed using low-temperature magnetic force microscopy (LT-MFM). Taken a 100 nm thin NbN film as an example, the depinning of vortices from natural defects under the influence of the force that the MFM tip exerts on the individual vortex was visualized and the local pinning force was estimated. The good agreement of these results with global transport measurements demonstrates that MFM is a powerful and reliable method to probe the local variation of the pinning landscape. Furthermore, it was demonstrated that the presence of an ordered array of 1-{mu}m-sized ferromagnetic permalloy dots being in a magneticvortex state underneath the Nb film significantly influences the natural pinning landscape of the superconductor leading to commensurate pinning effects. This strong pinning exceeds the repulsive interaction between the superconducting vortices and allows vortex clusters to be located at each dot. Additionally, for industrially applicable YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin films the main question discussed was the possibility of a direct correlation between vortices and artificial defects as well as vortex imaging on rough as-prepared thin films. Since the surface roughness (droplets, precipitates) causes a severe problem to the scanning MFM tip, a nanoscale wedge polishing technique that allows to overcome this problem was developed. Mounting the sample under a defined small angle results in a smooth surface and a monotonic thickness reduction of the film along the length of the sample. It provides a continuous insight from the film surface down to the substrate with surface sensitive scanning techniques. (orig.)

  2. Contribution of ion beam analysis methods to the development of second generation high temperature superconducting wires

    Science.gov (United States)

    Usov, I. O.; Arendt, P. N.; Foltyn, S. R.; Stan, L.; DePaula, R. F.; Holesinger, T. G.

    2010-06-01

    One of the crucial steps in the second generation high temperature superconducting wire program was development of the buffer-layer architecture. The architecture designed at the Superconductivity Technology Center at Los Alamos National Laboratory consists of several oxide layers wherein each layer plays a specific role, namely: nucleation layer, diffusion barrier, biaxially textured template, and intermediate layer providing a suitable lattice match to the superconducting Y 1Ba 2Cu 3O 7 (YBCO) compound. This report demonstrates how a wide range of ion beam analysis techniques (SIMS, RBS, channeling, PIXE, PIGE, NRA and ERD) was employed for analysis of each buffer layer and the YBCO film. These results assisted in understanding of a variety of physical processes occurring during the buffer layer fabrication and helped to optimize the buffer-layer architecture as a whole.

  3. Theoretical/Computational Studies of High-Temperature Superconductivity from Quantum Magnetism

    Science.gov (United States)

    2016-06-09

    AFRL-AFOSR-VA-TR-2016-0204 Theoretical/Computational Studies of High-Temperature Superconductivity from Quantum Magnetism Jose Rodriguez CALIFORNIA...TITLE AND SUBTITLE Theoretical/Computational Studies of High-Temperature Superconductivity from Quantum Magnetism 5a.  CONTRACT NUMBER 5b.  GRANT...SUBJECT TERMS quantum magnetism, HTS, superconductivity 16.  SECURITY CLASSIFICATION OF: 17.  LIMITATION OF       ABSTRACT UU 18.  NUMBER        OF

  4. a Thermohydraulic-Quenching Code for Superconducting Magnets in Network Circuits

    Science.gov (United States)

    Feng, Jun; Schultz, Joel; Minervini, Joe

    2010-04-01

    A thermohydraulic-quench code "Solxport3D-Quench" has been developed for a system of superconducting and normal solenoid magnets with supply network circuits. Each power supply network circuit consists of at least one superconducting magnet with parallel circuits including voltage sources, resistors or diodes. When used for analysis of a magnetic confinement fusion device, the plasma currents and passive structure eddy currents are also included in all scenarios. The simulation starts from superconducting stage for each magnet coil. The superconducting stage switches to quench stage if any one of the superconducting magnets quenches (i.e., exceeding the current sharing temperature.) It is followed by the dumping stage after a given quench detection time. The recovery of the superconducting stage is allowed at any time step before dumping. The currents of each magnetic coil are calculated by a time-difference method. The thermohydraulic parameters during superconducting and quench/dumping stage are obtained by a finite element method. The size and location of each finite element are dynamically defined at each time step during quench and dumping. Calibrations against test data are presented.

  5. Exotic Magnetic Orders and Their Interplay with Superconductivity

    DEFF Research Database (Denmark)

    Christensen, Morten Holm

    Superconductivity represents one of the most important scientific discoveries of the 20th century. The practical applications are numerous ranging from clean energy storage and MRI machines to quantum computers. However, the low temperatures required for superconductivity prohibits many practical...

  6. New 50 Hz Superconducting Power Supply for a 2 kA DC Magnet

    NARCIS (Netherlands)

    Chevtchenko, O.A.; ten Kate, Herman H.J.; Krooshoop, Hendrikus J.G.

    1994-01-01

    A new superconducting power supply able to operate directly from the mains voltage at a frequency of 50-60 Hz is under development in our institutes. It will be applied to power a separator magnet for iron ore recycling. The supply consists of a full wave superconducting converter, a `cold'

  7. Superconducting, magnetic, and charge correlations in the doped two-chain Hubbard model

    CERN Document Server

    Asai, Y

    1995-01-01

    Superconducting, magnetic, and charge correlation functions and dynamic spin correlation functions of the doped two-chain Hubbard model is studied with the projector Quantum Monte carlo method and Lanczos recursion method. Of the three correlation functions, the interchain singlet superconducting correlation function is the most long range. Our data is not consistent with the Luther-Emery picture.

  8. Interplay between magnetism and superconductivity in iron-chalcogenide superconductors: crystal growth and characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Wen Jinsheng; Birgeneau, R J [Physics Department, University of California, Berkeley, CA 94720 (United States); Xu Guangyong; Gu Genda; Tranquada, J M, E-mail: jinshengwen@berkeley.edu, E-mail: jtran@bnl.gov [Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2011-12-15

    In this review, we present a summary of results on single crystal growth of two types of iron-chalcogenide superconductors, Fe{sub 1+y}Te{sub 1-x}Se{sub x} (11), and A{sub x}Fe{sub 2-y}Se{sub 2} (A = K, Rb, Cs, Tl, Tl/K, Tl/Rb), using Bridgman, zone-melting, vapor self-transport and flux techniques. The superconducting and magnetic properties (the latter gained mainly from neutron scattering measurements) of these materials are reviewed to demonstrate the connection between magnetism and superconductivity. It will be shown that for the 11 system, while static magnetic order around the reciprocal lattice position (0.5, 0) competes with superconductivity, spin excitations centered around (0.5, 0.5) are closely coupled to the materials' superconductivity; this is made evident by the strong correlation between the spectral weight around (0.5, 0.5) and the superconducting volume fraction. The observation of a spin resonance below the superconducting temperature, T{sub c}, and the magnetic-field dependence of the resonance emphasize the close interplay between spin excitations and superconductivity, similar to cuprate superconductors. In A{sub x}Fe{sub 2-y}Se{sub 2}, superconductivity with T{sub c} {approx} 30 K borders an antiferromagnetic insulating phase; this is closer to the behavior observed in the cuprates but differs from that in other iron-based superconductors.

  9. Interplay between magnetism and superconductivity in iron-chalcogenide superconductors: crystal growth and characterizations

    Science.gov (United States)

    Wen, Jinsheng; Xu, Guangyong; Gu, Genda; Tranquada, J. M.; Birgeneau, R. J.

    2011-12-01

    In this review, we present a summary of results on single crystal growth of two types of iron-chalcogenide superconductors, Fe1+yTe1-xSex (11), and AxFe2-ySe2 (A = K, Rb, Cs, Tl, Tl/K, Tl/Rb), using Bridgman, zone-melting, vapor self-transport and flux techniques. The superconducting and magnetic properties (the latter gained mainly from neutron scattering measurements) of these materials are reviewed to demonstrate the connection between magnetism and superconductivity. It will be shown that for the 11 system, while static magnetic order around the reciprocal lattice position (0.5, 0) competes with superconductivity, spin excitations centered around (0.5, 0.5) are closely coupled to the materials' superconductivity; this is made evident by the strong correlation between the spectral weight around (0.5, 0.5) and the superconducting volume fraction. The observation of a spin resonance below the superconducting temperature, Tc, and the magnetic-field dependence of the resonance emphasize the close interplay between spin excitations and superconductivity, similar to cuprate superconductors. In AxFe2-ySe2, superconductivity with Tc ~ 30 K borders an antiferromagnetic insulating phase; this is closer to the behavior observed in the cuprates but differs from that in other iron-based superconductors.

  10. Interplay between superconductivity and magnetism in Fe(1-x)Pd(x)Te.

    Science.gov (United States)

    Karki, Amar B; Garlea, V Ovidiu; Custelcean, Radu; Stadler, Shane; Plummer, E W; Jin, Rongying

    2013-06-04

    The attractive/repulsive relationship between superconductivity and magnetic ordering has fascinated the condensed matter physics community for a century. In the early days, magnetic impurities doped into a superconductor were found to quickly suppress superconductivity. Later, a variety of systems, such as cuprates, heavy fermions, and Fe pnictides, showed superconductivity in a narrow region near the border to antiferromagnetism (AFM) as a function of pressure or doping. However, the coexistence of superconductivity and ferromagnetic (FM) or AFM ordering is found in a few compounds [RRh4B4 (R = Nd, Sm, Tm, Er), R'Mo6X8 (R' = Tb, Dy, Er, Ho, and X = S, Se), UMGe (M = Ge, Rh, Co), CeCoIn5, EuFe2(As(1-x)P(x))2, etc.], providing evidence for their compatibility. Here, we present a third situation, where superconductivity coexists with FM and near the border of AFM in Fe(1-x)Pd(x)Te. The doping of Pd for Fe gradually suppresses the first-order AFM ordering at temperature T(N/S), and turns into short-range AFM correlation with a characteristic peak in magnetic susceptibility at T'(N). Superconductivity sets in when T'(N) reaches zero. However, there is a gigantic ferromagnetic dome imposed in the superconducting-AFM (short-range) cross-over regime. Such a system is ideal for studying the interplay between superconductivity and two types of magnetic (FM and AFM) interactions.

  11. Exotic Magnetic Orders and Their Interplay with Superconductivity

    DEFF Research Database (Denmark)

    Christensen, Morten Holm

    applications. The more recent discovery of high-temperature superconductors, with superconducting transition temperatures above 100~K, has led to the hope that superconductivity at room-temperature might be achievable, although a complete theoretical understanding of the high-temperature superconductors......Superconductivity represents one of the most important scientific discoveries of the 20th century. The practical applications are numerous ranging from clean energy storage and MRI machines to quantum computers. However, the low temperatures required for superconductivity prohibits many practical...

  12. Photoinduced Magnetic Nanoprobe Excited by Azimuthally Polarized Vector Beam

    CERN Document Server

    Guclu, Caner; Capolino, Filippo

    2016-01-01

    The concept of magnetic nanoprobes (or magnetic nanoantennas) providing a magnetic near-field enhancement and vanishing electric field is presented and investigated, together with their excitation. It is established that a particular type of cylindrical vector beams called azimuthally electric polarized vector beams yield strong longitudinal magnetic field on the beam axis where the electric field is ideally null. These beams with an electric polarization vortex and cylindrical symmetry are important in generating high magnetic to electric field contrast, i.e., large local field admittance, and in allowing selective excitation of magnetic transitions in matter located on the beam axis. We demonstrate that azimuthally polarized vector beam excitation of a photoinduced magnetic nanoprobe made of a magnetically polarizable nano cluster leads to enhanced magnetic near field with resolution beyond diffraction limit. We introduce two figures of merit as magnetic field enhancement and local field admittance normaliz...

  13. Superconducting Pb stripline resonators in parallel magnetic field and their application for microwave spectroscopy

    Science.gov (United States)

    Ebensperger, Nikolaj G.; Thiemann, Markus; Dressel, Martin; Scheffler, Marc

    2016-11-01

    Planar superconducting microwave resonators are key elements in a variety of technical applications and also act as sensitive probes for microwave spectroscopy of various materials of interest in present solid state research. Here superconducting Pb is a suitable material as a basis for microwave stripline resonators. To utilize Pb stripline resonators in a variable magnetic field (e.g. in ESR measurements), the electrodynamics of such resonators in a finite magnetic field has to be fully understood. Therefore we performed microwave transmission measurements (with ample applied power to work in linear response) on superconducting Pb stripline resonators in a variable, parallel magnetic field. We determined surface resistance, penetration depth, as well as real and imaginary parts, {σ }1 and {σ }2, of the complex conductivity of superconducting Pb as a function of a magnetic field. Here we find features reminiscent of those in temperature-dependent measurements, such as a maximum in {σ }1 (coherence peak). At magnetic fields above the critical field of this type-I superconductor we still find a low-loss microwave response, which we assign to remaining superconductivity in the form of filaments within the Pb. Hysteresis effects are found in the quality factor of resonances once the swept magnetic field has exceeded the critical magnetic field. This is due to normal conducting areas that are pinned and can therefore persist in the superconducting phase. Besides zero-field-cooling we show an alternative way to eliminate these even at T\\lt {T}c. Based on our microwave data, we also determine the critical magnetic field and the critical temperature of Pb in a temperature range between 1.6 K and 6.5 K and magnetic fields up to 140 mT, showing good agreement with BCS predictions. We also study a Sn sample in a Pb resonator to demonstrate the applicability of superconducting Pb stripline resonators in the experimental study of other (super-)conducting materials in a

  14. Fabrication of superconducting nanowires from ultrathin MgB2 films via focused ion beam milling

    Directory of Open Access Journals (Sweden)

    Chen Zhang

    2015-02-01

    Full Text Available High quality superconducting nanowires were fabricated from ultrathin MgB2 films by a focused ion beam milling technique. The precursor MgB2 films in 10 nm thick were grown on MgO substrates by using a hybrid physical-chemical vapor deposition method. The nanowires, in widths of about 300-600 nm and lengths of 1 or 10 μm, showed high superconducting critical temperatures (Tc’s above 34 K and narrow superconducting transition widths (ΔTc’s of 1-3 K. The superconducting critical current density Jc of the nanowires was above 5 × 107 A/cm2 at 20 K. The high Tc, narrow ΔTc, and high Jc of the nanowires offered the possibility of making MgB2-based nano-devices such as hot-electron bolometers and superconducting nanowire single-photon detectors with high operating temperatures at 15-20 K.

  15. Numerical and experimental investigations of coupled electromagnetic and thermal fields in superconducting accelerator magnets; Numerische und experimentelle Untersuchungen gekoppelter elektromagnetischer und thermischer Felder in supraleitenden Beschleunigermagneten

    Energy Technology Data Exchange (ETDEWEB)

    Mierau, Anna

    2013-10-01

    The new international facility for antiproton and ion research FAIR will be built in Darmstadt (Germany). The existing accelerator facility of GSI Helmholtzzentrum for Heavy Ion Research will serve as a pre-accelerator for the new facility. FAIR will provide high-energy antiproton and ion beams with unprecedented intensity and quality for fundamental research of states of matter and the evolution of the universe. The central component of FAIR's accelerator and storage rings complex is a double-ring accelerator consisting of two heavy ion synchrotrons SIS100 and SIS300. The SIS100 is the primary accelerator of FAIR. The desired beam properties of SIS100 require a design of the machine much more challenging than the conventional design of existing proton and ion synchrotrons. The key technical components of each synchrotron are the special electromagnets, which allow guiding the charged particles on their orbits in the synchrotron during the acceleration processes. For a stable operation of the SIS100's the magnets have to produce extremely homogeneous magnetic fields. Furthermore, the SIS100 high-intensity ion beam modes, for example with U{sup 28+} ions, require an ultra-high vacuum in the beam pipe of the synchrotron, which can be generated effectively only at low temperatures below 15 K. Due to the field quality requirements for the magnets, the properties of the dynamic vacuum in the beam pipe but also in order to minimise future operating costs, fast ramped superconducting magnets will be used to guide the beam in SIS100. These magnets have been developed at GSI within the framework of the FAIR project. Developing a balanced design of a superconducting accelerator magnet requires a sound understanding of the interaction between its thermal and electromagnetic fields. Of special importance in this case are the magnetic field properties such as the homogeneity of the static magnetic field in the aperture of the magnet, and the dynamic heat losses of the

  16. Capture cavity cryomodule for quantum beam experiment at KEK superconducting RF test facility

    Science.gov (United States)

    Tsuchiya, K.; Hara, K.; Hayano, H.; Kako, E.; Kojima, Y.; Kondo, Y.; Nakai, H.; Noguchi, S.; Ohuchi, N.; Terashima, A.; Horikoshi, A.; Semba, T.

    2014-01-01

    A capture cavity cryomodule was fabricated and used in a beam line for quantum beam experiments at the Superconducting RF Test Facility (STF) of the High Energy Accelerator Research Organization in Japan. The cryomodule is about 4 m long and contains two nine-cell cavities. The cross section is almost the same as that of the STF cryomodules that were fabricated to develop superconducting RF cavities for the International Linear Collider. An attempt was made to reduce the large deflection of the helium gas return pipe (GRP) that was observed in the STF cryomodules during cool-down and warm-up. This paper briefly describes the structure and cryogenic performance of the captures cavity cryomodule, and also reports the measured displacement of the GRP and the cavity-containing helium vessels during regular operation.

  17. Capture cavity cryomodule for quantum beam experiment at KEK superconducting RF test facility

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, K.; Hara, K.; Hayano, H.; Kako, E.; Kojima, Y.; Kondo, Y.; Nakai, H.; Noguchi, S.; Ohuchi, N.; Terashima, A. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Horikoshi, A.; Semba, T. [Hitachi, Ltd., Hitachi Works, Hitachi, Ibaraki 317-8511 (Japan)

    2014-01-29

    A capture cavity cryomodule was fabricated and used in a beam line for quantum beam experiments at the Superconducting RF Test Facility (STF) of the High Energy Accelerator Research Organization in Japan. The cryomodule is about 4 m long and contains two nine-cell cavities. The cross section is almost the same as that of the STF cryomodules that were fabricated to develop superconducting RF cavities for the International Linear Collider. An attempt was made to reduce the large deflection of the helium gas return pipe (GRP) that was observed in the STF cryomodules during cool-down and warm-up. This paper briefly describes the structure and cryogenic performance of the captures cavity cryomodule, and also reports the measured displacement of the GRP and the cavity-containing helium vessels during regular operation.

  18. Cryogenic magnetic coil and superconducting magnetic shield for neutron electric dipole moment searches

    Science.gov (United States)

    Slutsky, S.; Swank, C. M.; Biswas, A.; Carr, R.; Escribano, J.; Filippone, B. W.; Griffith, W. C.; Mendenhall, M.; Nouri, N.; Osthelder, C.; Pérez Galván, A.; Picker, R.; Plaster, B.

    2017-08-01

    A magnetic coil operated at cryogenic temperatures is used to produce spatial, relative field gradients below 6 ppm/cm, stable for several hours. The apparatus is a prototype of the magnetic components for a neutron electric dipole moment (nEDM) search, which will take place at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory using ultra-cold neutrons (UCN). That search requires a uniform magnetic field to mitigate systematic effects and obtain long polarization lifetimes for neutron spin precession measurements. This paper details upgrades to a previously described apparatus [1], particularly the introduction of super-conducting magnetic shielding and the associated cryogenic apparatus. The magnetic gradients observed are sufficiently low for the nEDM search at SNS.

  19. Superior homogeneity of trapped magnetic field in superconducting MgB2 bulk magnets

    Science.gov (United States)

    Ishihara, A.; Akasaka, T.; Tomita, M.; Kishio, K.

    2017-03-01

    Homogeneity of trapped magnetic field in radial and circumferential directions of high temperature superconducting bulk magnets, MgB2 (T c ˜38.3 K) and YBa2Cu3O y (T c ˜91.5 K), have been measured. In polycrystalline MgB2 bulks, the circularity of trapped magnetic field in a cylindrical disk is over 97% at 20-32.5 K, while that of YBa2Cu3O y was ˜87% at 77 K. Magnetic field distribution of MgB2 bulk was satisfactorily homogeneous and these measurements suggest MgB2 bulks with highly efficient cryocoolers should be very useful for novel high field permanent magnet applications.

  20. Resistive wall heating due to image current on the beam chamber for a superconducting undulator.

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H. (Accelerator Systems Division (APS))

    2012-03-27

    The image-current heating on the resistive beam chamber of a superconducting undulator (SCU) was calculated based on the normal and anomalous skin effects. Using the bulk resistivity of copper for the beam chamber, the heat loads were calculated for the residual resistivity ratios (RRRs) of unity at room temperature to 100 K at a cryogenic temperature as the reference. Then, using the resistivity of the specific aluminum alloy 6053-T5, which will be used for the SCU beam chamber, the heat loads were calculated. An electron beam stored in a storage ring induces an image current on the inner conducting wall, mainly within a skin depth, of the beam chamber. The image current, with opposite charge to the electron beam, travels along the chamber wall in the same direction as the electron beam. The average current in the storage ring consists of a number of bunches. When the pattern of the bunched beam is repeated according to the rf frequency, the beam current may be expressed in terms of a Fourier series. The time structure of the image current is assumed to be the same as that of the beam current. For a given resistivity of the chamber inner wall, the application ofthe normal or anomalous skin effect will depend on the harmonic numbers of the Fourier series of the beam current and the temperature of the chamber. For a round beam chamber with a ratius r, much larger than the beam size, one can assume that the image current density as well as the density square, may be uniform around the perimeter 2{pi}r. For the SCU beam chamber, which has a relatively narrow vertical gap compared to the width, the effective perimeter was estimated since the heat load should be proportional to the inverse of the perimeter.

  1. Resistive wall heating due to image current on the beam chamber for a superconducting undulator.

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H. (Accelerator Systems Division (APS))

    2012-03-27

    The image-current heating on the resistive beam chamber of a superconducting undulator (SCU) was calculated based on the normal and anomalous skin effects. Using the bulk resistivity of copper for the beam chamber, the heat loads were calculated for the residual resistivity ratios (RRRs) of unity at room temperature to 100 K at a cryogenic temperature as the reference. Then, using the resistivity of the specific aluminum alloy 6053-T5, which will be used for the SCU beam chamber, the heat loads were calculated. An electron beam stored in a storage ring induces an image current on the inner conducting wall, mainly within a skin depth, of the beam chamber. The image current, with opposite charge to the electron beam, travels along the chamber wall in the same direction as the electron beam. The average current in the storage ring consists of a number of bunches. When the pattern of the bunched beam is repeated according to the rf frequency, the beam current may be expressed in terms of a Fourier series. The time structure of the image current is assumed to be the same as that of the beam current. For a given resistivity of the chamber inner wall, the application ofthe normal or anomalous skin effect will depend on the harmonic numbers of the Fourier series of the beam current and the temperature of the chamber. For a round beam chamber with a ratius r, much larger than the beam size, one can assume that the image current density as well as the density square, may be uniform around the perimeter 2{pi}r. For the SCU beam chamber, which has a relatively narrow vertical gap compared to the width, the effective perimeter was estimated since the heat load should be proportional to the inverse of the perimeter.

  2. Magnetic field induced optical vortex beam rotation

    CERN Document Server

    Shi, Shuai; Zhou, Zhi-Yuan; Li, Yan; Zhang, Wei; Shi, Bao-Sen

    2015-01-01

    Light with orbital angular momentum (OAM) has drawn a great deal of attention for its important applications in the fields of precise optical measurements and high capacity optical communications. Here we adopt a method to study the rotation of a light beam, which is based on magnetic field induced circular birefringence in warm 87Rb atomic vapor. The dependence of the rotation angle to the intensity of the magnetic field makes it appropriate for weak magnetic field measurement. We derive a detail theoretical description that is in well agreement with the experimental observations. The experiment shows here provides a new method for precise measurement of magnetic field intensity and expands the application of OAM-carrying light.

  3. Vafa-Witten theorem, vector meson condensates and magnetic-field-induced electromagnetic superconductivity of vacuum

    CERN Document Server

    Chernodub, M N

    2012-01-01

    We show that the electromagnetic superconductivity of vacuum in strong magnetic field background is consistent with the Vafa-Witten theorem because the charged vector meson condensates lock relevant internal global symmetries of QCD with the electromagnetic gauge group.

  4. Magnetic Field-Induced Superconductivity in the Ferromagnet URhGe

    Science.gov (United States)

    Lévy, F.; Sheikin, I.; Grenier, B.; Huxley, A. D.

    2005-08-01

    In several metals, including URhGe, superconductivity has recently been observed to appear and coexist with ferromagnetism at temperatures well below that at which the ferromagnetic state forms. However, the material characteristics leading to such a state of coexistence have not yet been fully elucidated. We report that in URhGe there is a magnetic transition where the direction of the spin axis changes when a magnetic field of 12 tesla is applied parallel to the crystal b axis. We also report that a second pocket of superconductivity occurs at low temperature for a range of fields enveloping this magnetic transition, well above the field of 2 tesla at which superconductivity is first destroyed. Our findings strongly suggest that excitations in which the spins rotate stimulate superconductivity in the neighborhood of a quantum phase transition under high magnetic field.

  5. 2D Analysis of Thermomechanical Response to Unbalanced Currents in Quenching Superconducting Magnets

    CERN Document Server

    AUTHOR|(CDS)2140986

    The thesis aims at studying coupling between electromagneticthermal and mechanical phenomena occurring after a quench in the superconducting magnets. For this reason, two models representing both domains are coupled by means of area-based coupling.

  6. Study of some superconducting and magnetic materials on high T sub c oxide superconductors

    Science.gov (United States)

    Wu, M. K.

    1987-01-01

    On the basis of existing data it appears that the high-temperature superconductivity above 77 K reported here, occurs only in compound systems consisting of a phase other than the K2NiF4 phase. A narrow superconducting transition was obtained with T sub c0 = 98 K and T sub c1 = 94 K in Y-Ba-Cu-O (YBCO). Preliminary results indicate that YBCO is rather different from the layered LaBCO, LaSCO, and LaCCO. While electron-photon interaction cannot be absent from this compound system, nonconventional enhanced superconducting interactions due to interfaces, Resonating Valence Bond (RVB) states, or even a superconducting state beyond the BCS framework, may be required to account for the high T sub c in YBCO. It is believed that study of the possible subtle correlation between magnetism and superconductivity will definitely provide important insight into the superconducting mechanism in YBCO and other oxides.

  7. Sensitivity of Niobium Superconducting RF Cavities to Magnetic Field

    CERN Document Server

    Gonnella, Dan

    2015-01-01

    Future particle accelerators such as the the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting RF (SRF) cavities operating in continuous wave (CW) mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0). In order to reach these high Q0's in the case of LCLS-II, nitrogen-doping has been proposed as a cavity preparation technique. When dealing with Q0's greater than 1x10^10, the effects of ambient magnetic field on Q0 become significant. Here we show that the sensitivity that a cavity has to ambient magnetic field is highly dependent on the cavity preparation. Specifically, standard electropolished and 120C baked cavities show a sensitivity of ~0.8 and ~0.6 nOhm/mG trapped, respectively, while nitrogen-doped cavities show a sensitivity of ~2 to 5 nOhm/mG trapped. Less doping results in weaker sensitivity. This difference in sensitivities is ...

  8. Synthesis of as-grown superconducting MgB{sub 2} thin films by molecular beam epitaxy in UHV conditions

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Y.; Uduka, M.; Nakanishi, Y.; Yoshimoto, N.; Yoshizawa, M

    2004-10-01

    As-grown superconducting MgB{sub 2} thin films have been grown on SrTiO{sub 3}(0 0 1), MgO(0 0 1), and Al{sub 2}O{sub 3}(0 0 0 1) substrates by a molecular beam epitaxy (MBE) method with novel co-evaporation conditions of low deposition rate in ultra-high vacuum. The structural and physical properties of the films were studied by RHEED, XRD, electrical resistivity measurements, and SQUID magnetometer. The RHEED patterns indicate three-dimensional growth for MgB{sub 2}. The highest T{sub c} determined by resistivity measurement was about 36 K in these samples. And a clear Meissner effect below T{sub c} was observed using magnetic susceptibility measurement. We will discuss the influence of B buffer layer on the structural and physical properties.

  9. Superconductivity

    CERN Document Server

    Ketterson, John B

    2008-01-01

    Conceived as the definitive reference in a classic and important field of modern physics, this extensive and comprehensive handbook systematically reviews the basic physics, theory and recent advances in the field of superconductivity. Leading researchers, including Nobel laureates, describe the state-of-the-art in conventional and unconventional superconductors at a particularly opportune time, as new experimental techniques and field-theoretical methods have emerged. In addition to full-coverage of novel materials and underlying mechanisms, the handbook reflects continued intense research into electron-phone based superconductivity. Considerable attention is devoted to high-Tc superconductivity, novel superconductivity, including triplet pairing in the ruthenates, novel superconductors, such as heavy-Fermion metals and organic materials, and also granular superconductors. What’s more, several contributions address superconductors with impurities and nanostructured superconductors. Important new results on...

  10. Investigation of spontaneous magnetization of coupled 2×2 superconducting π ring array

    Institute of Scientific and Technical Information of China (English)

    Li Zhuang-Zhi; Wang Fu-Ren; Yang Tao; Liu Xin-Yuan; Ma Ping; Xie Fei-Xiang; Nie Rui-Juan; Dai Yuan-Dong

    2004-01-01

    We present the theoretical investigation of spontaneous magnetization of a coupled 2 × 2 π ring array. It is indicated by free energy calculation that the system has the lowest energy when the four π rings have the full antiparallel configuration. Furthermore, the numerical evaluation results show that the system which favours full antiparallel spontaneous magnetization is a quantum effect deriving from the phase cohering of the superconducting quantum wavefunctions in the four superconducting rings through the shared Josephson junctions.

  11. Spontaneous electromagnetic superconductivity of vacuum induced by a strong magnetic field: QCD and electroweak theory

    CERN Document Server

    Chernodub, M N; Verschelde, H

    2012-01-01

    Both in electroweak theory and QCD, the vacuum in strong magnetic fields develops charged vector condensates once a critical value of the magnetic field is reached. Both ground states have a similar Abrikosov lattice structure and superconducting properties. It is the purpose of these proceedings to put the condensates and their superconducting properties side by side and obtain a global view on this type of condensates. Some peculiar aspects of the superfluidity and backreaction of the condensates are also discussed.

  12. Letter report for the Superconducting Magnet Development Program, April 1, 1977--June 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Fietz, W. A.; Lubell, M. S. [eds.

    1977-11-01

    The results and accomplishments of the Superconducting Magnet Development Program (SCMDP) for the second quarter of the calendar year 1977 are summarized. The presentations are arranged according to projects rather than the group organization by discipline of the Magnetics and Superconductivity Section. The design, procurement, and fabrication of the Large Coil Segment are well under way. Significant progress is reported on the conductor stability and loss experiments for both toroidal field coils and poloidal field coils.

  13. Study on magnetic separation for decontamination of cesium contaminated soil by using superconducting magnet

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, Susumu, E-mail: igarashi@qb.see.eng.osaka-u.ac.jp; Nomura, Naoki; Mishima, Fumihito; Akiyama, Yoko, E-mail: yoko-ak@see.eng.osaka-u.ac.jp

    2014-09-15

    Highlights: • The method for the soil decontamination by the superconducting magnet is proposed. • Magnetic separation of clay minerals was performed by HGMS. • Soil separation ratio was evaluated by quantitative analysis using XRD. • It is expected that HGMS can be applied to the actual soil decontamination. - Abstract: The accident of Fukushima Daiichi nuclear power plant caused the diffusion of radioactive cesium over the wide area. We examined the possibility of applying magnetic separation method using the superconducting magnet, which can process a large amount of the soil in high speed, to the soil decontamination and volume reduction of the radioactive cesium contaminated soil. Clay minerals are classified as 2:1 and 1:1 types by the difference of their layer structures, and these types of minerals are respectively paramagnetic and diamagnetic including some exception. It is known that most of the radioactive cesium is strongly adsorbed on the clay, especially on 2:1 type clay minerals. It is expected that the method which can separate only 2:1 type clay minerals selectively from the mixture clay minerals can enormously contribute to the volume reduction of the contaminated soil. In this study, the components in the clay before and after separation were evaluated to estimate the magnetic separation efficiency by using X-ray diffraction. From the results, the decontamination efficiency and the volume reduction ratio were estimated in order to examine the appropriate separation conditions for the practical decontamination of the soil.

  14. Mercury removal from solution by superconducting magnetic separation with nanostructured magnetic adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, T., E-mail: okamoto-takayuki@ed.tmu.ac.jp [Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Tachibana, S.; Miura, O. [Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Takeuchi, M. [Komazawa Jin Clinic, 1-19-8 Komazawa, Setagayaku, Tokyo 154-0012 (Japan)

    2011-11-15

    Recently, mercury Hg concentration in human blood increases due to expanding the global mercury contamination. Excess mercury bioaccumulation poses a significant health risk. In order to decrease mercury concentration in the environment and human blood, we have developed two different kinds of nanostructured magnetic adsorbents for mercury to apply them to superconducting magnetic separation instead of conventional filtration. One is magnetic beads (MBs) which have nanosize magnetite particles in the core and a lot of SH radicals on the surface to adsorb Hg ions effectively. MBs were developed mainly to remove mercury from human blood. The maximum amount of the adsorption for MBs is 6.3 mg/g in the solution in less than a minute. Dithiothreitol can easily remove mercury adsorbed to MBs, hence MBs can be reusable. The other is nanostructured magnetic activated carbon (MAC) which is activated carbon with mesopores and nanosize magnetite. The maximum amount of the adsorption for MAC is 38.3 mg/g in the solution. By heat-treatment mercury can be easily removed from MAC. We have studied superconducting magnetic separation using each adsorbent for mercury removal from solution.

  15. New, coupling loss induced, quench protection system for superconducting accelerator magnets

    NARCIS (Netherlands)

    Ravaioli, E.; Datskov, V.I.; Giloux, C.; Kirby, G.; Kate, ten H.H.J.; Verweij, A.P.

    2014-01-01

    A new and promising method for the protection of superconducting high-field magnets is developed and tested on the so-called MQXC quadrupole magnet in the CERN magnet test facility. The method relies on a capacitive discharge system inducing during a few periods an oscillation of the transport curre

  16. Magnetic conveyor belt transport of ultracold atoms to a superconducting atomchip

    CERN Document Server

    Minniberger, Stefan; Haslinger, Stefan; Hufnagel, Christoph; Novotny, Christian; Lippok, Nils; Majer, Johannes; Schneider, Stephan; Schmiedmayer, Jörg

    2013-01-01

    We report the realization of a robust magnetic transport scheme to bring 3x10^8 ultracold 87Rb atoms into a cryostat. The sequence starts with standard laser cooling and trapping of 87Rb atoms, transporting first horizontally and then vertically through the radiation shields into a cryostat by a series of normal- and superconducting magnetic coils. Loading the atoms in a superconducting microtrap paves the way for studying the interaction of ultracold atoms with superconducting surfaces and quantum devices requiring cryogenic temperatures.

  17. Magnetoresistance peculiarities and magnetization of materials with two kinds of superconducting inclusions

    Directory of Open Access Journals (Sweden)

    Shevtsova O. N.

    2015-03-01

    Full Text Available Low-temperature properties of a crystal containing type I superconducting inclusions of two different materials have been studied. In the approximation assuming that the inclusions size is much smaller than the coherence length/penetration depth of the magnetic field, the theory of magnetoresistance of a crystal containing spherical superconducting inclusions of two different materials has been developed, and magnetization of crystals has been calculated. The obtained results can be used for correct explanation of the low temperature conductivity in binary and more complex semiconductors, in which precipitation of the superconducting phase is possible during the technological processing or under external impact.

  18. Liquid-He-free 10-T superconducting magnet for neutron scattering

    CERN Document Server

    Katano, S; Metoki, N; Osakabe, T; Suzuki, J; Koike, Y; Ishii, Y

    2002-01-01

    A new type of superconducting magnet, which is directly cooled by two 4-K GM cryocoolers (i.e. liquid-He-free), has been developed for neutron-scattering experiments. The magnet consists of a split pair of a (Nb,Ti) sub 3 Sn inner coil and a NbTi outer coil. The gap between the coils is 29 mm, and the upper and lower coils are supported by three rings made of Al alloy (4.5, 7.5, and 8 mm in thickness) and a plate of Al alloy (42.5 in angle). The total thickness of the Al alloy in the neutron path is 52 mm, and the transmission of the beam is about 60% for neutrons with 20 meV. The room-temperature bore is 51 mm in diameter, and in this bore one of the sample-cooling systems (4-K cryocooler or liquid-He-free dilution refrigerator) is inserted. The maximum field of 10 T is very stably obtained. Some results on the magnetism of strongly correlated electron systems obtained with this cryomagnet are presented. (orig.)

  19. Superconducting magnet system of in-flight separator for a heavy ion accelerator planned in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. W.; Kim, D. G.; Jo, H. C. [Institute for Basic Science, Daejeon (Korea, Republic of); Choi, Y. S. [Korea Basic Science Institute, Daejeon (Korea, Republic of); Kim, S. H. [Changwon National University, Changwon (Korea, Republic of); Sim, K. D.; Sohn, M. H. [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

    2015-03-15

    An in-flight fragment separator, which aims to produce and study rare isotopes, consists of superferric quadrupole triplets and dipole magnets to focus and bend the beams for achromatic focusing and momentum dispersion, respectively. The separator is divided into pre and main stages, and we plan to use superconducting magnets employing high-Tc superconductor (HTS) coils in the pre-separator area, where radiation heating is high. The HTS coils will be cooled by cold He gas in 20-50 K, and in the other area, superferric magnets using low-temperature superconductor (LTS) will be used at 4 K. A few LTS coils were wound and successfully tested in a LHe dewar, and the design of cryostat has been optimized. Development of the HTS coils is ongoing in collaboration with a group at KERI. An HTS coil of racetrack shape was wound and tested in a bath and in a dewar with cryocooler. No degradation on critical current due to coil winding was found.

  20. Fast Cycled Superconducting Magnet - Connecting hydraulically the Fast Cycled magnet to the cryogenic feed box.

    CERN Multimedia

    Maximilien Brice

    2012-01-01

    Photo 1 : Connecting hydraulically the Fast Cycled magnet to the cryogenic feed box. Patrck Viret and Guy Deferne technicians of TE-MSC-TF in SM18. - Photo 2 : Installation of the Fast Cycled Superconducting Magnet (FCM) to the new cold feed box in Sm18. - Photo 3 : Connecting the powering cables of the FCM to the feed box. - Photo 5/6 : The connections of the Fast Cycled Magnet. Intermediate pieces. - Photo 7 : Hydraulic connections of the Fast Cycle Magnet cable to allow the cooling of the magnet’s conductor ( Cable in conduit type) with supercritical helium. - Photo 8 : Verification of the connection: design versus reality. Guy Deferne and Frederick Rougemont, technicians of TE-MSC-TE in SM18.

  1. Trapped magnetic field of a superconducting bulk magnet in high- T sub c RE-Ba-Cu-O

    CERN Document Server

    Fujimoto, H; Higuchi, T; Nakamura, Y; Kamijo, H; Nagashima, K; Murakami, M

    1999-01-01

    Superconducting magnets made of high-T sub c superconductors are promising for industrial applications. It is well known that REBa sub 2 Cu sub 3 O sub 7 sub - sub x and LRE (light rare-earth) Ba sub 2 Cu sub 3 O sub 7 sub - sub x superconductors prepared by melt processes have a high critical current density, J sub c , at 77 K and high magnetic fields. Therefore, the materials are very prospective for high magnetic field application as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. LREBaCuO bulks, compared with REBaCuO bulks, exhibit a larger J sub c in high magnetic fields and a much improved irreversibility field, H sub i sub r sub r , at 77 K. In this study, we discuss the possibility and trapped field properties of a superconducting bulk magnet, as well as the melt processing for bulk superconductors and their characteristic superconducting properties. One of the applications is a superconducting magnet for the future magnetically levitated (Maglev) train.

  2. Trapped magnetic field of a superconducting bulk magnet in high- T{sub c} RE-Ba-Cu-O

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Hiroyuki; Yoo, Sang Im; Higuchi, Takamitsu; Nakamura, Yuichi; Kamijo, Hiroki; Nagashima, Ken [Railway Technical Research Institute, Tokyo (Japan); Murakami, Masato [International Superconductivity Technology Center, Tokyo (Japan)

    1999-07-01

    Superconducting magnets made of high-T{sub c} superconductors are promising for industrial applications. It is well known that REBa{sub 2}Cu{sub 3}O{sub 7-x} and LRE (light rare-earth) Ba{sub 2}Cu{sub 3}O{sub 7-x} superconductors prepared by melt processes have a high critical current density, J{sub c}, at 77 K and high magnetic fields. Therefore, the materials are very prospective for high magnetic field application as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. LREBaCuO bulks, compared with REBaCuO bulks, exhibit a larger J{sub c} in high magnetic fields and a much improved irreversibility field, H{sub irr}, at 77 K. In this study, we discuss the possibility and trapped field properties of a superconducting bulk magnet, as well as the melt processing for bulk superconductors and their characteristic superconducting properties. One of the applications is a superconducting magnet for the future magnetically levitated (Maglev) train.

  3. A Superconducting Magnet with Center Field of 10 T and φ100 mm Warm Bore

    Institute of Scientific and Technical Information of China (English)

    王秋良; 严陆光; 赵宝志; 宋守森

    2006-01-01

    A conduction-cooled superconducting magnet with central field of 10T and warm bore of 100 mm was designed based on a Nb3Sn and two NbTi superconducting coils. At the first stage, the NbTi coils have been fabricated and tested. A two-stage 4 K Gifford-McMahon (GM) cryocooler with the second-stage power in 1W, 4.2K is used to cool the magnet from room temperature to 4 K. The superconducting magnet with the same power supply has the operating current of 116A. The magnet can be rotated with a support frame to be operated with either horizontal or vertical position. A pair of Bi-2223 high temperature superconducting current leads was employed to reduce heat leakage into 4.2K level. The NbTi coils reachto the operating current of 120A without training effect to be observed during charging of the magnet during 40 minutes charging time and generate the center field of 6.5T. The training effect in the NbTi magnet directly cool-down by cryocooler and inter-winding support structure in magnet can be remarkably improved. The superconducting magnet has been stably operated for more than 275 hours with 6.5T. In this paper, the detailed design, fabrication, stress analysis and quench protection characteristics are presented.

  4. Experimental validation of field cooling simulations for linear superconducting magnetic bearings

    Energy Technology Data Exchange (ETDEWEB)

    Dias, D H N; Motta, E S; Sotelo, G G; De Andrade Jr, R, E-mail: ddias@coe.ufrj.b [Laboratorio de aplicacao de Supercondutores (LASUP), Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil)

    2010-07-15

    For practical stability of a superconducting magnetic bearing the refrigeration process must occur with the superconductor in the presence of the magnetic field (a field cooling (FC) process). This paper presents an experimental validation of a method for simulating this system in the FC case. Measured and simulated results for a vertical force between a high temperature superconductor and a permanent magnet rail are compared. The main purpose of this work is to consolidate a simulation tool that can help in future projects on superconducting magnetic bearings for MagLev vehicles.

  5. A Conduction-Cooled Superconducting Magnet System-Design, Fabrication and Thermal Tests

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Holbøll, Joachim; Wang, Qiuliang

    2015-01-01

    A conduction-cooled superconducting magnet system with an operating current of 105.5 A was designed, fabricated and tested for material processing applications. The magnet consists of two coaxial NbTi solenoid coils with an identical vertical height of 300 mm and is installed in a high-vacuumed c......A conduction-cooled superconducting magnet system with an operating current of 105.5 A was designed, fabricated and tested for material processing applications. The magnet consists of two coaxial NbTi solenoid coils with an identical vertical height of 300 mm and is installed in a high...

  6. Jefferson Lab CLAS12 Superconducting Solenoid magnet Requirements and Design Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Rajput-Ghoshal, Renuka [Jefferson Lab, Newport News, VA; Hogan, John P. [Jefferson Lab, Newport News, VA; Fair, Ruben J. [Jefferson Lab, Newport News, VA; Ghoshal, Probir K. [Jefferson Lab, Newport News, VA; Luongo, Cesar [Jefferson Lab, Newport News, VA; Elouadrhiri, Latifa [Jefferson Lab, Newport News, VA

    2014-12-01

    As part of the Jefferson Lab 12GeV accelerator upgrade project, one of the experimental halls (Hall B) requires two superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. In this presentation the physics requirements for the 5 T solenoid magnet, design constraints, conductor decision, and cooling choice will be discussed. The various design iterations to meet the specification will also be discussed in this presentation.

  7. Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Sun, L., E-mail: sunlt@impcas.ac.cn; Lu, W.; Zhang, W. H.; Feng, Y. C.; Qian, C.; Ma, H. Y.; Zhang, X. Z.; Zhao, H. W. [Institute of Modern Physics, CAS, Lanzhou 730000 (China); Guo, J. W.; Yang, Y.; Fang, X. [Institute of Modern Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2016-02-15

    At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω{sup 2} scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE{sub 01} and HE{sub 11} modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar{sup 12+}, 0.92 emA Xe{sup 27+}, and so on, will be presented.

  8. Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited)

    Science.gov (United States)

    Sun, L.; Guo, J. W.; Lu, W.; Zhang, W. H.; Feng, Y. C.; Yang, Y.; Qian, C.; Fang, X.; Ma, H. Y.; Zhang, X. Z.; Zhao, H. W.

    2016-02-01

    At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω2 scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE01 and HE11 modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar12+, 0.92 emA Xe27+, and so on, will be presented.

  9. Superconducting bulk magnet for maglev vehicle: Stable levitation performance above permanent magnet guideway

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z.; Zheng, J.; Li, J.; Ma, G.; Lu, Y.; Zhang, Y.; Wang, S. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China); Wang, J. [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu 610031 (China)], E-mail: jsywang@home.swjtu.edu.cn

    2008-06-15

    High-temperature superconducting (HTS) maglev vehicle is well known as one of the most potential applications of bulk high-temperature superconductors (HTSCs) in transported levitation system. Many efforts have promoted the practice of the HTS maglev vehicle in people's life by enhancing the load capability and stability. Besides improving the material performance of bulk HTSC and optimizing permanent magnet guideway (PMG), magnetization method of bulk HTSC is also very effective for more stable levitation. Up to now, applied onboard bulk HTSCs are directly magnetized by field cooling above the PMG for the present HTS maglev test vehicles or prototypes in China, Germany, Russia, Brazil, and Japan. By the direct-field-cooling-magnetization (DFCM) over PMG, maglev performances of the bulk HTSCs are mainly depended on the PMG's magnetic field. However, introducing HTS bulk magnet into the HTS maglev system breaks this dependence, which is magnetized by other non-PMG magnetic field. The feasibility of this HTS bulk magnet for maglev vehicle is investigated in the paper. The HTS bulk magnet is field-cooling magnetized by a Field Control Electromagnets Workbench (FCEW), which produces a constant magnetic field up to 1 T. The levitation and guidance forces of the HTS bulk magnet over PMG with different trapped flux at 15 mm working height (WH) were measured and compared with that by DFCM in the same applied PMG magnetic field at optimal field-cooling height (FCH) 30 mm, WH 15 mm. It is found that HTS bulk magnet can also realize a stable levitation above PMG. The trapped flux of HTS bulk magnet is easily controllable by the charging current of FCEW, which implies the maglev performances of HTS bulk magnet above PMG will be adjustable according to the practical requirement. The more trapped flux HTS bulk magnet will lead to bigger guidance force and smaller repulsion levitation force above PMG. In the case of saturated trapped flux for experimental HTS bulk

  10. Superconducting curved transport solenoid with dipole coils for charge selection of the muon beam

    Energy Technology Data Exchange (ETDEWEB)

    Strasser, P., E-mail: patrick.strasser@kek.jp [Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Ikedo, Y.; Miyake, Y.; Shimomura, K.; Kawamura, N.; Nishiyama, K.; Makimura, S.; Fujimori, H.; Koda, A.; Nakamura, J.; Nagatomo, T. [Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Adachi, T. [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Pant, A.D. [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511 (Japan); Ogitsu, T. [Cryogenic Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Makida, Y.; Yoshida, M. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Sasaki, K. [Cryogenic Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Okamura, T. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); and others

    2013-12-15

    Highlights: • Superconducting curved transport solenoid. • Muon charge selection by superimposed dipole field. • World strongest pulsed muon source. -- Abstract: At the J-PARC Muon Science Facility (MUSE) the Super-Omega muon beamline is now under construction in the experimental hall No. 2 of the Materials and Life Science Facility building. Muons up to 45 MeV/c will be extracted with a large acceptance solid angle to produce the world highest intensity pulsed muon beam. This beamline comprises three parts, a normal-conducting capture solenoid, a superconducting curved transport solenoid and an axial focusing solenoid. Since only solenoids are used, both surface μ{sup +} and cloud μ{sup −} are extracted simultaneously. To accommodate future experiments that would only require either μ{sup +} or μ{sup −} beam, two dipole coils located on the straight section of the curved solenoid provide the muon charge selection by directing one of the beam onto the solenoid inner-wall. The design parameters, the construction status and the initial beam commissioning are reported.

  11. Single-Plane Magnetically Focused Elongated Small Field Proton Beams.

    Science.gov (United States)

    McAuley, Grant A; Slater, James M; Wroe, Andrew J

    2015-08-01

    We previously performed Monte Carlo simulations of magnetically focused proton beams shaped by a single quadrapole magnet and thereby created narrow elongated beams with superior dose delivery characteristics (compared to collimated beams) suitable for targets of similar geometry. The present study seeks to experimentally validate these simulations using a focusing magnet consisting of 24 segments of samarium cobalt permanent magnetic material adhered into a hollow cylinder. Proton beams with properties relevant to clinical radiosurgery applications were delivered through the magnet to a water tank containing a diode detector or radiochromic film. Dose profiles were analyzed and compared with analogous Monte Carlo simulations. The focused beams produced elongated beam spots with high elliptical symmetry, indicative of magnet quality. Experimental data showed good agreement with simulations, affirming the utility of Monte Carlo simulations as a tool to model the inherent complexity of a magnetic focusing system. Compared to target-matched unfocused simulations, focused beams showed larger peak to entrance ratios (26% to 38%) and focused simulations showed a two-fold increase in beam delivery efficiency. These advantages can be attributed to the magnetic acceleration of protons in the transverse plane that tends to counteract the particle outscatter that leads to degradation of peak to entrance performance in small field proton beams. Our results have important clinical implications and suggest rare earth focusing magnet assemblies are feasible and could reduce skin dose and beam number while delivering enhanced dose to narrow elongated targets (eg, in and around the spinal cord) in less time compared to collimated beams.

  12. Design of microchannels for cryostabilization of high temperature superconducting magnets

    Science.gov (United States)

    Cha, Y. S.; Hull, J. R.; Niemann, R. C.

    Microchannel cooling using subcooled liquid nitrogen is proposed to cryogenically stabilize high-temperature superconducting magnets. Various design constraints and parameters are identified and summarized. A graphical method is proposed for the design of microchannel systems. This graphical method helps to reduce the amount of work towards achieving optimum design for a specific application because there are a large number of parameters involved in the design of a microchannel system. The proposed graphical method are illustrated by three examples. The results show that a design window may appear for a given application. Any point within this window is an acceptable design. Another advantage of the graphical method is that, by selecting a design point, the design margin against various design contrains can be easily identified. Any two of the design variables can be selected as the independent variables. The choice depends on specific application and, to a certain extent, on individual preference. The three examples revealed that, for high current density applications, the most scattering constraints are the coolant temperature rise and the fin tip temperatures provided that a moderate pressure drop can be tolerated.

  13. Contribution to the study of superconducting magnetic systems in the frame of fusion projects

    Energy Technology Data Exchange (ETDEWEB)

    Duchateau, J.L.; Artiguelongue, H.; Bej, Z.; Ciazynski, D.; Cloez, H.; Decool, P.; Hertout, P.; Libeyre, P.; Martinez, A.; Nicollet, S.; Rubino, M.; Schild, T.; Verger, J.M. [Association Euratom-CEA, CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee DRFC, 13 - Saint-Paul-lez-Durance (France)

    2000-02-01

    This report is a presentation of all the 55 publications made by the Magnet Group of the 'Departement de Recherche sur la Fusion Controlee' during the 94-99 period. These publications have been made mainly in the frame of EURATOM contracts and task for ITER. This collection deals with most of the dimensioning aspects of large superconducting magnets and hence the field interest is wider than the restricted field of magnets for fusion by magnetic confinement. Whenever it is possible, simple expressions and criteria are given for dimensioning superconducting strands, assembling them to build cables and cooling them by an adapted forced flow cooling. This is hence a major for the understanding of the behaviour of large modern superconducting magnets and provides many tools for design and construction. (author)

  14. Magnetic field dependence of the superconducting proximity effect in a two atomic layer thin metallic film

    Energy Technology Data Exchange (ETDEWEB)

    Caminale, Michael; Leon Vanegas, Augusto A.; Stepniak, Agnieszka; Oka, Hirofumi; Fischer, Jeison A.; Sander, Dirk; Kirschner, Juergen [Max-Planck-Institut fuer Mikrostrukturphysik, Halle (Germany)

    2015-07-01

    The intriguing possibility to induce superconductivity in a metal, in direct contact with a superconductor, is under renewed interest for applications and for fundamental aspects. The underlying phenomenon is commonly known as proximity effect. In this work we exploit the high spatial resolution of scanning tunneling spectroscopy at sub-K temperatures and in magnetic fields. We probe the differential conductance along a line from a superconducting 9 ML high Pb nanoisland into the surrounding two layer thin Pb/Ag wetting layer on a Si(111) substrate. A gap in the differential conductance indicates superconductivity of the Pb island. We observe an induced gap in the wetting layer, which decays with increasing distance from the Pb island. This proximity length is 21 nm at 0.38 K and 0 T. We find a non-trivial dependence of the proximity length on magnetic field. Surprisingly, we find that the magnetic field does not affect the induced superconductivity up to 0.3 T. However, larger fields of 0.6 T suppress superconductivity in the wetting layer, where the Pb island still remains superconducting. We discuss the unexpected robustness of induced superconductivity in view of the high electronic diffusivity in the metallic wetting layer.

  15. Combined hydrogen and lithium beam emission spectroscopy observation system for Korea Superconducting Tokamak Advanced Research

    Energy Technology Data Exchange (ETDEWEB)

    Lampert, M. [Wigner RCP, Euratom Association-HAS, Budapest (Hungary); BME NTI, Budapest (Hungary); Anda, G.; Réfy, D.; Zoletnik, S. [Wigner RCP, Euratom Association-HAS, Budapest (Hungary); Czopf, A.; Erdei, G. [Department of Atomic Physics, BME IOP, Budapest (Hungary); Guszejnov, D.; Kovácsik, Á.; Pokol, G. I. [BME NTI, Budapest (Hungary); Nam, Y. U. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-07-15

    A novel beam emission spectroscopy observation system was designed, built, and installed onto the Korea Superconducting Tokamak Advanced Research tokamak. The system is designed in a way to be capable of measuring beam emission either from a heating deuterium or from a diagnostic lithium beam. The two beams have somewhat complementary capabilities: edge density profile and turbulence measurement with the lithium beam and two dimensional turbulence measurement with the heating beam. Two detectors can be used in parallel: a CMOS camera provides overview of the scene and lithium beam light intensity distribution at maximum few hundred Hz frame rate, while a 4 × 16 pixel avalanche photo-diode (APD) camera gives 500 kHz bandwidth data from a 4 cm × 16 cm region. The optics use direct imaging through lenses and mirrors from the observation window to the detectors, thus avoid the use of costly and inflexible fiber guides. Remotely controlled mechanisms allow adjustment of the APD camera’s measurement location on a shot-to-shot basis, while temperature stabilized filter holders provide selection of either the Doppler shifted deuterium alpha or lithium resonance line. The capabilities of the system are illustrated by measurements of basic plasma turbulence properties.

  16. Development of a machine protection system for the Superconducting Beam Test Facility at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Warner, A.; Carmichael, L.; Church, M.; Neswold, R.; /Fermilab

    2011-09-01

    Fermilab's Superconducting RF Beam Test Facility currently under construction will produce electron beams capable of damaging the acceleration structures and the beam line vacuum chambers in the event of an aberrant accelerator pulse. The accelerator is being designed with the capability to operate with up to 3000 bunches per macro-pulse, 5Hz repetition rate and 1.5 GeV beam energy. It will be able to sustain an average beam power of 72 KW at the bunch charge of 3.2 nC. Operation at full intensity will deposit enough energy in niobium material to approach the melting point of 2500 C. In the early phase with only 3 cryomodules installed the facility will be capable of generating electron beam energies of 810 MeV and an average beam power that approaches 40 KW. In either case a robust Machine Protection System (MPS) is required to mitigate effects due to such large damage potentials. This paper will describe the MPS system being developed, the system requirements and the controls issues under consideration.

  17. Superconductivity

    CERN Document Server

    Poole, Charles P; Creswick, Richard J; Prozorov, Ruslan

    2014-01-01

    Superconductivity, Third Edition is an encyclopedic treatment of all aspects of the subject, from classic materials to fullerenes. Emphasis is on balanced coverage, with a comprehensive reference list and significant graphics from all areas of the published literature. Widely used theoretical approaches are explained in detail. Topics of special interest include high temperature superconductors, spectroscopy, critical states, transport properties, and tunneling. This book covers the whole field of superconductivity from both the theoretical and the experimental point of view. This third edition features extensive revisions throughout, and new chapters on second critical field and iron based superconductors.

  18. A Fast Switchyard for the TESLA FEL-Beam Using a Superconducting Transverse Mode Cavity

    CERN Document Server

    Wanzenberg, R

    2000-01-01

    In the present design of the TESLA Linear Collider with integrated X-ray Laser Facility it is necessary that 1 ms long bunch trains with about 10000 bunches are generated and distributed to several free electron laser (FEL) beam lines. The different scientific applications of the X-ray FELs need specific filling patterns of the bunches in the bunch train. It is shown that a fast switch-yard based on a superconducting transverse mode cavity can be used to generate the required bunch pattern in a flexible way while keeping the beam loading in the main linear accelerator constant. The conceptual design of the beam optics and the transverse mode cavity are presented.

  19. Narrow dip around zero magnetic field in magnetization hysteresis loops of thin YBCO superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Delimova, L [Wihuri Physical Laboratory, Department of Physics, University of Turku, FIN-20014 Turku (Finland); Liniichuk, I [A F Ioffe Physico-Technical Institute, St. Petersburg (Russian Federation); Laehderanta, E [Wihuri Physical Laboratory, Department of Physics, University of Turku, FIN-20014 Turku (Finland); Safonchik, M [Wihuri Physical Laboratory, Department of Physics, University of Turku, FIN-20014 Turku (Finland); Traito, K B [Wihuri Physical Laboratory, Department of Physics, University of Turku, FIN-20014 Turku (Finland)

    2003-01-01

    A narrow dip is observed around zero magnetic field in magnetization curves M(B) of superconducting YBCO films with about 10 nm thickness. This anomaly occurs in the same field range with an anomaly of ac surface impedance Z(B) found recently in thin YBCO films. Because the thickness of our films is considerably less than the London penetration depth, two-dimensional limit of the critical state model is applied. In the framework of this model the magnetic field dependence of the critical current density j{sub c}(B) is found. The obtained j{sub c}(B) function agrees well with that found in the ac surface impedance investigation.

  20. Molecular-Beam Epitaxially Grown MgB2 Thin Films and Superconducting Tunnel Junctions

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Laloë

    2011-01-01

    Full Text Available Since the discovery of its superconducting properties in 2001, magnesium diboride has generated terrific scientific and engineering research interest around the world. With a of 39 K and two superconducting gaps, MgB2 has great promise from the fundamental point of view, as well as immediate applications. Several techniques for thin film deposition and heterojunction formation have been established, each with its own advantages and drawbacks. Here, we will present a brief overview of research based on MgB2 thin films grown by molecular beam epitaxy coevaporation of Mg and B. The films are smooth and highly crystalline, and the technique allows for virtually any heterostructure to be formed, including all-MgB2 tunnel junctions. Such devices have been characterized, with both quasiparticle and Josephson tunneling reported. MgB2 remains a material of great potential for a multitude of further characterization and exploration research projects and applications.

  1. High quality YBCO superconductive thin films fabricated by laser molecular beam epitaxy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    High quality YBa2Cu3O6+x (YBCO) superconductive thin films have been fabricated on the SrTiO3(100) substrate using laser molecular beam epitaxy (laser-MBE).The active oxygen source was used,which made the necessary ambient oxygen pressure be 2-3 orders lower than that in pulsed laser deposition (PLD).Tc0 is 85-87 K,and Jc~1.0×106 A/cm2.Atomic force microscopy (AFM) measurements show that no obvious particulates can be observed and the root mean square roughness is 7.8 nm.High stability DC superconducting quantum interference devices (DC-SQUID) was fabricated using this YBCO thin film.

  2. Professor Jesse W. Beams and the first practical magnetic suspension

    Science.gov (United States)

    Allaire, P. E.; Humphris, R. R.; Lewis, D. W.

    1992-01-01

    Dr. Jesse W. Beams developed the first practical magnetic suspension for high speed rotating devices. The devices included high speed rotating mirrors, ultracentrifuges, and high speed centrifugal field rotors. A brief biography of Dr. Beams is presented, and the following topics are discussed: (1) early axial magnetic suspension for ultracentrifuges; and (2) magnetic suspension for high centrifugal fields.

  3. Spiral magnetic order and pressure-induced superconductivity in transition metal compounds

    Science.gov (United States)

    Wang, Yishu; Feng, Yejun; Cheng, J.-G.; Wu, W.; Luo, J. L.; Rosenbaum, T. F.

    2016-10-01

    Magnetic and superconducting ground states can compete, cooperate and coexist. MnP provides a compelling and potentially generalizable example of a material where superconductivity and magnetism may be intertwined. Using a synchrotron-based non-resonant X-ray magnetic diffraction technique, we reveal a spiral spin order in MnP and trace its pressure evolution towards superconducting order via measurements in a diamond anvil cell. Judging from the magnetostriction, ordered moments vanish at the quantum phase transition as pressure increases the electron kinetic energy. Spins remain local in the disordered phase, and the promotion of superconductivity is likely to emerge from an enhanced coupling to residual spiral spin fluctuations and their concomitant suppression of phonon-mediated superconductivity. As the pitch of the spiral order varies across the 3d transition metal compounds in the MnP family, the magnetic ground state switches between antiferromagnet and ferromagnet, providing an additional tuning parameter in probing spin-fluctuation-induced superconductivity.

  4. Spiral magnetic order and pressure-induced superconductivity in transition metal compounds

    Science.gov (United States)

    Wang, Yishu; Feng, Yejun; Cheng, J.-G.; Wu, W.; Luo, J. L.; Rosenbaum, T. F.

    2016-01-01

    Magnetic and superconducting ground states can compete, cooperate and coexist. MnP provides a compelling and potentially generalizable example of a material where superconductivity and magnetism may be intertwined. Using a synchrotron-based non-resonant X-ray magnetic diffraction technique, we reveal a spiral spin order in MnP and trace its pressure evolution towards superconducting order via measurements in a diamond anvil cell. Judging from the magnetostriction, ordered moments vanish at the quantum phase transition as pressure increases the electron kinetic energy. Spins remain local in the disordered phase, and the promotion of superconductivity is likely to emerge from an enhanced coupling to residual spiral spin fluctuations and their concomitant suppression of phonon-mediated superconductivity. As the pitch of the spiral order varies across the 3d transition metal compounds in the MnP family, the magnetic ground state switches between antiferromagnet and ferromagnet, providing an additional tuning parameter in probing spin-fluctuation-induced superconductivity. PMID:27708255

  5. DESIGN OF BEAM-EXTRACTION SEPTUM MAGNET FOR THE SNS.

    Energy Technology Data Exchange (ETDEWEB)

    TSOUPAS,N.; LEE,Y.Y.; RANK,J.; TUOZZOLO,J.

    2001-06-18

    The beam-extraction process from the SNS accumulator ring [1,2] requires a Lambertson septum magnet. In this paper we discuss the geometrical and magnetic field requirements of the magnet and present results obtained from two and three dimensional magnetic field calculations that shows the field quality in the regions of interest of the septum magnet.

  6. submitter Development of a Superconducting Magnet for a Compact Cyclotron for Radioisotope Production

    CERN Document Server

    Garcia-Tabares, Luis; Calero, Jesus; Gutierrez, Jose L; Munilla, Javier; Obradors, Diego; Perez, Jose M; Toral, Fernando; Iturbe, Rafael; Minguez, Leire; Gomez, Jose; Rodilla, Elena; Bajko, Marta; Michels, Matthias; Berkowitz, Daniel; Haug, Friedrich

    2016-01-01

    The present paper describes the development process of a low critical temperature superconducting magnet to be installed in a compact cyclotron producing single-dose radioisotopes for clinical and preclinical applications. After a brief description of the accelerator, the magnet development process is described, starting from the magnetic, mechanical, quench, and thermal calculations, continuing with the designing process, particularly the support structure of the magnet and the cryogenic supply system, to finish with the fabrication and the first tests than have been performed.

  7. Nonlinear resonances of three modes in a high-T{sub c} superconducting magnetic levitation system

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Masahiko, E-mail: galian@z2.keio.jp; Sakaguchi, Ryunosuke; Sugiura, Toshihiko, E-mail: sugiura@mach.keio.ac.jp

    2013-11-15

    Highlights: •We studied two nonlinear vibrations of a levitated beam supported by superconductors. •One of the vibrations is combination resonance of the 1st mode and the 3rd mode. •The other vibration is autoparametric resonance of the 2nd mode. •When the amplitude of the 2nd mode is small, the combination resonance is suppressed. •Otherwise, the two resonances can be resonated simultaneously. -- Abstract: In a high-T{sub c} superconducting magnetic levitation system, an object can levitate without control and contact. So it is expected to be applied to magnetically levitated transportation. To use it safely, lightening the levitated object is necessary. But this reduces the bending stiffness of the object. Besides, the system has nonlinearity. Therefore nonlinear elastic vibration can occur. This study focused on how plural nonlinear elastic vibrations of the 1st, 2nd and 3rd modes simultaneously occur. Our numerical calculation and experiment found out that the three modes simultaneously resonate when the amplitude of the 2nd mode is large enough whereas only the 2nd mode resonates when it is small.

  8. Propagation of ion beams through a tenuous magnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chrien, E.F.; Valeo, E.J.; Kulsrud, R.M.; Oberman, C.R.

    1985-10-01

    When an ion beam is propagated through a plasma, the question of charge neutralization is critical to its propagation. We consider such a problem where the plasma is magnetized with magnetic field perpendicular to the beam. The plasma-number density and beam-number density are assumed comparable. We reduce the problem to a two-dimensional model, which we solve. The solution suggests that it should be possible to attain charge neutralization if the beam density is properly varied along itself.

  9. OPERATIONAL EXPERIENCE WITH BEAM ABORT SYSTEM FOR SUPERCONDUCTING UNDULATOR QUENCH MITIGATION*

    Energy Technology Data Exchange (ETDEWEB)

    Harkay, Katherine C.; Dooling, Jeffrey C.; Sajaev, Vadim; Wang, Ju

    2017-06-25

    A beam abort system has been implemented in the Advanced Photon Source storage ring. The abort system works in tandem with the existing machine protection system (MPS), and its purpose is to control the beam loss location and, thereby, minimize beam loss-induced quenches at the two superconducting undulators (SCUs). The abort system consists of a dedicated horizontal kicker designed to kick out all the bunches in a few turns after being triggered by MPS. The abort system concept was developed on the basis of single- and multi-particle tracking simulations using elegant and bench measurements of the kicker pulse. Performance of the abort system—kick amplitudes and loss distributions of all bunches—was analyzed using beam position monitor (BPM) turn histories, and agrees reasonably well with the model. Beam loss locations indicated by the BPMs are consistent with the fast fiber-optic beam loss monitor (BLM) diagnostics described elsewhere [1,2]. Operational experience with the abort system, various issues that were encountered, limitations of the system, and quench statistics are described.

  10. Interaction between an electric charge and a magnetic dipole of any kind (permanent, para- or dia- magnetic or superconducting)

    CERN Document Server

    Coïsson, R

    2015-01-01

    The interaction between point charge and magnetic dipole is usually considered only for the case of a rigid ferromagnetic dipole (constant-current): here the analysis of force, momentum and energy (including the energy provided by the internal current generator) is generalised to any magnetic dipole behaviour: rigid, paramagnetic, diamagnetic or superconducting (perfectly diamagnetic).

  11. Magnetic and superconducting quantum critical points of heavy-fermion systems

    Energy Technology Data Exchange (ETDEWEB)

    Demuer, A.; Sheikin, I.; Braithwaite, D. E-mail: dbraithwaite@cea.fr; Faak, B.; Huxley, A.; Raymond, S.; Flouquet, J

    2001-05-01

    Two examples of heavy-fermion systems are presented : CePd{sub 2}Si{sub 2}, an antiferromagnet with a quantum critical point at P{sub C}=28 kbar and UGe{sub 2} an itinerant ferromagnet which transits in a paramagnetic phase above P{sub C}=16 kbar. In CePd{sub 2}Si{sub 2} the superconductivity domain is centered on P{sub C}. Special attention was given to the superconducting and magnetic anomalies at their superconducting and Neel temperatures. In UGe{sub 2} superconductivity appears in 9 kbar at a temperature T{sub S}, more than two orders of magnitude lower than the Curie temperature; furthermore, it occurs only on the magnetic border (P

  12. Magnetic and superconducting quantum critical points of heavy-fermion systems

    Science.gov (United States)

    Demuer, A.; Sheikin, I.; Braithwaite, D.; Fåk, B.; Huxley, A.; Raymond, S.; Flouquet, J.

    2001-05-01

    Two examples of heavy-fermion systems are presented : CePd 2Si 2, an antiferromagnet with a quantum critical point at PC=28 kbar and UGe 2 an itinerant ferromagnet which transits in a paramagnetic phase above PC=16 kbar. In CePd 2Si 2 the superconductivity domain is centered on PC. Special attention was given to the superconducting and magnetic anomalies at their superconducting and Néel temperatures. In UGe 2 superconductivity appears in 9 kbar at a temperature TS, more than two orders of magnitude lower than the Curie temperature; furthermore, it occurs only on the magnetic border ( P< PC). Another characteristic temperature TX is detected by resistivity; the zigzag uranium chain of the lattice may favor a supplementary nesting in the majority spin band.

  13. Superconductivity and magnetism in intermetallic Bi3Ni1-xFex superconductor

    Science.gov (United States)

    Gonsalves, Silvio Henrique; Opata, Yuri Aparecido; Pinheiro, Lincoln Brum Leite Gusmão; Da Silva Leal, Adriane Consuelo; Monteiro, João Frederico Haas Leandro; Siqueira, Ezequiel Costa; de Andrade, André Vitor Chaves; Jurelo, Alcione Roberto

    2016-09-01

    In this work, we investigated the apparent coexistence of superconductivity and magnetism in polycrystalline Bi3Ni1-xFex samples for low concentrations of iron (0 ≤ x ≤ 0.10). The compound was synthesized by the solid-state reaction method and characterized by X-ray diffraction and magnetic measurements. From X-ray, it was observed that the main phase corresponds to an orthorhombic structure with space group Pnma and shows no dependence on the Fe concentration. From magnetic measurements, it was observed that the critical temperature was not affected by iron doping and that ferromagnetism and superconductivity coexist apparently in an interesting interplay.

  14. Mechanical behavior of the mirror fusion test Facility superconducting magnet coils

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, J.A.

    1980-01-01

    The mechanical response to winding and electromagnetic loads of the Mirror Fusion Test Facility (MFTF) superconducting coil pack is presented. The 375-ton (3300 N) MFTF Yin-Yang magnet, presently the world's largest superconducting magnet, is scheduled for acceptance cold-testing in May of 1981. The assembly is made up of two identical coils which together contain over 15 miles (24 km) of superconductor wound in 58 consecutive layers of 24 turns each. Topics associated with mechanical behavior include physical properties of the coil pack and its components, winding pre-load effects, finite element analysis, magnetic load redistribution, and the design impact of predicted conductor motion.

  15. Pressure induced superconductivity on the border of magnetic order in MnP.

    Science.gov (United States)

    Cheng, J-G; Matsubayashi, K; Wu, W; Sun, J P; Lin, F K; Luo, J L; Uwatoko, Y

    2015-03-20

    We report the discovery of superconductivity on the border of long-range magnetic order in the itinerant-electron helimagnet MnP via the application of high pressure. Superconductivity with T(sc)≈1  K emerges and exists merely near the critical pressure P(c)≈8  GPa, where the long-range magnetic order just vanishes. The present finding makes MnP the first Mn-based superconductor. The close proximity of superconductivity to a magnetic instability suggests an unconventional pairing mechanism. Moreover, the detailed analysis of the normal-state transport properties evidenced non-Fermi-liquid behavior and the dramatic enhancement of the quasiparticle effective mass near P(c) associated with the magnetic quantum fluctuations.

  16. Correlated trends of coexisting magnetism and superconductivity in optimally electron-doped oxypnictides.

    Science.gov (United States)

    Sanna, S; Carretta, P; Bonfà, P; Prando, G; Allodi, G; De Renzi, R; Shiroka, T; Lamura, G; Martinelli, A; Putti, M

    2011-11-25

    We report on the recovery of the short-range static magnetic order and on the concomitant degradation of the superconducting state in optimally F-doped SmFe(1-x)Ru(x)AsO(0.85)F(0.15) for 0.1≤x≲0.5. The two reduced order parameters coexist within nanometer-size domains in the FeAs layers and eventually disappear around a common critical threshold x(c)~0.6. Superconductivity and magnetism are shown to be closely related to two distinct well-defined local electronic environments of the FeAs layers. The two transition temperatures, controlled by the isoelectronic and diamagnetic Ru substitution, scale with the volume fraction of the corresponding environments. This fact indicates that superconductivity is assisted by magnetic fluctuations, which are frozen whenever a short-range static order appears, and totally vanish above the magnetic dilution threshold x(c).

  17. Magnet tests and status of the superconducting electron cyclotron resonance source SERSE

    Energy Technology Data Exchange (ETDEWEB)

    Ciavola, G.; Gammino, S.; Cafici, M.; Castro, M.; Chines, F.; Marletta, S. [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy); Alessandria, F. [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy); Bourg, F.; Briand, P.; Melin, G.; Lagnier, R.; Seyfert, P. [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France); Gaggero, G.; Losasso, M.; Penco, R. [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)

    1996-03-01

    At Laboratorio Nazionale del Sud a superconducting 14.5 GHz electron cyclotron resonance (ECR) source will be used as injector for the K-800 superconducting cyclotron. The original project of its magnetic system has been upgraded by taking into account the results of the high B mode operation of the 6.4 GHz SC-ECRIS at MSU-NSCL and now the mirror field may achieve 2.7 T, which is much higher than the confining field of any other ECR source. The magnet design will allow us to operate in a wide range of magnetic configurations making it easy to tune the source. The status of the project will be outlined and the preliminary results of the tests of the superconducting magnets will be described. A brief description of the tests to be carried out on the source during the first period of operation on the test bench in Grenoble follows. {copyright} {ital 1996 American Institute of Physics.}

  18. Neutron scattering study on the magnetic and superconducting phases of MnP

    Science.gov (United States)

    Yano, Shinichiro; Lancon, Diane; Ronnow, Henrik; Hansen, Thomas; Gardner, Jason

    We have performed series of neutron scattering experiments on MnP. MnP has been investigated for decades because of its rich magnetic phase diagram. The magnetic structure of MnP is ferromagnetic (FM) below TC = 291 K. It transforms into a helimagnetic structure at TS = 47 K with a propagation vector q = 0 . 117a* . Superconductivity was found in MnP under pressures of 8 GPa with a TSC around 1 K by J.-G. Cheng. Since Mn-based superconductors are rare, and the superconducting phase occurs in the vicinity of FM, new magnetic and helimagnetic phases, there is a need to understand how the magnetism evolves as one approach the superconducting state. MnP is believed to be a double helix magnetic structure at TS = 47 K. We observed new 2 δ and 3 δ satellite peaks whose intensity are 200 ~ 1000 times smaller than these of 1 δ satellite peaks on the cold triple axis spectrometer SIKA under zero magnetic fields. We also found the periods of helimagnetic structure changes as a function of temperature. If time permits, we will discuss recent experiments under pressure. However, we have complete picture of magnetic structure of this system with and without applied pressure, revealing the interplay between the magnetic and superconducting phases.

  19. New magnetic coherence effect in superconducting La2-xSrxCuO4

    DEFF Research Database (Denmark)

    Mason, T.E.; Schröder, A.; Aeppli, G.

    1996-01-01

    We have used inelastic neutron scattering to examine the magnetic fluctuations at intermediate frequencies in the simplest high temperature superconductor, La2-xSrxCuO4. The suppression of the low energy magnetic response in the superconducting state is accompanied by an increase in the response...

  20. Novel Ways of Heat Removal from Highly Irradiated Superconducting Windings in Accelerator Magnets

    NARCIS (Netherlands)

    Bielert, Erwin R.; Verweij, Arjan P.; Kate, ten Herman H.J.

    2012-01-01

    Novel ideas of heat removal from superconducting windings in accelerator type magnets are investigated with the help of a recently developed and validated thermal model of a magnet cold mass implemented in COMSOL Multiphysics. Here the focus is on how to improve heat removal from the midplane of a s

  1. Spin superconductivity and ac-Josephson effect in Graphene system under strong magnetic field

    Science.gov (United States)

    Liu, Haiwen; Jiang, Hua; Sun, Qing-Feng; Xie, X. C.; Collaborative Innovation Center of Quantum Matter, Beijing, China Collaboration

    We study the spin superconductivity in Graphene system under strong magnetic field. From the microscopically Gor'kov method combined with the Aharonov-Casher effect, we derive the effective Landau-Ginzburg free energy and analyze the time evolution of order parameter, which is confirmed to be the off-diagonal long range order. Meanwhile, we compare the ground state of spin superconductivity to the canted-antiferromagnetic state, and demonstrate the equivalence between these two states. Moreover, we give out the pseudo-field flux quantization condition of spin supercurrent, and propose an experimental measurable ac-Josephson effect of spin superconductivity in this system.

  2. Competitions of magnetism and superconductivity in FeAs-based materials

    Institute of Scientific and Technical Information of China (English)

    Yang Shuo; You Wen-Long; Gu Shi-Jian; Lin Hai-Qing

    2009-01-01

    Using the numerical unrestricted Hartree-Fock approach, we study the ground state of a two-orbital model describing newly discovered FeAs-based superconductors. We observe the competition of a (0, π) mode spin-density wave and the superconductivity as the doping concentration changes. There might be a small region in the electron-doping side where the magnetism and superconductivity coexist. The superconducting pairing is found to be spin singlet,orbital even, and coexisting sxy + dx2-y2 wave (even parity).

  3. Classification of magnetic inhomogeneities and 0 -π transitions in superconducting-magnetic hybrid structures

    Science.gov (United States)

    Baker, Thomas E.; Richie-Halford, Adam; Bill, Andreas

    2016-09-01

    We present a comparative study of pair correlations and currents through superconducting-magnetic hybrid systems with a particular emphasis on the tunable Bloch domain wall of an exchange spring. This study of the Gor'kov functions contrasts magnetic systems with domain walls that change at discrete points in the magnetic region with those that change continuously throughout. We present results for misaligned homogeneous magnetic multilayers, including spin valves, for discrete domain walls, as well as exchange springs and helical domain walls—such as Holmium—for the continuous case. Introducing a rotating basis to disentangle the role of singlet and triplet correlations, we demonstrate that substantial amounts of (so-called short-range) singlet correlations are generated throughout the magnetic system in a continuous domain wall via the cascade effect. We propose a classification of 0 -π transitions of the Josephson current into three types, according to the predominant pair correlations symmetries involved in the current. Properties of exchange springs for an experimental study of the proposed effects are discussed. The interplay between components of the Gor'kov function that are parallel and perpendicular to the local magnetization lead to a novel prediction about their role in a proximity system with a progressively twisting helix that is experimentally measurable.

  4. Battery energy storage and superconducting magnetic energy storage for utility applications: A qualitative analysis

    Energy Technology Data Exchange (ETDEWEB)

    Akhil, A.A.; Butler, P.; Bickel, T.C.

    1993-11-01

    This report was prepared at the request of the US Department of Energy`s Office of Energy Management for an objective comparison of the merits of battery energy storage with superconducting magnetic energy storage technology for utility applications. Conclusions are drawn regarding the best match of each technology with these utility application requirements. Staff from the Utility Battery Storage Systems Program and the superconductivity Programs at Sandia National contributed to this effort.

  5. A novel electron beam evaporation technique for the deposition of superconducting thin films

    Science.gov (United States)

    Krishna, M. G.; Muralidhar, G. K.; Rao, K. N.; Rao, G. M.; Mohan, S.

    1991-05-01

    Superconducting thin films of BiSrCaCuO have been deposited using a novel electron beam evaporation technique. In this technique the crucible has a groove around its circumference and rotates continuously during deposition. The source material is loaded in the form of pellets of the composite. Both oxides as well as flourides have been used in the starting material and a comparison of the film properties has been made. The best film was obtained on a MgO(100) substrate with a Tc onset at 85 K and Tc zero at 77 K using calcium flouride in the source material.

  6. Vibrational excitation induced by electron beam and cosmic rays in normal and superconductive aluminum bars

    CERN Document Server

    Bassan, M; Cavallari, G; Coccia, E; D'Antonio, S; Fafone, V; Foggetta, L G; Ligi, C; Marini, A; Mazzitelli, G; Modestino, G; Pizzella, G; Quintieri, L; Ronga, F; Valente, P; Vinko, S M

    2011-01-01

    We report new measurements of the acoustic excitation of an Al5056 superconductive bar when hit by an electron beam, in a previously unexplored temperature range, down to 0.35 K. These data, analyzed together with previous results of the RAP experiment obtained for T > 0.54 K, show a vibrational response enhanced by a factor 4.9 with respect to that measured in the normal state. This enhancement explains the anomalous large signals due to cosmic rays previously detected in the NAUTILUS gravitational wave detector.

  7. Linear beam dynamics and ampere class superconducting RF cavities at RHIC

    Science.gov (United States)

    Calaga, Rama R.

    The Relativistic Heavy Ion Collider (RHIC) is a hadron collider designed to collide a range of ions from protons to gold. RHIC operations began in 2000 and has successfully completed five physics runs with several species including gold, deuteron, copper, and polarized protons. Linear optics and coupling are fundamental issues affecting the collider performance. Measurement and correction of optics and coupling are important to maximize the luminosity and sustain stable operation. A numerical approach, first developed at SLAC, was implemented to measure linear optics from coherent betatron oscillations generated by ac dipoles and recorded at multiple beam position monitors (BPMs) distributed around the collider. The approach is extended to a fully coupled 2D case and equivalence relationships between Hamiltonian and matrix formalisms are derived. Detailed measurements of the transverse coupling terms are carried out at RHIC and correction strategies are applied to compensate coupling both locally and globally. A statistical approach to determine BPM reliability and performance over the past three runs and future improvements also discussed. Aiming at a ten-fold increase in the average heavy-ion luminosity, electron cooling is the enabling technology for the next luminosity upgrade (RHIC II). Cooling gold ion beams at 100 GeV/nucleon requires an electron beam of approximately 54 MeV and a high average current in the range of 50-200 mA. All existing e-Coolers are based on low energy DC accelerators. The only viable option to generate high current, high energy, low emittance CW electron beam is through a superconducting energy-recovery linac (SC-ERL). In this option, an electron beam from a superconducting injector gun is accelerated using a high gradient (˜ 20 MV/m) superconducting RF (SRF) cavity. The electrons are returned back to the cavity with a 180° phase shift to recover the energy back into the cavity before being dumped. A design and development of a half

  8. Local destruction of superconductivity by non-magnetic impurities in mesoscopic iron-based superconductors.

    Science.gov (United States)

    Li, Jun; Ji, Min; Schwarz, Tobias; Ke, Xiaoxing; Van Tendeloo, Gustaaf; Yuan, Jie; Pereira, Paulo J; Huang, Ya; Zhang, Gufei; Feng, Hai-Luke; Yuan, Ya-Hua; Hatano, Takeshi; Kleiner, Reinhold; Koelle, Dieter; Chibotaru, Liviu F; Yamaura, Kazunari; Wang, Hua-Bing; Wu, Pei-Heng; Takayama-Muromachi, Eiji; Vanacken, Johan; Moshchalkov, Victor V

    2015-07-03

    The determination of the pairing symmetry is one of the most crucial issues for the iron-based superconductors, for which various scenarios are discussed controversially. Non-magnetic impurity substitution is one of the most promising approaches to address the issue, because the pair-breaking mechanism from the non-magnetic impurities should be different for various models. Previous substitution experiments demonstrated that the non-magnetic zinc can suppress the superconductivity of various iron-based superconductors. Here we demonstrate the local destruction of superconductivity by non-magnetic zinc impurities in Ba0.5K0.5Fe2As2 by exploring phase-slip phenomena in a mesoscopic structure with 119 × 102 nm(2) cross-section. The impurities suppress superconductivity in a three-dimensional 'Swiss cheese'-like pattern with in-plane and out-of-plane characteristic lengths slightly below ∼1.34 nm. This causes the superconducting order parameter to vary along abundant narrow channels with effective cross-section of a few square nanometres. The local destruction of superconductivity can be related to Cooper pair breaking by non-magnetic impurities.

  9. Design and Manufacture of the Superconducting Bus-bars for the LHC Main Magnets

    CERN Document Server

    Belova, L M; Perinet-Marquet, J L; Ivanov, P; Urpin, C

    2002-01-01

    The main magnets of the LHC are series-connected electrically in different powering circuits by means of superconducting bus-bars, carrying a maximum current of 13 kA. These superconducting bus-bars consist of a superconducting cable thermally and electrically coupled to a copper profile all along the length. The function of the copper profile is essentially to provide an alternative path for the current in case the superconducting cable loses its superconducting state and returns to normal state because of a transient disturbance or of a normal zone propagation coming from the neighbouring magnets. When a superconducting bus-bar quenches to normal state its temperature must always stay below a safe values of about 100°C while the copper is conducting. When a resistive transition is detected, the protection systems triggers the ramping down of the current from 13000 A to 0. The ramp rate must not exceed a maximum value to avoid the transition of magnets series-connected in the circuit. This paper concerns th...

  10. Roles of superconducting magnetic bearings and active magnetic bearings in attitude control and energy storage flywheel

    Science.gov (United States)

    Tang, Jiqiang; Fang, Jiancheng; Ge, Shuzhi Sam

    2012-12-01

    Compared with conventional energy storage flywheel, the rotor of attitude control and energy storage flywheel (ACESF) used in space not only has high speed, but also is required to have precise and stable direction. For the presented superconducting magnetic bearing (SMB) and active magnetic bearing (AMB) suspended ACESF, the rotor model including gyroscopic couples is established originally by taking the properties of SMB and AMB into account, the forces of SMB and AMB are simplified by linearization within their own neighbors of equilibrium points. For the high-speed rigid discal rotor with large inertia, the negative effect of gyroscopic effect of rotor is prominent, the radial translation and tilting movement of rotor suspended by only SMB, SMB with equivalent PMB, or SMB together with PD controlled AMB are researched individually. These analysis results proved originally that SMB together with AMB can make the rotor be stable and make the radial amplitude of the vibration of rotor be small while the translation of rotor suspended by only SMB or SMB and PM is not stable and the amplitude of this vibration is large. For the stability of the high-speed rotor in superconducting ACESF, the AMB can suppress the nutation and precession of rotor effectively by cross-feedback control based on the separated PD type control or by other modern control methods.

  11. Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Baffes, C.; Church, M.; Leibfritz, J.; Oplt, S.; Rakhno, I.; /Fermilab

    2012-05-10

    A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type SRF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. The potential for radiation-induced degradation of the graphite is discussed.

  12. Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

    CERN Document Server

    Baffes, C; Leibfritz, J; Oplt, S; Rakhno, I

    2013-01-01

    A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type RF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a Helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. In addition, the potential for radiation-induced degradation of the graphite is discussed.

  13. Polymorphism control of superconductivity and magnetism in Cs(3)C(60) close to the Mott transition.

    Science.gov (United States)

    Ganin, Alexey Y; Takabayashi, Yasuhiro; Jeglic, Peter; Arcon, Denis; Potocnik, Anton; Baker, Peter J; Ohishi, Yasuo; McDonald, Martin T; Tzirakis, Manolis D; McLennan, Alec; Darling, George R; Takata, Masaki; Rosseinsky, Matthew J; Prassides, Kosmas

    2010-07-08

    The crystal structure of a solid controls the interactions between the electronically active units and thus its electronic properties. In the high-temperature superconducting copper oxides, only one spatial arrangement of the electronically active Cu(2+) units-a two-dimensional square lattice-is available to study the competition between the cooperative electronic states of magnetic order and superconductivity. Crystals of the spherical molecular C(60)(3-) anion support both superconductivity and magnetism but can consist of fundamentally distinct three-dimensional arrangements of the anions. Superconductivity in the A(3)C(60) (A = alkali metal) fullerides has been exclusively associated with face-centred cubic (f.c.c.) packing of C(60)(3-) (refs 2, 3), but recently the most expanded (and thus having the highest superconducting transition temperature, T(c); ref. 4) composition Cs(3)C(60) has been isolated as a body-centred cubic (b.c.c.) packing, which supports both superconductivity and magnetic order. Here we isolate the f.c.c. polymorph of Cs(3)C(60) to show how the spatial arrangement of the electronically active units controls the competing superconducting and magnetic electronic ground states. Unlike all the other f.c.c. A(3)C(60) fullerides, f.c.c. Cs(3)C(60) is not a superconductor but a magnetic insulator at ambient pressure, and becomes superconducting under pressure. The magnetic ordering occurs at an order of magnitude lower temperature in the geometrically frustrated f.c.c. polymorph (Néel temperature T(N) = 2.2 K) than in the b.c.c.-based packing (T(N) = 46 K). The different lattice packings of C(60)(3-) change T(c) from 38 K in b.c.c. Cs(3)C(60) to 35 K in f.c.c. Cs(3)C(60) (the highest found in the f.c.c. A(3)C(60) family). The existence of two superconducting packings of the same electronically active unit reveals that T(c) scales universally in a structure-independent dome-like relationship with proximity to the Mott metal-insulator transition

  14. Cumulative beam break-up study of the spallation neutron source superconducting linac

    CERN Document Server

    Jeon, D; Krafft, G A; Yunn, B; Sundelin, R; Delayen, J; Kim, S; Doleans, M

    2002-01-01

    Beam instabilities due to High Order Modes (HOMs) are a concern to superconducting (SC) linacs such as the Spallation Neutron Source (SNS) linac. The effects of pulsed mode operation on transverse and longitudinal beam breakup instability are studied for H sup - beam in a consistent manner for the first time. Numerical simulation indicates that cumulative transverse beam breakup instabilities are not a concern in the SNS SC linac, primarily due to the heavy mass of H sup - beam and the HOM frequency spread resulting from manufacturing tolerances. As little as +-0.1 MHz HOM frequency spread stabilizes all the instabilities from both transverse HOMs, and also acts to stabilize the longitudinal HOMs. Such an assumed frequency spread of +-0.1 MHz HOM is small, and hence conservative compared with measured values of sigma=0.00109(f sub H sub O sub M -f sub 0)/f sub 0 obtained from Cornell and the Jefferson Lab Free Electron Laser cavities. However, a few cavities may hit resonance lines and generate a high heat lo...

  15. Pulsed field magnetization strategies and the field poles composition in a bulk-type superconducting motor

    Science.gov (United States)

    Huang, Zhen; Ruiz, H. S.; Coombs, T. A.

    2017-03-01

    High temperature superconducting (HTS) bulks offer the potential of trapping and maintaining much higher magnetic loading level compared with the conventional permanent magnets used in rotary machines, although the effective magnetization of multiple HTS bulks with different relative orientations over the surface of cylindrical rotors creates new challenges. In this paper, we present the design and numerical validation of the Pulse Field Magnetization (PFM) strategy considered for the magnetization of the four-pole synchronous fully superconducting motor developed at the University of Cambridge. In a first instance, singular columns of up to five HTS bulks aligned over the height of the rotor were subjected to up to three magnetic pulses of 1.5 T peak, and the experimental results have been simulated by considering the electrical and thermal properties of the system in a 2D approach. The entire active surface of the rotor is covered by HTS bulks of approximately the same dimensions, resulting in an uneven distribution of pole areas with at least one of the poles formed by up to 3 columns of magnetized bulks, with relatively the same peaks of trapped magnetic field. Thus, in order to effectively use the entire area of the superconducting rotor, multiple pulsed fields per column have been applied under the same experimental conditions, what results in about three times larger magnetic pole areas but with an average drop on the peaks of trapped magnetic field of about 50%.

  16. LHC magnet quench test with beam loss generated by wire scan

    CERN Document Server

    Sapinski, M; Dahlerup-Petersen, K; Dehning, B; Emery, j; Ferrari, A; Guerrero, A; Holzer, E B; Koujili, M; Lechner, A; Nebot, E; Scheubel, M; Steckert, J; Verweij, A; Wenninger, J

    2011-01-01

    Beam losses with millisecond duration have been observed in the LHC in 2010 and 2011. They are thought to be provoked by dust particles falling into the beam. These losses could compromise the LHC availability if they provoke quenches of superconducting magnets. In order to investigate the quench limits for this loss mechanism, a quench test using a wire scanner has been performed, with the wire movement through the beam mimicking a loss with similar spatial and temporal distribution as in the case of dust particles. This paper will show the conclusions reached for millisecond-duration dust-provoked quench limits. It will include details on the maximum energy deposited in the coil as estimated using FLUKA code, showing a reasonable agreement with quench limit estimated from the heat transfer code QP3. In addition, information on the damage limit for carbon wires in proton beamswill be presented, following electronmicroscope analysis which revealed strong wire sublimation.

  17. Superconductivity and magnetism in the presence of interface-induced Rashba spin-orbit coupling

    Energy Technology Data Exchange (ETDEWEB)

    Loder, Florian; Kampf, Arno P.; Kopp, Thilo [Zentrum fuer Elektronische Korrelationen und Magnetismus, Institut fuer Physik, Universitaet Augsburg (Germany)

    2012-07-01

    Two dimensional electron systems at oxide interfaces are often influenced by a Rashba type spin-orbit coupling (SOC), which is tunable by a transverse electric field. Ferromagnetism at the interface can simultaneously induce strong local magnetic fields. This combination of SOC and magnetism leads to anisotropic two-sheeted Fermi surfaces, on which superconductivity with finite-momentum pairing is favored. The superconducting order parameter is derived within a generalized pairing model realizing both, the FFLO superconductor in the limit of vanishing SOC and a mixed-parity pairing state with zero pair momentum if the magnetism vanishes. The nature of the pairing state is discussed in the context of interface superconductivity and ferromagnetism at LAO-STO interfaces.

  18. Vortex liquid in magnetic-field-induced superconducting vacuum of quenched lattice QCD

    CERN Document Server

    Braguta, V V; Chernodub, M N; Kotov, A Yu; Polikarpov, M I

    2013-01-01

    In the background of the strong magnetic field the vacuum is suggested to possess an electromagnetically superconducting phase characterised by the emergence of inhomogeneous quark-antiquark vector condensates which carry quantum numbers of the charged rho mesons. The rho-meson condensates are inhomogeneous due to the presence of the stringlike defects ("the rho vortices") which are parallel to the magnetic field (the superconducting vacuum phase is similar to the mixed Abrikosov phase of a type-II superconductor). In agreement with these expectations, we have observed the presence of the rho vortices in numerical simulations of the vacuum of the quenched two-color lattice QCD in strong magnetic field background. We have found that in the quenched QCD the rho vortices form a liquid. The transition between the usual (insulator) phase at low B and the superconducting vortex liquid phase at high B turns out to be very smooth, at least in the quenched QCD.

  19. Anomalous magnetism of superconducting Mg-doped InN film

    Directory of Open Access Journals (Sweden)

    P. H. Chang

    2016-02-01

    Full Text Available We report on the Meissner effect of Mg-doped InN film with superconducting transition onset temperature Tc,onset of 5 K. Mg-doped InN is magnetically ordered and exhibits a simultaneous first-order magnetic and electric transition near 50 K. Its behavior is similar to that of iron-based superconductors. A strong correlation is proposed to exist between structural distortion and superconductivity when Mg is doped into InN. The suppression of magnetic ordering close to Tc by doping is further demonstrated by anisotropic magnetoresistance and M-H measurements. The findings suggest that the superconducting mechanism in the system may not be conventional BCS.

  20. Feasibility of Using Conductively Cooled Magnets in Cryomidules of Superconducting Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Terechkine, I. [Fermilab; Cheban, Cheban,S. [Fermilab; Nicol. T., Nicol. T. [Fermilab; Poloubotko, V. [Fermilab; Sergatskov, D. [Fermilab

    2013-09-01

    As part of a search for optimal ways to configure cryomodules of the low-beta section of a high-current, high-power superconducting linac, an option of using conductively cooled superconducting focusing lenses was evaluated. Superconducting magnet was installed inside existing test cryostat, which was modified by adding current feed-throughs and two conductively cooled current leads. Each lead was equipped with heat sinks at the temperatures of liquid nitrogen and liquid helium. The magnet was mounted inside the cryostat on an individual heat sink plate, and thermometers were installed on the leads, heat sinks, and on the magnet. In this report we provide some details of the test setup and analyse results of the temperature measurements.

  1. First Demonstration of Electron Beam Generation and Characterization with an All Superconducting Radio-frequency (SRF) Photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Kamps, T; Barday, R; Jankowiak, A; Knobloch, J; Kugeler, O; Matveenko, A N; Neumann, A; Quast, T; Rudolph, J; Schubert, S G; Volker, J; Kneisel, P; Nietubyc, R; Sekutowicz, J K; Smedley, J; Volkov, V; Weinberg, G

    2011-09-01

    In preparation for a high brightness, high average current electron source for the energy-recovery linac BERLinPro an all superconducting radio-frequency photoinjector is now in operation at Helmholtz-Zentrum Berlin. The aim of this experiment is beam demonstration with a high brightness electron source able to generate sub-ps pulse length electron bunches from a superconducting (SC) cathode film made of Pb coated on the backwall of a Nb SRF cavity. This paper describes the setup of the experiment and first results from beam measurements.

  2. High Temperature Superconducting Magnets: Revolutionizing Next Generation Accelerators and Other Applications (466th Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ramesh (BNL Superconducting Magnet Division)

    2011-02-16

    BNL has always been a leader in the world of superconducting magnets, which are essential to the great modern ccelerators such as the Relativistic Heavy Ion Collider at BNL, or the Large Hadron Collider at CERN, Switzerland. These magnets are made of material that, cooled to 4 Kelvins (K) (-452° Farenheit) become superconducting, that is, lose essentially all resistance to electricity. For the past decade, however, Lab researchers have been exploring the use of new materials that become superconducting at higher temperatures. These materials can operate at the relatively high temperature of 77 K (-351°F), allowing them to be cooled by cheap, plentiful liquid nitrogen, rather than helium, and can create very high magnetic fields. Now far in the lead of this area of research, BNL scientists are exploring avenues for high temperature superconducting magnets that are energy efficient and have magnetic fields that are a million times stronger than the Earth’s. If successful, these new magnets could potentially revolutionize usage in future accelerators, play a key role in energy efficiency and storage, and make possible new applications such as muon colliders and MRI screening in remote areas.

  3. Development of Superconducting Combined Function Magnets for the Proton Transport Line for the J-PARC Neutrino Experiments

    CERN Document Server

    Nakamoto, Tatsushi; Anerella, Michael; Escallier, John; Fujii, T; Fukui, Yuji; Ganetis, George; Gupta, Ramesh C; Harrison, Michael; Hashiguchi, E; Higashi, Norio; Ichikawa, Atsuko; Iwamoto, Yosuke; Jain, Animesh K; Kanahara, T; Kimura, Nobuhiro; Kobayashi, Takashi; Makida, Yasuhiro; Muratore, Joseph F; Obana, Tetsuhiro; Ogitsu, T; Ohhata, Hirokatsu; Okamura, T; Orikasa, T; Parker, Brett; Sasaki, Ken Ichi; Takasaki, Minoru; Tanaka, Ken Ichi; Terashima, Akio; Tomaru, Takayuki; Wanderer, Peter; Yamamoto, Akira

    2005-01-01

    A second generation of long-baseline neutrino oscillation experiments has been proposed as one of the main projects at J-PARC jointly built by JAERI and KEK. Superconducting combined function magnets, SCFMs, will be utilized for the 50 GeV, 750 kW proton beam line for the neutrino experiment and an R&D program is in underway at KEK. The magnet is designed to provide a combined function of a dipole field of 2.6 T with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm. A series of 28 magnets in the beam line will be operated DC in supercritical helium cooling below 5 K. A design feature of the SCFM is the left-right asymmetry of the coil cross section: current distributions for superimposed dipole- and quadrupole- fields are combined in a single layer coil. Another design feature is the adoption of glass-fiber reinforced phenolic plastic spacers to replace the conventional metallic collars. To evaluate this unique design, fabrication of full-scale prototype magnets is in progress at KEK and the fi...

  4. Mathematical formulation to predict the harmonics of the superconducting Large Hadron Collider magnets. II. Dynamic field changes and scaling laws

    Directory of Open Access Journals (Sweden)

    Nicholas J. Sammut

    2007-08-01

    Full Text Available A superconducting particle accelerator like the LHC (Large Hadron Collider at CERN, can only be controlled well if the effects of the magnetic field multipoles on the beam are compensated. The demands on a control system solely based on beam feedback may be too high for the requirements to be reached at the specified bandwidth and accuracy. Therefore, we designed a suitable field description for the LHC (FIDEL as part of the machine control baseline to act as a feed-forward magnetic field prediction system. FIDEL consists of a physical and empirical parametric field model based on magnetic measurements at warm and in cryogenic conditions. The performance of FIDEL is particularly critical at injection when the field decays, and in the initial part of the acceleration when the field snaps back. These dynamic components are both current and time dependent and are not reproducible from cycle to cycle since they also depend on the magnet powering history. In this paper a qualitative and quantitative description of the dynamic field behavior substantiated by a set of scaling laws is presented.

  5. Effect of superconducting solenoid model cores on spanwise iron magnet roll control

    Science.gov (United States)

    Britcher, C. P.

    1985-01-01

    Compared with conventional ferromagnetic fuselage cores, superconducting solenoid cores appear to offer significant reductions in the projected cost of a large wind tunnel magnetic suspension and balance system. The provision of sufficient magnetic roll torque capability has been a long-standing problem with all magnetic suspension and balance systems; and the spanwise iron magnet scheme appears to be the most powerful system available. This scheme utilizes iron cores which are installed in the wings of the model. It was anticipated that the magnetization of these cores, and hence the roll torque generated, would be affected by the powerful external magnetic field of the superconducting solenoid. A preliminary study has been made of the effect of the superconducting solenoid fuselage model core concept on the spanwise iron magnet roll torque generation schemes. Computed data for one representative configuration indicate that reductions in available roll torque occur over a range of applied magnetic field levels. These results indicate that a 30-percent increase in roll electromagnet capacity over that previously determined will be required for a representative 8-foot wind tunnel magnetic suspension and balance system design.

  6. Undulator Beam Pipe Magnetic Shielding Effect Tests

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Andrew; Wolf, Zachary; /SLAC

    2010-11-23

    The proposed stainless steel beampipe for the LCLS undulator has a measurable shielding effect on the magnetic field of the LCLS undulators. This note describes the tests used to determine the magnitude of the shielding effect, as well as deviations in the shielding effect caused by placing different phase shims in the undulator gap. The effect of the proposed Steel strongback which will be used to support the beam pipe, was also studied. A hall probe on a 3 axis movement system was set up to measure the main component of the magnetic field in the Prototype Undulator. To account for temperature variations of the magnetic field of the undulator for successive tests, a correction is applied which is described in this technical note. Using this method, we found the shielding effect, the amount which the field inside the gap was reduced due to the placement of the beampipe, to be {approx}10 Gauss. A series of tests was also performed to determine the effect of phase shims and X and Y correction shims on the shielding. The largest effect on shielding was found for the .3 mm phase shims. The effect of the .3 mm phase shims was to increase the shielding effect {approx}4 Gauss. The tolerance for the shielding effect of the phase shims is less than 1 gauss. The effect of the strongback was seen in its permanent magnetic field. It introduced a dipole field across the measured section of the undulator of {approx}3 gauss. This note documents the tests performed to determine these effects, as well as the results of those tests.

  7. Magnetic Force Microscopy Using Electron-Beam Fabricated Tips

    NARCIS (Netherlands)

    Rührig, M.; Porthun, S.; Lodder, J.C.

    1994-01-01

    We used a new concept of tip preparation for magnetic force microscopy (MFM) proposed recently based on coating electron beam deposited carbon needles with appropriate magnetic thin film materials. In combining the advantages of electron beam fabricated needles with those of already widely used thin

  8. Enhancement of critical current in mesoscopic superconducting strips by external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ilin, Konstantin; Henrich, Dagmar; Luck, Yannick; Fuchs, Lea; Meckbach, Johannes Maximilian; Siegel, Michael [Institut fuer Mikro- und Nanoelektronische Systeme, Karlsruher Institut fuer Technologie, Hertzstrasse 16, 76187 Karlsruhe (Germany)

    2013-07-01

    Current crowding in superconducting mesoscopic strips with bends results in decrease of critical current in these structures with respect to the strips without geometrical non-uniformities. Recently it has been shown that Meissner currents induced by externally applied magnetic field of appropriate direction allow to suppress this effect so that I{sub c}(B) can exceed I{sub c}(0). Experimental dependencies of critical current in mesoscopic bended strips made from ultra-thin superconducting films on externally applied magnetic field and their comparison to the theoretical predictions are presented and discussed.

  9. Concepts of flywheels for energy storage using autostable high-T(sub c) superconducting magnetic bearings

    Science.gov (United States)

    Bornemann, Hans J.; Zabka, R.; Boegler, P.; Urban, C.; Rietschel, H.

    1994-01-01

    A flywheel for energy storage using autostable high-T(sub c) superconducting magnetic bearings has been built. The rotating disk has a total weight of 2.8 kg. The maximum speed is 9240 rpm. A process that allows accelerated, reliable and reproducible production of melt-textured superconducting material used for the bearings has been developed. In order to define optimum configurations for radial and axial bearings, interaction forces in three dimensions and vertical and horizontal stiffness have been measured between superconductors and permanent magnets in different geometries and various shapes. Static as well as dynamic measurements have been performed. Results are being reported and compared to theoretical models.

  10. Magnetic response and critical current properties of mesoscopic-size YBCO superconducting samples

    Energy Technology Data Exchange (ETDEWEB)

    Lisboa-Filho, P N [UNESP - Universidade Estadual Paulista, Grupo de Materiais Avancados, Departamento de Fisica, Bauru (Brazil); Deimling, C V; Ortiz, W A, E-mail: plisboa@fc.unesp.b [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, Sao Carlos (Brazil)

    2010-01-15

    In this contribution superconducting specimens of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} were synthesized by a modified polymeric precursor method, yielding a ceramic powder with particles of mesoscopic-size. Samples of this powder were then pressed into pellets and sintered under different conditions. The critical current density was analyzed by isothermal AC-susceptibility measurements as a function of the excitation field, as well as with isothermal DC-magnetization runs at different values of the applied field. Relevant features of the magnetic response could be associated to the microstructure of the specimens and, in particular, to the superconducting intra- and intergranular critical current properties.

  11. Frustrated magnetic response of a superconducting Nb film with a square lattice of columnar defects

    Energy Technology Data Exchange (ETDEWEB)

    Zadorosny, R; Ortiz, W A [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil); Lepienski, C M [Universidade Federal do Parana, Departamento de Fisica, Curitiba, PR (Brazil); Patino, E; Blamire, M G [Department of Materials Science, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)], E-mail: rafazad@df.ufscar.br

    2008-02-01

    The magnetic response of a superconducting system presenting a frustrated state is investigated. The system is a superconducting film with mechanically pierced columns, cooled in a field which is then removed. Frustration originates from the competition between return flux of a dipole - created by flux trapped in the empty columns - and flux exclusion by the surrounding superconductor in the Meissner state. The system resolves the incompatibility among conflicting constraints, leading to frustration, by eliminating return flux, which is possibly assimilated by nearby columns, as manifested by a sudden reduction of the magnetic moment on the decreasing field branch of the hysteresis loop.

  12. Precooling of a superconducting magnet using a cryocooler and thermal switches.

    Science.gov (United States)

    Yamamoto, J; Yanai, M

    1979-11-01

    A simple precooling system for a superconducting magnet is developed using a Cryomech GB02 cryocooler and gas filled thermal switches. A superconducting magnet (NbTi wire, 7 T of maximum field, 5.6 kg of weight) is precooled to 16 K in about 70 h without any manual control. Heat transfer rate of each thermal switch (H2 or N2 gas filled at 1.3 MPa at room temperature) is about 3x10(-1) W/K during the ON state, and 5x10(-3) W/K during the OFF state.

  13. Design of a superconducting insert to obtain a high and quasi-uniform magnetic force field

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, Jean [GREEN, University of Nancy BP 239, 54506 Vandoeuvre (France); Netter, Denis [GREEN, University of Nancy BP 239, 54506 Vandoeuvre (France); Quettier, Lionel [DAPNIA, CEA Saclay (France); Mailfert, Alain [INPL, 2 av de la foret de Haye, 54516 Vandoeuvre (France)

    2005-10-01

    In this paper, we study the magnetic force generated by the combination of a solenoid and a superconducting ring insert. We have focused our study on the uniformity of the magnetic force. We use a genetic algorithm to determine the optimal shape of the superconducting ring. We are able to obtain uniformity of 0.5% variance. We also study the influence of several factors on uniformity, such as the critical current of the coil, the ring, and the size of the working area.

  14. Impact of Dynamic Magnetic fields on the CLIC Main Beam

    CERN Document Server

    Snuverink, J; Jach, C; Jeanneret, JB; Schulte, D; Stulle, F

    2010-01-01

    The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the position of the beam. The beam position will be sensitive to external dynamic magnetic fields (stray fields) in the nanotesla regime. The impact of these fields on the CLIC main beam has been studied by performing simulations on the lattices and tolerances have been determined. Several mitigation techniques will be discussed.

  15. Numerical analysis of the superconducting magnet outer vessel of a Maglev train by a structural and electromagnetic coupling method

    Science.gov (United States)

    Matsue, H.; Demachi, K.; Miya, K.

    2001-09-01

    The harmonic magnetic field generated by the ground coils can cause vibration of the superconducting magnet, which must be reduced as it generates heat in the liquid helium temperature range. Therefore, it is important for the design of lighter magnets to exactly estimate the electromagnetic force on the superconducting magnet. Some causes of the vibration were analyzed by the structural and electromagnetic coupling FEM-BEM method.

  16. Design and analysis of the tooling upgrade for the production of the superconductive main dipole magnet prototypes of LHC

    CERN Document Server

    AUTHOR|(CDS)2093638

    Design and analysis of the tooling upgrade for the production of the superconductive main dipole magnet prototypes of LHC Master of Science Thesis, 110 pages, 12 Appendix pages September 2013 Major: Design of machines and systems Examiner: Professor Reijo Kouhia Keywords: CERN, LHC, High Luminosity LHC project, superconductive dipole magnet, welding press, Nb3Sn, pre-stress, Ar-inert gas furnace This thesis work has been carried out as a contribution to the development program of superconductive magnets within the LHC High Luminosity study. The thesis provides an insight to the steps that need to be taken in order to produce a superconductive magnet mainly focusing on mechanical assembly. Tooling upgrade is necessary for the production of the superconductive dipole magnet prototypes in near future. Major attention is given by the introduction of the welding assembly in chapter three. The structural compression is given by the so called shell stress defined by the thermal shrinkage of the weld. The associated ...

  17. Feasibility of turbidity removal by high-gradient superconducting magnetic separation.

    Science.gov (United States)

    Zeng, Hua; Li, Yiran; Xu, Fengyu; Jiang, Hao; Zhang, Weimin

    2015-01-01

    Several studies have focused on pollutant removal by magnetic seeding and high-gradient superconducting magnetic separation (HGSMS). However, few works reported the application of HGSMS for treating non-magnetic pollutants by an industrial large-scale system. The feasibility of turbidity removal by a 600 mm bore superconducting magnetic separation system was evaluated in this study. The processing parameters were evaluated by using a 102 mm bore superconducting magnetic separation system that was equipped with the same magnetic separation chamber that was used in the 600 mm bore system. The double-canister system was used to process water pollutants. Analytical grade magnetite was used as a magnetic seed and the turbidity of the simulated raw water was approximately 110 NTU, and the effects of polyaluminum chloride (PAC) and magnetic seeds on turbidity removal were evaluated. The use of more PAC and magnetic seeds had few advantages for the HGSMS at doses greater than 8 and 50 mg/l, respectively. A magnetic intensity of 5.0 T was beneficial for HGSMS, and increasing the flow rate through the steel wool matrix decreased the turbidity removal efficiency. In the breakthrough experiments, 90% of the turbidity was removed when 100 column volumes were not reached. The processing capacity of the 600 mm bore industry-scale superconducting magnetic separator for turbidity treatment was approximately 78.0 m(3)/h or 65.5 × 10(4) m(3)/a. The processing cost per ton of water for the 600 mm bore system was 0.1 $/t. Thus, the HGSMS separator could be used in the following special circumstances: (1) when adequate space is not available for traditional water treatment equipment, especially the sedimentation tank, and (2) when decentralized sewage treatment HGSMS systems are easier to transport and install.

  18. Effects of pressure and magnetic field on superconductivity in ZrTe3: local pair-induced superconductivity

    Science.gov (United States)

    Tsuchiya, S.; Matsubayashi, K.; Yamaya, K.; Takayanagi, S.; Tanda, S.; Uwatoko, Y.

    2017-06-01

    In this work, the origin of the highly anisotropic superconducting transition in ZrTe3, where the resistance along the a axis, R a , is reduced at 4 K but those along the b axis, R b , and {c}\\prime axis, R c‧, are reduced at 2 K, was explored with the application of a magnetic field and pressure by the electrical resistance measurements. We found that the behavior of the upper critical field and its anisotropy as well as the pressure dependence determined by the R a measurements are quite similar to those of R b . Moreover, the excess conductivity for R b indicates anomalous behavior. These results support an unconventional origin for the anisotropic transition rather than conventional superconducting fluctuation. The reduction in R a is due to filamentary superconductivity (SC) induced by locally bound electron pairs (local pairs), which correspond to bi-polarons, and the transition of R b corresponds to the emergence of bulk SC originating from the Cooper pairs triggered by the transfer of the local pairs.

  19. Local magnetic order vs superconductivity in a layered cuprate

    Science.gov (United States)

    Ichikawa; Uchida; Tranquada; Niemoller; Gehring; Lee; Schneider

    2000-08-21

    We report on the phase diagram for charge-stripe order in La1.6-xNd0. 4SrxCuO4, determined by neutron and x-ray scattering studies and resistivity measurements. From an analysis of the in-plane resistivity motivated by recent nuclear-quadrupole-resonance studies, we conclude that the transition temperature for local charge ordering decreases monotonically with x, and hence that local antiferromagnetic order is uniquely correlated with the anomalous depression of superconductivity at x approximately 1 / 8. This result is consistent with theories in which superconductivity depends on the existence of charge-stripe correlations.

  20. Design And Tests Of A Superconducting Magnet With A Cryocooler For The Ion Source Decris-sc

    CERN Document Server

    Datskov, V I; Bekhterev, V V; Bogomolov, S L; Bondarenko, P G; Dmitriev, S N; Drobin, V M; Efremov, A A; Iakovlev, B I; Leporis, M; Malinowski, H; Nikiforov, S A; Paschenko, S V; Seleznev, V V; Shishov, Yu A; Tsvineva, G P; Yazvitsky, N Yu

    2004-01-01

    A superconducting magnet system (SMS) for the multicharged ion source DECRIS-SC was designed and manufactured at the Joint Institute for Nuclear Research. Successful tests of the SMS were conducted in late 2003 - early 2004. The peculiarities of this system are stipulated by using of a cryocooler 1 W in power for the cryostabilization of the magnet, and also by a special configuration of the magnetic field demanded for the source of ions. Four coils ensure induction of a magnetic field on the axes of the source of up to 3T (the mirror ratio of ~6) which considerably extends possibilities of the ion source from the point of view of producing intense highly charged ion beams. The problem of compensating large forces of interaction between the coils and surrounding iron yoke in this magnet has been successfully solved, and a reliable suspension of the magnet in a cryostat realized. For compounding of the windings working in vacuum at indirect cryostabilization prepreg is used. There has been applied a new techno...

  1. Development of a Superconducting Magnet System for the ONR/General Atomics Homopolar Motor

    Science.gov (United States)

    Schaubel, K. M.; Langhorn, A. R.; Creedon, W. P.; Johanson, N. W.; Sheynin, S.; Thome, R. J.

    2006-04-01

    This paper describes the design, testing and operational experience of a superconducting magnet system presently in use on the Homopolar Motor Program. The homopolar motor is presently being tested at General Atomics in San Diego, California for the U.S Navy Office of Naval Research. The magnet system consists of two identical superconducting solenoid coils housed in two cryostats mounted integrally within the homopolar motor housing. The coils provide the static magnetic field required for motor operation and are wound using NbTi superconductor in a copper matrix. Each magnet is conduction cooled using a Gifford McMahon cryocooler. The coils are in close proximity to the iron motor housing requiring a cold to warm support structure with high stiffness and strength. The design of the coils, cold to warm support structure, cryogenic system, and the overall magnet system design will be described. The test results and operational experience will also be described.

  2. CLIQ – Coupling-Loss Induced Quench System for Protecting Superconducting Magnets

    CERN Multimedia

    Ravaioli, E; Kirby, G; ten Kate, H H J; Verweij, A P

    2014-01-01

    The recently developed Coupling-Loss-Induced Quench (CLIQ) protection system is a new method for initiating a fast and voluminous transition to the normal state for protecting high energy density superconducting magnets. Upon quench detection, CLIQ is triggered to generate an oscillating current in the magnet coil by means of a capacitive discharge. This in turn introduces a high coupling loss in the superconductor which provokes a quick transition to the normal state of the coil windings. The system is now implemented for the protection of a two meter long superconducting quadrupole magnet and characterized in the CERN magnet test facility. Various CLIQ configurations with different current injection points are tested and the results compared to similar transients lately measured with a not optimized configuration. Test results convincingly show that the newly tested design allows for a more global quench initiation and thus a faster discharge of the magnet energy. Moreover, the performance of CLIQ for reduc...

  3. Mechanics of a magnet and a Meissner superconducting ring at arbitrary position and orientation

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Diaz, J.L., E-mail: jlperez@ing.uc3m.e [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque, 15. E28911 Leganes (Spain); Garcia-Prada, J.C.; Diaz-Garcia, J.A. [Departamento de Ingenieria Mecanica, Universidad Carlos III de Madrid, Butarque, 15. E28911 Leganes (Spain)

    2009-04-01

    The force and torque exerted by a magnetic dipole on a superconducting ring (or hollow cylinder) in the Meissner state at arbitrary position and orientation are calculated using a Maxwell-London model previously proposed by the authors. The center of the ring is an unstable equilibrium point for the magnet. At this point the ring tends to align the magnet but tends to expel it for any small axial deviation from the center. There is also a non-monotonic and oscillatory dependence of the forces and torques on the position caused by the finiteness of the ring and a torque arises when the magnet is displaced both radially and axially from the center of the cylinder which corresponds to the experimental data. Therefore, the use of a magnet in a Meissner superconducting ring as a self aligning bearing requires a centered position and that the axial unstability to be compensated by additional mechanical means.

  4. Possible coexistence of superconductivity and magnetic order in NdPt2B2C

    Indian Academy of Sciences (India)

    S K Dhar; A D Chinchure; E Alleno; C Godart; L C Gupta; R Nagarajan

    2002-05-01

    Coexistence of superconductivity and magnetic order has been one of the exciting aspects of the quaternary borocarbide superconductors. So far, RNi2B2C (R=Tm, Er, Ho and Dy) are the only known magnetic superconductors in this family. Here, we present our resistivity, magnetization and heat capacity studies on NdPt2B2C (nominal composition, NdPt1.5Au0.6B2C and NdPt2.1B2.4C1.2). We find superconductivity in both samples with c,onset∼ 3 K. Bulk magnetic order is found to occur below 1.7 K. We suggest that NdPt2B2C is a possible magnetic superconductor.

  5. DFBX boxes - electrical and cryogenic distribution boxes for the superconducting magnets in the LHC straight sections

    CERN Document Server

    Zbasnik, J P; Gourlay, S A; Green, M A; Hafalia, A Q; Kajiyama, Y; Knolls, M J; La Mantia, R F; Rasson, J E; Reavill, D; Turner, W C

    2003-01-01

    DFBX distribution boxes provide cryogenic and electrical services to superconducting quadrupoles and to a superconducting dipole at either end of four of the long straight sections in the LHC. The DFBX boxes also provide instrumentation and quench protection to the magnets. Current for the quadrupole and the dipole magnet is delivered through leads that combine HTS and gas cooled leads. Current for the 600 A and 120 A correction magnets is provided by pure gas-cooled leads. The bus bars from the leads to the magnets pass through low leak-rate lambda plugs between 1.8 K and 4.4 K. The heat leak into the 1.9 K region from the liquid helium tank is determined by the design of the lambda plugs. This paper describes the DFBX boxes and their function of delivering current and instrumentation signals to the magnets. (2 refs).

  6. Electromagnetic Characteristics of a Superconducting Magnet for 28GHz ECR Ion Source according to the Series Resistance of a Protection Circuit

    CERN Document Server

    Lee, Hongseok; Lee, Onyou; Kim, Junil; Bang, Seungmin; Kang, Jong O; Hong, Jonggi; Nam, Seokho; Choi, Sukjin; Hong, In Seok; Ahn, Min Chul; Kang, Hyoungku

    2015-01-01

    A linear accelerator, called RAON, has been being developed as a part of Rare Isotope Science Project (RISP) by Institute for Basic Science (IBS) [1]. The linear accelerator utilizes an electron cyclotron resonance (ECR) ion source for providing intense highly charged ion beams to the linear accelerator. 28GHz ECR ion source can extract heavy ion beams from proton to uranium. A superconducting magnet system for 28GHz ECR ion source is composed of hexapole coils and four solenoid coils made with low Tc superconducting wires of NbTi [2]. The electromagnetic force acts on the superconducting magnets due to the magnetic field and flowing current in case of not only normal state but also quench state [3]. In case of quench on hexapole coils, unbalanced flowing current among the hexapole coils is generated and it causes unbalanced electromagnetic force. Coil motions and coil strains in quench state are larger than those in normal state due to unbalanced electromagnetic force among hexapole coils. Therefore, analysi...

  7. Materials, Strands, and Cables for Superconducting Accelerator Magnets. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sumption, Mike D. [Ohio State University, Columbia, OH (United States); Collings, Edward W. [Ohio State University, Columbia, OH (United States)

    2014-09-19

    This report focuses on Materials, Strands and Cables for High Energy Physics Particle accelerators. In the materials area, work has included studies of basic reactions, diffusion, transformations, and phase assemblage of Nb3Sn. These materials science aspects have been married to results, in the form of flux pinning, Bc2, Birr, and transport Jc, with an emphasis on obtaining the needed Jc for HEP needs. Attention has also been paid to the “intermediate-temperature superconductor”, magnesium diboride emphasis being placed on (i) irreversibility field enhancement, (ii) critical current density and flux pinning, and (iii) connectivity. We also report on studies of Bi-2212. The second area of the program has been in the area of “Strands” in which, aside from the materials aspect of the conductor, its physical properties and their influence on performance have been studied. Much of this work has been in the area of magnetization estimation and flux jump calculation and control. One of the areas of this work was strand instabilities in high-performance Nb3Sn conductors due to combined fields and currents. Additionally, we investigated quench and thermal propagation in YBCO coated conductors at low temperatures and high fields. The last section, “Cables”, focussed on interstrand contact resistance, ICR, it origins, control, and implications. Following on from earlier work in NbTi, the present work in Nb3Sn has aimed to make ICR intermediate between the two extremes of too little contact (no current sharing) and too much (large and unacceptable magnetization and associated beam de-focussing). Interstrand contact and current sharing measurements are being made on YBCO based Roebel cables using transport current methods. Finally, quench was investigated for YBCO cables and the magnets wound from them, presently with a focus on 50 T solenoids for muon collider applications.

  8. Magnetic proximity effect and superconducting triplet correlations at the cuprate superconductor and oxide spin valve interface

    Science.gov (United States)

    Ovsyannikov, G. A.; Constantinian, K. Y.; Demidov, V. V.; Khaydukov, Yu. N.

    2016-10-01

    A heterostructure consisting of a cuprate superconductor YBa2Cu3O7-δ and a ruthenate/manganite (SrRuO3/La0.7Sr0.3MnO3) spin valve was studied using SQUID magnetometry, ferromagnetic resonance, and neutron reflectometry. It is shown that because of the magnetic proximity effect a magnetic moment is excited in the superconducting portion of the heterostructure, whereas the magnetic moment in the spin valve becomes suppressed. The experimentally obtained value of a typical penetration depth of a magnetic moment into the superconductor is significantly greater than the coherence length of the cuprate superconductor, which indicates that the induced magnetic moment mechanism of Cu atoms is dominant. The mesastructure prepared by adding niobium film as a second superconducting electrode to the existing heterostructure, exhibited a superconducting current (dc Josephson effect) at interlayer thicknesses that are much greater than the coherence length of the ferromagnetic materials. The maximum of the critical current density dependence on the thickness of the spin valve material corresponds to the interlayer coherence length, which agrees with the theoretical predictions associated with spin-triplet pairing. The superconducting current is observed at magnetic fields that are two orders of magnitude greater than the field corresponding to the occurrence of one magnetic flux quantum in the mesastructure. The ratio of the second harmonic of the current-phase dependence of the mesastructure superconducting current to the first, determined according to the dependence of the Shapiro steps on the amplitude of microwave exposure, did not exceed 50%.

  9. A Cryogenic Magnetostrictive Actuator Using a Persistent High Temperature Superconducting Magnet. Part 1; Concept and Design

    Science.gov (United States)

    Horner, Garnett; Bromberg, Leslie; Teter, J. P.

    2000-01-01

    Cryogenic magnetostrictive materials, such as rare earth zinc crystals, offer high strains and high forces with minimally applied magnetic fields, making the material ideally suited for deformable optics applications. For cryogenic temperature applications the use of superconducting magnets offer the possibility of a persistent mode of operation, i.e., the magnetostrictive material will maintain a strain field without power. High temperature superconductors (HTS) are attractive options if the temperature of operation is higher than 10 degrees Kelvin (K) and below 77 K. However, HTS wires have constraints that limit the minimum radius of winding, and even if good wires can be produced, the technology for joining superconducting wires does not exist. In this paper, the design and capabilities of a rare earth zinc magnetostrictive actuator using bulk HTS is described. Bulk superconductors can be fabricated in the sizes required with excellent superconducting properties. Equivalent permanent magnets, made with this inexpensive material, are persistent, do not require a persistent switch as in HTS wires, and can be made very small. These devices are charged using a technique which is similar to the one used for charging permanent magnets, e.g., by driving them into saturation. A small normal conducting coil can be used for charging or discharging. Because of the magnetic field capability of the superconductor material, a very small amount of superconducting magnet material is needed to actuate the rare earth zinc. In this paper, several designs of actuators using YBCO and BSCCO 2212 superconducting materials are presented. Designs that include magnetic shielding to prevent interaction between adjacent actuators will also be described. Preliminary experimental results and comparison with theory for BSCCO 2212 with a magnetostrictive element will be discussed.

  10. A superconducting conveyer system using multiple bulk Y-Ba-Cu-O superconductors and permanent magnets

    Science.gov (United States)

    Kinoshita, T.; Koshizuka, N.; Nagashima, K.; Murakami, M.

    Developments of non-contact superconducting devices like superconducting magnetic levitation transfer and superconducting flywheel energy storage system have been performed based on the interactions between bulk Y-Ba-Cu-O superconductors and permanent magnets, in that the superconductors can stably be levitated without any active control. The performances of noncontact superconducting devices are dependent on the interaction forces like attractive forces and stiffness. In the present study, we constructed a non-contact conveyer for which the guide rails were prepared by attaching many Fe-Nd-B magnets onto an iron base plate. Along the translational direction, all the magnets were arranged as to face the same pole, and furthermore their inter-distance was made as small as possible. The guide rail has three magnet rows, for which the magnets were glued on the iron plate such that adjacent magnet rows have opposite poles like NSN. At the center row, the magnetic field at zero gap reached 0.61T, while the field strengths of two rows on the side edges were only 0.48T due to magnetic interactions among permanent magnets. We then prepared a cryogenic box made with FRP that can store several bulk Y-Ba-Cu-O superconductors 25 mm in diameter cooled by liquid nitrogen. It was found that the levitation forces and stiffness increased with increasing the number of bulk superconductors installed in the box, although the levitation force per unit bulk were almost the same. We also confirmed that these forces are dependent on the configuration of bulk superconductors.

  11. Theory of using magnetic deflections to combine charged particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Steckbeck, Mackenzie K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Several radiation effects projects in the Ion Beam Lab (IBL) have recently required two disparate charged particle beams to simultaneously strike a single sample through a single port of the target chamber. Because these beams have vastly different mass–energy products (MEP), the low-MEP beam requires a large angle of deflection toward the sample by a bending electromagnet. A second electromagnet located further upstream provides a means to compensate for the small angle deflection experienced by the high-MEP beam during its path through the bending magnet. This paper derives the equations used to select the magnetic fields required by these two magnets to achieve uniting both beams at the target sample. A simple result was obtained when the separation of the two magnets was equivalent to the distance from the bending magnet to the sample, and the equation is given by: Bs= 1/2(rc/rs) Bc, where Bs and Bc are the magnetic fields in the steering and bending magnet and rc/rs is the ratio of the radii of the bending magnet to that of the steering magnet. This result is not dependent upon the parameters of the high MEP beam, i.e. energy, mass, charge state. Therefore, once the field of the bending magnet is set for the low-MEP beam, and the field in the steering magnet is set as indicted in the equation, the trajectory path of any high-MEP beam will be directed into the sample.

  12. Vlasov analysis of microbunching instability for magnetized beams

    Directory of Open Access Journals (Sweden)

    C.-Y. Tsai

    2017-05-01

    Full Text Available For a high-brightness electron beam with high bunch charge traversing a recirculation beam line, coherent synchrotron radiation and space charge effects may result in microbunching instability (MBI. Both tracking simulation and Vlasov analysis for an early design of a circulator cooler ring (CCR for the Jefferson Lab Electron Ion Collider (JLEIC reveal significant MBI [Ya. Derbenev and Y. Zhang, Proceedings of the Workshop on Beam Cooling and Related Topics, COOL’09, Lanzhou, China, 2009 (2009, FRM2MCCO01]. It is envisioned that the MBI could be substantially suppressed by using a magnetized beam. In this paper we have generalized the existing Vlasov analysis, originally developed for a nonmagnetized beam (or transversely uncoupled beam, to the description of transport of a magnetized beam including relevant collective effects. The new formulation is then employed to confirm prediction of microbunching suppression for a magnetized beam transport in the recirculation arc of a recent JLEIC energy recovery linac (ERL based cooler design for electron cooling. It is found that the smearing effect in the longitudinal beam phase space originates from the large transverse beam size as a nature of the magnetized beams and becomes effective through the x-z correlation when the correlated distance is larger than the microbunched scale. As a comparison, MBI analysis of the early design of JLEIC CCR is also presented in this paper.

  13. Magnetic Exchange Between Superconducting and Ferromagnetic Oxide Layers

    Science.gov (United States)

    Giblin, Sean; Taylor, Jon; Duffy, Jon; Dugdale, Stephen; Nakamura, T.; Santamaria, Jacobo

    2012-02-01

    The origins of high temperature superconductivity and the rich phase diagrams in complex oxides are still a matter of contention that have stimulated many novel experimental studies and observations. Recently the improvement of layer by layer growth techniques of thin films has enabled investigations of both bulk and surface properties. For most common superconductors the order parameter is thought to be antagonistic to that of the exchange mechanism in ferromagnets. Accurately grown thin fllms have enabled these competing interactions to be probed experimentally. In particular, the growth of epitaxial oxide layers, with well-characterized atomically flat interfaces, consisting of superconducting layers of YBa2Cu3O7 (YBCO) and lattice-matched ferromagnetic La2/3Ca1/3MnO3 (LCMO) has flourished. Using XMCD we demonstrate that the known superexchange between Mn and Cu across the YBCO/LCMO is modified when an apparent critical thickness of the superconducting layer is reduced. All samples show an apparent exchange below the superconducting transition but above it is dependent on the YBCO thickness. Possible origins of this behaviour will be discussed.

  14. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob, E-mail: ihahn@caltech.edu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    2014-09-15

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems.

  15. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system

    Science.gov (United States)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2014-09-01

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems.

  16. Study on cooling process of cryogenic system for superconducting magnets of BEPCⅡ

    Institute of Scientific and Technical Information of China (English)

    ZONG Zhan-Guo; LIU Li-Qiang; XIONG Lian-You; LI Shao-Peng; XU Qing-Jin; HE Kun; ZHANG Liang; GAO Jie

    2008-01-01

    In the upgrade project of the Beijing Electron Positron Collider(BEPCⅡ),three superconducting magnets are employed to realize the goal of two orders of magnitude higher luminosity.A cryogenic system with a total capacity of 0.5 kW at 4.5 K was built at the Institute of High Energy Physics(IHEP)to support the operations of these superconducting devices.For preparing the commissioning of the system,the refrigeration process Was simulated and analyrzed numerically.The numerical model Was based on the latest engineering progress and focused on the normal operation mode.The pressure and temperature profiles of the cryogenic system are achieved with the simulation.The influence of the helium mass flow rates to cool superconducting magnets on the thermodynamic parameters of their normal operation is also studied and discussed in this paper.

  17. Optical Probe of the Superconducting Normal Mixed State in a Magnetic Penetration Thermometer

    Science.gov (United States)

    Stevenson, T. R.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Lee, S. -J.; Nagler, P. C.; Smith, S. J.

    2016-01-01

    Using ultraviolet photon pulses, we have probed the internal behavior of a molybdenum-gold Magnetic Penetration Thermometer (MPT) that we designed for x-ray microcalorimetry. In this low-temperature detector, the diamagnetic response of a superconducting MoAu bilayer is used to sense temperature changes in response to absorbed photons. We have previously described an approximate model that explains the high responsivity of the detector to temperature changes as a consequence of a Meissner transition of the molybdenum-gold film in the magnetic field applied by the superconducting circuit used to bias the detector. We compare measurements of MPT heat capacity and thermal conductance, derived from UV photon pulse data, to our model predictions for the thermodynamic properties of the sensor and for the electron cooling obtained by quasiparticle recombination. Our data on electron cooling power is also relevant to the operation of other superconducting detectors, such as Microwave Kinetic Inductance Detectors.

  18. A high current sinusoidal pulse generator for the diluter magnets of the LHC beam dump system

    CERN Document Server

    Vossenberg, Eugène B; Ducimetière, L; Schröder, G H

    2000-01-01

    CERN is constructing the Large Hadron Collider (LHC), a superconducting accelerator that will collide protons at a center of mass energy of 14 TeV. The two colliding beams will each store an energy of up to 540 MJ, which must be safely deposited within one beam revolution of 89 mu s on two external absorbers located about 700 m from the extraction points at the end of dedicated extraction tunnels. To avoid evaporation of the graphite absorber material by the very high energy density of the incident beams, the deposition area of the beams on the absorber front face will be increased. This is done by a pair of sinusoidally powered orthogonal magnet systems producing approximately an e-shape figure of about 35 mm diameter, with a minimum velocity of 10 mm/ mu s during the dumping process. The pulse generators of the horizontally and vertically deflecting diluter magnets are composed of capacitor banks, discharged by stacks of solid state closing switches. They are connected to the magnets by 28 m long low induct...

  19. The winding and testing of a 10 cm superconductive quadrupole for CERN

    CERN Document Server

    Williams, J.E.C.; Cornish, D.N.

    1970-01-01

    The construction and testing of the first of a pair of quadrupole magnets, designed for use as superconductive beam handling elements at CERN, is described. Tests showed this magnet to be eminently suitable for nuclear physics applications.

  20. Squids, snakes, and polarimeters: A new technique for measuring the magnetic moments of polarized beams

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, P.R.; Luccio, A.U.; Shea, T.J.; Tsoupas, N. [Brookhaven National Laboratory, Upton, New York 11973 (United States of America); Goldberg, D.A. [Lawrence Berkeley Laboratory, Berkeley, California (United States of America)

    1997-01-01

    Effective polarimetry at high energies in hadron and lepton synchrotrons has been a long-standing and difficult problem. In synchrotrons with polarized beams it is possible to cause the direction of the polarization vector of a given bunch to alternate at a frequency which is some subharmonic of the rotation frequency. This can result in the presence of lines in the beam spectrum which are due only to the magnetic moment of the beam and which are well removed from the various lines due to the charge of the beam. The magnitude of these lines can be calculated from first principles. They are many orders of magnitude weaker than the Schottky signals. Measurement of the magnitude of one of these lines would be an absolute measurement of beam polarization. For measuring magnetic field, the Superconducting Quantum Interference Device, or squid, is about five orders of magnitude more sensitive than any other transducer. Using a squid, such a measurement might be accomplished with the proper combination of shielding, pickup loop design, and filtering. The resulting instrument would be fast, non-destructive, and comparatively cheap. In addition, techniques developed in the creation of such an instrument could be used to measure the Schottky spectrum in unprecedented detail. We present specifics of a polarimeter design for the Relativistic Heavy Ion Collider (RHIC) and briefly discuss the possibility of using this technique to measure polarization at high-energy electron machines like LEP and HERA. {copyright} {ital 1997 American Institute of Physics.}

  1. Magnetic and superconductivity studies on (In{sub 1−x}Fe{sub x}){sub 2}O{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sai Krishna, N. [Thin Films Laboratory, School of Advanced Sciences, VIT University, Vellore 632 014, Tamil Nadu (India); Kaleemulla, S., E-mail: skaleemulla@gmail.com [Thin Films Laboratory, School of Advanced Sciences, VIT University, Vellore 632 014, Tamil Nadu (India); Amarendra, G. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); UGC-DAE-CSR, Kalpakkam Node, Kokilamedu 603 104, Tamil Nadu (India); Madhusudhana Rao, N.; Krishnamoorthi, C.; Rigana Begam, M. [Thin Films Laboratory, School of Advanced Sciences, VIT University, Vellore 632 014, Tamil Nadu (India); Omkaram, I. [Department of Electronics and Radio Engineering, Kyung Hee University, Yongin-si Gyeonggi-do 446-701 (Korea, Republic of); Sreekantha Reddy, D. [Department of Physics and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-07-15

    Highlights: • Fe doped In{sub 2}O{sub 3} thin films deposited using electron beam evaporation technique. • Characterization of the samples using XRD, SEM, EDAX, AES, Raman spectroscopy, FT-IR, VSM and magnetoresistance. • All Fe doped In{sub 2}O{sub 3} thin films exhibited the cubic structure of In{sub 2}O{sub 3}. • Pure and Fe doped In{sub 2}O{sub 3} samples exhibited room temperature ferromagnetism and superconductivity at 2 K. - Abstract: Magnetic, magnetoresistivity and superconductivity studies were carried out on (In{sub 1−x}Fe{sub x}){sub 2}O{sub 3} (x = 0.00, 0.03, 0.05 and 0.07) thin films (2D structures) grown on glass substrate by electron beam evaporation technique at 350 °C. The films have an average size of 120 nm particles. All the samples shown soft ferromagnetic hysteresis loops at room temperature and saturation magnetization increased with iron dopant concentration. Observed magnetization could be best interpreted by F-center mediated magnetic exchange interaction in the samples. Temperature dependent resistivity of the sample (x = 0.00 and 0.07) showed metallic behavior down to very low temperatures and superconductivity at 2 K for undoped In{sub 2}O{sub 3} whereas the In{sub 1.86}Fe{sub 0.14}O{sub 3} sample shows superconductivity below 2 K in the absence of magnetic fields. The reduction in transition temperature was attributed to increase electrical disorder with iron doping. Both samples showed positive magnetoresistivity (MR) in superconducting state due to increase of resistivity resulting from breaking of superconducting Cooper pairs upon application of magnetic field. In addition, both the samples show feeble negative MR in normal electrical state. The observed MR in normal state is not due to spin polarized tunneling instead it is due to suppression of scattering of charge carrier by single occupied localized states.

  2. Performance of the Superconducting Corrector Magnet Circuits during the Commissioning of the LHC

    CERN Document Server

    Venturini-Delsolaro, W; Ballarino, A; Bellesia, B; Bordry, Frederick; Cantone, A; Casas Lino, M; Castaneda Serra, A; Castillo Trello, C; Catalan-Lasheras, N; Charifoulline, Z; Charrondiere, C; Dahlerup-Petersen, K; D'Angelo, G; Denz, R; Fehér, S; Flora, R; Gruwé, M; Kain, V; Karppinen, M; Khomenko, B; Kirby, G; MacPherson, A; Marqueta Barbero, A; Mess, K H; Modena, M; Mompo, R; Montabonnet, V; le Naour, S; Nisbet, D; Parma, V; Pojer, M; Ponce, L; Raimondo, A; Redaelli, S; Remondino, V; Reymond, H; de Rijk, G; Rijllart, A; Romera Ramirez, I; Saban, R; Sanfilippo, S; Schirm, K; Schmidt, R; Siemko, A; Solfaroli Camillocci, M; Thurel, Y; Thiesen, H; Vergara Fernandez, A; Verweij, A; Wolf, R; Zerlauth, M

    2008-01-01

    The LHC is a complex machine requiring more than 7400 superconducting corrector magnets distributed along a circumference of 26.7 km. These magnets are powered in 1446 different electrical circuits at currents ranging from 60 A up to 600 A. Among the corrector circuits the 600 A corrector magnets form the most diverse and differentiated group. All together, about 60000 high current connections had to be made. A fault in a circuit or one of the superconducting connections would have severe consequences for the accelerator operation. All magnets are wound from various types of Nb-Ti superconducting strands, and many contain parallel protection resistors to by-pass the current still flowing in the other magnets of the same circuit when they quench. In this paper the performance of these magnet circuits is presented, focussing on the quench behaviour of the magnets. Quench detection and the performance of the electrical interconnects will be dealt with. The results as measured on the entire circuits are compar...

  3. Heat load tests of superconducting magnets vibrated electromagnetically for the Maglev train

    Science.gov (United States)

    Ohmori, J.; Nakao, H.; Yamashita, T.; Sanada, Y.; Shudou, M.; Kawai, M.; Fujita, M.; Terai, M.; Miura, A.

    Superconducting magnets on Maglev trains vibrate due to harmonic ripples of electromagnetic flux generated by ground coils. Heat load caused by vibration in the magnet amounted to several tens of watts in the electromagnetic vibration test. This was mainly because a.c. loss was induced in the helium vessel housing the superconducting coil, due to relative vibration between the aluminium thermal shield and the coil. The heat load caused by vibration should be strictly restricted to less than 4W due to limited cryogenic refrigeration capacity. The heat load was tested using electromagnetic flux ripples for a superconducting magnet model of one coil which corresponds to 1/4 of an actual magnet. The flux ripples simulated the 6th harmonic of the actual ground levitation coil. Some ideas to reduce the heat load were tried for the magnet model, such as applying high resistance thermal radiation shielding, increasing rigidity of the vacuum vessel, and using high purity copper plating on the helium vessel. These ideas proved effective, and the maximum heat load due to vibration was held to less than 4 W per magnet for the one coil magnet model.

  4. Thermal and magnetic behaviors of a melt-textured superconducting bulk magnet in the zero-field-cooling magnetizing process

    Energy Technology Data Exchange (ETDEWEB)

    Oka, T [Faculty of Engineering, Niigata University, 8050 Ikarashi-Nino-cho, Nishi-ku, Niigata 950-2181 (Japan); Yokoyama, K [Ashikaga Department of Electrical and Electronic Engineering, Institute of Technology, 268-1 Ohmae-cho, Ashikaga, Tochigi 326-8558 (Japan); Fujishiro, H; Noto, K [Faculty of Engineering, Iwate University, 3-4-5 Ueda, Morioka, Iwate 020-8551 (Japan)], E-mail: okat@eng.niigata-u.ac.jp

    2009-06-15

    The heat generation and magnetic field trapping behaviors of the melt-textured single-domain Sm-Ba-Cu-O bulk superconductor have been precisely investigated in the zero-field-cooling magnetizing processes (ZFC). The temperature and magnetic flux density were simultaneously measured in the temperature range of 50-60 K. Since the invasion of magnetic flux is suppressed by the superconducting pinning effect, the applied magnetic field is not supplied to the whole of the sample. Therefore, the trapped field distributions consequently exhibit trapezoid shapes. According to the balance of heat generation and draining, the temperature profiles show us distinctive behaviors of magnetic fluxes. Both the temperature and the magnetic flux density kept increasing even after the external magnetic field has stopped growing at 5 T. This is attributed to the flux creeping phenomenon which propagates from the periphery to the center portion of the sample like a snow slide. The highest temperature rise due to the flux motion reached 7.5 K even when the sample was magnetized at a slow sweeping rate of 5.06 mT s{sup -1}. As the temperature profiles were different between the ascending and descending field processes, it is suggested that the magnetic fluxes invade in and diffuse out in different heating manners between the processes. This assists the hypothesis that the time while the moving fluxes heat the sample strongly affects the total amount of heat generation, which acts contrary to the FC case. This behavior implies that the improvements of the heat propagation property of the HTS bulk material by embedding metallic membranes and more powerful/efficient cooling systems must suppress the temperature increases and enhance the field trapping abilities.

  5. A new ring-shape high-temperature superconducting trapped-field magnet

    Science.gov (United States)

    Sheng, Jie; Zhang, Min; Wang, Yawei; Li, Xiaojian; Patel, Jay; Yuan, Weijia

    2017-09-01

    This paper presents a new trapped-field magnet made of second-generation high-temperature superconducting (2G HTS) rings. This so-called ring-shape 2G HTS magnet has the potential to provide much stronger magnetic fields relative to existing permanent magnets. Compared to existing 2G HTS trapped- field magnets, e.g. 2G HTS bulks and stacks, this new ring-shape 2G HTS magnet is more flexible in size and can be made into magnets with large dimensions for industrial applications. Effective magnetization is the key to being able to use trapped-field magnets. Therefore, this paper focuses on the magnetization mechanism of this new magnet using both experimental and numerical methods. Unique features have been identified and quantified for this new type of HTS magnet in the field cooling and zero field cooling process. The magnetization mechanism can be understood by the interaction between shielding currents and the penetration of external magnetic fields. An accumulation in the trapped field was observed by using multiple pulse field cooling. Three types of demagnetization were studied to measure the trapped-field decay for practical applications. Our results show that this new ring-shape HTS magnet is very promising in the trapping of a high magnetic field. As a super-permanent magnet, it will have a significant impact on large-scale industrial applications, e.g. the development of HTS machines with a very high power density and HTS magnetic resonance imaging devices.

  6. Angular Dependence of Lateral and Levitation Forces in Asymmetric Small Magnet/Superconducting Systems

    Institute of Scientific and Technical Information of China (English)

    H. M. Al-Khateeb; M. K. Alqadi; F. Y. Alzoubi; N. Y. Ayoub

    2007-01-01

    The dipole-dipole interaction model is used to calculate the angular dependence of lateral and levitation forces on a small permanent magnet and a cylindrical superconductor in the Meissner state lying laterally offthe symmetric axis of the cylinder. Under the assumption that the lateral displacement of the magnet is small compared with the physical dimensions of the system, we obtain analytical expressions for the lateral and levitation forces as functions of geometrical parameters of the superconductor as well as the height, the lateral displacement and the orientation of magnetic moment of the magnet. The effect of thickness and radius of the superconductor on the levitation force is similar to that for a symmetric magnet/superconducting cylinder system, but within the range of lateral displacement. The splitting in the levitation force increases with the increasing angle of orientation of the magnetic moment of the magnet. For a given lateral displacement of the magnet, the lateral force vanishes when the magnetic moment is perpendicular to the surface of the superconductor and has a maximum value when the moment is parallel to the surface. For a given orientation of the magnetic moment, the lateral force has a linear relationship with the lateral displacement. The stability of the magnet above the superconducting cylinder is discussed in detail.

  7. Beam position diagnostics with higher order modes in third harmonic superconducting accelerating cavities

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pei

    2013-02-15

    various dipole modes on the oset of the excitation beam were subsequently studied using a spectrum analyzer. Various data analysis methods were used: modal identication, direct linear regression, singular value decomposition and k-means clustering. These studies lead to three modal options promising for beam position diagnostics, upon which a set of test electronics has been built. The experiments with these electronics suggest a resolution of 50 micron accuracy in predicting local beam position in the cavity and a global resolution of 20 micron over the complete module. This constitutes the first demonstration of HOM-based beam diagnostics in a third harmonic 3.9 GHz superconducting cavity module. These studies have finalized the design of the online HOM-BPM for 3.9 GHz cavities at FLASH.

  8. A design of novel type superconducting magnet for super-high field functional magnetic resonance imaging by using the harmonic analysis method of magnetic vector potentials

    Institute of Scientific and Technical Information of China (English)

    俎栋林; 郭华; 宋枭禹; 包尚联

    2002-01-01

    The approach of expanding the magnetic scalar potential in a series of Legendre polynomials is suitable for designing a conventional superconducting magnetic resonance imaging magnet of distributed solenoidal configuration. Whereas the approach of expanding the magnetic vector potential in associated Legendre harmonics is suitable for designing a single-solenoid magnet that has multiple tiers, in which each tier may have multiple layers with different winding lengths. A set of three equations to suppress some of the lowest higher-order harmonics is found. As an example, a 4T single-solenoid magnetic resonance imaging magnet with 4 × 6 layers of superconducting wires is de signed The degree of homogeneity in the 0.5m diameter sphere volume is better than 5.8 ppm. The same degree of homogeneity is retained after optimal integralization of turns in each correction layer. The ratio Bm/Bo in the single-solenoid magnet is 30%lower than that in the conventional six-solenoid magnet. This tolerates higher rated superconducting current in the coil. The Lorentz force of the coil in the single-solenoid system is also much lower than in the six-solenoid system. This novel type of magnet possesses significant advantage over conventional magnets, especially when used as a super-high field functional magnetic resonance imaging magnet.

  9. Vlasov Analysis of Microbunching Gain for Magnetized Beams

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Cheng Ying [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-10-01

    For a high-brightness electron beam with low energy and high bunch charge traversing a recirculation beamline, coherent synchrotron radiation and space charge effect may result in the microbunching instability (MBI). Both tracking simulation and Vlasov analysis for an early design of Circulator Cooler Ring for the Jefferson Lab Electron Ion Collider reveal significant MBI. It is envisioned these could be substantially suppressed by using a magnetized beam. In this work, we extend the existing Vlasov analysis, originally developed for a non-magnetized beam, to the description of transport of a magnetized beam including relevant collective effects. The new formulation will be further employed to confirm prediction of microbunching suppression for a magnetized beam transport in a recirculating machine design.

  10. Electric-Field-Induced Superconductivity Detected by Magnetization Measurements of an Electric-Double-Layer Capacitor

    NARCIS (Netherlands)

    Kasahara, Yuichi; Nishijima, Takahiro; Sato, Tatsuya; Takeuchi, Yuki; Ye, Jianting; Yuan, Hongtao; Shimotani, Hidekazu; Iwasa, Yoshihiro

    We report evidence for superconductivity induced by the application of strong electric fields onto the surface of a band insulator, ZrNCl, provided by the observation of a shielding diamagnetic signal. We introduced an electric-double-layer capacitor configuration and in situ magnetization

  11. Europium-based iron pnictides: a unique laboratory for magnetism, superconductivity and structural effects.

    Science.gov (United States)

    Zapf, Sina; Dressel, Martin

    2017-01-01

    Despite decades of intense research, the origin of high-temperature superconductivity in cuprates and iron-based compounds is still a mystery. Magnetism and superconductivity are traditionally antagonistic phenomena; nevertheless, there is basically no doubt left that unconventional superconductivity is closely linked to magnetism. But this is not the whole story; recently, also structural effects related to the so-called nematic phase gained considerable attention. In order to obtain more information about this peculiar interplay, systematic material research is one of the most important attempts, revealing from time to time unexpected effects. Europium-based iron pnictides are the latest example of such a completely paradigmatic material, as they display not only spin-density-wave and superconducting ground states, but also local Eu(2+) magnetism at a similar temperature scale. Here we review recent experimental progress in determining the complex phase diagrams of europium-based iron pnictides. The conclusions drawn from the observations reach far beyond these model systems. Thus, although europium-based iron pnictides are very peculiar, they provide a unique platform to study the common interplay of structural-nematic, magnetic and electronic effects in high-temperature superconductors.

  12. Modeling heat transfer from quench protection heaters to superconducting cables in Nb3Sn magnets

    CERN Document Server

    Salmi, T; Caspi, S; Felice, H; Prestemon, S; Chlachidze, G; Kate, H H J ten

    2013-01-01

    We use a recently developed quench protection heater modeling tool for an analysis of heater delays in superconducting high-field Nb3Sn accelerator magnets. The results suggest that the calculated delays are consistent with experimental data, and show how the heater delay depends on the main heater design parameters.

  13. Design of Anti-windup Compensator for Superconducting Magnetic Energy Storage

    DEFF Research Database (Denmark)

    Fang, Jiakun; Chen, Zhe; Su, Chi

    2013-01-01

    -windup compensator (AWC) is applied to the controller of the superconducting magnetic energy storage (SMES) system to improve power system stability. First, power system with actuator saturation is described to formulate the problem mathematically. Then, uniform anti-windup scheme is studied and compensator...

  14. AC Loss in the Superconducting Cables of the CERN Fast Cycled Magnet Prototype

    NARCIS (Netherlands)

    Borgnolutti, F.; Bottura, L.; Nijhuis, A.; Zhou, C.; Liu, B.; Miyoshi, Y.; Krooshoop, H.J.G.; Richter, D.

    2012-01-01

    Fast Cycled Superconducting Magnets (FCM's) are an option of interest for the long-term consolidation and upgrade plan of the LHC accelerator complex. The economical advantage of FCM's in the range of 2 T bore field, continuously cycled at 0.5 Hz repetition rate, depends critically on the AC loss pr

  15. Europium-based iron pnictides: a unique laboratory for magnetism, superconductivity and structural effects

    Science.gov (United States)

    Zapf, Sina; Dressel, Martin

    2017-01-01

    Despite decades of intense research, the origin of high-temperature superconductivity in cuprates and iron-based compounds is still a mystery. Magnetism and superconductivity are traditionally antagonistic phenomena; nevertheless, there is basically no doubt left that unconventional superconductivity is closely linked to magnetism. But this is not the whole story; recently, also structural effects related to the so-called nematic phase gained considerable attention. In order to obtain more information about this peculiar interplay, systematic material research is one of the most important attempts, revealing from time to time unexpected effects. Europium-based iron pnictides are the latest example of such a completely paradigmatic material, as they display not only spin-density-wave and superconducting ground states, but also local Eu2+ magnetism at a similar temperature scale. Here we review recent experimental progress in determining the complex phase diagrams of europium-based iron pnictides. The conclusions drawn from the observations reach far beyond these model systems. Thus, although europium-based iron pnictides are very peculiar, they provide a unique platform to study the common interplay of structural-nematic, magnetic and electronic effects in high-temperature superconductors.

  16. Electric-Field-Induced Superconductivity Detected by Magnetization Measurements of an Electric-Double-Layer Capacitor

    NARCIS (Netherlands)

    Kasahara, Yuichi; Nishijima, Takahiro; Sato, Tatsuya; Takeuchi, Yuki; Ye, Jianting; Yuan, Hongtao; Shimotani, Hidekazu; Iwasa, Yoshihiro

    2011-01-01

    We report evidence for superconductivity induced by the application of strong electric fields onto the surface of a band insulator, ZrNCl, provided by the observation of a shielding diamagnetic signal. We introduced an electric-double-layer capacitor configuration and in situ magnetization measureme

  17. Numerical calculation of superheating magnetic fields and currents for superconducting slabs

    Science.gov (United States)

    Landau, I. L.; Rinderer, L.

    1995-08-01

    Numerical calculations of superheating magnetic fields and superheating currents for superconducting slabs for a wide range of the sample thickness are presented. The calculations were made for low values of Ginzburg-Landau parameter κ, i.e., for type-1 superconductors. We propose also experimental procedures to measure superheating fields and currents in films and bulk samples.

  18. Electric-Field-Induced Superconductivity Detected by Magnetization Measurements of an Electric-Double-Layer Capacitor

    NARCIS (Netherlands)

    Kasahara, Yuichi; Nishijima, Takahiro; Sato, Tatsuya; Takeuchi, Yuki; Ye, Jianting; Yuan, Hongtao; Shimotani, Hidekazu; Iwasa, Yoshihiro

    2011-01-01

    We report evidence for superconductivity induced by the application of strong electric fields onto the surface of a band insulator, ZrNCl, provided by the observation of a shielding diamagnetic signal. We introduced an electric-double-layer capacitor configuration and in situ magnetization measureme

  19. On the Coexistence of Superconductivity and Magnetic Ordering in Unconventional Superconductors

    Science.gov (United States)

    Rodrigues de Campos, Fillipi Klos; Zanella, Fernando; Dartora, C. A.

    2017-04-01

    It is demonstrated that the coexistence of superconductivity and magnetic ordering, occurring, for instance, in iron-based pnictides and uranium compounds, is not forbidden by classical Maxwell's equations and London-type equations. It predicts simply that internal magnetization is allowed but localized magnetic moments are screened at distances of the order of the London penetration depth. A microscopic theory is considered for the case of ferromagnetic ordering, described in simple terms by electron-magnon coupling. For the sake of simplicity, we assume that itinerant electrons are not responsible for the magnetic ordering, but interact with phonon and magnon excitations, leading to an alternative Cooper pair channel. The temperature dependence and the isotope effect of the superconducting gap is also analysed.

  20. Investigation of the Periodic Magnetic Field Modulation in LHC Superconducting Dipoles

    CERN Document Server

    Pugnat, P; Siemko, A

    2002-01-01

    The windings of high-field accelerator magnets are usually made of Rutherford-type superconducting cables. The magnetic field distribution along the axis of such magnets exhibits a periodic modulation with a wavelength equal to the twist pitch length of the cable used in the winding. This effect, resulting from quasi-persistent currents, was investigated with a Hall probes array inserted inside the aperture of the LHC superconducting dipoles, both in short models and full-scale prototypes. The amplitude and the time dependence of this periodic field oscillation have been studied as a function of the magnet current history. The origin and the impact on the LHC dipoles stability of the non-uniform current redistribution producing such a field modulation are discussed.

  1. Using LSTM recurrent neural networks for detecting anomalous behavior of LHC superconducting magnets

    CERN Document Server

    Wielgosz, Maciej; Mertik, Matej

    2016-01-01

    The superconducting LHC magnets are coupled with an electronic monitoring system which records and analyses voltage time series reflecting their performance. A currently used system is based on a range of preprogrammed triggers which launches protection procedures when a misbehavior of the magnets is detected. All the procedures used in the protection equipment were designed and implemented according to known working scenarios of the system and are updated and monitored by human operators. This paper proposes a novel approach to monitoring and fault protection of the Large Hadron Collider (LHC) superconducting magnets which employs state-of-the-art Deep Learning algorithms. Consequently, the authors of the paper decided to examine the performance of LSTM recurrent neural networks for anomaly detection in voltage time series of the magnets. In order to address this challenging task different network architectures and hyper-parameters were used to achieve the best possible performance of the solution. The regre...

  2. Superconductivity and Magnetism in Organic Materials Studied with μSR

    Science.gov (United States)

    Pratt, Francis

    2016-09-01

    A review is given of the current status and recent progress in the use of μSR for the study of superconductivity and magnetism in organic materials. For organic superconductors, important factors are discussed that influence the observed μSR line widths and their field and temperature dependences in the superconducting state. The accumulated μSR results give direct information about the scaling relationship between superfluid stiffness and transition temperature that provides a strong constraint for theories of organic superconductors. For organic magnetism, μSR offers a sensitive probe for detecting various weak magnetic phenomena ranging from spin-density-wave transitions through spin dynamics and 3D ordering of Heisenberg chain systems to field induced magnetism of quantum spin liquids. Finally, experiments are described that focus on two current issues in organic spintronics: direct measurement of the spin coherence length and the identification of the relative importance of different mechanisms of spin decoherence.

  3. Fabrication of superconducting MgB2 nanostructures by an electron beam lithography-based technique

    Science.gov (United States)

    Portesi, C.; Borini, S.; Amato, G.; Monticone, E.

    2006-03-01

    In this work, we present the results obtained in fabrication and characterization of magnesium diboride nanowires realized by an electron beam lithography (EBL)-based method. For fabricating MgB2 thin films, an all in situ technique has been used, based on the coevaporation of B and Mg by means of an e-gun and a resistive heater, respectively. Since the high temperatures required for the fabrication of good quality MgB2 thin films do not allow the nanostructuring approach based on the lift-off technique, we structured the samples combining EBL, optical lithography, and Ar milling. In this way, reproducible nanowires 1 μm long have been obtained. To illustrate the impact of the MgB2 film processing on its superconducting properties, we measured the temperature dependence of the resistance on a nanowire and compared it to the original magnesium diboride film. The electrical properties of the films are not degraded as a consequence of the nanostructuring process, so that superconducting nanodevices may be obtained by this method.

  4. Aperiodic magnetic turbulence produced by relativistic ion beams

    CERN Document Server

    Niemiec, Jacek; Bret, Antoine; Stroman, Thomas

    2009-01-01

    Magnetic-field generation by a relativistic ion beam propagating through an electron-ion plasma along a homogeneous magnetic field is investigated with 2.5D high-resolution particle-in-cell (PIC) simulations. The studies test predictions of a strong amplification of short-wavelength modes of magnetic turbulence upstream of nonrelativistic and relativistic parallel shocks associated with supernova remnants, jets of active galactic nuclei, and gamma-ray bursts. We find good agreement in the properties of the turbulence observed in our simulations compared with the dispersion relation calculated for linear waves with arbitrary orientation of ${\\vec k}$. Depending on the parameters, the backreaction on the ion beam leads to filamentation of the ambient plasma and the beam, which in turn influences the properties of the magnetic turbulence. For mildly- and ultra-relativistic beams, the instability saturates at field amplitudes a few times larger than the homogeneous magnetic field strength. This result matches our...

  5. Fabrication of a superconducting cable for construction of Hi-Lumi Magnet

    CERN Multimedia

    2016-01-01

    A Rutherford cabling machine is operated in the superconducting laboratory in building 163. The machine was used for the production of the Nb-Ti cables in the LHC magnets. Today, it is operated for the assembly of the high-performance cables made from state-of-the-art Nb3Sn conductor. The video shows the production of a long length Nb3Sn cable that will be use in a 11 T High Luminosity LHC dipole magnet.

  6. LETTER TO THE EDITOR: Experimental evidence for Fröhlich superconductivity in high magnetic fields

    Science.gov (United States)

    Harrison, N.; Mielke, C. H.; Singleton, J.; Brooks, J. S.; Tokumoto, M.

    2001-05-01

    Resistivity and irreversible magnetization data taken within the high magnetic field CDWx phase of the quasi-two-dimensional organic metal α-(BEDT-TTF)2KHg(SCN)4 are shown to be consistent with a field-induced inhomogeneous superconducting phase. In-plane skin depth measurements show that the resistive transition on entering the CDWx phase is both isotropic and representative of the bulk.

  7. Magnetic design and modelling of a 14 mm-period prototype superconducting undulator.

    Science.gov (United States)

    Mishra, G; Gehlot, Mona; Sharma, Geetanjali; Trillaud, Frederic

    2017-03-01

    The magnetic design of a ten-period (each period 14 mm) prototype superconducting undulator is reported using RADIA. The results of modelling the magnetic flux density are presented in an analytical formula. The dependence of the field integrals and phase error on the current density and undulator gap has been calculated, and temperature curves are determined for the models and are compared with earlier reported Moser-Rossmanith fits.

  8. Finite Element Model of Training in the superconducting quadrupole magnet SQ02

    Energy Technology Data Exchange (ETDEWEB)

    Caspi, Shlomo; Ferracin, Paolo

    2007-11-01

    This paper describes the use of 3D finite element models to study training in superconducting magnets. The simulations are used to examine coil displacements when the electromagnetic forces are cycled, and compute the frictional energy released during conductor motion with the resulting temperature rise. A computed training curve is then presented and discussed. The results from the numerical computations are compared with test results of the Nb{sub 3}Sn racetrack quadrupole magnet SQ02.

  9. Local Magnetic Order vs Superconductivity in a Layered Cuprate

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, N. [Department of Superconductivity, School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, (Japan); Uchida, S. [Department of Superconductivity, School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, (Japan); Tranquada, J. M. [Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States); Niemoeller, T. [Hamburger Synchrotronstrahlungslabor HASYLAB at Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22603 Hamburg, (Germany); Gehring, P. M. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Lee, S.-H. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); University of Maryland, College Park, Maryland 20742 (United States); Schneider, J. R. [Hamburger Synchrotronstrahlungslabor HASYLAB at Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22603 Hamburg, (Germany)

    2000-08-21

    We report on the phase diagram for charge-stripe order in La{sub 1.6-x} Nd{sub 0.4}Sr {sub x}CuO{sub 4} , determined by neutron and x-ray scattering studies and resistivity measurements. From an analysis of the in-plane resistivity motivated by recent nuclear-quadrupole-resonance studies, we conclude that the transition temperature for local charge ordering decreases monotonically with x , and hence that local antiferromagnetic order is uniquely correlated with the anomalous depression of superconductivity at x{approx_equal}(1/8) . This result is consistent with theories in which superconductivity depends on the existence of charge-stripe correlations. (c) 2000 The American Physical Society.

  10. Principles Developed for the Construction of the High Performance, Low-cost Superconducting LHC corrector Magnets

    CERN Document Server

    Allitt, M; Ijspeert, Albert; Karppinen, M; Mazet, J; Pérez, J; Salminen, J; Karmarkar, M; Puntambekar, A

    2002-01-01

    The Large Hadron Collider (LHC) needs more than 6000 superconducting corrector magnets. These must be sufficiently powerful, have enough margin, be compact and of low cost. The development of the 11 types of magnets was spread over several years and included the magnetic and mechanical design as well as prototype building and testing. It gradually led to the systematic application of a number of interesting construction principles that allow to realize the above mentioned goals. The paper describes the techniques developed and presently used in practically all the LHC corrector magnets ranging from dipoles to dodecapoles.

  11. Topology optimization of magnetic source distributions for diamagnetic and superconducting levitation

    Science.gov (United States)

    Kuznetsov, Sergey; Guest, James K.

    2017-09-01

    Topology optimization is used to obtain a magnetic source distribution providing levitation of a diamagnetic body or type I superconductor with maximized thrust force. We show that this technique identifies non-trivial source distributions and may be useful to design devices based on non-contact magnetic suspension and other magnetic devices, such as micro-magneto-mechanical devices, high field magnets etc. Diamagnetic and superconducting suspensions are often used in physical experiments and thus we believe this approach will be interesting to physics community as it may generate non-trivial and often unexpected topologies and may be useful to create new experiments and devices.

  12. Electromagnetic superconductivity of vacuum induced by strong magnetic field: Numerical evidence in lattice gauge theory

    Energy Technology Data Exchange (ETDEWEB)

    Braguta, V.V. [IHEP, Protvino, Moscow region, 142284 (Russian Federation); ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); Buividovich, P.V. [ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); JINR, Joliot-Curie str. 6, Dubna, Moscow region, 141980 (Russian Federation); Institute of Theoretical Physics, University of Regensburg, Universitaetsstrasse 31, D-93053 Regensburg (Germany); Chernodub, M.N., E-mail: maxim.chernodub@lmpt.univ-tours.fr [CNRS, Laboratoire de Mathematiques et Physique Theorique, Universite Francois-Rabelais Tours, Parc de Grandmont, 37200 Tours (France); Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium); Kotov, A.Yu.; Polikarpov, M.I. [ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); MIPT, Institutskii per. 9, Dolgoprudny, Moscow region, 141700 (Russian Federation)

    2012-12-05

    Using numerical simulations of quenched SU(2) gauge theory we demonstrate that an external magnetic field leads to spontaneous generation of quark condensates with quantum numbers of electrically charged {rho} mesons if the strength of the magnetic field exceeds the critical value eB{sub c}=0.927(77) GeV{sup 2} or B{sub c}=(1.56{+-}0.13) Dot-Operator 10{sup 16} Tesla. The condensation of the charged {rho} mesons in strong magnetic field is a key feature of the magnetic-field-induced electromagnetic superconductivity of the vacuum.

  13. Repeated magnetization with temperature control in a high-Tc superconducting bulk; Ondo seigyo wo tomonatta koon chodendo baaruku tai no dotai no kurikaeshi no chakuji ho

    Energy Technology Data Exchange (ETDEWEB)

    Kamijo, H.; Fujimoto, H. [Railway tech. Research Inst., Tokyo (Japan)

    2000-05-29

    It examines applicability of the hulk magnet which uses magnetize-ingly the high-temperature superconductivity bulk body to the superconducting magnet for levitation system railway. It must be magnetized to the superconductive bulk body in respect of as much as possible large magnetic flux in order to obtain the powerful bulk magnet. Therefore, large coil for the impression magnetic field and power are required, and there is a problem of the growth of large electromagnetic mosquito even in the magnetizing process. Then, it is trying the method for magnetizing large magnetic field to the superconductive bulk body by comparatively small impression magnetic field by the method for repeatedly carrying out field cool and pulse magnetizing, while it gradually lowers the temperature of the superconductive bulk body from the critical temperature. (NEDO)

  14. Thermo-hydraulic Quench Propagation at the LHC Superconducting Magnet String

    CERN Document Server

    Rodríguez-Mateos, F; Serio, L

    1998-01-01

    The superconducting magnets of the LHC are protected by heaters and cold by-pass diodes. If a magnet quenches, the heaters on this magnet are fired and the magnet chain is de-excited in about two minu tes by opening dump switches in parallel to a resistor. During the time required for the discharge, adjacent magnets might quench due to thermo-hydraulic propagation in the helium bath and/or heat con duction via the bus bar. The number of quenching magnets depends on the mechanisms for the propagation. In this paper we report on quench propagation experiments from a dipole magnet to an adjacent ma gnet. The mechanism for the propagation is hot helium gas expelled from the first quenching magnet. The propagation changes with the pressure opening settings of the quench relief valves.

  15. The role of superconductivity in magnetic bearings for high-load applications

    Science.gov (United States)

    Downer, James; Eisenhaure, David

    1993-01-01

    Slewing of large payloads will require control torque and angular momentum storage capacities that are large in comparison to the capabilities of available control moment gyros (CMG's). SatCon Technology Corporation is currently designing a CMG which may be employed as a slew actuator for large spacecraft or other payloads. The slew actuator employs a type of magnetic bearing which may be used in high load applications. The magnetic bearing is also used to fully gimbal the suspended rotor of the slew actuator. The use of magnetic bearings in angular momentum exchange actuators has the primary advantage that physical contact between the rotor and stator is eliminated. This leads to greatly extended life, increased reliability, and reduced vibrations. Several actuators operating on magnetic bearings have been demonstrated in previous research efforts. These were sized for use in small satellites. For conventional magnetic bearings, which employ magnetic cores, high torsional loading may require that the magnetic structure be excessively massive. An alternative magnetic bearing design which employs a superconducting coil and eliminates conventional magnetic structures is discussed. The baseline approach is to replace the field coil of a conventional magnetic bearing with the superconducting coil.

  16. Magnetic levitation using a stack of high temperature superconducting tape annuli

    Science.gov (United States)

    Patel, A.; Hahn, S.; Voccio, J.; Baskys, A.; Hopkins, S. C.; Glowacki, B. A.

    2017-02-01

    Stacks of large width superconducting tape can carry persistent currents over similar length scales to bulk superconductors, therefore giving them potential for trapped field magnets and magnetic levitation. 46 mm wide high temperature superconducting tape has previously been cut into square annuli to create a 3.5 T persistent mode magnet. The same tape pieces were used here to form a composite bulk hollow cylinder with an inner bore of 26 mm. Magnetic levitation was achieved by field cooling with a pair of rare-earth magnets. This paper reports the axial levitation force properties of the stack of annuli, showing that the same axial forces expected for a uniform bulk cylinder of infinite J c can be generated at 20 K. Levitation forces up to 550 N were measured between the rare-earth magnets and stack. Finite element modelling in COMSOL Multiphysics using the H-formulation was also performed including a full critical state model for induced currents, with temperature and field dependent properties as well as the influence of the ferromagnetic substrate which enhances the force. Spark erosion was used for the first time to machine the stack of tapes proving that large stacks can be easily machined to high geometric tolerance. The stack geometry tested is a possible candidate for a rotary superconducting bearing.

  17. Superconducting/magnetic Three-state Nanodevice for Memory and Reading Applications.

    Science.gov (United States)

    del Valle, J; Gomez, A; Gonzalez, E M; Osorio, M R; Granados, D; Vicent, J L

    2015-10-15

    We present a simple nanodevice that can operate in two modes: i) non-volatile three-state memory and ii) reading device. The nanodevice can retain three well defined states -1, 0 and +1 and can operate in a second mode as a sensor for external magnetic fields. The nanodevice is fabricated with an array of ordered triangular-shaped nanomagnets embedded in a superconducting thin film gown on Si substrates. The device runs based on the combination of superconducting vortex ratchet effect (superconducting film) with the out of plane magnetization (nanomagnets). The input signals are ac currents and the output signal are dc voltages. The memory mode is realized without applying a magnetic field and the nanomagnet stray magnetic fields govern the effect. In the sensor mode an external magnetic field is applied. The main characteristic of this mode is that the output signal is null for a precise value of the external magnetic field that only depends on the fabrication characteristics of the nanodevice.

  18. Electron beam welding of copper-stabilized superconductors for a large bubble chamber magnet

    CERN Document Server

    Albrecht, C

    1972-01-01

    In the European Nuclear Research Center CERN in Geneva, the presently largest hydrogen bubble chamber of the world is due to be put into operation at the end of 1972. The magnetic flux density of 3.5 T necessary for the detection of the high-energy elementary particles is generated by superconducting coils of 4.7 m inner diameter. The fully stabilized conductor for half of these coils was fabricated from component conductors by longitudinal seam welding with the electron beam under vacuum. The conductor design, the design and the method of operation of the electron beam welding installation and the operating and fabricating experience gained by the processing of approximately 60 t of conductor material are discussed. (7 refs).

  19. Helium mass flow measurement in the International Fusion Superconducting Magnet Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, L.R.

    1986-08-01

    The measurement of helium mass flow in the International Fusion Superconducting Magnet Test Facility (IFSMTF) is an important aspect in the operation of the facility's cryogenic system. Data interpretation methods that lead to inaccurate results can cause severe difficulty in controlling the experimental superconducting coils being tested in the facility. This technical memorandum documents the methods of helium mass flow measurement used in the IFSMTF for all participants of the Large Coil Program and for other cryogenic experimentalists needing information on mass flow measurements. Examples of experimental data taken and calculations made are included to illustrate the applicability of the methods used.

  20. Competing superconducting and magnetic order parameters and field-induced magnetism in electron doped Ba(Fe1-xCox)2As2

    DEFF Research Database (Denmark)

    Larsen, Jacob; Uranga, B. Mencia; Stieber, G.

    2015-01-01

    We have studied the magnetic and superconducting properties of Ba(Fe1-xCox)2As2 as a function of temperature and external magnetic field using neutron scattering and muon spin rotation. Below the superconducting transition temperature the magnetic and superconducting order parameters coexist...