WorldWideScience

Sample records for superconducting magnetic sensors

  1. High Tc superconducting magnetic multivibrators for fluxgate magnetic-field sensors

    International Nuclear Information System (INIS)

    Mohri, K.; Uchiyama, T.; Ozeki, A.

    1989-01-01

    Sensitive and quick-response nonlinear inductance characteristics are found for high Tc superconducting (YBa 2 Cu 3 O 7-chi ) disk cores at 77K in which soft magnetic BH hysteresis loops are observed. Various quick response magnetic devices such as modulators, amplifiers and sensors are built using these cores. The magnetizing frequency can be set to more than 20 MHz, which is difficult for conventional ferromagnetic bulk materials such as Permalloy amorphous alloys and ferrite. New quick-response fluxgate type magnetic-field sensors are made using ac and dc voltage sources. The former is used for second-harmonic type sensors, while the latter is for voltage-output multivibrator type sensors. Stable and quick-response sensor characteristics were obtained for two-core type multivibrators

  2. Fiber optic cryogenic sensors for superconducting magnets and superconducting power transmission lines at CERN

    Science.gov (United States)

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

    2014-08-01

    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.

  3. Superconducting Film Flux Transformer for a Sensor of a Weak Magnetic Field

    International Nuclear Information System (INIS)

    Ichkitidze, L; Mironyuk, A

    2012-01-01

    The object of study is a superconducting film flux transformer in the form of a square shaped loop with the tapering operative strip used in a sensor of a weak magnetic field. The magnetosensitive film element based on the giant magnetoresistance effect is overlapped with the tapering operative strip of the flux transformer; it is separated from the latter by the insulator film. It is shown that the topological nanostructuring of the operative strip of the flux transformer increases its gain factor by one or more orders of magnitude, i.e. increases its efficiency, which leads to a significant improvement of important parameters of a magnetic-field sensor.

  4. Invisible magnetic sensors

    Science.gov (United States)

    Mach-Batlle, Rosa; Navau, Carles; Sanchez, Alvaro

    2018-04-01

    Sensing magnetic fields is essential in many applications in biomedicine, transportation, or smart cities. The distortion magnetic sensors create in response to the field they are detecting may hinder their use, for example, in applications requiring dense packaging of sensors or accurately shaped field distributions. For sensing electromagnetic waves, cloaking shells that reduce the scattering of sensors have been introduced. However, the problem of making a magnetic sensor undetectable remains unsolved. Here, we present a general strategy on how to make a sensor magnetically invisible while keeping its ability to sense. The sensor is rendered undetectable by surrounding it with a spherical shell having a tailored magnetic permeability. Our method can be applied to arbitrary shaped magnetic sensors in arbitrary magnetic fields. The invisibility can be made exact when the sensor is spherical and the probed field is uniform. A metasurface composed of superconducting pieces is presented as a practical realization of the ideal invisibility shell.

  5. Study of Mechanical Disturbances in Superconducting Magnets using Piezoelectric Sensors and Quench Antenna

    CERN Document Server

    Artoos, K; Mompo, R; Siemko, A; Tommasini, D

    2003-01-01

    Mechanical disturbances in superconducting magnets were studied by recording and characterising the signals induced in piezo-electric ceramic sensors (piezos) and accelerometers by spontaneous acoustic emission (AE) during magnet excitation. The localisation of AE sources as recorded by the piezos corresponds to the localisation obtained by another, indirect technique, the so-called Quench Antenna. Dominant acoustic wave velocities along the magnet were measured by using selected piezos as active actuators. A mechanical disturbance energy calibration is shown and a way to estimate the minimum energy needed for quenching is proposed. A statistical approach is given in order to estimate the most probable amplitude of AE.

  6. Cryogenic test facility instrumentation with fiber optic and fiber optic sensors for testing superconducting accelerator magnets

    Science.gov (United States)

    Chiuchiolo, A.; Bajas, H.; Bajko, M.; Castaldo, B.; Consales, M.; Cusano, A.; Giordano, M.; Giloux, C.; Perez, J. C.; Sansone, L.; Viret, P.

    2017-12-01

    The magnets for the next steps in accelerator physics, such as the High Luminosity upgrade of the LHC (HL- LHC) and the Future Circular Collider (FCC), require the development of new technologies for manufacturing and monitoring. To meet the HL-LHC new requirements, a large upgrade of the CERN SM18 cryogenic test facilities is ongoing with the implementation of new cryostats and cryogenic instrumentation. The paper deals with the advances in the development and the calibration of fiber optic sensors in the range 300 - 4 K using a dedicated closed-cycle refrigerator system composed of a pulse tube and a cryogen-free cryostat. The calibrated fiber optic sensors (FOS) have been installed in three vertical cryostats used for testing superconducting magnets down to 1.9 K or 4.2 K and in the variable temperature test bench (100 - 4.2 K). Some examples of FOS measurements of cryostat temperature evolution are presented as well as measurements of strain performed on a subscale of High Temperature Superconducting magnet during its powering tests.

  7. A fiber optics sensor for strain and stress management in superconducting accelerator magnets

    International Nuclear Information System (INIS)

    van Oort, J.M.; ten Kate, H.H.J.

    1993-01-01

    A novel cryogenic interferometric fiber optics sensor for the measurement of strain and stress in the coil windings of superconducting accelerator magnets is described. The sensor can operate with two different readout sources, monochromatic laser light and white light respectively. The sensor head is built up as an extrinsic Fabry-Perot interferometer formed with two cleaved fiber surfaces, and can be mounted in several configurations. When read with laser light, the sensor is an extremely sensitive relative strain or temperature detector. When read with white light the absolute strain and pressure can be measured. Results are presented of tests in several configurations at 77 K and 4.2 K, both for the relative and absolute readout method. Finally, the possible use for quench localization using the temperature sensitivity is described

  8. High-performance magnetic field sensor based on superconducting quantum interference filters

    Science.gov (United States)

    Caputo, P.; Oppenländer, J.; Häussler, Ch.; Tomes, J.; Friesch, A.; Träuble, T.; Schopohl, N.

    2004-08-01

    We have developed an absolute magnetic field sensor using a superconducting quantum interference filter (SQIF) made of high-Tc grain-boundary Josephson junctions. The device shows the typical magnetic-field-dependent voltage response V(B ), which is a sharp deltalike dip in the vicinity of zero-magnetic field. When the SQIF is cooled with magnetic shield, and then the shield is removed, the presence of the ambient magnetic field induces a shift of the dip position from B0≈0 to a value B ≈B1, which is about the average value of the Earth's magnetic field, at our latitude. When the SQIF is cooled in the ambient field without shielding, the dip is first found at B ≈B1, and the further shielding of the SQIF results in a shift of the dip towards B0≈0. The low hysteresis observed in the sequence of experiments (less than 5% of B1) makes SQIFs suitable for high precision measurements of the absolute magnetic field. The experimental results are discussed in view of potential applications of high-Tc SQIFs in magnetometry.

  9. Low-level-signal data acquisition for the MFTF superconducting-magnet system

    International Nuclear Information System (INIS)

    Montoya, C.R.

    1981-01-01

    Acquisition of low level signals from sensors mounted on the superconducting yin-yang magnet in the Mirror Fusion Test Facility (MFTF) imposes very strict requirements on the magnet signal conditioning and data acquisition system. Of the various types of sensors required, thermocouples, strain gages, and voltage taps produce very low level outputs. These low level outputs must be accurately measured in the harsh environment of slowly varying magnetic fields, cryogenic temperatures, high vacuum, pulse power and 60 Hz electrical noise, possible neutron radiation, and high common mode voltage resulting from superconducting magnet quench. Successful measurements require careful attention to grounding, shielding, signal handling and processing in the data acquisition system. The magnet instrumentation system provides a means of effectively measuring both low level signals and high level signals from all types of sensors

  10. Structural Health Monitoring of Superconducting Magnets at CERN Using Fiber Bragg Grating Sensors

    CERN Document Server

    Chiuchiolo, A; Perez, J C; Bajas, H; Guinchard, M; Giordano, M; Breglio, G; Consales, M; Cusano, A

    2014-01-01

    The use of Fiber Bragg Grating sensors is becoming particularly challenging for monitoring different parameters in extreme operative conditions such as ultra-low temperatures, high electromagnetic fields and strong mechanical stresses. This work reports the use of the FBG for a new generation of accelerator magnets with the goal to develop an adequate sensing technology able to provide complementary or alternative information to the conventional strain gauges through the whole service life of the magnet. The study is focused on the mechanical performances of the magnet structure, which has to preserve the sensitive coils from any damage during the entire magnet fabrication process preventing even microscopic movements of the winding that can eventually initiate a transition from superconducting to normal conducting state of the material used (called in the specific literature as “quench”). The FBGs have been glued on the aluminium structure of two magnets prototypes by using an adhesive suitable for cryog...

  11. Magnet options for sensors for the pulp and paper industry

    International Nuclear Information System (INIS)

    Green, M.A.; Barale, P.J.; Fong, C.G.; Luft, P.A.; Reimer, J.A.; Yahnke, M.S.

    2001-01-01

    The Lawrence Berkeley National Laboratory (LBNL) has been developing sensors for the pulp and paper industry that uses a magnetic field. The applications for magnetic sensors that have studied include (1) sensors for the measurement of the water and ice content of wood chips entering the pulping mill, (2) sensors for measuring the water content and other constituents of the black liquor leaving the paper digester, and (3) sensors for measuring paper thickness and water content as the paper is being processed. These tasks can be done using nuclear magnetic resonance (NMR). The magnetic field used for doing the NMR can come from either permanent magnets or superconducting magnets. The choice of the magnet is dependent on a number of factors, which include the size of the sample and field strength needed to do the sensing task at hand. This paper describes some superconducting magnet options that can be used in the pulp and paper industry.

  12. 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....

  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. Advances in Fiber Optic Sensors Technology Development for temperature and strain measurements in Superconducting magnets and devices

    CERN Document Server

    Chiuchiolo, A.; Bajko, M.; Bottura, L.; Consales, M.; Cusano, A.; Giordano, M.; Perez, J. C.

    2016-01-01

    The luminosity upgrade of the Large Hadron Collider (HL-LHC) requires the development of a new generation of superconducting magnets based on Nb$_{3}$Sn technology. In order to monitor the magnet thermo-mechanical behaviour during its service life, from the coil fabrication to the magnet operation, reliable sensing systems need to be implemented. In the framework of the FP7 European project EUCARD, Nb$_{3}$Sn racetrack coils are developed as test beds for the fabrication validation, the cable characterization and the instrumentation development. Fiber optic sensors (FOS) based on Fiber Bragg Grating (FBG) technology have been embedded in the coils of the Short Model Coil (SMC) magnet. The FBG sensitivity to both temperature and strain required the development of a solution able to separate the mechanical and temperature effects. This work presents the feasibility study of the implementation of embedded FBG sensors for the temperature and strain monitoring of the 11 T type conductor. We aim to monitor and regi...

  15. Superconducting magnets of SST-1 tokamak

    International Nuclear Information System (INIS)

    Subrata Pradhan; Saxena, Y.C.; Sarkar, B.; Bansal, G.; Sharma, A.N.; Thomas, K.J.; Bedakihale, V.; Doshi, B.; Dhard, C.P.; Prasad, U.; Rathod, P.; Bahl, R.; Varadarajulu, A.; Mankani, A.

    2005-01-01

    Magnet System of SST-1 comprises of sixteen superconducting D-shaped Toroidal Field (TF) coils, nine superconducting Poloidal Field (PF) coils and a pair of resistive PF coils inside the vacuum vessel. TF magnets generate the basic 3.0 T field at the major radius of 1.1 m. Low resistance lap inter-pancake joints within and inter-coil joints between the coils have been made. Magnets are cooled with supercritical helium at 4 bar and 4.5 K, which is fed at the high field region in the middle of each of the double pancake over a hydraulic path length of 47 m. Voltage taps across joints and termination location are used for quench detection. The quench detection front-end electronics ensures fail proof quench detection based on subtraction logic. Quench detection system sends the quench trigger to the power supply system directly on a dedicated fiber optic link. Flow meters at the inlet of the TF and PF magnets, temperature sensors at the critical joint locations and at the outlet of the flow paths for enthalpy estimation, hall probes for field direction and magnitude measurements are the other sensors. A 20 V, 10 kA power supply will excite the TF magnets whereas the PF power supplies have voltages from few volts to in excess of 100 V to cater the fast current ramp-up of the PF magnets during start-up scenarios. All power supplies have been equipped with dump resisters of appropriate ratings in parallel with a series combination of DC circuit interrupters and pyro-breakers. (author)

  16. Embedded fiber Bragg grating sensors for true temperature monitoring in Nb3Sn superconducting magnets for high energy physics

    Science.gov (United States)

    Chiuchiolo, A.; Bajas, H.; Bajko, M.; Consales, M.; Giordano, M.; Perez, J. C.; Cusano, A.

    2016-05-01

    The luminosity upgrade of the Large Hadron Collider (HL-LHC) planned at the European Organization for Nuclear Research (CERN) requires the development of a new generation of superconducting magnets based on Nb3Sn technology. The instrumentation required for the racetrack coils needs the development of reliable sensing systems able to monitor the magnet thermo-mechanical behavior during its service life, from the coil fabrication to the magnet operation. With this purpose, Fiber Bragg Grating (FBG) sensors have been embedded in the coils of the Short Model Coil (SMC) magnet fabricated at CERN. The FBG sensitivity to both temperature and strain required the development of a solution able to separate mechanical and temperature effects. This work presents for the first time a feasibility study devoted to the implementation of an embedded FBG sensor for the measurement of the "true" temperature in the impregnated Nb3Sn coil during the fabrication process.

  17. Hybrid superconducting magnetic suspensions

    International Nuclear Information System (INIS)

    Tixador, P.; Hiebel, P.; Brunet, Y.; Chaud, X.; Gautier-Picard, P.

    1996-01-01

    Superconductors, especially high T c ones, are the most attractive materials to design stable and fully passive magnetic suspensions which have to control five degrees of freedom. The hybrid superconducting magnetic suspensions present high performances and a simple cooling mode. They consist of a permanent magnet bearing, stabilized by a suitable magnet-superconductor structure. Several designs are given and compared in terms of forces and stiffnesses. The design of the magnet bearing plays an important part. The superconducting magnetic bearing participates less in levitation but must provide a high stabilizing stiffness. This is achieved by the magnet configuration, a good material in term of critical current density and field cooling. A hybrid superconducting suspension for a flywheel is presented. This system consists of a magnet thrust bearing stabilized by superconductors interacting with an alternating polarity magnet structure. First tests and results are reported. Superconducting materials are magnetically melt-textured YBaCuO

  18. Superconducting magnet

    Science.gov (United States)

    1985-01-01

    Extensive computer based engineering design effort resulted in optimization of a superconducting magnet design with an average bulk current density of approximately 12KA/cm(2). Twisted, stranded 0.0045 inch diameter NbTi superconductor in a copper matrix was selected. Winding the coil from this bundle facilitated uniform winding of the small diameter wire. Test coils were wound using a first lot of the wire. The actual packing density was measured from these. Interwinding voltage break down tests on the test coils indicated the need for adjustment of the wire insulation on the lot of wire subsequently ordered for construction of the delivered superconducting magnet. Using the actual packing densities from the test coils, a final magnet design, with the required enhancement and field profile, was generated. All mechanical and thermal design parameters were then also fixed. The superconducting magnet was then fabricated and tested. The first test was made with the magnet immersed in liquid helium at 4.2K. The second test was conducted at 2K in vacuum. In the latter test, the magnet was conduction cooled from the mounting flange end.

  19. 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.

  20. Embedded fiber Bragg grating sensors for true temperature monitoring in Nb$_3$Sn superconducting magnets for high energy physics

    CERN Document Server

    Chiuchiolo, A; Bajko, M; Consales, M; Giordano, M; Perez, J C; Cusano, A

    2016-01-01

    The luminosity upgrade of the Large Hadron Collider (HL-LHC) planned at the European Organization for Nuclear Research (CERN) requires the development of a new generation of superconducting magnets based on Nb$_{3}$Sn technology. The instrumentation required for the racetrack coils needs the development of reliable sensing systems able to monitor the magnet thermo-mechanical behavior during its service life, from the coil fabrication to the magnet operation. With this purpose, Fiber Bragg Grating (FBG) sensors have been embedded in the coils of the Short Model Coil (SMC) magnet fabricated at CERN. The FBG sensitivity to both temperature and strain required the development of a solution able to separate mechanical and temperature effects. This work presents for the first time a feasibility study devoted to the implementation of an embedded FBG sensor for the measurement of the "true" temperature in the impregnated Nb$_{3}$Sn coil during the fabrication process. © (2016) COPYRIGHT Society of Photo-Optical Inst...

  1. Superconducting magnets for a muon collider

    International Nuclear Information System (INIS)

    Green, M.A.

    1996-01-01

    The existence of a muon collider will be dependent on the use of superconducting magnets. Superconducting magnets for the μ - μ + collider will be found in the following locations: the π - π + capture system, the muon phase rotation system, the muon cooling system, the recirculating acceleration system, the collider ring, and the collider detector system. This report describes superconducting magnets for each of these sections except the detector. In addition to superconducting magnets, superconducting RF cavities will be found in the recirculating accelerator sections and the collider ring. The use of superconducting magnets is dictated by the need for high magnetic fields in order to reduce the length of various machine components. The performance of all of the superconducting magnets will be affected the energy deposited from muon decay products. (orig.)

  2. Quenches in large superconducting magnets

    International Nuclear Information System (INIS)

    Eberhard, P.H.; Alston-Garnjost, M.; Green, M.A.; Lecomte, P.; Smits, R.G.; Taylor, J.D.; Vuillemin, V.

    1977-08-01

    The development of large high current density superconducting magnets requires an understanding of the quench process by which the magnet goes normal. A theory which describes the quench process in large superconducting magnets is presented and compared with experimental measurements. The use of a quench theory to improve the design of large high current density superconducting magnets is discussed

  3. Process of producing superconducting bar magnets

    International Nuclear Information System (INIS)

    Wilson, M.A.

    1988-01-01

    A method of forming a magnet having an established magnetic field is described comprising; (1) establishing a magnetic field of the desired extent and shape; (2) providing a superconducting material of desired shape; (3) positioning the material of (2) in field (1) while at a temperature above the critical temperature of the superconducting material so as to apply a magnetic field on the superconducting material; (4) cooling the superconducting material while in magnetic field (1) to below the critical temperature of the superconducting material; (5) removing the superconducting material from the magnetic field while in the supercooled condition; and (6) maintaining the material at or below the critical temperature

  4. Superconducting accelerator magnet design

    International Nuclear Information System (INIS)

    Wolff, S.

    1994-01-01

    Superconducting dipoles, quadrupoles and correction magnets are necessary to achieve the high magnetic fields required for big accelerators presently in construction or in the design phase. Different designs of superconducting accelerator magnets are described and the designs chosen at the big accelerator laboratories are presented. The most frequently used cosθ coil configuration is discussed in detail. Approaches for calculating the magnetic field quality including coil end fields are presented. Design details of the cables, coils, mechanical structures, yokes, helium vessels and cryostats including thermal radiation shields and support structures used in superconducting magnets are given. Necessary material properties are mentioned. Finally, the main results of magnetic field measurements and quench statistics are presented. (orig.)

  5. A parasitic magnetic refrigerator for cooling superconducting magnet

    International Nuclear Information System (INIS)

    Nakagome, H.; Takahashi, M.; Ogiwara, H.

    1988-01-01

    The application of magnetic refrigeration principle at a liquid helium temperature (4.2K) is very useful for cooling a superconducting magnet for its potential of high efficiency. The magnetic refrigerator equipped with 14 pieces of GGG (gadolinium-gallium-garnet) single crystal unit (30mm in diameter 10mm in length) in the rotating disk operates along the gradient of the magnetic field produced by a racetrack superconducting magnet, whose maximum magnetic field is 4.5 Tesla and the minimum field is 1.1 Tesla. The final goal of their program is to liquefy gaseous helium evaporated from a liquid helium vessel of the racetrack superconducting magnet by the rotating magnetic refrigerator which operates by using the magnetic field of the superconducting magnet. A 0.12W refrigeration power in the 0.72rpm operation has been achieved under condition of 4.2K to 11.5K operation. The helium evaporation rate of this magnet system is estimated as the order of 10mW, and the achieved refrigeration power of 0.12W at 4.2K is sufficient for cooling the superconducting magnet

  6. Superconducting pipes and levitating magnets.

    Science.gov (United States)

    Levin, Yan; Rizzato, Felipe B

    2006-12-01

    Motivated by a beautiful demonstration of the Faraday and the Lenz laws in which a small neodymium magnet falls slowly through a conducting nonferromagnetic tube, we consider the dynamics of a magnet falling coaxially through a superconducting pipe. Unlike the case of normal conducting pipes, in which the magnet quickly reaches the terminal velocity, inside a superconducting tube the magnet falls freely. On the other hand, to enter the pipe the magnet must overcome a large electromagnetic energy barrier. For sufficiently strong magnets, the barrier is so large that the magnet will not be able to penetrate it and will be levitated over the mouth of the pipe. We calculate the work that must done to force the magnet to enter a superconducting tube. The calculations show that superconducting pipes are very efficient at screening magnetic fields. For example, the magnetic field of a dipole at the center of a short pipe of radius a and length L approximately > a decays, in the axial direction, with a characteristic length xi approximately 0.26a. The efficient screening of the magnetic field might be useful for shielding highly sensitive superconducting quantum interference devices. Finally, the motion of the magnet through a superconducting pipe is compared and contrasted to the flow of ions through a trans-membrane channel.

  7. Magnetization Controlled Superconductivity in a Film with Magnetic Dots

    International Nuclear Information System (INIS)

    Lyuksyutov, I.F.; Pokrovsky, V.; Pokrovsky, V.

    1998-01-01

    We consider a superconducting film with a magnetic dots array (MDA) placed upon it. Magnetic moments of the dots are normal to the film and strong enough to create vortices in the superconducting film. Magnetic interaction between dots is negligible. Zero-field cooling leads to random magnetization of the MDA well above the superconducting temperature. With this cooling, the film is in a resistive state below the (expected) superconducting transition. Paradoxically, when field cooled, the film with MDA can be superconducting. copyright 1998 The American Physical Society

  8. Fast superconducting magnetic field switch

    Science.gov (United States)

    Goren, Yehuda; Mahale, Narayan K.

    1996-01-01

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles.

  9. Fast superconducting magnetic field switch

    International Nuclear Information System (INIS)

    Goren, Y.; Mahale, N.K.

    1996-01-01

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. 6 figs

  10. Superconducting magnet development in Japan

    International Nuclear Information System (INIS)

    Yasukochi, K.

    1983-01-01

    The present state of R and D works on the superconducting magnet and its applications in Japan are presented. On electrical rotating machines, 30 MVA superconducting synchronous rotary condenser (Mitsubishi and Fuji) and 50 MVA generator are under construction. Two ways of ship propulsion by superconducting magnets are developing. A superconducting magnetically levitated and linear motor propelled train ''MAGLEV'' was developed by the Japan National Railways (JNR). The superconducting magnet development for fusion is the most active field in Japan. The Cluster Test program has been demonstrated on a 10 T Nb 3 Sn coil and the first coil of Large Coil Task in IEA collaboration has been constructed and the domestic test was completed in JAERI. These works are for the development of toroidal coils of the next generation tokamak machine. R and D works on superconducting ohmic heating coil are in progress in JAERI and ETL. The latter group has constructed 3.8 MJ pulsed coil. A high ramp rate of changing field in pulsed magnet, 200 T/s, has been tested successfully. High Energy Physics Laboratory (KEK) are conducting active works. The superconducting μ meson channel and π meson channel have been constructed and are operating successfully. KEK has also a project of big accelerator named ''TRISTAN'', which is similar to ISABELLE project of BNL. Superconducting synchrotron magnets are developed for this project. The development of superconducting three thin wall solenoid has been started. One of them, CDF, is progressing under USA-Japan collaboration

  11. Stacked magnet superconducting bearing

    International Nuclear Information System (INIS)

    Rigney, T.K. II; Saville, M.P.

    1993-01-01

    A superconducting bearing is described, comprising: a plurality of permanent magnets magnetized end-to-end and stacked side-by-side in alternating polarity, such that flux lines flow between ends of adjacent magnets; isolating means, disposed between said adjacent magnets, for reducing flux leakage between opposing sides of said adjacent magnets; and a member made of superconducting material having at least one surface in communication with said flux lines

  12. Superconducting permanent magnets and their application in magnetic levitation

    International Nuclear Information System (INIS)

    Schultz, L.; Krabbes, G.; Fuchs, G.; Pfeiffer, W.; Mueller, K.H.

    2002-01-01

    Superconducting permanent magnets form a completely new class of permanent magnets. Of course, they must be cooled to 77 K or below. At very low temperatures (24 K) their magnetization can be a factor of 10 higher than that of the best conventional magnets, providing magnetic forces and energies which are up to two orders of magnitude higher. These new supermagnets became only recently available by the extreme improvement of the quality of melt-textured massive YBa 2 Cu 3 O x samples. Besides having a high magnetization, these superconducting permanent magnets can freeze in any given magnetic field configuration allowing completely new applications like superconducting transport systems or superconducting magnetic bearings. (orig.)

  13. Superconducting magnets for HERA

    International Nuclear Information System (INIS)

    Wolff, S.

    1987-01-01

    The Hadron-Electron-Ring Accelerator (HERA) presently under construction at DESY, Hamburg, consists of an electron storage ring of 30 GeV and a proton storage ring of 820 GeV. Superconducting magnets are used for the proton ring. There are 416 superconducting bending magnets of 4.698 T central field and 8.824 m magnetic length, 224 superconducting quadrupoles of 91.2 T/m central gradient and many superconducting correction dipoles, quadrupoles and sextupoles. The main dipoles and quadrupoles consist of two-layer coils of 75 mm inner diameter clammed with aluminium (for the dipoles) or stainless steel laminations (for the quadrupoles). The collared coils are surrounded by a laminated cold iron yoke and supported inside a low loss cryostat. The protection system uses cold diodes to bypass the current around a quenching magnet. The magnets are cooled with one phase helium supplied by a 3 block central refrigeration system of 20 kW refrigeration power at 4.3 K. Two helium is returned through the magnets in good thermal contact with the one phase helium in the dipoles for temperature control. This paper describes the magnet system and gives the results obtained for prototype magnets

  14. Superconducting magnets technologies for large accelerator

    International Nuclear Information System (INIS)

    Ogitsu, Toru

    2017-01-01

    The first hadron collider with superconducting magnet technologies was built at Fermi National Accelerator Laboratory as TEVATRON. Since then, the superconducting magnet technologies are widely used in large accelerator applications. The paper summarizes the superconducting magnet technologies used for large accelerators. (author)

  15. 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 Nb$_{3}$Sn 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.

  16. Large Superconducting Magnet Systems

    Energy Technology Data Exchange (ETDEWEB)

    Védrine, P [Saclay (France)

    2014-07-01

    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.

  17. Superconductivity from magnetic elements under high pressure

    International Nuclear Information System (INIS)

    Shimizu, Katsuya; Amaya, Kiichi; Suzuki, Naoshi; Onuki, Yoshichika

    2006-01-01

    Can we expect the appearance of superconductivity from magnetic elements? In general, superconductivity occurs in nonmagnetic metal at low temperature and magnetic impurities destroy superconductivity; magnetism and superconductivity are as incompatible as oil and water. Here, we present our experimental example of superconducting elements, iron and oxygen. They are magnetic at ambient pressure, however, they become nonmagnetic under high pressure, then superconductor at low temperature. What is the driving force of the superconductivity? Our understanding in the early stages was a simple scenario that the superconductive state was obtained as a consequence of an emergence of the nonmagnetic states. In both cases, we may consider another scenario for the appearance of superconductivity; the magnetic fluctuation mechanism in the same way as unconventional superconductors

  18. Magnetic levitation force between a superconducting bulk magnet and a permanent magnet

    International Nuclear Information System (INIS)

    Wang, J J; He, C Y; Meng, L F; Li, C; Han, R S; Gao, Z X

    2003-01-01

    The current density J(ρ, z) in a disc-shaped superconducting bulk magnet and the magnetic levitation force F SBM z exerted on the superconducting bulk magnet by a cylindrical permanent magnet are calculated from first principles. The effect of the superconducting parameters of the superconducting bulk is taken into account by assuming the voltage-current law E = E c (J/J c ) n and the material law B = μ 0 H. The magnetic levitation force F SBM z is dominated by the remnant current density J' 2 (ρ, z), which is induced by switching off the applied magnetizing field. High critical current density and flux creep exponent may increase the magnetic levitation force F SBM z . Large volume and high aspect ratio of the superconducting bulk can further enhance the magnetic levitation force F SBM z

  19. Ultrasensitive Inertial and Force Sensors with Diamagnetically Levitated Magnets

    Science.gov (United States)

    Prat-Camps, J.; Teo, C.; Rusconi, C. C.; Wieczorek, W.; Romero-Isart, O.

    2017-09-01

    We theoretically show that a magnet can be stably levitated on top of a punctured superconductor sheet in the Meissner state without applying any external field. The trapping potential created by such induced-only superconducting currents is characterized for magnetic spheres ranging from tens of nanometers to tens of millimeters. Such a diamagnetically levitated magnet is predicted to be extremely well isolated from the environment. We propose to use it as an ultrasensitive force and inertial sensor. A magnetomechanical readout of its displacement can be performed by using superconducting quantum interference devices. An analysis using current technology shows that force and acceleration sensitivities on the order of 10-23 N /√{Hz } (for a 100-nm magnet) and 10-14 g /√{Hz } (for a 10-mm magnet) might be within reach in a cryogenic environment. Such remarkable sensitivities, both in force and acceleration, can be used for a variety of purposes, from designing ultrasensitive inertial sensors for technological applications (e.g., gravimetry, avionics, and space industry), to scientific investigations on measuring Casimir forces of magnetic origin and gravitational physics.

  20. Magnetic levitation force between a superconducting bulk magnet and a permanent magnet

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J J; He, C Y; Meng, L F; Li, C; Han, R S; Gao, Z X [Department of Physics, Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871 (China)

    2003-04-01

    The current density J({rho}, z) in a disc-shaped superconducting bulk magnet and the magnetic levitation force F{sup SBM}{sub z} exerted on the superconducting bulk magnet by a cylindrical permanent magnet are calculated from first principles. The effect of the superconducting parameters of the superconducting bulk is taken into account by assuming the voltage-current law E = E{sub c}(J/J{sub c}){sup n} and the material law B = {mu}{sub 0}H. The magnetic levitation force F{sup SBM}{sub z} is dominated by the remnant current density J'{sub 2}({rho}, z), which is induced by switching off the applied magnetizing field. High critical current density and flux creep exponent may increase the magnetic levitation force F{sup SBM}{sub z}. Large volume and high aspect ratio of the superconducting bulk can further enhance the magnetic levitation force F{sup SBM}{sub z}.

  1. Controllable manipulation of superconductivity using magnetic vortices

    International Nuclear Information System (INIS)

    Villegas, J E; Schuller, Ivan K

    2011-01-01

    The magneto-transport of a superconducting/ferromagnetic hybrid structure, consisting of a superconducting thin film in contact with an array of magnetic nanodots in the so-called 'magnetic vortex state', exhibits interesting properties. For certain magnetic states, the stray magnetic field from the vortex array is intense enough to drive the superconducting film into the normal state. In this fashion, the normal-to-superconducting phase transition can be controlled by the magnetic history. The strong coupling between superconducting and magnetic subsystems allows characteristically ferromagnetic properties, such as hysteresis and remanence, to be dramatically transferred into the transport properties of the superconductor.

  2. Magnetically leviated superconducting bearing

    Science.gov (United States)

    Weinberger, Bernard R.; Lynds, Jr., Lahmer

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  3. Cryogenic Fiber Optic Sensors for Superconducting Magnets and Power Transmission Lines in High Energy Physics Applications

    CERN Document Server

    AUTHOR|(CDS)2081689; Bajko, Marta

    In the framework of the Luminosity upgrade of the Large Hadron Collider (HL - LHC), a remarkable R&D effort is now ongoing at the European Organization for Nuclear Research (CERN) in order to develop a new generation of accelerator magnets and superconducting power transmission lines. The magnet technology will be based on Nb$_{3}$Sn enabling to operate in the 11 - 13 T range. In parallel, in order to preserve the power converters from the increasing radiation level, high power transmission lines are foreseen to feed the magnets from free - radiation zones. These will be based on high temperature superconductors cooled down with helium gas in the range 5 - 30 K. The new technologies will require advanced design and fabrication approaches as well as adapted instrumentation for monitoring both the R&D phase and operation. Resistive sensors have been used so far for voltage, temperature and strain monitoring but their integration still suffers from the number of electrical wires and the complex compensat...

  4. Generation of high magnetic fields using superconducting magnets

    International Nuclear Information System (INIS)

    Kiyoshi, T.; Otsuka, A.; Kosuge, M.; Yuyama, M.; Nagai, H.; Matsumoto, F.

    2006-01-01

    High-field superconducting magnets have opened new frontiers for several kinds of applications, such as fusion reactors, particle accelerators, and nuclear magnetic resonance (NMR) spectrometers. The present record for the highest field in a fully superconducting state is 23.4 T. It was achieved with a combination of NbTi, Nb 3 Sn, and Bi-2212 conductors in 1999. Since high T c (critical temperature) superconductors (HTS) have sufficiently high critical current density even in excess of 30 T, they are promising for use as high-field superconducting magnets. However, several problems still remain to be resolved for practical applications, and the use of HTS coils will be limited to the inner part of a high-field magnet system in the near future. The required technologies to develop a high-field superconducting magnet with a field of up to 28 T have already been established. Such a magnet is certain to provide information to all leading research areas

  5. Superconducting magnets

    International Nuclear Information System (INIS)

    Willen, E.

    1996-01-01

    Superconducting dipole magnets for high energy colliders are discussed. As an example, the magnets recently built for the Relativistic Heavy Ion Collider at Brookhaven are reviewed. Their technical performance and the cost for the industry-built production dipoles are given. The cost data is generalized in order to extrapolate the cost of magnets for a new machine

  6. Superconducting magnet for 'ML-100'

    Energy Technology Data Exchange (ETDEWEB)

    Saito, R; Fujinaga, T; Tada, N; Kimura, H

    1974-07-01

    A magneticaly levitated experimental vehicle (Ml-100) was designed and constructed in commemoration of the centenary of the Japanese National Railways. For magnetic levitation the vehicle is provided with two superconducting magnets. In the test operation of the vehicle, these superconducting magnets showed stable performance in levitating vehicle body.

  7. Superconducting materials and magnets

    International Nuclear Information System (INIS)

    1991-04-01

    The Technical Committee Meeting on Superconducting Materials and Magnets was convened by the IAEA and held by invitation of the Japanese government on September 4-6, 1989 in Tokyo. The meeting was hosted by the National Research Institute for Metals. Topics of the conference related to superconducting magnets and technology with particular application to fusion and the superconducting supercollider. Technology using both high and low-temperature superconductors was discussed. This document is a compendium of the papers presented at the meeting. Refs, figs and tabs

  8. High Tc superconducting nonlinear inductance and quick response magnetic sensor devices

    International Nuclear Information System (INIS)

    Uchiyama, T.; Mohri, K.; Ozeki, A.; Shibata, T.

    1990-01-01

    A flux penetration model considering the demagnetizing effect is presented in order to analyze the nonlinear inductance characteristics for HTcSC. Various quick response magnetic devices such as modulators, magnetic switches and magnetic sensors were constructed. The magnetizing frequency can be set up more than 10 MHz which is difficult to achieve with the conventional ferromagnetic bulk cores. The cut-off frequency of 1.6 MHz was obtained for the sensors using the HTcSC cores at a magnetizing frequency of 11.5 MHz

  9. Magnetic shield effect simulation of superconducting film shield covering directly coupled HTS dc-SQUID magnetometer

    International Nuclear Information System (INIS)

    Terauchi, N.; Noguchi, S.; Igarashi, H.

    2011-01-01

    A superconducting film shield over a SQUID ring improves the robustness of the SQUID with respect to magnetic noise. Supercurrent in the SQUID magnetometer and the superconducting film shield were simulated. The superconducting film shield reduces the influence of the external magnetic field on the SQUID ring. An HTS SQUID is a high sensitive magnetic sensor. In recent years, the HTS SQUID is widely used in various applications. In some applications, high robustness with respect to magnetic noise is required to realize stable operation at outside of a magnetic shielding room. The target of this paper is a directly coupled HTS dc-SQUID magnetometer. To enhance the robustness of the SQUID magnetometer, use of a superconducting thin film shield has been proposed. The magnetic field directly penetrating the SQUID ring causes the change of the critical current of Josephson junction, and then the SQUID magnetometer transitions into inoperative state. In order to confirm the magnetic shield effect of the superconducting film shield, electromagnetic field simulation with 3D edge finite element method was performed. To simulate the high temperature superconductor, E-J characteristics and c-axis anisotropy are considered. To evaluate the effect of the superconducting film shield, an external magnetic field which is supposed to be a magnetic noise is applied. From the simulation results, the time transition of the magnetic flux penetrating the SQUID ring is investigated and the effect of the superconducting film shield is confirmed. The amplitude of the magnetic flux penetrating the SQUID ring can be reduced to about one-sixth since the superconducting film shield prevents the magnetic noise from directly penetrating the SQUID ring.

  10. Superconducting Metallic Glass Transition-Edge-Sensors

    Science.gov (United States)

    Hays, Charles C. (Inventor)

    2013-01-01

    A superconducting metallic glass transition-edge sensor (MGTES) and a method for fabricating the MGTES are provided. A single-layer superconducting amorphous metal alloy is deposited on a substrate. The single-layer superconducting amorphous metal alloy is an absorber for the MGTES and is electrically connected to a circuit configured for readout and biasing to sense electromagnetic radiation.

  11. 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.

  12. Superconducting magnets 1992

    International Nuclear Information System (INIS)

    1993-06-01

    This report discusses the following topics on Superconducting Magnets; SSC Magnet Industrialization; Collider Quadrupole Development; A Record-Setting Magnet; D20: The Push Beyond 10T; Nonaccelerator Applications; APC Materials Development; High-T c at Low Temperature; Cable and Cabling-Machine Development; and Analytical Magnet Design

  13. Superconducting magnets

    International Nuclear Information System (INIS)

    1994-08-01

    This report discusses the following topics on superconducting magnets: D19B and -C: The next steps for a record-setting magnet; D20: The push beyond 10 T: Beyond D20: Speculations on the 16-T regime; other advanced magnets for accelerators; spinoff applications; APC materials development; cable and cabling-machine development; and high-T c superconductor at low temperature

  14. Development of high field superconducting magnet

    International Nuclear Information System (INIS)

    Irie, Fujio; Takeo, Masakatsu.

    1986-01-01

    Recently, in connection with nuclear fusion research, the development of high field superconducting magnets showed rapid progress. The development of high field magnets of 15 T class by the techniques of winding after heat treatment has been continued in various places, as these techniques are suitable to make large magnets. In 1985, Kyushu University attained the record of 15.5 T. However in high field magnets, there are many problems peculiar to them, and the basic research related to those is demanded. In this report, these general problems, the experience of the design and manufacture in Kyushu University and the related problems are described. The superconducting magnet installed in the Superconducting Magnet Research Center of Kyushu University attained the record of 15.5 T for the first time in March, 1985. In superconducting magnets, very difficult problem must be solved since superconductivity, heat and mechanical force are inter related. The problems of the wire materials for high field, the scale of high field magnets, the condition limiting mean current density, and the development of high field magnets in Kyushu University are described. (Kako, I.)

  15. Superconducting magnets in high energy physics

    International Nuclear Information System (INIS)

    Prodell, A.G.

    1978-01-01

    The applications of superconducting magnets in high energy physics in the last ten years have made feasible developments which are vital to high energy research. These developments include high magnetic field, large volume detectors, such as bubble chambers, required for effective resolution of high energy particle trajectories, particle beam transport magnets, and superconducting focusing and bending magnets for the very high energy accelerators and storage rings needed to pursue the study of interactions between elementary particles. The acceptance of superconductivity as a proven technology in high energy physics was reinforced by the recognition that the existing large accelerators using copper-iron magnets had reached practical limits in terms of magnetic field intensity, cost, space, and energy usage, and that large-volume, high-field, copper-iron magnets were not economically feasible. Some of the superconducting magnets and associated systems being used in and being developed for high energy physics are described

  16. Study on magnetic field distribution in superconducting magnetic systems with account of magnetization of a superconducting winding

    International Nuclear Information System (INIS)

    Shakhtarin, V.N.; Koshurnikov, E.K.

    1977-01-01

    A method for investigating a magnetic field in a superconducting magnetic system with an allowance for magnetization of the superconducting winding material is described. To find the field, use was made of the network method for solving a nonlinear differential equation for the scalar magnetic potential of the magnetization field with adjustment of the boundary conditions by the boundary relaxation method. It was assumed that the solenoid did not pass into the normal state, and there were no flow jumps. The calculated dependences for the magnetization field of a superconducting solenoid with an inner diameter of 43 mm, an outer diameter of 138 mm, and a winding of 159 mm length are presented. The solenoid is wound with a 37-strand niobium-titanium wire. The magnetization field gradient in the area of the geometrical centre with a magnetic field strength of 43 kOe was equal to 1 Oe/cm, this meaning that within a sphere of 1 cm radius the inhomogeneity of the magnetization field was 2.5 x 10 -5

  17. Freely oriented portable superconducting magnet

    Science.gov (United States)

    Schmierer, Eric N [Los Alamos, NM; Prenger, F Coyne [Los Alamos, NM; Hill, Dallas D [Los Alamos, NM

    2010-01-12

    A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

  18. Superconductivity and magnet technology

    International Nuclear Information System (INIS)

    Lubell, M.S.

    1975-01-01

    The background theory of superconducting behavior is reviewed. Three parameters that characterize superconducting materials with values of commercial materials as examples are discussed. More than 1000 compounds and alloy systems and 26 elements are known to exhibit superconducting properties under normal conditions at very low temperatures. A wide variety of crystal structures are represented among the known superconductors. The most important ones do seem to have cubic symmetry such as the body-centered cubic (NbZr and NbTi), face-centered cubic (NbN), and the A15 or β-tungsten structures (Nb 3 Sn), V 3 Ga, Nb 3 Ge, Nb 3 Al, and V 3 Si). Attempts to understand some of the particular phenomena associated with superconductors as a necessary prelude to constructing superconducting magnets are discussed by the author. The origin of degradation is briefly discussed and methods to stabilize magnets are illustrated. The results of Oak Ridge National Laboratory design studies of toroidal magnet systems for fusion reactors are described

  19. Coexistence of magnetism and superconductivity in the hole doped FeAs-based superconducting compound

    International Nuclear Information System (INIS)

    Lu, T.P.; Wu, C.C.; Chou, W.H.; Lan, M.D.

    2010-01-01

    The magnetic and superconducting properties of the Sm-doped FeAs-based superconducting compound were investigated under wide ranges of temperature and magnetic field. After the systematical magnetic ion substitution, the superconducting transition temperature decreases with increasing magnetic moment. The hysteresis loop of the La 0.87-x Sm x Sr 0.13 FeAsO sample shows a superconducting hysteresis and a paramagnetic background signal. The paramagnetic signal is mainly attributed to the Sm moments. The experiment demonstrates that the coexistence of magnetism and superconductivity in the hole doped FeAs-based superconducting compounds is possible. Unlike the electron doped FeAs-based superconducting compounds SmFeAsOF, the hole doped superconductivity is degraded by the substitution of La by Sm. The hole-doped and electron-doped sides are not symmetric.

  20. A study on metastable superconducting magnets

    International Nuclear Information System (INIS)

    Koyama, Kenichi

    1976-01-01

    It is important to construct superconducting magnets as cheap as possible. One of the methods to achieve such a purpose is to save the superconducting material and operate the magnets at a high current density. Therefore it is useful to investigate the requirements for the operation of metastable superconducting magnets which can work at a current higher than the recovery current. Using the theory of flux jump, we introduce a ''stable current'' below which no flux jump can occur. On a rough approximation, it is given by I sub(s) =√A P sub(i) H sub(e) T sub(o) f(x)/rho where A : cross-section of the composite conductor. P sub(i) : total perimeter of all the superconducting cores. h sub(e) : effective heat transfer coefficient to the liquid helium through the stabilizer. T sub(o) : a characteristic temperature of the superconducting cores. f(x) : a characteristic function for the relative core radius x. rho : effective resistivity of the composite. Then it is shown that superconducting magnets can operate without unexpected normal transitions in the region enclosed by the two curves of I sub(s) and I sub(c). Next, we discuss the characteristics of our saddle shaped superconducting magnet for an one-KW MHD generator. We found that, 1) the magnet does safely operate in the metastable state; 2) the characteristics of the magnet are consistent with our theoretical results. (auth.)

  1. Interplay of magnetism and superconductivity

    International Nuclear Information System (INIS)

    Akhavan, M.

    2006-01-01

    After about two decades of intense research since the discovery of high-temperature superconductivity (HTSC) in cuprates, although many aspects of the physics and chemistry of these cuprate superconductors are now well understood, the underlying pairing mechanism remains elusive. Magnetism and superconductivity are usually thought as incompatible, but in number of special materials including HTSCs these two mutually excluding mechanisms are found to coexist. The presence in a system of superconductivity and magnetism, gives rise to a large number of interesting phenomenon. This article provides perspective on recent developments and their implications for our understanding of the interplay between magnetism and superconductivity in new materials. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  2. ESCAR superconducting magnet system

    International Nuclear Information System (INIS)

    Gilbert, W.S.; Meuser, R.B.; Pope, W.L.; Green, M.A.

    1975-01-01

    Twenty-four superconducting dipoles, each about 1 meter long, provide the guide field for the Experimental Superconducting Accelerator Ring proton accelerator--storage ring. Injection of 50 MeV protons corresponds to a 3 kG central dipole field, and a peak proton energy of 4.2 GeV corresponds to a 46 kG central field. Thirty-two quadrupoles provide focusing. The 56 superconducting magnets are contained in 40 cryostats that are cryogenically connected in a novel series ''weir'' arrangement. A single 1500 W refrigeration plant is required. Design and testing of the magnet and cryostat system are described. (U.S.)

  3. Superconducting magnets for accelerators

    International Nuclear Information System (INIS)

    Denisov, Yu.N.

    1979-01-01

    Expediency of usage and possibilities arising in application of superconducting devices in magnetic systems of accelerators and experimental nuclear-physical devices are studied. Parameters of specific devices are given. It is emphasized that at the existing level of technological possibilities, construction and usage of superconducting magnetic systems in experimental nuclear physics should be thought of as possible, from the engineering, and expedient, from the economical viewpoints [ru

  4. Instrumentation for status monitoring and protection of SST-1 superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, A.N., E-mail: aashoo.sharma@yahoo.com; Prasad, U.; Doshi, K.; Varmora, P.; Khristi, Y.; Patel, D.; Pradhan, S.

    2016-11-15

    Highlights: • Details of status monitoring instrumentation are presented. • Protection instrumentation details are presented. • Instrumentation installation details, signal conditioning and DAQ system details and the results during SST-1 operation are presented. - Abstract: Superconducting magnets of SST-1 are extensively instrumented to continuously monitor the health of magnets during machine cool-down, plasma experiments and also during the machine warm-up phase. These instrumentations include temperature sensors, flow meters, hall probes, strain gages, displacement sensors, pressure sensors and voltage taps. The number of sensors and their locations has been optimized to systematically monitor all important magnet parameters to ensure its safety. In-house developed modular signal conditioning cards have been developed for these instrumentations. The data is acquired on a Versa Module Europa bus based data acquisition system (VME DAQ). This paper gives an overview of selection, installation, laboratory scale validations, and distribution logics of these instrumentations. Results during plasma campaigns and the up-gradation aspects of these instrumentations are also discussed in this paper.

  5. 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 ...

  6. Radiation considerations for superconducting fusion magnets

    International Nuclear Information System (INIS)

    Abdou, M.A.

    1977-01-01

    Radiation environment for the magnets is characterized for various conditions expected for tokamak power reactor operation. The radiation levels are translated into radiation effects using available experimental data. The impact of the tradeoffs in radiation shielding and the change in the properties of the superconducting magnets on reactor performance and economics is examined. It is shown that (1) superconducting magnets in fusion reactors will operate at much higher radiation level than was previously anticipated; (2) additional data on radiation damage is required to better accuracy than is presently available in order to accurately quantify the change in properties in the superconducting magnet components; and (3) there is a substantial penalty for increasing (or overestimating) the shielding requirements. A perspective of future tokamak power reactors is presented and questions relating to desirable magnetic field strength and selection of materials for superconducting magnets are briefly examined

  7. Designing of superconducting magnet for clinical MRI

    International Nuclear Information System (INIS)

    Kar, Soumen; Choudhury, A.; Sharma, R.G.; Datta, T.S.

    2015-01-01

    Superconducting technology of Magnetic Resonance Imaging (MRI) scanner is closely guarded technology as it has huge commercial application for clinical diagnostics. This is a rapidly evolving technology which requires innovative design of magnetic and cryogenic system. A project on the indigenous development of 1.5 T (B_0) MRI scanner has been initiated by SAMEER, Mumbai funded by DeitY, Gov. of India. IUAC is the collaborating institute for designing and developing the superconducting magnets and the cryostat for 1.5 T MRI scanner. The superconducting magnet is heart of the present day MRI system. The performance of the magnet has the highest impact on the overall image quality of the scanner. The stringent requirement of the spatial homogeneity (few parts per million within 50 cm diametrical spherical volume), the temporal stability (0.1 ppm/hr.) of the superconducting magnet and the safety standard (5 G in 5 m x 3 m ellipsoidal space) makes the designing of the superconducting magnet more complex. MRI consists of set of main coils and shielding coils. The large ratio between the diameter and the winding length of each coil makes the B_p_e_a_k/B_0 ratio much higher, which makes complexity in selecting the load line of the magnet. Superconducting magnets will be made of NbTi wire-in-channel (WIC) conductor with high copper to superconducting (NbTi) ratio. Multi-coil configuration on multi-bobbin architecture is though is cost effective but poses complexity in the mechanical integration to achieve desired homogeneity. Some of the major sources of inhomogeneities, in a multi-bobbin configuration, are the imperfect axial positioning and angular shift. We have simulated several factors which causes the homogeneity in six (main) coils configuration for a 1.5 T MRI magnet. Differential thermal shrinkage between the bobbin and superconducting winding is also a major source of inhomogeneity in a MRI magnet. This paper briefly present the different designing aspects of the

  8. Thermo-magnetic instabilities in Nb3Sn Superconducting Accelerator Magnets

    International Nuclear Information System (INIS)

    Bordini, Bernardo; Pisa U.

    2006-01-01

    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 Nb 3 Sn. Several laboratories in the US and Europe are currently working on developing Nb 3 Sn 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 Nb 3 Sn 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 Nb 3 Sn; a description of the manufacturing process of Nb 3 Sn strands; superconducting cables; a typical layout of superconducting accelerator magnets; the current state of the art of Nb 3 Sn accelerator magnets; the High Field Magnet program at Fermilab; and the scope of the thesis

  9. A high Tc superconducting liquid nitrogen level sensor

    International Nuclear Information System (INIS)

    Jin, J. X.; Liu, H. K.; Dou, S. X.; Grantham, C.; Beer, J.

    1996-01-01

    Full text: The dramatic resistance change in the superconducting-normal transition temperature range enables a high T c superconductor to be considered for designing a liquid nitrogen level sensor. A (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10+x Ag clad superconducting wire is selected and tested as a continuous liquid nitrogen level sensor to investigate the possibility for this application. The (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10+x Ag clad superconducting wire has approximately 110 K critical temperature, with more flexible and stable properties compared with bulk shape ceramic high T c superconductors. The voltage drops across the sensor are tested with different immersion lengths in liquid nitrogen. The accuracy of the HTS sensor is analysed with its dR/dT in the superconducting-normal transition range. The voltage signal is sensitive to liquid nitrogen level change, and this signal can be optimized by controlling the transport current. The problems of the Ag clad superconductor are that the Ag sheath thermal conductivity is very high, and the sensor normal resistance is low. These are the main disadvantages for using such a wire as a continuous level sensor. However, a satisfactory accuracy can be achieved by control of the transport current. A different configuration of the wire sensor is also designed to avoid this thermal influence

  10. Cooldown of superconducting magnet strings

    International Nuclear Information System (INIS)

    Yuecel, A.; Carcagno, R.H.

    1995-01-01

    A numerical model for the cooldown of the superconducting magnet strings in the Accelerator System String Test (ASST) Facility at the Superconducting Super Collider (SSC) Laboratory is presented. Numerical results are compared with experimental data from the ASST test runs. Agreement between the numerical predictions and experiments is very good over the entire range from room temperature to liquid helium temperatures. The model can be readily adapted to predict the cooldown and warmup behavior of other superconducting magnets or cold masses

  11. Design considerations for superconducting magnets as a maglev pad

    International Nuclear Information System (INIS)

    Ichikawa, H.; Ogiwara, H.

    1974-01-01

    The design and construction of a thin superconducting magnet for a magnetically suspended high-speed train are explained. The superconducting magnet, which is to be used in a null-flux maglev train system, is called a 'wing-type' superconducting magnet because of its geometry. The wing-type superconducting magnet is about 1.5m long and weighs about 500kg, but its heat loss is within 1W, which is very small compared with that of conventional superconducting magnets. (author)

  12. Civilian applications for superconducting magnet technology developed for defense

    International Nuclear Information System (INIS)

    Johnson, R.A.; Klein, S.W.; Gurol, H.

    1986-01-01

    Seventy years after its discovery, superconducting technology is beginning to play an important role in the civilian sector. Strategic defense initiative (SDI)-related research in space- and ground-based strategic defense weapons, particularly research efforts utilizing superconducting magnet energy storage, magnetohydrodynamics (MHD), and superconducting pulsed-power devices, have direct applications in the civilian sector as well and are discussed in the paper. Other applications of superconducting magnets, which will be indirectly enhanced by the overall advancement in superconducting technology, include high-energy physics accelerators, magnetic resonance imaging, materials purifying, water purifying, superconducting generators, electric power transmission, magnetically levitated trains, magnetic-fusion power plants, and superconducting computers

  13. Superconducting magnetic shielding apparatus and method

    Science.gov (United States)

    Clem, John R.; Clem, John R.

    1983-01-01

    Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

  14. Superconducting magnetic shielding apparatus and method

    Science.gov (United States)

    Clem, J.R.

    1982-07-09

    Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

  15. Superconducting composite for magnetic bearings

    International Nuclear Information System (INIS)

    Rigney, T.K. II.

    1995-01-01

    A composite includes granules of Type II superconducting material and granules of rare-earth permanent magnets that are distributed in a binder. The composite is a two-phase structure that combines the properties of the superconductor and magnets with the flexibility and toughness of a polymeric material. A bearing made from this composite has the load capacity and stiffness of a permanent magnet bearing with added stability from a Type II superconducting material. 7 figs

  16. Fiber Bragg Grating Sensors Based Monitoring System for Superconducting Accelerator Magnets

    CERN Document Server

    Chiuchiolo, A; Perez, J C; Bajas, H; Consales, M; Giordano, M; Breglio, G; Cusano, A

    2014-01-01

    New generation of accelerator magnets for high energy applications currently designed, manufactured and tested at the European Organization for Nuclear Research (CERN) require the implementation of precise cryogenic sensors with long-term robustness and reliability able to withstand cryogenic temperature and to monitor the mechanical stresses affecting the winding during all the stages of his service life, assembly, cool down and powering. Monitoring the mechanical behavior of the magnet from assembly to operation is a critical task which aims to assure the integrity of the magnet and to safely handle the coils made of new brittle material. This contribution deals with the first successful embedding of Fiber Bragg Grating sensors in a subscale Nb$_{3}$Sn dipole magnet in order to monitor the strain developed in the coil during the cool down to 1.9 K, the powering up to 15.8 kA and the warm up, offering new perspectives for the development of a complementary sensing technology based on fiber optic sensors.

  17. Reluctance motor employing superconducting magnetic flux switches

    International Nuclear Information System (INIS)

    Spyker, R.L.; Ruckstadter, E.J.

    1992-01-01

    This paper reports that superconducting flux switches controlling the magnetic flux in the poles of a motor will enable the implementation of a reluctance motor using one central single phase winding. A superconducting flux switch consists of a ring of superconducting material surrounding a ferromagnetic pole of the motor. When in the superconducting state the switch will block all magnetic flux attempting to flow in the ferromagnetic core. When switched to the normal state the superconducting switch will allow the magnetic flux to flow freely in that pole. By using one high turns-count coil as a flux generator, and selectively channeling flux among the various poles using the superconducting flux switch, 3-phase operation can be emulated with a single-hase central AC source. The motor will also operate when the flux generating coil is driven by a DC current, provided the magnetic flux switches see a continuously varying magnetic flux. Rotor rotation provides this varying flux due to the change in stator pole inductance it produces

  18. Design of shared instruments to utilize simulated gravities generated by a large-gradient, high-field superconducting magnet.

    Science.gov (United States)

    Wang, Y; Yin, D C; Liu, Y M; Shi, J Z; Lu, H M; Shi, Z H; Qian, A R; Shang, P

    2011-03-01

    A high-field superconducting magnet can provide both high-magnetic fields and large-field gradients, which can be used as a special environment for research or practical applications in materials processing, life science studies, physical and chemical reactions, etc. To make full use of a superconducting magnet, shared instruments (the operating platform, sample holders, temperature controller, and observation system) must be prepared as prerequisites. This paper introduces the design of a set of sample holders and a temperature controller in detail with an emphasis on validating the performance of the force and temperature sensors in the high-magnetic field.

  19. High-field superconducting nested coil magnet

    Science.gov (United States)

    Laverick, C.; Lobell, G. M.

    1970-01-01

    Superconducting magnet, employed in conjunction with five types of superconducting cables in a nested solenoid configuration, produces total, central magnetic field strengths approaching 70 kG. The multiple coils permit maximum information on cable characteristics to be gathered from one test.

  20. Superconductivity application technologies. Superconducting quadrupole magnet and cooling system for KEK B factory

    International Nuclear Information System (INIS)

    Tsuchiya, Kiyosumi; Yamaguchi, Kiyoshi; Sakurabata, Hiroaki; Seido, Masahiro; Matsumoto, Kozo.

    1997-01-01

    At present in National Laboratory for High Energy Physics (KEK), the construction of B factory is in progress. By colliding 8 GeV electrons and 3.5 GeV positrons, this facility generates large amounts of B mesons and anti-B mesons, and performs the elementary particle experiment of high accuracy. It is the collision type accelerator of asymmetric two-ring type comprising 8 GeV and 3.5 GeV rings. In the field of high energy physics, superconductivity technology has been put to practical use. As the objects of superconductivity technology, there are dipole magnet for bending beam, quadrupole magnet for adjusting beam, large solenoid magnet used for detector and so on. Superconducting magnets which are indispensable for high energy, superconducting wire material suitable to accelerators, and the liquid helium cooling system for maintaining superconducting magnets at 4.4 K are reported. The technologies of metallic conductors and making their coils have advanced rapidly, and also cooling technology has advanced, accordingly, superconductivity technology has reached the stage of practical use perfectly. (K.I.)

  1. Superconducting magnet system for the J-PARC neutrino beam line. Development, construction and operation of superconducting magnets

    International Nuclear Information System (INIS)

    Sasaki, Ken-ichi; Nakamoto, Tatsushi; Ajima, Yasuo; Okamura, Takahiro; Ogitsu, Toru; Kimura, Nobuhiro; Terashima, Akio; Tomaru, Takayuki; Higashi, Norio

    2010-01-01

    Superconducting combined-function magnets have been utilized for the 50-GeV, 750-kW proton beam line in the J-PARC neutrino experiment. The magnets are designed to provide a dipole field of 2.6 T combined with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm at a nominal current of 7,345 A. Following the success of a prototype R and D project, a superconducting magnet system for the J-PARC neutrino beam line has been constructed since 2005. Using a new conceptual beam line with the superconducting combined-function magnets has demonstrated successful beam transport to the target neutrino production. (author)

  2. Superconducting magnet activities at CEN Saclay

    International Nuclear Information System (INIS)

    Lesmond, C.

    1981-07-01

    The activities in superconducting magnets at DPhPE/Saclay spread over a wide range from DC magnets mainly for particle and nuclear physics and also for other fields of research, pulsed magnets for particle accelerators and for a controlled fusion tokamak machine. The superconducting magnets designed during recent years involve a variety of conductor types, winding schemes, materials and cooling modes, including the use of superfluid helium. (author)

  3. Low level signal data acquisition for the MFTF-B superconducting magnet system

    International Nuclear Information System (INIS)

    Montoya, C.R.

    1984-01-01

    Acquisition of low level signals from sensors mounted on the superconducting magnets in the Tandem Mirror Fusion Test Facility (MFTF-B) impose very strict requirements on the magnet signal conditioning and data acquisition system. Of the various types of sensors required, thermocouples and strain gages produce very low level outputs. These low level outputs must be accurately measured in the harsh environment of slowly varying magnetic fields, cryogenic temperatures, high vacuum, 80 kV pulse power, 60 Hz, 17 MHz and 28, 35, and 56 GHz electrical noise and possible neutron radiation. Successful measurements require careful attention to grounding, shielding, signal handling and processing in the data acquisition system. The magnet instrumentation system provides a means of effectively measuring both low level signals and high level signals from all types of sensors. Various methods involved in the design and implementation of the system for signal conditioning and data gathering will be presented

  4. Optimization study on the magnetic field of superconducting Halbach Array magnet

    Science.gov (United States)

    Shen, Boyang; Geng, Jianzhao; Li, Chao; Zhang, Xiuchang; Fu, Lin; Zhang, Heng; Ma, Jun; Coombs, T. A.

    2017-07-01

    This paper presents the optimization on the strength and homogeneity of magnetic field from superconducting Halbach Array magnet. Conventional Halbach Array uses a special arrangement of permanent magnets which can generate homogeneous magnetic field. Superconducting Halbach Array utilizes High Temperature Superconductor (HTS) to construct an electromagnet to work below its critical temperature, which performs equivalently to the permanent magnet based Halbach Array. The simulations of superconducting Halbach Array were carried out using H-formulation based on B-dependent critical current density and bulk approximation, with the FEM platform COMSOL Multiphysics. The optimization focused on the coils' location, as well as the geometry and numbers of coils on the premise of maintaining the total amount of superconductor. Results show Halbach Array configuration based superconducting magnet is able to generate the magnetic field with intensity over 1 Tesla and improved homogeneity using proper optimization methods. Mathematical relation of these optimization parameters with the intensity and homogeneity of magnetic field was developed.

  5. Superconducting magnet package for the TESLA test facility

    International Nuclear Information System (INIS)

    Koski, A.; Bandelmann, R.; Wolff, S.

    1996-01-01

    The magnetic lattice of the TeV electron superconducting linear accelerator (TESLA) will consist of superconducting quadrupoles for beam focusing and superconducting correction dipoles for beam steering, incorporated in the cryostats containing the superconducting cavities. This report describes the design of these magnets, presenting details of the magnetic as well as the mechanical design. The measured characteristics of the TESLA Test Facility (TTF) quadrupoles and dipoles are compared to the results obtained from numerical computations

  6. Stable superconducting magnet. [high current levels below critical temperature

    Science.gov (United States)

    Boom, R. W. (Inventor)

    1967-01-01

    Operation of a superconducting magnet is considered. A method is described for; (1) obtaining a relatively high current in a superconducting magnet positioned in a bath of a gas refrigerant; (2) operating a superconducting magnet at a relatively high current level without training; and (3) operating a superconducting magnet containing a plurality of turns of a niobium zirconium wire at a relatively high current level without training.

  7. Mechanical Design of Superconducting Accelerator Magnets

    International Nuclear Information System (INIS)

    Toral, F

    2014-01-01

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques

  8. Mechanical Design of Superconducting Accelerator Magnets

    CERN Document Server

    Toral, Fernando

    2014-07-17

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques.

  9. Mechanical Design of Superconducting Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Toral, F [Madrid, CIEMAT (Spain)

    2014-07-01

    This paper is about the mechanical design of superconducting accelerator magnets. First, we give a brief review of the basic concepts and terms. In the following sections, we describe the particularities of the mechanical design of different types of superconducting accelerator magnets: solenoids, costheta, superferric, and toroids. Special attention is given to the pre-stress principle, which aims to avoid the appearance of tensile stresses in the superconducting coils. A case study on a compact superconducting cyclotron summarizes the main steps and the guidelines that should be followed for a proper mechanical design. Finally, we present some remarks on the measurement techniques.

  10. Structural performance of the first SSC [Superconducting Super Collider] Design B dipole magnet

    International Nuclear Information System (INIS)

    Nicol, T.H.

    1989-09-01

    The first Design B Superconducting Super Collider (SSC) dipole magnet has been successfully tested. This magnet was heavily instrumented with temperature and strain gage sensors in order to evaluate its adherence to design constraints and design calculations. The instrumentation and associated data acquisition system allowed monitoring of the magnet during cooldown, warmup, and quench testing. This paper will focus on the results obtained from structural measurements on the suspension system during normal and rapid cooldowns and during quench studies at full magnet current. 4 refs., 9 figs

  11. Random errors in the magnetic field coefficients of superconducting magnets

    International Nuclear Information System (INIS)

    Herrera, J.; Hogue, R.; Prodell, A.; Wanderer, P.; Willen, E.

    1985-01-01

    Random errors in the multipole magnetic coefficients of superconducting magnet have been of continuing interest in accelerator research. The Superconducting Super Collider (SSC) with its small magnetic aperture only emphasizes this aspect of magnet design, construction, and measurement. With this in mind, we present a magnet model which mirrors the structure of a typical superconducting magnet. By taking advantage of the basic symmetries of a dipole magnet, we use this model to fit the measured multipole rms widths. The fit parameters allow us then to predict the values of the rms multipole errors expected for the SSC dipole reference design D, SSC-C5. With the aid of first-order perturbation theory, we then give an estimate of the effect of these random errors on the emittance growth of a proton beam stored in an SSC. 10 refs., 6 figs., 2 tabs

  12. Prototype superconducting magnet for the FFAG accelerator

    International Nuclear Information System (INIS)

    Obana, T.; Ogitsu, T.; Yamamoto, A.; Yoshimoto, M.; Mori, Y.; Fujii, T.; Iwasa, M.; Orikasa, T.

    2006-01-01

    A study of a superconducting magnet for the Fixed Field Alternating Gradient (FFAG) accelerator has been performed. The FFAG accelerator requires static magnetic field, and it is suitable for superconducting magnet applications, because problems associated with time varying magnetic field such as eddy current loss can be eliminated. The superconducting magnet, which can generate high magnetic field, is possible to realize a higher beam energy with a given accelerator size or the size to be smaller for a given beam energy. The FFAG accelerator magnet is demanded to have a complicated nonlinear magnetic field with high accuracy. As a first prototype superconducting coil, the coil configuration which consists of left-right asymmetric cross-section and large aperture has been designed. The prototype coil has been successfully developed by using a 6-axis Computer Numerical Control (CNC) winding machine. The magnetic field of the prototype coil has been demonstrated in warm measurement. As a consequence, the technical feasibility has been verified with the prototype coil development and the performance test. In addition, the technology components developed in the prototype coil have a possibility to transfer to a fusion magnet

  13. Superconducting Magnets for Accelerators

    Science.gov (United States)

    Brianti, G.; Tortschanoff, T.

    1993-03-01

    This chapter describes the main features of superconducting magnets for high energy synchrotrons and colliders. It refers to magnets presently used and under development for the most advanced accelerators projects, both recently constructed or in the preparatory phase. These magnets, using the technology mainly based on the NbTi conductor, are described from the aspect of design, materials, construction and performance. The trend toward higher performance can be gauged from the doubling of design field in less than a decade from about 4 T for the Tevatron to 10 T for the LHC. Special properties of the superconducting accelerator magnets, such as their general layout and the need of extensive computational treatment, the limits of performance inherent to the available conductors, the requirements on the structural design are described. The contribution is completed by elaborating on persistent current effects, quench protection and the cryostat design. As examples the main magnets for HERA and SSC, as well as the twin-aperture magnets for LHC, are presented.

  14. Sweeping a persisting superconducting magnet with a transformer

    International Nuclear Information System (INIS)

    Spencer, G.F.; Alexander, P.W.; Ihas, G.G.

    1982-01-01

    A method for sweeping a persisting superconducting magnet is described. The field sweep is achieved by including in the superconducting loop of the magnet a coil which acts as the secondary coil of a transformer. Variation of the current in the primary coil of the transformer, controlled from outside the cryostat, causes the field-sweeping action through flux-linking with the superconducting loop. Compared to directly changing the current in a magnet, this technique improves control by the ratio of the magnet's inductance to the transformer's inductance. The advantages of using an all-metal vacuum-tight superconducting feedthrough are discussed. (author)

  15. The Magnetically-Tuned Transition-Edge Sensor

    Science.gov (United States)

    Sadleir, John E.; Lee, Sang-Jun; Smith, Stephen J.; Busch, Sarah E.; Bandler, Simon R.; Adams, Joseph S.; Eckart, Megan E.; Chevenak, James A.; Kelley, Richard L.; Kilbourne, Caroline A.; hide

    2014-01-01

    We present the first measurements on the proposed magnetically-tuned superconducting transition-edge sensor (MTES) and compare the modified resistive transition with the theoretical prediction. A TES's resistive transition is customarily characterized in terms of the unit less device parameters alpha and beta corresponding to the resistive response to changes in temperature and current respectively. We present a new relationship between measured IV quantities and the parameters alpha and beta and use these relations to confirm we have stably biased a TES with negative beta parameter with magnetic tuning. Motivated by access to this new unexplored parameter space, we investigate the conditions for bias stability of a TES taking into account both self and externally applied magnetic fields.

  16. Superconducting magnets and cryogenics for the steady state superconducting tokamak SST-1

    International Nuclear Information System (INIS)

    Saxena, Y.C.

    2000-01-01

    SST-1 is a steady state superconducting tokamak for studying the physics of the plasma processes in tokamak under steady state conditions and to learn technologies related to the steady state operation of the tokamak. SST-1 will have superconducting magnets made from NbTi based conductors operating at 4.5 K temperature. The design of the superconducting magnets and the cryogenic system of SST-1 tokamak are described. (author)

  17. Novel Approach to Linear Accelerator Superconducting Magnet System

    International Nuclear Information System (INIS)

    Kashikhin, Vladimir

    2011-01-01

    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.

  18. Commissioning of the Main Magnet of Kolkata K-500 Superconducting Cyclotron

    CERN Document Server

    Bhandari, Rakesh K

    2005-01-01

    Main magnet of the K-500 superconducting cyclotron at Kolkata has been fully assembled in the cyclotron vault. The assembly includes alpha and beta superconducting coils inside the liquid helium chamber, coil tank for the outer vacuum, liquid nitrogen shield, support links, cryogenic instrumentation and 80 ton magnet frame forming the pill box structure. Cooling of the coils was started in mid-December. It took about three weeks to fill the liquid helium chamber - fully immersing the coils. All the four temperature sensors embedded in the coil are steady at about 4.4K. At this time the liquid nitrogen line for cooling the shield seems to show a leak. So, we are not cooling the shield. The helium liquefier/regrigerator of 200W capacity has been functioning well and so is the network of vacuum jacketted and liquid nitrogen cooled cryogenic transfer lines. Energization of the main magnet will begin soon. Magnetic field measurement set up is in place to start the mapping. In this presentation, our experiences wit...

  19. Development of superconducting magnetic bearing using superconducting coil and bulk superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Seino, H; Nagashima, K; Arai, Y [Railway Technical Research Institute, Hikari-cho 2-8-38, Kokubunji-shi, Tokyo (Japan)], E-mail: seino@rtri.or.jp

    2008-02-01

    The authors conducted a study on superconducting magnetic bearing, which consists of superconducting rotor and stator to apply the flywheel energy-storage system for railways. In this study, high temperature bulk superconductor (HTS bulk) was combined with superconducting coils to increase the load capacity of the bearing. In the first step of the study, the thrust rolling bearing was selected for application by using liquid nitrogen cooled HTS bulk. 60mm-diameter HTS bulks and superconducting coil which generated a high gradient of magnetic field by cusp field were adopted as a rotor and a stator for superconducting magnetic bearing, respectively. The results of the static load test and the rotation test, creep of the electromagnetic forces caused by static flux penetration and AC loss due to eccentric rotation were decreased to the level without any problems in substantial use by using two HTS bulks. In the result of verification of static load capacity, levitation force (thrust load) of 8900N or more was supportable, and stable static load capacity was obtainable when weight of 460kg was levitated.

  20. Development of superconducting magnetic bearing using superconducting coil and bulk superconductor

    International Nuclear Information System (INIS)

    Seino, H; Nagashima, K; Arai, Y

    2008-01-01

    The authors conducted a study on superconducting magnetic bearing, which consists of superconducting rotor and stator to apply the flywheel energy-storage system for railways. In this study, high temperature bulk superconductor (HTS bulk) was combined with superconducting coils to increase the load capacity of the bearing. In the first step of the study, the thrust rolling bearing was selected for application by using liquid nitrogen cooled HTS bulk. 60mm-diameter HTS bulks and superconducting coil which generated a high gradient of magnetic field by cusp field were adopted as a rotor and a stator for superconducting magnetic bearing, respectively. The results of the static load test and the rotation test, creep of the electromagnetic forces caused by static flux penetration and AC loss due to eccentric rotation were decreased to the level without any problems in substantial use by using two HTS bulks. In the result of verification of static load capacity, levitation force (thrust load) of 8900N or more was supportable, and stable static load capacity was obtainable when weight of 460kg was levitated

  1. The investigation of the superconducting NMR-imaging main magnets

    International Nuclear Information System (INIS)

    Zhang, Y.; Han, S.; Feng, Z.X.

    1989-01-01

    The design principles of MRI main magnets and the problems in the design process have been analyzed. A computer program in which the critical characteristics of superconductor, the uniformity of the magnetic field, the economization of magnet and the selection of magnet constructions are considered has been established. The program can also be used to design high uniformity superconducting magnet in some other uses. In designing MRI superconducting main magnet, five different magnet constructions have been analyzed. Using this computer program the authors made a series of designs of MRI superconducting main magnets with different construction, different central magnetic field, and different bore diameters. By analyzing the computing results some conclusions useful for the practical design of the MRI superconducting main magnets are obtained

  2. Electrical protection of superconducting magnet systems

    International Nuclear Information System (INIS)

    Sutter, D.F.; Flora, R.H.

    1975-01-01

    The problem of dissipating the energy stored in the field of a superconducting magnet when a quench occurs has received considerable study. However, when the magnet becomes a system 4 miles in length whose normal operation is an ac mode, some re-examination of standard techniques for dissipating energy outside the magnets is in order. Data accumulated in the Fermilab Energy Doubler magnet development program shows that heating associated with the temporal and spatial development of quenches is highly localized and can result in temperatures damaging to the superconducting wire. The design and operation are discussed for several energy dumping schemes, compatible with the operation of ac superconducting magnets, wherein more than 70 percent of the stored energy can be dissipated outside the magnet. Instrumentation to detect quenches early in their development and circuits for dumping the field energy are described, and representative operating performance data for the dump circuits and data showing temporal development of quenches are presented. (auth)

  3. Superconducting magnet applications in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, P; Collan, H K; Lounasmaa, O V

    1983-01-01

    A short review of superconducting magnet applications in Finland is presented. The development work was done in areas that seem to offer potential for a significant break-through technology. So far our efforts have covered magnetic separation, electric DC machinery and medical NMR imaging, and it is now being extended to biological NMR on living tissue and to particle physics experiments. Our work has been facilitated by the recently started fabrication of domestic superconducting wire.

  4. Superconducting self-correcting harmonic coils for pulsed superconducting dipole or multipole magnets

    International Nuclear Information System (INIS)

    Dael, A.; Kircher, F.; Perot, J.

    1975-01-01

    Due to the zero resistance of a superconducting wire, an induced current in a closed superconducting circuit is continuously exactly opposed to its cause. This phenomenon was applied to the correction of the field harmonics of a pulsed magnet by putting short-circuited superconducting coils of particular symmetry in the useful aperture of the magnet. After a review of the main characteristics of such devices, the construction of two correcting coils (quadrupole and sextupole) is described. Experimental results of magnetic efficiency and time behavior are given; they are quite encouraging, since the field harmonics were reduced by one or two orders of magnitude

  5. Decay and snapback in superconducting accelerator magnets

    OpenAIRE

    Haverkamp, M.

    2003-01-01

    This thesis deals with the explanation and compensation of the effects ‘decay’ and ‘snapback’ in superconducting accelerator magnets, in particular in those used in the new Large Hardron Collider at CERN. During periods of constant magnet excitation, as for example during the injection of particles in the storage ring, the magnetic field in superconducting accelerator magnets shows a decay behavior. As soon as the particles are accelerated, the magnets are ramped, and the magnetic field ‘snap...

  6. US superconducting magnet data base assessment for INTOR

    International Nuclear Information System (INIS)

    Schultz, J.H.; Montgomery, D.B.

    1984-01-01

    Because of its size, performance requirements and exposure to neutron and gamma irradiation, the superconducting magnet system for INTOR would represent a significant advance in superconducting magnet technology. US programs such as LCP, MFTF-B and others provide a significant data base for the INTOR application. The assessment of the adequacy of the US data base for the INTOR magnets is largely generic, and applies to the superconducting magnet systems for other magnetic confinement fusion reactors. Assessments of the data base generated by other national magnet technology programs are being prepared by the other INTOR participants

  7. A Method for Suppressing Superconductivity of Thin Films

    Science.gov (United States)

    Suppula, Tarmo; Pekola, Jukka; Kauppinen, Juha

    2003-03-01

    We have developed a method for suppressing superconductivity of thin films. Thin stripes of cobalt grown by e-gun evaporation and patterned by e-beam lithography were placed in the vicinity of aluminium thin film structures. The cobalt stripes were magnetized at 4.2 K with a superconducting coil and the remanence suppressed superconductivity of the Al stripe at temperatures down to 50 mK at least. The magnetization remained in thermal cycling and in a longer storage at room temperature. Motivation for this work is the Coulomb Blockade Thermometer(CBT)^1 which has to be in a normal state to operate. The CBT sensor contains aluminium which is superconducting at temperatures below 1.4 K. An external magnetic field is not always available or acceptable in cryostats. A small grain of permanent magnet mounted to the sensor is another solution, but suspicious if the sensor is put in strong magnetic fields or if "zero field" environment is required. We have shown that suitably patterned and magnetized Co stripes in the vicinity of tunnel junctions of the CBT can solve this problem. The amount of magnetic material in the sensor, as well as the stray field, is very small. This technique may be useful in other low temperature thin film devices also. 1) Product of Nanoway Ltd.

  8. 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.

  9. Thermal analysis of the cryocooled superconducting magnet for the liquid helium-free hybrid magnet

    International Nuclear Information System (INIS)

    Ishizuka, Masayuki; Hamajima, Takataro; Itou, Tomoyuki; Sakuraba, Junji; Nishijima, Gen; Awaji, Satoshi; Watanabe, Kazuo

    2010-01-01

    The liquid helium-free hybrid magnet, which consists of an outer large bore cryocooled superconducting magnet and an inner water-cooled resistive magnet, was developed for magneto-science in high fields. The characteristic features of the cryogen-free outsert superconducting magnet are described in detail in this paper. The superconducting magnet cooled by Gifford-McMahon cryocoolers, which has a 360 mm room temperature bore in diameter, was designed to generate high magnetic fields up to 10 T. The hybrid magnet has generated the magnetic field of 27.5 T by combining 8.5 T generation of the cryogen-free superconducting magnet with 19 T generation of the water-cooled resistive magnet. The superconducting magnet was composed of inner Nb 3 Sn coils and outer NbTi coils. In particular, inner Nb 3 Sn coils were wound using high-strength CuNi-NbTi/Nb 3 Sn wires in consideration of large hoop stress. Although the cryocooled outsert superconducting magnet achieved 9.5 T, we found that the outsert magnet has a thermal problem to generate the designed maximum field of 10 T in the hybrid magnet operation. This problem is associated with unexpected AC losses in Nb 3 Sn wires.

  10. Superconducting property measuring system by magnetization method

    International Nuclear Information System (INIS)

    Ikisawa, K.; Mori, T.; Takasu, N.

    1988-01-01

    Superconducting property measuring system (CMS-370B) for high temperature oxide superconductor has been developed. This system adopts magnetization measurement. The superconducting properties are able to be measured automatically and continuously changing the temperature and external magnetic field. The critical current density as a function of temperature and magnetic field of high temperature superconductor YBa 2 Cu 3 O 7-y (YBCO) has been measured. This paper reports how it was confirmed that this system having the high performance and the accuracy gave the significant contribution to the superconducting material development

  11. Superconducting magnetic systems and electrical machines

    International Nuclear Information System (INIS)

    Glebov, I.A.

    1975-01-01

    The use of superconductors for magnets and electrical machines attracts close attention of designers and scientists. A description is given of an ongoing research program to create superconductive magnetic systems, commutator motors, homopolar machines, topological generators and turbogenerators with superconductive field windings. All the machines are tentative experimental models and serve as a basis for further developments

  12. Decay and Snapback in Superconducting Accelerator Magnets

    CERN Document Server

    Haverkamp, M

    2003-01-01

    This thesis deals with the explanation and compensation of the effects 'decay' and 'snapback' in superconducting accelerator magnets, in particular in those used in the new Large Hardron Collider at CERN. During periods of constant magnet excitation, as for example during the injection of particles in the storage ring, the magnetic field in superconducting accelerator magnets shows a decay behavior. As soon as the particles are accelerated, the magnets are ramped, and the magnetic field 'snaps back' to the original hysteresis curve. Decay and snapback affect the beam in the machine and have tobe compensated precisely in order to avoid losses of particles. The research presented in this thesis is a step towards a better understanding of 'decay' and 'snapback' in superconducting particle accelerators. The thesis provides tools for the prediction and compensation of both effects in the magnets, and for the analysis of correlations between different magnet parameters.

  13. 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

    The work concentrates on few important tasks in enabling techniques for search of superconducting compressed hydrogen compounds and pure hydrogen, investigation of mechanisms of high-Tc superconductivity, and exploring new superconducting materials. Along that route we performed several challenging tasks, including discovery of new forms of polyhydrides of alkali metal Na at very high pressures. These experiments help us to establish the experimental environment that will provide important information on the high-pressure properties of hydrogen-rich compounds. Our recent progress in RIXS measurements opens a whole field of strongly correlated 3d materials. We have developed a systematic approach to measure major electronic parameters, like Hubbard energy U, and charge transfer energy Δ, as function of pressure. This technique will enable also RIXS studies of magnetic excitations in iridates and other 5d materials at the L edge, which attract a lot of interest recently. We have developed new magnetic sensing technique based on optically detected magnetic resonance from NV centers in diamond. The technique can be applied to study superconductivity in high-TC materials, to search for magnetic transitions in strongly correlated and itinerant magnetic materials under pressure. Summary of Project Activities; development of high-pressure experimentation platform for exploration of new potential superconductors, metal polyhydrides (including newly discovered alkali metal polyhydrides), and already known superconductors at the limit of static high-pressure techniques; investigation of special classes of superconducting compounds (high-Tc superconductors, new superconducting materials), that may provide new fundamental knowledge and may prove important for application as high-temperature/high-critical parameter superconductors; investigation of the pressure dependence of superconductivity and magnetic/phase transformations in 3d transition metal compounds, including

  14. Stress analysis of superconducting magnets for magnetic fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Akin, J.E.; Gray, W.H.; Baudry, T.V.

    1980-01-01

    Superconducting devices involve several factors that normally are not encountered in the structural analysis of more common systems. Several of these factors ae noted and methods for including them in an analysis are cited. To illustrate the state of the analysis art for superconducting magnets, in magnetic fusion reactors, two specific projects are illustrated. They are the Large Coil Program (LCP) and the Engineering Test Facility (ETF).

  15. Stress analysis of superconducting magnets for magnetic fusion reactors

    International Nuclear Information System (INIS)

    Akin, J.E.; Gray, W.H.; Baudry, T.V.

    1980-01-01

    Superconducting devices involve several factors that normally are not encountered in the structural analysis of more common systems. Several of these factors ae noted and methods for including them in an analysis are cited. To illustrate the state of the analysis art for superconducting magnets, in magnetic fusion reactors, two specific projects are illustrated. They are the Large Coil Program (LCP) and the Engineering Test Facility

  16. Superconducting transition edge sensors and methods for design and manufacture thereof

    Science.gov (United States)

    Sadleir, John E. (Inventor)

    2013-01-01

    Methods for forming sensors using transition edge sensors (TES) and sensors therefrom are described. The method includes forming a plurality of sensor arrays includes at least one TES device. The TES device includes a TES device body, a first superconducting lead contacting a first portion of the TES device body, and a second superconducting lead contacting of a second portion of the TES device body, where the first and second superconducting leads separated on the TES device body by a lead spacing. The lead spacing can be selected to be different for at least two of the plurality of sensor arrays. The method also includes determining a transition temperature for each of the plurality of sensor arrays and generating a signal responsive to detecting a change in the electrical characteristics of one of the plurality of sensor arrays meeting a transition temperature criterion.

  17. Novel Hall sensors developed for magnetic field imaging systems

    International Nuclear Information System (INIS)

    Cambel, Vladimir; Karapetrov, Goran; Novosad, Valentyn; Bartolome, Elena; Gregusova, Dagmar; Fedor, Jan; Kudela, Robert; Soltys, Jan

    2007-01-01

    We report here on the fabrication and application of novel planar Hall sensors based on shallow InGaP/AlGaAs/GaAs heterostructure with a two-dimensional electron gas (2DEG) as an active layer. The sensors are developed for two kinds of experiments. In the first one, magnetic samples are placed directly on the Hall sensor. Room temperature experiments of permalloy objects evaporated onto the sensor are presented. In the second experiment, the sensor scans close over a multigranular superconducting sample prepared on a YBCO thin film. Large-area and high-resolution scanning experiments were performed at 4.2 K with the Hall probe scanning system in a liquid helium flow cryostat

  18. A superconducting magnetic gear

    International Nuclear Information System (INIS)

    Campbell, A M

    2016-01-01

    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. (paper)

  19. 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.

  20. Structural safety features for superconducting magnets

    International Nuclear Information System (INIS)

    Lehner, J.; Reich, M.; Powell, J.; Bezler, P.; Gardner, D.; Yu, W.; Chang, T.Y.

    1975-01-01

    A survey has been carried out for various potential structural safety problems of superconducting fusion magnets. These areas include: (1) Stresses due to inhomogeneous temperature distributions in magnets where normal regions have been initiated. (2) Stress distributions and yield forces due to cracks and failed regions. (3) Superconducting magnet response due to seismic excitation. These analyses have been carried out using a variety of large capacity finite element computer codes that allow for the evaluation of stresses in elastic or elastic-plastic zones and around singularities in the magnet structure. Thus far, these analyses have been carried out on UWMAK-I type magnet systems

  1. Superconducting magnet systems for MRI

    International Nuclear Information System (INIS)

    Hawksworth, D.G.

    1988-01-01

    MRI is the first large scale commercial application of superconductivity and has not achieved the status of a mature industry with an annual turnover in the magnet industry alone in excess of $150M. Conservative estimates put the investment of the medical industry in MRI as a whole at more than a billion dollars. In the nine years since shipment of the first superconducting whole body imaging magnets of 0.3 Tesla field the standard product of the industry has become a system of 1 meter bore and field strength 0.5 Tesla to 1.5 Tesla. In this paper the evolution of present day MRI magnets from small bore but high field spectrometer magnets is reviewed and the direction of future developments discussed

  2. State-of-the-art superconducting accelerator magnets

    CERN Document Server

    Rossi, L

    2002-01-01

    With the LHC the technology of NbTi-based accelerator magnets has been pushed to the limit. By operating in superfluid helium, magnetic fields in excess of 10 T have been reached in various one meter-long model magnets while full scale magnets, 15 meter-long dipoles, have demonstrated possibility of safe operation in the 8.3-9 tesla range, with the necessary, very tight, field accuracy. The paper reviews the key points of the technology that has permitted the construction of the largest existing superconducting installations (Fermilab, Desy and Brookhaven), highlighting the novelties of the design of the LHC dipoles, quadrupoles and other superconducting magnets. All together the LHC project will need more than 5000 km of fine filament superconducting cables capable of 14 kA @ 10 T, 1.9 K. (13 refs).

  3. Checking BEBC superconducting magnet

    CERN Multimedia

    CERN PhotoLab

    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.

  4. Permanent magnet design for high-speed superconducting bearings

    Science.gov (United States)

    Hull, John R.; Uherka, Kenneth L.; Abdoud, Robert G.

    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.

  5. Superconducting magnets and cryogenics: proceedings

    International Nuclear Information System (INIS)

    Dahl, P.F.

    1986-01-01

    Separate abstracts were prepared for 70 papers in these workshop proceeedings. Topics covered include: superconducting accelerator magnet research and development; superconductor development; electrical measurements; magnet design and construction methods; field correction methods; power schemes and quench protection; cryogenic systems; and magnet measurements

  6. Radiation resistant organic composites for superconducting fusion magnets

    International Nuclear Information System (INIS)

    Nishijima, S.; Okada, T.

    1993-01-01

    Organic composite materials (usually reinforced by glas fibers: GFRP) are to be used in fusion superconducting magnets as insulating and/or structural materials. The fusion superconducting magnets are operated under radiation environments and hence the radiation induced degradation of magnet components is ought to be estimated. Among the components the organic composite materials were evaluated to be the most radiation sensitive. Consequently the development of radiation resistant organic composite materials is thought one of the 'key' technologies for fusion superconducting magnets. The mechanism of radiation-induced degradation was studied and the degradation of interlaminar shear strength (ILSS) was found to be the intrinsic phenomenon which controlled the overall degradation of organic composite materials. The degradation of ILSS was studied changing matrix resin, reinforcement and type of fabrics. The possible combination of the organic composites for the fusion superconducting magnet will be discussed. (orig.)

  7. Superconducting solenoid model magnet test results

    International Nuclear Information System (INIS)

    Carcagno, R.; Dimarco, J.; Feher, S.; Ginsburg, C.M.; Hess, C.; Kashikhin, V.V.; Orris, D.F.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; Tompkins, J.C.; Wokas, T.; Fermilab

    2006-01-01

    Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab High Intensity Neutrino Source (formerly known as Proton Driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab Magnet Test Facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests

  8. Superconducting solenoid model magnet test results

    Energy Technology Data Exchange (ETDEWEB)

    Carcagno, R.; Dimarco, J.; Feher, S.; Ginsburg, C.M.; Hess, C.; Kashikhin, V.V.; Orris, D.F.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab

    2006-08-01

    Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab High Intensity Neutrino Source (formerly known as Proton Driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab Magnet Test Facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests.

  9. Calculation of magnetic field and electromagnetic forces in MHD superconducting magnets

    International Nuclear Information System (INIS)

    Martinelli, G.; Morini, A.; Moisio, M.F.

    1992-01-01

    The realization of a superconducting prototype magnet for MHD energy conversion is under development in Italy. Electromechanical industries and University research groups are involved in the project. The paper deals with analytical methods developed at the Department of Electrical Engineering of Padova University for calculating magnetic field and electromagnetic forces in MHD superconducting magnets and utilized in the preliminary design of the prototype

  10. Safety and reliability in superconducting MHD magnets

    International Nuclear Information System (INIS)

    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

  11. Permanent magnet design for high-speed superconducting bearings

    International Nuclear Information System (INIS)

    Hull, J.R.; Uherka, K.L.; Abdoud, R.G.

    1996-01-01

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure is disclosed. 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. 9 figs

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

    International Nuclear Information System (INIS)

    Ishizuka, M.; Hamajima, T.; Itou, T.; Sakuraba, J.; Nishijima, G.; Awaji, S.; Watanabe, K.

    2010-01-01

    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 3 Sn superconducting wires particularly showed a low mechanical strength due to those brittle property, Nb 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 ∂Bz/∂z) of 4500 T 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 3 Sn layer and its large diameter formed on Nb-barrier component in Nb 3 Sn wires.

  13. Study on optimization design of superconducting magnet for magnetic force assisted drug delivery system

    International Nuclear Information System (INIS)

    Fukui, S.; Abe, R.; Ogawa, J.; Oka, T.; Yamaguchi, M.; Sato, T.; Imaizumi, H.

    2007-01-01

    Analytical study on the design of the superconducting magnet for the magnetic force assisted drug delivery system is presented in this paper. The necessary magnetic field condition to reside the magnetic drug particle in the blood vessels is determined by analyzing the particle motion in the blood vessel. The design procedure of the superconducting magnet for the M-DDS is presented and some case studies are conducted. The analytical results show that the superconducting magnet to satisfy the magnetic field conduction for the M-DDS is practically feasible

  14. Analysis of Voltage Signals from Superconducting Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Lizarazo, J.; Caspi, S.; Ferracin, P.; Joseph, J.; Lietzke, A. F.; Sabbi, G. L.; Wang, X.

    2009-10-30

    We present two techniques used in the analysis of voltage tap data collected during recent tests of superconducting magnets developed by the Superconducting Magnet Program at Lawrence Berkeley National Laboratory. The first technique was used on a quadrupole to provide information about quench origins that could not be obtained using the time-of-flight method. The second technique illustrates the use of data from transient flux imbalances occurring during magnet ramping to diagnose changes in the current-temperature margin of a superconducting cable. In both cases, the results of this analysis contributed to make improvements on subsequent magnets.

  15. Safety and stability in superconducting magnets

    International Nuclear Information System (INIS)

    Herring, J.S.

    1989-01-01

    The increasing size and field of superconducting magnets required for new applications result in significant stored energy and magnetic forces. The use of superconducting magnets near humans has resulted in standards for limiting occupational exposures to magnetic field. While these standards are unofficial, they have been widely adopted. In addition, development of large magnet sets for the fusion program and for the MHD program has led to experiments on the behavior of shorted and arcing coils under transient conditions. In combination with various code development efforts, these experiments, in the US and Europe, are resulting in criteria for the design of stable coils which can safely discharge their stored energy. 22 refs., 6 tabs

  16. Strain-based quench detection for a solenoid superconducting magnet

    International Nuclear Information System (INIS)

    Wang Xingzhe; Guan Mingzhi; Ma Lizhen

    2012-01-01

    In this paper, we present a non-electric quench detection method based on the strain gauge measurement of a superconducting solenoid magnet at cryogenic temperature under an intense magnetic field. Unlike the traditional voltage measurement of quench detection, the strain-based detection method utilizes low-temperature strain gauges, which evidently reduce electromagnetic noise and breakdown, to measure the magneto/thermo-mechanical behavior of the superconducting magnet during excitation. The magnet excitation, quench tests and trainings were performed on a prototype 5 T superconducting solenoid magnet. The transient strains and their abrupt changes were compared with the current, magnetic field and temperature signals collected during excitation and quench tests to indicate that the strain gauge measurements can detect the quench feature of the superconducting magnet. The proposed method is expected to be able to detect the quench of a superconducting coil independently or utilized together with other electrical methods. In addition, the axial quench propagation velocity of the solenoid is evaluated by the quench time lags among different localized strains. The propagation velocity is enhanced after repeated quench trainings. (paper)

  17. 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.

  18. Superconducting magnets for particle large accelerators

    International Nuclear Information System (INIS)

    Kircher, F.

    1994-01-01

    The different accelerator types (linear, circular) and the advantages of using superconductivity in particle accelerator are first reviewed. Characteristics of some large superconducting accelerators (Tevatron, HERA, RHIC, LHC CERN) are presented. The design features related to accelerator magnets are reviewed: magnet reproducibility, stability, field homogeneity, etc. and the selected design characteristics are discussed: manufacturing method, winding, shielding, cryostat. CEA involvement in this domain mainly addressing quadrupoles, is presented together with the Large Hadron Collider (LHC) project at CERN. Characteristics and design of detector magnets are also described. 5 figs., 2 tabs

  19. Superconducting magnet for a Ku-band maser.

    Science.gov (United States)

    Berwin, R.; Wiebe, E.; Dachel, P.

    1972-01-01

    A superconducting magnet to provide a uniform magnetic field of up to 8000 G in a 1.14-cm gap for the 15.3-GHz (Ku-band) traveling wave maser is described. The magnet operates in a persistent mode in the vacuum environment of a closed-cycle helium refrigerator (4.5 K). The features of a superconducting switch, which has both leads connected to 4.5 K heat stations and thereby does not receive heat generated by the magnet charging leads, are described.

  20. Hybrid superconducting-magnetic memory device using competing order parameters.

    Science.gov (United States)

    Baek, Burm; Rippard, William H; Benz, Samuel P; Russek, Stephen E; Dresselhaus, Paul D

    2014-05-28

    In a hybrid superconducting-magnetic device, two order parameters compete, with one type of order suppressing the other. Recent interest in ultra-low-power, high-density cryogenic memories has spurred new efforts to simultaneously exploit superconducting and magnetic properties so as to create novel switching elements having these two competing orders. Here we describe a reconfigurable two-layer magnetic spin valve integrated within a Josephson junction. Our measurements separate the suppression in the superconducting coupling due to the exchange field in the magnetic layers, which causes depairing of the supercurrent, from the suppression due to the stray magnetic field. The exchange field suppression of the superconducting order parameter is a tunable and switchable behaviour that is also scalable to nanometer device dimensions. These devices demonstrate non-volatile, size-independent switching of Josephson coupling, in magnitude as well as phase, and they may enable practical nanoscale superconducting memory devices.

  1. Flux penetration in a ferromagnetic/superconducting bilayer

    Energy Technology Data Exchange (ETDEWEB)

    Adamus, Z.; Cieplak, M.Z.; Abal' Oshev, A. [Polish Acad Sci, Inst Phys, PL-02668 Warsaw, (Poland); Konczykowski, M. [CEA/DSM/DRECAM, Laboratoire des Solides Irradies, F-91191 Gif Sur Yvette, (France); Konczykowski, M. [Ecole Polytech, CNRS - UMR 7642, F-91128 Palaiseau, (France); Cheng, X.M.; Zhu, L.Y.; Chien, C.L. [Johns Hopkins Univ, Dept Phys and Astron, Baltimore, MD 21218 (United States)

    2007-07-01

    An array of miniature Hall sensors is used to study the magnetic flux penetration in a ferromagnetic/superconducting bilayer consisting of Nb as a superconducting layer and Co/Pt multilayer with perpendicular magnetic anisotropy as a ferromagnetic layer, separated by an amorphous Si layer to avoid the proximity effect. It is found that the magnetic domains in the ferromagnetic layer create a large edge barrier in the superconducting layer which delays flux penetration. The smooth flux profiles observed in the absence of magnetic pinning change into terraced profiles in the presence of domains. (authors)

  2. Investigation of transient electrical, magnetic, and mechanical phenomena in large superconducting magnet coils

    International Nuclear Information System (INIS)

    Sihler, C.

    1996-07-01

    The progress in the field of technology for superconducting magnets led to the necessity of transferring existing calculation methods from electrical power engineering, modifying these tools to satisfy the boundary conditions for superconducting magnets, and also developing new calculation methods for special purposes. In this work suitable calculation methods are elaborated. Their validity and applicability is demonstrated in employing these scientific engineering tools to actual developments of the Forschungszentrum Karlsruhe. In detail this work deals with: 1. calculating eddy current and force densities in the conducting environment of a superconducting magnet or magnet system. 2. the effects of eddy current forces in experimental engineering; 3. transient effects of electrical surges acting on new coil designs; and 4. the electrical and magnetic properties of superconducting cables. Especially, the magnetic properties can lead to an inhomogeneous current distribution in the cable and, thus, to a considerable reduction of the current carrying capacity of the whole magnet. These investigations demonstrate that a detailed analysis of electrodynamic phenomena is indispensable in order to find the optimum technical way to make use of the physical potential of superconductivity. (orig./MM) [de

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    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 Bi 2 Sr 2 Ca 2 Cu 3 O 10 superconducting 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

  4. Superconducting magnets and leads thereto

    International Nuclear Information System (INIS)

    Biltcliffe, M.N.; Hanley, P.E.; McKinnon, J.B.; Wheatley, R.W.

    1975-01-01

    The magnet described comprises a cryostat containing a superconducting coil for the generation of a magnetic field, with a short-circuiting superconducting link connected across the coil, and electrical leads extending through the cryostat to the coil; these leads are provided with joints within the cryostat to enable them to be detached from the coil and removed from the cryostat without interrupting the current through the coil, thus reducing heat conduction to the cryostat through the leads. The joints are arranged so that the leads can be readily detached and re-attached to the coil from outside the cryostat. Gas-tight seals are provided where the leads pass through the outer wall of the cryostat, with caps that can be secured after removal of the leads. This kind of magnet can provide a stable magnetic field continuously over long periods, such as is required in nuclear magnetic resonance spectrometers. (U.K.)

  5. 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.......A single-crystal Nd30La10 superlattice grown using molecular beam epitaxy is found to consist of alternating antiferromagnetic and superconducting layers at low temperature. The superlattice has the DHCP crystal structure, and the stacking sequence of close-packed planes is coherent over many...

  6. Superconducting magnetic shields for neutral beam injectors. Final report

    International Nuclear Information System (INIS)

    1985-04-01

    Large high energy deuterium neutral beams which must be made from negative ions require extensive magnetic shielding against the intense fringe fields surrounding a magnetic fusion power plant. The feasibility of shielding by multilayer sheets of copper-superconducting laminated material was investigated. It was found that, if necessary fabrication techniques are developed, intrinsically stable type II superconductors will be able to shield against the magnetic fields of the fusion reactors. Among the immediate benefits of this research is better magnetic shields for neutral beam injectors in support of DOE's fusion program. Another application may be in the space vehicles, where difficulties in transporting heavy μ-metal sections may make a comparatively light superconducting shield attractive. Also, as high-field superconducting magnets find widespread applications, the need for high-intensity magnetic shielding will increase. As a result, the commercial market for the magnetic shields should expand along with the market for superconducting magnets

  7. Magnetism and superconductivity in Eu-based iron pnictides

    Energy Technology Data Exchange (ETDEWEB)

    Zapf, Sina [1. Physikalisches Institut, Universitaet Stuttgart (Germany)

    2015-07-01

    EuFe{sub 2}As{sub 2} is an extraordinary parent compound of the iron pnictides, as it exhibits at low temperatures - additional to the Fe spin density wave - long-range magnetic order of the Eu{sup 2+} local moments. Nevertheless, bulk superconductivity around 30 K can be induced by mechanical pressure or chemical substitution. In this talk we review the remarkable interplay of unconventional superconductivity, itinerant and local magnetism in Eu based iron pnictides. We focus on the appearance of a re-entrant spin glass phase that coexists with superconductivity and an indirect magneto-elastic coupling, enabling the persistent magnetic detwinning by small magnetic fields.

  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. Nematicity, magnetism and superconductivity in FeSe.

    Science.gov (United States)

    Böhmer, Anna E; Kreisel, Andreas

    2018-01-17

    Iron-based superconductors are well known for their complex interplay between structure, magnetism and superconductivity. FeSe offers a particularly fascinating example. This material has been intensely discussed because of its extended nematic phase, whose relationship with magnetism is not obvious. Superconductivity in FeSe is highly tunable, with the superconducting transition temperature, T c , ranging from 8 K in bulk single crystals at ambient pressure to almost 40 K under pressure or in intercalated systems, and to even higher temperatures in thin films. In this topical review, we present an overview of nematicity, magnetism and superconductivity, and discuss the interplay of these phases in FeSe. We focus on bulk FeSe and the effects of physical pressure and chemical substitutions as tuning parameters. The experimental results are discussed in the context of the well-studied iron-pnictide superconductors and interpretations from theoretical approaches are presented.

  10. Trapped magnetic field of a superconducting bulk magnet in high- Tc RE-Ba-Cu-O

    International Nuclear Information System (INIS)

    Fujimoto, Hiroyuki; Yoo, Sang Im; Higuchi, Takamitsu; Nakamura, Yuichi; Kamijo, Hiroki; Nagashima, Ken; Murakami, Masato

    1999-01-01

    Superconducting magnets made of high-T c superconductors are promising for industrial applications. It is well known that REBa 2 Cu 3 O 7-x and LRE (light rare-earth) Ba 2 Cu 3 O 7-x superconductors prepared by melt processes have a high critical current density, J 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 c in high magnetic fields and a much improved irreversibility field, H 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

  11. Superconductivity : Controlling magnetism

    NARCIS (Netherlands)

    Golubov, Alexandre Avraamovitch; Kupriyanov, Mikhail Yu.

    Manipulation of the magnetic state in spin valve structures by superconductivity has now been achieved, opening a new route for the development of ultra-fast cryogenic memories. Spintronics is a rapidly developing field that allows insight into fundamental spin-dependent physical properties and the

  12. Magnetic shielding of an inhomogeneous magnetic field source by a bulk superconducting tube

    International Nuclear Information System (INIS)

    Hogan, K; Fagnard, J-F; Wéra, L; Vanderheyden, B; Vanderbemden, P

    2015-01-01

    Bulk type-II irreversible superconductors can act as excellent passive magnetic shields, with a strong attenuation of low frequency magnetic fields. Up to now, the performances of superconducting magnetic shields have mainly been studied in a homogenous magnetic field, considering only immunity problems, i.e. when the field is applied outside the tube and the inner field should ideally be zero. In this paper, we aim to investigate experimentally and numerically the magnetic response of a high-T c bulk superconducting hollow cylinder at 77 K in an emission problem, i.e. when subjected to the non-uniform magnetic field generated by a source coil placed inside the tube. A bespoke 3D mapping system coupled with a three-axis Hall probe is used to measure the magnetic flux density distribution outside the superconducting magnetic shield. A finite element model is developed to understand how the magnetic field penetrates into the superconductor and how the induced superconducting shielding currents flow inside the shield in the case where the emitting coil is placed coaxially inside the tube. The finite element modelling is found to be in excellent agreement with the experimental data. Results show that a concentration of the magnetic flux lines occurs between the emitting coil and the superconducting screen. This effect is observed both with the modelling and the experiment. In the case of a long tube, we show that the main features of the field penetration in the superconducting walls can be reproduced with a simple analytical 1D model. This model is used to estimate the maximum flux density of the emitting coil that can be shielded by the superconductor. (paper)

  13. Superconducting energy storage magnet

    International Nuclear Information System (INIS)

    Eyssa, Y.M.; Boom, R.W.; Young, W.C.; McIntosh, G.E.; Abdelsalam, M.K.

    1986-01-01

    A superconducting magnet is described comprising: (a) a first, outer coil of one layer of conductor including at least a superconducting composite material; (b) a second, inner coil of one layer of conductor including at least a superconducting composite material. The second coil disposed adjacent to the first coil with each turn of the second inner coil at substantially the same level as a turn on the first coil; (c) an inner support structure between the first and second coils and engaged to the conductors thereof, including support rails associated with each turn of conductor in each coil and in contact therewith along its length at positions on the inwardly facing periphery of the conductor. The rail associated with each conductor is electrically isolated from other rails in the inner support structure. The magnetic field produced by a current flowing in the same direction through the conductors of the first and second coils produces a force on the conductors that are directed inwardly toward the inner support structure

  14. SCMS-1, Superconducting Magnet System for an MHD generator

    International Nuclear Information System (INIS)

    Zenkevich, V.B.; Kirenin, I.A.; Tovma, V.A.

    1977-01-01

    The research and development effort connected with the building of the superconducting magnet systems for MHD generators at the Institute for High Temperatures of the U.S.S.R. Academy of Sciences included the designing, fabrication and testing of the superconducting magnet system for an MHD generator (SCMS-1), producing a magnetic field up to 4 Tesla in a warm bore tube 300 mm in diameter and 1000 mm long (the nonuniformity of the magnetic field in the warm bore did not exceed +-5%. The superconducting magnet system is described. The design selected consisted of a dipole, saddle-form coil, wound around a tube. The cooling of the coils is of the external type with helium access to each layer of the winding. For winding of the superconducting magnet system a 49-strand cable was used consisting of 42 composition conductors, having a diameter of 0.3 mm each, containing six superconducting strands with a niobium-titanium alloy base (the superconducting strands were 70 microns in diameter), and seven copper conductors of the same diameter as the composite conductors. The cable is made monolithic with high purity indium and insulated with lavsan fiber. The cable diameter with insulation is 3.5 mm

  15. Development of magnetic order in superconducting systems

    International Nuclear Information System (INIS)

    Moncton, D.E.; Shirane, G.; Thomlinson, W.

    1979-08-01

    Two different classes of rare-earth (RE) ternary superconductors (RERh 4 B 4 and REMo 6 S 8 , X=S, Se) have provided the first instances in which chemically ordered sublattices of magnetic ions exist in superconductors. Neutron scattering studies show that simple, conventional antiferromagnetism coexists with superconductivity in a number of systems, while destruction of superconductivity occurs with the onset of ferromagnetism. The magnetic structural details are summarized for the coexistent antiferromagnets, and review measurements on the superconducting → ferromagnetic transition in ErRh 4 B 4

  16. Superconducting magnet technology for particle accelerators and detectors seminar

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    This lecture is an introduction to superconducting magnets for particle accelerators and detectors, the aim being to explain the vocabulary and describe the basic technology of modern superconducting magnets, and to explore the limits of the technology. It will include the following: - Why we need superconducting magnets - Properties of superconductors, critical field, critical temperature - Why accelerators need fine filaments and cables; conductor manufacture - Temperature rise and temperature margin: the quench process, training - Quench protection schemes. Protection in the case of the LHC. - Magnets for detectors - The challenges of state-of-the-art magnets for High Energy Physics

  17. Characterisation of superconducting capillaries for magnetic shielding of twisted-wire pairs in a neutron electric dipole moment experiment

    Energy Technology Data Exchange (ETDEWEB)

    Henry, S., E-mail: s.henry@physics.ox.ac.uk; Pipe, M.; Cottle, A.; Clarke, C.; Divakar, U.; Lynch, A.

    2014-11-01

    The cryoEDM neutron electric dipole moment experiment requires a SQUID magnetometry system with pick-up loops inside a magnetically shielded volume connected to SQUID sensors by long (up to 2 m) twisted-wire pairs (TWPs). These wires run outside the main shield, and therefore must run through superconducting capillaries to screen unwanted magnetic pick-up. We show that the average measured transverse magnetic pick-up of a set of lengths of TWPs is equivalent to a loop area of 5.0×10{sup −6} m{sup 2}/m, or 14 twists per metre. From this we set the requirement that the magnetic shielding factor of the superconducting capillaries used in the cryoEDM system must be greater than 8.0×10{sup 4}. The shielding factor—the ratio of the signal picked-up by an unshielded TWP to that induced in a shielded TWP—was measured for a selection of superconducting capillaries made from solder wire. We conclude the transverse shielding factor of a uniform capillary is greater than 10{sup 7}. The measured pick-up was equal to, or less than that due to direct coupling to the SQUID sensor (measured without any TWP attached). We show that discontinuities in the capillaries substantially impair the magnetic shielding, yet if suitably repaired, this can be restored to the shielding factor of an unbroken capillary. We have constructed shielding assemblies for cryoEDM made from lengths of single core and triple core solder capillaries, joined by a shielded Pb cylinder, incorporating a heater to heat the wires above the superconducting transition as required.

  18. Superconducting Magnets for Particle Accelerators

    CERN Document Server

    Bottura, Luca; Yamamoto, Akira; Zlobin, Alexander V

    2016-01-01

    In this paper we summarize the evolution and contributions of superconducting magnets to particle accelerators as chronicled over the last 50 years of Particle Accelerator Conferences (PAC, NA-PAC and IPAC). We begin with an historical overview based primarily on PAC Proceedings augmented with references to key milestones in the development of superconducting magnets for particle accelerators. We then provide some illustrative examples of applications that have occurred over the past 50 years, focusing on those that have either been realized in practice or provided technical development for other projects, with discussion of possible future applications.

  19. Current leads for superconducting magnets

    International Nuclear Information System (INIS)

    Ishibashi, Kenji

    1989-01-01

    Current leads for superconducting magnets have been studied since 1960's. The technology of current leads may seem to have been established both in theory and experiment before the middle of 1970's. Nevertheless, a wide variety of superconducting magnets have been introduced in the last 15 years, and the demands for special current leads have increased in accordance to the variety. A steady advance has been made in the design theory and fabrication of current leads. This paper describes the recent current lead technology regarding the design theory, safety in accidents, and high current capability. (author)

  20. A superconductive electromagnet for nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Jelinek, J.; Srnka, A.; Studenik, J.

    1989-01-01

    The superconductive magnet includes at least three concentric frames mounted onto each other; they can be dismantled, or readjusted by axial or rotary motion. The frames carry the main coils and the inner and outer balancing coils. This arrangement offers a higher number of degrees of freedom for the calculation of the system geometry so as to attain the optimum magnetic field configuration. The design also allows the superconductive magnet to be operated at a liquid helium level depressed below the upper magnet plate. (J.B.). 1 fig

  1. Electrical supply for MFTF-B superconducting magnet system

    International Nuclear Information System (INIS)

    Shimer, D.W.; Owen, E.W.

    1985-01-01

    The MFTF-B magnet system consists of 42 superconducting magnets which must operate continuously for long periods of time. The magnet power supply system is designed to meet the operational requirements of accuracy, flexibility, and reliability. The superconducting magnets require a protection system to protect against critical magnet faults of quench, current lead overtemperature, and overcurrent. The protection system is complex because of the large number of magnets, the strong coupling between magnets, and the high reliability requirement. This paper describes the power circuits and the components used in the design

  2. Superconducting magnetic energy storage and superconducting self-supplied electromagnetic launcher

    Science.gov (United States)

    Ciceron, Jérémie; Badel, Arnaud; Tixador, Pascal

    2017-10-01

    Superconductors can be used to build energy storage systems called Superconducting Magnetic Energy Storage (SMES), which are promising as inductive pulse power source and suitable for powering electromagnetic launchers. The second generation of high critical temperature superconductors is called coated conductors or REBCO (Rare Earth Barium Copper Oxide) tapes. Their current carrying capability in high magnetic field and their thermal stability are expanding the SMES application field. The BOSSE (Bobine Supraconductrice pour le Stockage d'Energie) project aims to develop and to master the use of these superconducting tapes through two prototypes. The first one is a SMES with high energy density. Thanks to the performances of REBCO tapes, the volume energy and specific energy of existing SMES systems can be surpassed. A study has been undertaken to make the best use of the REBCO tapes and to determine the most adapted topology in order to reach our objective, which is to beat the world record of mass energy density for a superconducting coil. This objective is conflicting with the classical strategies of superconducting coil protection. A different protection approach is proposed. The second prototype of the BOSSE project is a small-scale demonstrator of a Superconducting Self-Supplied Electromagnetic Launcher (S3EL), in which a SMES is integrated around the launcher which benefits from the generated magnetic field to increase the thrust applied to the projectile. The S3EL principle and its design are presented. Contribution to the topical issue "Electrical Engineering Symposium (SGE 2016)", edited by Adel Razek

  3. AGS superconducting bending magnets

    International Nuclear Information System (INIS)

    Robins, K.E.; Sampson, W.B.; McInturff, A.D.; Dahl, P.F.; Abbatiello, F.; Aggus, J.; Bamberger, J.; Brown, D.; Damm, R.; Kassner, D.; Lasky, C.; Schlafke, A.

    1976-01-01

    Four large aperture superconducting bending magnets are being built for use in the experimental beams at the AGS. Each of these magnets is 2.5 m long and has a room temperature aperture of 20 cm. The magnets are similar in design to the dipoles being developed for ISABELLE and employ a low temperature iron core. Results are presented on the ''training'' behavior of the magnets and a comparison will be made with the smaller aperture versions of this design. The magnet field measurements include end fields and leakage fields as well as the harmonic components of the straight section of the magnet

  4. Large superconducting magnet systems for plasma and fusion applications

    International Nuclear Information System (INIS)

    Heinz, W.

    1976-05-01

    Work on superconducting magnet systems and state of the art of superconducting magnet technology are described. Conceptual design consideration and problems of large magnet systems (stability, magnetic forces, cooling modes, safety) are discussed. Recent results of experimental work at Karlsruhe are reported. An outline of American and European programs is given. (orig.) [de

  5. Superconducting magnet for MAGLEV

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Fumio; Miyairi,; Komei,; Goto, Fumihiko [Hitachi, Ltd., Tokyo, (Japan)

    1989-07-25

    In the superconducting magnet for MAGLEV , the magnet itself travels. It is, therefore, important to know the dynamic behavior which accompanies the traveling; and for the designing of a superconducting magnet, analysis of mechanical characteristics as well as electromagnetic characteristics is required. This is a report on the recent analyzing technology of mechanical characteristics by CAE(Computer Aided Engineering). The analysis is conducted by an on-line system of finite element method. Most important for the analysis are that the analysis model is appropriate and that basic data coincide with the actual condition. Recent analysis results are as follows. Equivalent rigidity of coils can be calculated by an analysis model and the calculated value agrees with the experiment value. Structure of the internal drum can be optimized with the parameter of deformation or stress. Analysis result of a load supporting material agrees with the experiment value when a correction coefficient (0.5) is introduced to the elastic modulus of FRP. 2 refs., 10 figs.

  6. Longitudinal Proximity Effect Superconducting Transition-Edge Sensor

    Data.gov (United States)

    National Aeronautics and Space Administration — Superconducting Transition-Edge Sensors (TESs) hold the highest energy resolving power of any nondispersive spectrometer.   They are used for imaging spectroscopy...

  7. Contribution to the study of superconducting magnets using high transition temperature superconducting materials

    International Nuclear Information System (INIS)

    Lecrevisse, Thibault

    2012-01-01

    The new industrial superconductors using high critical temperature compounds offer new possibilities for superconducting magnetism. Indeed they allow higher magnetic field with the same classical cryogenics at 4.2 K on one hand, and on the other hand they also pave the way for superconducting magnets working between 10 K and 30 K. The high temperature superconductors are then needed in order to produce magnetic fields higher than 16 T (case of HTS dipole insert for Large Hadron Collider at CERN) or to increase the specific density stored in one SMES (Superconducting Magnetic Energy Storage, in the case of the SuperSMES ANR Project).Nevertheless the indisputable assets (critical temperature, critical magnetic field, mechanical stresses) brought by the use of High critical temperature superconductors like YBCO, used in superconducting magnets, require to solve some challenges. Their behavior is still badly understood, especially during the resistive transitions. To succeed in protecting these conductors we need a new reflection on protection schemes designed to avoid the thermal and mechanical damages. The answer to the question: 'Can we use those materials in the long run inside superconducting magnets?' is now inescapable.Some answers are given here. The use of the conductors is approached through various experimental studies to understand the material (electrical characterization and modeling of the critical surface) and to define the key stages of high critical temperature superconducting magnets manufacturing (work on the junctions between conductors and pancakes). This study led to the creation of two coils in order to identify the issues related to the use of YBCO tapes. A numerical thermo-electrical model of the high critical temperature superconductor has been developed and a numerical code based on the CEA software CASTEM (Finish Elements Model) allowed to study the resistive transition (or quench) behavior of those conductor and coil. The code has been

  8. 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.

  9. Superconducting Magnet Performance in LCLS-II Cryomodules

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V. [Fermilab; Cheban, S. [Fermilab; DiMarco, J. [Fermilab; Harms, E. [Fermilab; Makarov, A. [Fermilab; Strauss, T. [Fermilab; Tartaglia, M. [Fermilab

    2018-04-01

    New LCLS-II Linear Superconducting Accelerator Cry-omodules are under construction at Fermilab. Installed in-side each SCRF Cryomodule is a superconducting magnet package to focus and steer an electron beam. The magnet package is an iron dominated configuration with conduc-tively cooled racetrack-type quadrupole and dipole coils. For easier installation the magnet can be split in the vertical plane. Initially the magnet was tested in a liquid helium bath, and high precision magnetic field measurements were performed. The first (prototype) Cryomodule with the magnet inside was built and successfully tested at Fermilab test facility. In this paper the magnet package is discussed, the Cryomodule magnet test results and current leads con-duction cooling performance are presented. So far magnets in nine Cryomodules were successfully tested at Fermilab.

  10. Determination of the magnetic penetration depth in a superconducting Pb film

    International Nuclear Information System (INIS)

    Brisbois, J.; Silhanek, A. V.; Raes, B.; Van de Vondel, J.; Moshchalkov, V. V.

    2014-01-01

    By means of scanning Hall probe microscopy technique, we accurately map the magnetic field pattern produced by Meissner screening currents in a thin superconducting Pb stripe. The obtained field profile allows us to quantitatively estimate the Pearl length Λ without the need of pre-calibrating the Hall sensor. This fact contrasts with the information acquired through the spatial field dependence of an individual flux quantum where the scanning height and the magnetic penetration depth combine in a single inseparable parameter. The derived London penetration depth λ L coincides with the values previously reported for bulk Pb once the kinetic suppression of the order parameter is properly taken into account

  11. Optimization of a quench detection system for superconducting magnets

    International Nuclear Information System (INIS)

    Borlein, M.

    2004-12-01

    Subject of this report is the detection of a quench in a superconducting magnet. For the safe operation of superconducting magnets one of the most important issues is the quench detection system which controls the superconducting state of the magnet and triggers a safety discharge if necessary. If it comes to a breakdown of the superconductivity (quench), the magnet has to be discharged very quickly to avoid any damage or danger for the magnet or its environment. First an introducing overview is given. Next different methods of quench detection will be presented, partially on the basis of existing quench detection systems and the applicability of these methods in different states of the magnet operation will be shown. The different quench detection methods are compared and evaluated partially by using test experiments described in the appendix. As an application example this report contains a proposal for the quench detection system for the Wendelstein 7-X facility, actually built by the Institute for Plasma Physics, Garching [de

  12. Development of Fe-based superconducting wires for liquid-hydrogen level sensors

    Science.gov (United States)

    Ishida, S.; Tsuchiya, Y.; Mawatari, Y.; Eisaki, H.; Nakano, A.; Yoshida, Y.

    2017-07-01

    We developed liquid-hydrogen (LH2) level sensors with Ba(Fe1-x Co x )2As2 superconducting wires (Co-Ba122 wires) as their detection elements. We fabricated Co-Ba122 wires with different Co concentrations x by using the powder-in-tube method. The superconducting transition temperatures of the wires were successfully controlled in the range of 20-25 K by changing x from 0.06 to 0.10. The resistance-temperature curves of the wires exhibited sharp superconducting transitions with widths of 0.5-1.0 K. In addition, we performed an operation test of the Co-Ba122 level sensors with LH2. Close correspondence between the output resistance and the actual LH2 level was observed for a sensor equipped with x = 0.09 wire, demonstrating that this sensor can accurately measure LH2 levels.

  13. Thermally and magnetically controlled superconducting rectifiers

    International Nuclear Information System (INIS)

    Mulder, G.B.J.; TenKate, H.H.J.; Krooshoop, H.J.G.; Van de Klundert, L.J.M.

    1989-01-01

    The switches of a superconducting rectifier can be controlled either magnetically or thermally. The main purpose of this paper is to point out the differences between both methods of switching and discuss the consequences for the operation of the rectifier. The discussion is illustrated by the experimental results of a rectifier which was tested with magnetically as well as thermally controlled switches. It has an input current of 30 A, an output current of more than 1 kA and an operating frequency of a few Hertz. A superconducting magnet connected to this rectifier can be energized at a rate exceeding 1 MJ/hour and an efficiency of about 97%

  14. Development of superconducting magnets for magnetically levitated trains

    International Nuclear Information System (INIS)

    Ohno, E.; Iwamoto, M.; Ogino, O.; Kawamura, T.

    1974-01-01

    Superconducting magnets will play a vital role in magnetically levitated trains, producing lift, guidance and propulsion forces. The main problems in the design are the current density of coils and the cryogenic thermal insulation. This paper describes the development of full-scale levitation magnets with length of 1.55m and width of 0.3 or 0.5m. Dynamic levitation tests using small model magnets are also presented. (author)

  15. Magnetic Design of Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Todesco, E [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    In this paper we discuss the main principles of magnetic design for superconducting magnets (dipoles and quadrupoles) for particle accelerators. We give approximated equations that govern the relation between the field/gradient, the current density, the type of superconductor (Nb−Ti or Nb3Sn), the thickness of the coil, and the fraction of stabilizer. We also state the main principle controlling the field quality optimization, and discuss the role of iron. A few examples are given to show the application of the equations and their validity limits.

  16. Study on magnetic separation system using high Tc superconducting bulk magnets for water purification technique

    International Nuclear Information System (INIS)

    Oka, T; Kanayama, H; Tanaka, K; Fukui, S; Ogawa, J; Sato, T; Ooizumi, M; Yamaguchi, M; Yokoyama, K; Noto, K

    2009-01-01

    The application of superconducting bulk magnets to the magnetic separation techniques has been investigated for the Mn-bearing waste water drained from the university laboratories. The research has been conducted in comparison with the electromagnets, and the cryo-cooled superconducting solenoid magnet. The separation ratios of ferrite precipitates including Mn element in the waste slurry were estimated by means of the high gradient magnetic separation method with ferromagnetic iron filters in the water channel and open gradient magnetic separation without them. As the magnetic force acting on the particles is given by the product of a magnetization of particles and a gradient of magnetic field, and a superconducting bulk magnet shows a sharp gradient of the magnetic field on the surface, the performances of the bulk magnet system were almost equivalent to those of the superconducting solenoid magnet with wide bore with respect to the magnetic separation ratios. The separation ratios for Mn have reached over 80 % for HGMS and 10 % for OGMS under the flow rates less than 3 liter/min.

  17. Sensing with Superconducting Point Contacts

    Directory of Open Access Journals (Sweden)

    Argo Nurbawono

    2012-05-01

    Full Text Available Superconducting point contacts have been used for measuring magnetic polarizations, identifying magnetic impurities, electronic structures, and even the vibrational modes of small molecules. Due to intrinsically small energy scale in the subgap structures of the supercurrent determined by the size of the superconducting energy gap, superconductors provide ultrahigh sensitivities for high resolution spectroscopies. The so-called Andreev reflection process between normal metal and superconductor carries complex and rich information which can be utilized as powerful sensor when fully exploited. In this review, we would discuss recent experimental and theoretical developments in the supercurrent transport through superconducting point contacts and their relevance to sensing applications, and we would highlight their current issues and potentials. A true utilization of the method based on Andreev reflection analysis opens up possibilities for a new class of ultrasensitive sensors.

  18. Structural aspects of superconducting fusion magnets

    International Nuclear Information System (INIS)

    Reich, M.; Lehner, J.; Powell, J.

    1977-01-01

    Some methods for studying various static, dynamic, elastic-plastic, and fracture mechanics problems of superconducting magnets are described. Sample solutions are given for the UWMAK-I magnet. Finite element calculations were used

  19. Quench protection and design of large high-current-density superconducting magnets

    International Nuclear Information System (INIS)

    Green, M.A.

    1981-03-01

    Although most large superconducting magnets have been designed using the concept of cryostability, there is increased need for large magnets which operate at current densities above the cryostable limit (greater than 10 8 Am -2 ). Large high current density superconducting magnets are chosen for the following reasons: reduced mass, reduced coil thickness or size, and reduced cost. The design of large high current density, adiabatically stable, superconducting magnets requires a very different set of design rules than either large cryostable superconducting magnets or small self-protected high current density magnets. The problems associated with large high current density superconducting magnets fall into three categories; (a) quench protection, (b) stress and training, and (c) cryogenic design. The three categories must be considered simultaneously. The paper discusses quench protection and its implication for magnets of large stored energies (this includes strings of smaller magnets). Training and its relationship to quench protection and magnetic strain are discussed. Examples of magnets, built at the Lawrence Berkeley Laboratory and elsewhere using the design guidelines given in this report, are presented

  20. Qualifying tests for TRIAM-1M superconducting toroidal magnetic field coil

    Energy Technology Data Exchange (ETDEWEB)

    Nakanura, Yukio; Hiraki, Naoji; Nakamura, Kazuo; Tanaka, Masayoshi; Nagao, Akihiro; Kawasaki, Shoji; Itoh, Satoshi

    1984-09-01

    In the strong toroidal magnetic field experimental facility ''TRIAM-1M'' currently under construction, construction of the superconducting toroidal magnetic field coil and the following qualifying tests conducted on the full-scale superconducting toroidal magnetic field coil actually fabricated are described: (1) coil excitation test, (2) superconducting stability test, (3) external magnetic field application test, and (4) high-speed excitation test. On the basis of these test results, stability was evaluated of the superconducting coil being operated in the tokamak device. In normal tokamak operation, there occurs no normal conduction transition. At the time of plasma disruption, though this transition takes place in part of the coil, the superconducting state is immediately restored. By its electromagnetic force analysis, the superconducting coil is also stable in structure.

  1. A contribution to the study of superconducting magnets

    International Nuclear Information System (INIS)

    Ciazynski, D.

    1983-09-01

    The protection study of a Nb 3 Sn superconducting magnet with high current density brought new information on the calculus of maximum temperature in the coil, the longitudinal and transversal propagation velocity of the normal zone. It has finally led to realization and using as protection device of a superconducting switch allowing to rapidly ''open'' the feeding circuit of the magnet and of a secondary circuit magnetically coupled to the magnet to accelerate the decreasing of the current without increasing the maximum voltage at the magnet connections [fr

  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. Modeling the static fringe field of superconducting magnets.

    Science.gov (United States)

    Jeglic, P; Lebar, A; Apih, T; Dolinsek, J

    2001-05-01

    The resonance frequency-space and the frequency gradient-space relations are evaluated analytically for the static fringe magnetic field of superconducting magnets used in the NMR diffusion measurements. The model takes into account the actual design of the high-homogeneity magnet coil system that consists of the main coil and the cryoshim coils and enables a precise calibration of the on-axis magnetic field gradient and the resonance frequency inside and outside of the superconducting coil. Copyright 2001 Academic Press.

  4. Summary of existing superconducting magnet experience and its relevance to the safety of fusion magnet

    International Nuclear Information System (INIS)

    Hsieh, S.Y.; Allinger, J.; Danby, G.; Keane, J.; Powell, J.; Prodell, A.

    1975-01-01

    A comprehensive summary of experience with over twenty superconducting magnet systems has been collected through visits to and discussions about existing facilities including, for example, the bubble chamber magnets at Brookhaven National Laboratory, Argonne National Laboratory and Fermi National Accelerator Laboratory, and the large superconducting spectrometer at Stanford Linear Accelerator Center. This summary includes data relating to parameters of these magnets, magnet protection methods, and operating experiences. The information received is organized and presented in the context of its relevance to the safe operation of future, very large superconducting magnet systems for fusion power plants

  5. Superconducting and hybrid systems for magnetic field shielding

    International Nuclear Information System (INIS)

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

    2016-01-01

    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 (MgB 2 ) and in a hybrid configuration (MgB 2 /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. (paper)

  6. Numerical simulation of superconducting accelerator magnets

    CERN Document Server

    Kurz, Stefan

    2002-01-01

    Modeling and simulation are key elements in assuring the fast and successful design of superconducting magnets. After a general introduction the paper focuses on electromagnetic field computations, which are an indipensable tool in the design process. A technique which is especially well suited for the accurate computation of magnetic fields in superconducting magnets is presented. This method couples Boundary Elements (BEM) which discretize the surface of the iron yoke and Finite Elements (FEM) for the modeling of the non linear interior of the yoke. The formulation is based on a total magnetic scalar potential throughout the whole problem domain. The results for a short dipole model are presented and compared to previous results, which have been obtained from a similar BEM-FEM coupled vector potential formulation. 10 Refs. --- 25 --- AN

  7. Parallel magnetic field suppresses dissipation in superconducting nanostrips

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yong-Lei; Glatz, Andreas; Kimmel, Gregory J.; Aranson, Igor S.; Thoutam, Laxman R.; Xiao, Zhi-Li; Berdiyorov, Golibjon R.; Peeters, François M.; Crabtree, George W.; Kwok, Wai-Kwong

    2017-11-13

    The motion of Abrikosov vortices in type-II superconductors results in a finite resistance in the presence of an applied electric current. Elimination or reduction of the resistance via immobilization of vortices is the "holy grail" of superconductivity research. Common wisdom dictates that an increase in the magnetic field escalates the loss of energy since the number of vortices increases. Here we show that this is no longer true if the magnetic field and the current are applied parallel to each other. Our experimental studies on the resistive behavior of a superconducting Mo0.79Ge0.21 nanostrip reveal the emergence of a dissipative state with increasing magnetic field, followed by a pronounced resistance drop, signifying a reentrance to the superconducting state. Large-scale simulations of the 3D time-dependent Ginzburg-Landau model indicate that the intermediate resistive state is due to an unwinding of twisted vortices. When the magnetic field increases, this instability is suppressed due to a better accommodation of the vortex lattice to the pinning configuration. Our findings show that magnetic field and geometrical confinement can suppress the dissipation induced by vortex motion and thus radically improve the performance of superconducting materials.

  8. Parallel magnetic field suppresses dissipation in superconducting nanostrips.

    Science.gov (United States)

    Wang, Yong-Lei; Glatz, Andreas; Kimmel, Gregory J; Aranson, Igor S; Thoutam, Laxman R; Xiao, Zhi-Li; Berdiyorov, Golibjon R; Peeters, François M; Crabtree, George W; Kwok, Wai-Kwong

    2017-11-28

    The motion of Abrikosov vortices in type-II superconductors results in a finite resistance in the presence of an applied electric current. Elimination or reduction of the resistance via immobilization of vortices is the "holy grail" of superconductivity research. Common wisdom dictates that an increase in the magnetic field escalates the loss of energy since the number of vortices increases. Here we show that this is no longer true if the magnetic field and the current are applied parallel to each other. Our experimental studies on the resistive behavior of a superconducting Mo 0.79 Ge 0.21 nanostrip reveal the emergence of a dissipative state with increasing magnetic field, followed by a pronounced resistance drop, signifying a reentrance to the superconducting state. Large-scale simulations of the 3D time-dependent Ginzburg-Landau model indicate that the intermediate resistive state is due to an unwinding of twisted vortices. When the magnetic field increases, this instability is suppressed due to a better accommodation of the vortex lattice to the pinning configuration. Our findings show that magnetic field and geometrical confinement can suppress the dissipation induced by vortex motion and thus radically improve the performance of superconducting materials.

  9. Magnetic-Field-Tunable Superconducting Rectifier

    Science.gov (United States)

    Sadleir, John E.

    2009-01-01

    Superconducting electronic components have been developed that provide current rectification that is tunable by design and with an externally applied magnetic field to the circuit component. The superconducting material used in the device is relatively free of pinning sites with its critical current determined by a geometric energy barrier to vortex entry. The ability of the vortices to move freely inside the device means this innovation does not suffer from magnetic hysteresis effects changing the state of the superconductor. The invention requires a superconductor geometry with opposite edges along the direction of current flow. In order for the critical current asymmetry effect to occur, the device must have different vortex nucleation conditions at opposite edges. Alternative embodiments producing the necessary conditions include edges being held at different temperatures, at different local magnetic fields, with different current-injection geometries, and structural differences between opposite edges causing changes in the size of the geometric energy barrier. An edge fabricated with indentations of the order of the coherence length will significantly lower the geometric energy barrier to vortex entry, meaning vortex passage across the device at lower currents causing resistive dissipation. The existing prototype is a two-terminal device consisting of a thin-film su - perconducting strip operating at a temperature below its superconducting transition temperature (Tc). Opposite ends of the strip are connected to electrical leads made of a higher Tc superconductor. The thin-film lithographic process provides an easy means to alter edge-structures, current-injection geo - metries, and magnetic-field conditions at the edges. The edge-field conditions can be altered by using local field(s) generated from dedicated higher Tc leads or even using the device s own higher Tc superconducting leads.

  10. Stability and disturbance of large dc superconducting magnets

    International Nuclear Information System (INIS)

    Wang, S.T.

    1981-01-01

    This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet performance and the observed coil disturbances

  11. Magnetic levitation systems using a high-Tc superconducting bulk magnet

    Energy Technology Data Exchange (ETDEWEB)

    Ohsaki, Hiroyuki [Dept. of Electrical Engineering, Univ. of Tokyo (Japan); Kitahara, Hirotaka [Dept. of Electrical Engineering, Univ. of Tokyo (Japan); Masada, Eisuke [Dept. of Electrical Engineering, Univ. of Tokyo (Japan)

    1996-12-31

    Recent development of high-performance high-Tc bulk superconductors is making their application for electromagnetic force use feasible. We have studied electromagnetic levitation systems using high-Tc bulk superconducting material. In this paper, after an overview of superconducting magnetic levitation systems, with an emphasis on high-Tc bulk superconductor applications, experimental results of a high-Tc bulk EMS levitation and FEM analysis results of magnetic gradient levitation using bulk superconductor are described. Problems to be solved for their application are also discussed. (orig.)

  12. Structural support system for a superconducting magnet coil

    International Nuclear Information System (INIS)

    Meuser, R.B.

    1977-01-01

    The purpose of the ESCAR (Experimental Superconducting Accelerator Ring) project, now under way at the Lawrence Berkeley Laboratory, is to gather data and experience in the design and operation of a relatively small synchrotron employing superconducting magnets. Such data are essential to ensure that the design of future large accelerators may proceed in a knowledgeable and responsible manner. One of the many engineering problems associated with a superconducting magnet is the design of the coil suspension system. The coil, maintained at the temperature of liquid helium, must be held rigidly by a structure that does not conduct too much heat into the liquid helium system. The suspension system used on the ESCAR magnets is described. Topics covered include the coil support system requirements, ESCAR magnet support system, and operating experience

  13. Lightweight superconducting magnet for a test facility of magnetic suspension for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, S; Fujino, H; Onodera, K; Hirai, K

    1973-01-01

    Light weight superconducting magnets are required in the magnetic suspension of high speed trains. A ring shaped magnet consisting of two C-shaped superconducting coils was manufactured and tested. Twisted multifilament Nb-TI wires were used for the superconducting coils and the concept of the pipe structure for a cryostat was adopted. These improved the reliability and reduced the weight. In order to minimize the amount of heat leak into the cryostat, and FRP support with a hinge structure was used against the lift force. The superconducting coil generates a magnetomotive force of 200 kAT at a rated current of 855 A and the dimensions and weight of the whole unit are 1540 mm (outer diameter) and 560 mm (height), and 650 kG, respectively. The suspension test was done in the persistent current mode. The suspension height of 80 mm was observed at an exciting current of 800 A.

  14. Unexpected Nonlinear Effects in Superconducting Transition-Edge Sensors

    Science.gov (United States)

    Sadleir, John

    2016-01-01

    When a normal metal transitions into the superconducting state the DC resistance drops from a finite value to zero over some finite transition width in temperature, current, and magnetic field. Superconducting transition-edge sensors (TESs) operate within this transition region and uses resistive changes to measure deposited thermal energy. This resistive transition is not perfectly smooth and a wide range of TES designs and materials show sub-structure in the resistive transition (as seen in smooth nonmonotonic behavior, jump discontinuities, and hysteresis in the devices current-voltage relation and derivatives of the resistance with respect to temperature, bias current, and magnetic field). TES technology has advanced to the point where for many applications this structure is the limiting factor in performance and optimization consists of finding operating points away from these structures. For example, operating at or near this structure can lead to nonlinearity in the detectors response and gain scale, limit the spectral range of the detector by limiting the usable resistive range, and degrade energy resolution. The origin of much of this substructure is unknown. This presentation investigates a number of possible sources in turn. First we model the TES as a superconducting weak-link and solve for the characteristic differential equations current and voltage time dependence. We find:(1) measured DC biased current-voltage relationship is the time-average of a much higher frequency limit cycle solution.(2) We calculate the fundamental frequency and estimate the power radiated from the TES treating the bias leads as an antennae.(3) The solution for a set of circuit parameters becomes multivalued leading to current transitions between levels.(4)The circuit parameters can change the measure resistance and mask the true critical current. As a consequence the TES resistance surface is not just a function of temperature, current, and magnetic field but is also a

  15. The effects of filament magnetization in superconducting magnets as calculated by POISSON

    International Nuclear Information System (INIS)

    Caspi, S.; Gilbert, W.S.; Helm, M.; Laslett, L.J.

    1986-09-01

    Magnetization of superconducting material can be introduced into POISSON through a field dependent permeability table (in the same way that iron characteristics are introduced). This can be done by representing measured magnetization data of the increasing and decreasing field by two independent B-γ curves (γ = 1/μ). Magnetization curves of this type were incorporated into the current regions of the program POISSON and their effect on the field coefficients observed. We have used this technique to calculate the effect of magnetization on the multipole coefficients of a SSC superconducting dipole magnet and to compare these coefficients with measured values

  16. Running Performance of a Pinning-Type Superconducting Magnetic Levitation Guide

    International Nuclear Information System (INIS)

    Okano, M; Iwamoto, T; Furuse, M; Fuchino, S; Ishii, I

    2006-01-01

    A pinning-type superconducting magnetic levitation guide with bulk high-Tc superconductors was studied for use as a goods transportation system, an energy storage system, etc. A superconducting magnetic levitation running test apparatus with a circular track of ca. 38 m length, 12 m diameter, which comprises the magnetic rail constituted by Nd-B-Fe rare-earth permanent magnets and steel plates, was manufactured to examine loss and high-speed performance of the magnetic levitation guide. Running tests were conducted in air. These tests clarify that a vehicle supported by a superconducting magnetic levitation guide runs stably at speeds greater than 42 km/h above the circular track

  17. Running Performance of a Pinning-Type Superconducting Magnetic Levitation Guide

    Science.gov (United States)

    Okano, M.; Iwamoto, T.; Furuse, M.; Fuchino, S.; Ishii, I.

    2006-06-01

    A pinning-type superconducting magnetic levitation guide with bulk high-Tc superconductors was studied for use as a goods transportation system, an energy storage system, etc. A superconducting magnetic levitation running test apparatus with a circular track of ca. 38 m length, 12 m diameter, which comprises the magnetic rail constituted by Nd-B-Fe rare-earth permanent magnets and steel plates, was manufactured to examine loss and high-speed performance of the magnetic levitation guide. Running tests were conducted in air. These tests clarify that a vehicle supported by a superconducting magnetic levitation guide runs stably at speeds greater than 42 km/h above the circular track.

  18. Magnetic shielding for MRI superconducting magnets

    International Nuclear Information System (INIS)

    Ishiyama, A.; Hirooka, H.

    1991-01-01

    This paper describes an optimal design of a highly homogeneous superconducting coil system with magnetic shielding for Magnetic Resonance Imaging (MRI). The presented optimal design method; which is originally proposed in our earlier papers, is a combination of the hybrid finite element and boundary element method for analysis of an axially symmetric nonlinear open boundary magnetic field problem, and the mathematical programming method for solving the corresponding optimization problem. In this paper, the multi-objective goal programming method and the nonlinear least squares method have been adopted. The optimal design results of 1.5- and 4.7-Tesla-magnet systems with different types of magnetic shielding for whole-body imaging are compared and the advantages of a combination of active and yoke shields are shown

  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. Superconducting magnets advanced in particle physics

    International Nuclear Information System (INIS)

    Yamamoto, Akira

    2000-01-01

    Superconducting magnet technology for particle detectors has been advanced to provide large-scale magnetic fields in particle physics experiments. The technology has been progressed to meet physics goals and the detector requirement of having maximum magnetic field with minimum material and space. This paper includes an overview of the advances of particle detector magnets and discusses key technologies

  1. Superconducting magnets for the RAON electron cyclotron resonance ion source.

    Science.gov (United States)

    Choi, S; Kim, Y; Hong, I S; Jeon, D

    2014-02-01

    The RAON linear accelerator of Rare Isotope Science Project has been developed since 2011, and the superconducting magnet for ECRIS was designed. The RAON ECR ion source was considered as a 3rd generation source. The fully superconducting magnet has been designed for operating using 28 GHz radio frequency. The RAON ECRIS operates in a minimum B field configuration which means that a magnetic sextupole field for radial confinement is superimposed with a magnetic mirror field for axial confinement. The highest field strength reaches 3.5 T on axis and 2 T at the plasma chamber wall for operating frequency up to 28 GHz. In this paper, the design results are presented of optimized superconducting magnet consisting of four solenoids and sextupole. The prototype magnet for ECRIS was fabricated and tested to verify the feasibility of the design. On the basis of test results, a fully superconducting magnet will be fabricated and tested.

  2. Design and control of a superconducting permanent magnet synchronous motor

    International Nuclear Information System (INIS)

    Jiang, Y; Pei, R; Hong, Z; Song, J; Fang, F; Coombs, T A

    2007-01-01

    This paper gives a detailed description of the design of a superconducting permanent magnet synchronous motor. The parameters of the motor have been identified, and the torque equation has been stated. A direct torque control algorithm is introduced and applied to a traditional permanent magnet synchronous motor and the superconducting permanent magnet synchronous motor described in this paper. The motor performance shows that the direct torque control algorithm provides excellent control to the superconducting motor, and guarantees that the magnitude of the operational armature currents is smaller than the value of the critical current of the superconducting tape used for stator winding

  3. Design and control of a superconducting permanent magnet synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Y [Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom); Pei, R [Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom); Hong, Z [Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom); Song, J [Huazhong University of Science of Technology, Wuhan 430074 (China); Fang, F [Huazhong University of Science of Technology, Wuhan 430074 (China); Coombs, T A [Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

    2007-07-15

    This paper gives a detailed description of the design of a superconducting permanent magnet synchronous motor. The parameters of the motor have been identified, and the torque equation has been stated. A direct torque control algorithm is introduced and applied to a traditional permanent magnet synchronous motor and the superconducting permanent magnet synchronous motor described in this paper. The motor performance shows that the direct torque control algorithm provides excellent control to the superconducting motor, and guarantees that the magnitude of the operational armature currents is smaller than the value of the critical current of the superconducting tape used for stator winding.

  4. Coexistence of incommensurate magnetism and superconductivity in the two-dimensional Hubbard model

    Energy Technology Data Exchange (ETDEWEB)

    Yamase, Hiroyuki [Max Planck Institute for Solid State Research, Stuttgart (Germany); National Institute for Materials Science, Tsukuba (Japan); Eberlein, Andreas [Max Planck Institute for Solid State Research, Stuttgart (Germany); Department of Physics, Harvard University, Cambridge (United States); Metzner, Walter [Max Planck Institute for Solid State Research, Stuttgart (Germany)

    2016-07-01

    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 Neel order coexisting with d-wave superconductivity, the calculations reveal further coexistence regions where superconductivity is accompanied by incommensurate magnetic order.

  5. Superconducting pulsed magnets

    CERN Multimedia

    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...

  6. Numerical analysis of magnetic field in superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    Kanamaru, Y.; Amemiya, Y.

    1991-01-01

    This paper reports that the superconducting magnetic energy storage (SMES) is more useful than the other systems of electric energy storage because of larger stored energy and higher efficiency. The other systems are the battery, the flywheel, the pumped-storage power station. Some models of solenoid type SMES are designed in U.S.A. and Japan. But a high magnetic field happens by the large scale SMES in the living environment, and makes the erroneous operations of the computer display, the pacemaker of the heart and the electronic equipments. We study some fit designs of magnetic shielding of the solenoidal type SMES for reduction of the magnetic field in living environment. When some superconducting shielding coils are over the main storage coil, magnetic field reduces remarkably than the case of non shielding coil. The calculated results of the magnetic field are obtained y the finite element method

  7. Can magnetism and superconductivity coexist

    International Nuclear Information System (INIS)

    Ishikawa, M.

    1982-01-01

    Recent syntheses of rare earth (RE) ternary superconductors such as (RE)Mo 6 X 8 (X=S or Se) and (RE)Rh 4 B 4 have provided the first opportunity to explore the interaction between magnetism and superconductivity in detail owing to their particular crystal structure. The regular sublattice of the rare-earth ions in these new ternary compounds undergoes a ferro- or antiferromagnetic phase transition in the superconducting state. If the transition is antiferromagnetic, the superconductivity is preserved so that true coexistence results. If it is ferromagnetic, on the other hand, the superconductivity eventually gives way to uniform ferromagnetism at low temperatures. However, recent theories predict several possible states of coexistence even in ferromagnetic superconductors. This article reviews aspects of these new phase transitions in ternary superconductors. (author)

  8. 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 Nb$_{3}$Sn 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.

  9. Manufacturing and Testing of Accelerator Superconducting Magnets

    International Nuclear Information System (INIS)

    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

  10. Manufacturing and Testing of Accelerator Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, L [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    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.

  11. Hermetically sealed superconducting magnet motor

    Science.gov (United States)

    DeVault, Robert C.; McConnell, Benjamin W.; Phillips, Benjamin A.

    1996-01-01

    A hermetically sealed superconducting magnet motor includes a rotor separated from a stator by either a radial gap, an axial gap, or a combined axial and radial gap. Dual conically shaped stators are used in one embodiment to levitate a disc-shaped rotor made of superconducting material within a conduit for moving cryogenic fluid. As the rotor is caused to rotate when the field stator is energized, the fluid is pumped through the conduit.

  12. 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).

  13. 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.

  14. Magnetic design of a FFAG superconducting magnet

    International Nuclear Information System (INIS)

    Obana, T.; Ogitsu, T.; Nakamoto, T.; Sasaki, K.; Yamamoto, A.; Yoshimoto, M.; Mori, Y.; Orikasa, T.

    2005-01-01

    A superconducting magnet for a Fixed Field Alternating Gradient (FFAG) accelerator has been proposed. The required magnetic field is static and proportional to the k-th power of the orbit radius where k is the geometrical field index of the accelerator. In 2D, the required magnetic field can be generated with the optimized cross section of the coil. The cross section of the coils is a left-right asymmetry to simplify the cross section and ellipse to downsize the magnet. Local and integral 3D fields along the beam trajectory are evaluated with using new type of 3D coil configuration

  15. Superconducting magnets in the world of energy, especially in fusion power

    International Nuclear Information System (INIS)

    Komarek, P.

    1976-01-01

    Industrial applications of superconducting magnets are only feasible in the near future for superconducting monopolar machines and possible MHD generators. For superconducting synchronous machines, after the successful operation of machines in the MVA range, a new phase of basic investigations has started. Fundamental problems which could not be studied in the MVA machines, but which influence the design of large turbo-alternators, must now be investigated. Fusion power by magnetic confinement will probably be the largest field of application for superconducting magnets in the long run. The present research programmes require large superconducting magnets by the mid-1980s for the experimental reactors envisaged at that time. In addition to dc windings, pulse-operated superconducting windings are required in some systems, such as Tokamak. The high sensitivity of the overall plant efficiency and the active power demand of the pulsed windings require great efficiency from energy storage and transfer systems. Superconducting energy storage systems would be suitable for this, if transfer between inductances could be provided with sufficient efficiency. Basic experiments gave encouraging results. In power plant systems and electric machines an extremely high level of reliability and availability has been achieved. Less reliability will not be accepted for systems with superconducting magnets. This requires great efforts during the development work. (author)

  16. A motor with superconducting magnetic bearings

    International Nuclear Information System (INIS)

    Gladun, A.; Stoye, P.; Verges, P.; Gawalek, W.; Habisreuther, T.; Goernert, P.

    1993-01-01

    Superconducting bearings may be one of the most promising near term applications of HTSC. For use at liquid nitrogen temperature and below, they offer the advantage of lower energy consumption and higher reliability. Different bearing configurations have been proposed. But in order to substitute for conventional bearings a further increase in the critical current density of the superconductor and improved bearing concepts are necessary. For this it is necessary to take into account the peculiarities of the interaction between permanent magnets and bulk superconductors. As a contribution to this programme we present the model of a motor with superconducting magnetic bearings. (orig.)

  17. Axicell MFTF-B superconducting-magnet system

    International Nuclear Information System (INIS)

    Wang, S.T.; Bulmer, R.; Hanson, C.; Hinkle, R.; Kozman, T.; Shimer, D.; Tatro, R.; VanSant, J.; Wohlwend, J.

    1982-01-01

    The Axicell MFTF-B magnet system will provide the field environment necessary for tandem mirror plasma physics investigation with thermal barriers. The performance of the device will stimulate DT to achieve energy break-even plasma conditions. Operation will be with deuterium only. There will be 24 superconducting coils consisting of 2 sets of yin-yang pairs, 14 central-cell solenoids, 2 sets of axicell mirror-coil pairs, and 2 transition coils between the axicell mirror coil-pairs and the yin-yang coils. This paper describes the progress in the design and construction of MFTF-B Superconducting-Magnet System

  18. Safety concerns for superconducting magnets of upcoming fusion experiments

    International Nuclear Information System (INIS)

    Turner, L.R.

    1983-01-01

    -Several fusion experiments being constructed (Tore Supra) or contemplated (DCT 8, Alcator DCT) feature superconducting coils. These coils introduce the following safety concerns: 1. Internally Cooled Conductor (ICC). ICC's are found to be highly stable against short heat pulses, even when the coolant is stagnant or moving at low steady-state velocity. However, a large heat pulse is certain to quench the conductor. Thus, determining the stability limits is vital. 2. Helium II Cooling. Helium II has both unique advantages as a coolant and unique safety problems. 3. Shorted Turns. In magnets with shorts from operational accidents, the current can switch back and forth between the short and the shorted turns, as those alternatively go normal and superconducting. 4. Hybrid Superconducting-Normal Conducting Coil System. The possibility of unequal currents in the different magnets and thus of unexpected forces on the superconducting magnets is much greater than for an all-superconducting system. Analysis of these problems are presented

  19. Case Studies on Superconducting Magnets for Particle Accelerators

    International Nuclear Information System (INIS)

    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

  20. Case Studies on Superconducting Magnets for Particle Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ferracin, P [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    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.

  1. Superconductive energy storage magnet study

    International Nuclear Information System (INIS)

    Rhee, S.W.

    1982-01-01

    Among many methods of energy storages the superconducting energy storage has been considered as the most promising method. Many related technical problems are still unsolved. One of the problems is the magnetizing and demagnetizing loss of superconducting coil. This loss is mainly because of hysteresis of pinning force. In this paper the hysteresis loss is calculated and field dependence of the a.c. losses is explained. The ratio of loss and stored energy is also calculated. (Author)

  2. A conceptual design of high-temperature superconducting isochronous cyclotron magnet

    International Nuclear Information System (INIS)

    Jiao, F.; Tang, Y.; Li, J.; Ren, L.; Shi, J.

    2011-01-01

    A design of High-temperature superconducting (HTS) isochronous cyclotron magnet is proposed. The maximum magnetic field of cyclotron main magnet reaches 3 T. Laying the HTS coil aboard the magnetic pole will raise the availability of the magnetic Field. Super-iron structure can provide a high uniformity and high gradient magnetic field. Super-iron structure can raise the availability of the HTS materials. Along with the development of High-temperature superconducting (HTS) materials, the technology of HTS magnet is becoming increasingly important in the Cyclotron, which catches growing numbers of scholars' attentions. Based on the analysis of the problems met in the process of marrying superconducting materials with ferromagnetic materials, this article proposes a design of HTS isochronous cyclotron magnet. The process of optimization of magnet and the methods of realizing target parameters are introduced after taking finite element software as analyzing tools.

  3. Superconducting magnet for maglev system. Fujoshiki tetsudoyo chodendo jishaku

    Energy Technology Data Exchange (ETDEWEB)

    Yamaji, M; Maeda, H; Sanada, Y [Toshiba Corp., Tokyo (Japan)

    1991-04-20

    The magnetically levitated vehicle (Maglev) system use superconducting magnet was explained in characteristics and present development status. The development of Maglev system, using superconducting magnet, commenced in 1960 {prime}s by ex-Japan National Railways, then succeeded by the Railway Technical Research Institute in 1987, made a long-term progress to be put to practical use. Then, added with the Central Japan Railway Company and Japan Railway Construction Public Company, the project team commenced the construction of Yamanashi test track in 1990, to aim at putting to practical use to be finally confirmed. On the other hand, actual vehicle use superconducting magnet has also entered the final development stage. For the superconducting coil for the Miyazaki test track use, development was made of integrated submersion technology of coil winding by resin, coil-binding structure with cramps to resist high electromagnetic force, generated in the superconducting coil, and coil inner vessel by welding thin stainless steel plate. For the Yamanashi test track use, made were heightening in thermal stability against the quenching phenomenon and optimization in coil inner vessel structure by simulation to confirm the highest magnetomotive force to be 1004kA. 8 figs., 1 tab.

  4. A superconducting magnet for whole-body magnetic-resonance imaging

    International Nuclear Information System (INIS)

    Kan, Hisao; Watanabe, Tsugio; Takechi, Moriaki; Ogino, Osamu; Yamada, Tadatoshi

    1986-01-01

    Magnetic-resonance imaging is a promising new clinical diagnosis system that employs magnetic resonance to generate cross-sectional images of the object under examination. A large magnet plays a critical role in this system-it must supply a high-strength magnetic field that meets rigid standards of space and time uniformity. Mitsubishi Electric has developed a superconducting magnet that not only offers excellent magnetic characteristics but also features reduced helium consumption and a horizontal service port, and permits direct mounting of a magnetic shield. (author)

  5. A Novel Device for the Measurement of the Mechanical and Magnetic Axes of Superconducting Magnet Assemblies for Accelerators

    CERN Document Server

    Aznar, S; Fischer, F; Galbraith, Peter; García-Pérez, J; Goy, S; Mermillod, N; Peiro, G; Patti, G; Rathjen, C

    2002-01-01

    In the context of the LHC superconducting magnet production, especially for dipoles and quadrupoles due to their complexity, it is foreseen to perform acceptance tests, at an early production stage, to detect possible significant deviations from the design values. The knowledge of the magnetic field geometry is very important, especially for the main magnets. In order to get this information a new device has been conceived that measures the magnets at room temperature during different stages of construction. This device incorporates a sensitive measuring probe and an efficient data acquisition system because the coils are only powered at about 10-5 of the nominal D.C. current. It is dedicated to Quadrupole and Dipole (by using Quadrupole-Configured Dipole (QCD) transformation) magnets, but is also easily adaptable to higher order magnets (n = 3, 4 and 5) by specific orientation of the search coils. It is equipped with magnetic sensors (4 fixed tangential coils and AC excitation current for the magnet) and p...

  6. Development of superconducting magnets for magnetically suspended highspeed trains

    Energy Technology Data Exchange (ETDEWEB)

    Ogiwara, H; Takano, N; Okamoto, H; Hayashi, K

    1975-01-01

    Three magnetic suspension/propulsion systems for trains faster than 500 km/h on the Tokaido line are discussed. The development of the three types of superconducting magnets and their feasibility and economic feasibility are discussed. An outline of the three year project (1971-73) is given.

  7. Magnetic nesting and co-existence of ferromagnetism and superconductivity

    International Nuclear Information System (INIS)

    Elesin, V.F.; Kapaev, V.V.; Kopaev, Yu.V.

    2004-01-01

    In the case of providing for the magnetic nesting conditions of the electron spin dispersion law the co-existence of ferromagnetism and superconductivity is possible by any high magnetization. The co-existence of ferromagnetism and superconductivity in the layered cuprate compounds of the RuSr 2 GdCu 2 O 8 -type is explained on this basis, wherein due to the nonstrict provision of the magnetic nesting condition there exists the finite but sufficiently high critical magnetization [ru

  8. 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.

  9. Transmission line properties of long strings of superconducting magnets

    International Nuclear Information System (INIS)

    Shafer, R.E.

    1980-09-01

    The purpose of this paper is to discuss the electrical characteristics of a long string of superconducting magnets, such as in a superconducting storage ring or accelerator. As the magnets have a shunt capacitance to ground as well as a series inductance, travelling waves can propagate along the string, as in a transmission line. As the string is of finite length, standing waves can also exist. In accelerator quality superconducting magnets, considerable effort has been devoted to minimizing ac losses, the net result being that the magnet string has a high Q precisely at the frequencies which are important for the standing and travelling waves. The magnitude of these effects are estimated, and the solution to be used at Fermilab will be discussed

  10. Experimental studies on the thermal properties of fast pulsed superconducting accelerator magnets

    International Nuclear Information System (INIS)

    Bleile, Alexander

    2016-01-01

    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

  11. 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.

  12. Investigation of wire motion in superconducting magnets

    International Nuclear Information System (INIS)

    Ogitsu, T.; Tsuchiya, K.; Devred, A.

    1990-09-01

    The large Lorentz forces occuring during the excitation of superconducting magnets can provoke sudden motions of wire, which eventually release enough energy to trigger a quench. These wire motions are accompanied by two electromagnetic effects: an induced emf along the moved wire, and a local change in flux caused by the minute dislocation of current. Both effects cause spikes in the coil voltage. Voltage data recorded during the excitation of a superconducting quadrupole magnet which early exhibit such events are here reported. Interpretations of the voltage spikes in terms of energy release are also presented, leading to insights on the spectrum of the disturbances which occur in real magnets. 15 refs

  13. Quench detection of superconducting magnets using ultrasonic wave

    International Nuclear Information System (INIS)

    Ninomiya, A.; Sakaniwa, K.; Kado, H.; Ishigohka, T.; Higo, Y.

    1989-01-01

    A method to detect a quench of a superconducting magnet using ultrasonic technique is presented. This method is a kind of non-destructive one which monitors a change of acoustic transfer function of a superconducting magnet induced by a local temperature rise or an epoxy crack etc.. Some experiments are carried out on a small epoxy impregnated magnet. The experimental results show that a local temperature rise of about 2-3K can be detected by this method. And, some leading symptoms before quench were detected

  14. Superconducting magnetic coil

    Science.gov (United States)

    Aized, Dawood; Schwall, Robert E.

    1996-06-11

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.

  15. 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.

  16. A study of an active magnetic shielding method for the superconductive Maglev vehicle

    International Nuclear Information System (INIS)

    Nemoto, K.; Komori, M.

    2010-01-01

    Various methods of magnetic shielding have been studied so far to reduce magnetic field strength inside the passenger room of the superconductive Maglev vehicle. Magnetic shielding methods with ferromagnetic materials are very useful, but they tend to be heavier for large space. Though some passive magnetic shielding methods using induced currents in superconducting bulks or superconducting coils have also been studied, the induced current is relatively small and it is difficult to get satisfactory magnetic shielding performance for the passenger room of the Maglev vehicle. Thus, we have proposed an active magnetic shielding method with some superconducting coils of the same length as propulsion-levitation-guidance superconducting coils of the Maglev vehicle. They are arranged under the passenger room of the Maglev vehicle. Then, we studied the shielding effect by canceling magnetic flux density in the passenger room by way of adjusting magnetomotive-forces of the magnetic shielding coils. As a result, it is found that a simple arrangement of two magnetic shielding coils for one propulsion-levitation-guidance superconducting coil on the vehicle shows an effective magnetic shielding.

  17. A study of an active magnetic shielding method for the superconductive Maglev vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, K., E-mail: nemoto@kamakuranet.ne.j [Kyushu Institute of Technology, Dept. of Applied Science for Integrated System Engineering, 1-1 Sensui, Tobata, Kitakyushu, Fukuoka 804-8550 (Japan); Komori, M. [Kyushu Institute of Technology, Dept. of Applied Science for Integrated System Engineering, 1-1 Sensui, Tobata, Kitakyushu, Fukuoka 804-8550 (Japan)

    2010-11-01

    Various methods of magnetic shielding have been studied so far to reduce magnetic field strength inside the passenger room of the superconductive Maglev vehicle. Magnetic shielding methods with ferromagnetic materials are very useful, but they tend to be heavier for large space. Though some passive magnetic shielding methods using induced currents in superconducting bulks or superconducting coils have also been studied, the induced current is relatively small and it is difficult to get satisfactory magnetic shielding performance for the passenger room of the Maglev vehicle. Thus, we have proposed an active magnetic shielding method with some superconducting coils of the same length as propulsion-levitation-guidance superconducting coils of the Maglev vehicle. They are arranged under the passenger room of the Maglev vehicle. Then, we studied the shielding effect by canceling magnetic flux density in the passenger room by way of adjusting magnetomotive-forces of the magnetic shielding coils. As a result, it is found that a simple arrangement of two magnetic shielding coils for one propulsion-levitation-guidance superconducting coil on the vehicle shows an effective magnetic shielding.

  18. The design, magnetization and control of a superconducting permanent magnet synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Y; Pei, R; Xian, W; Hong, Z; Coombs, T A [Engineering Department, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)], E-mail: yj222@cam.ac.uk

    2008-06-15

    This paper describes in detail the method of magnetization of a superconducting permanent magnet synchronous motor. The rotor of the motor consists of 60 superconducting pucks, which are magnetized by two additional copper windings. The pulse field magnetization (PFM) method is considered and the resulted distribution of the magnetizing flux linkage from the rotor is not a perfect sine wave in the air gap, which leads to a large torque ripple and harmonics of the stator currents. In order to suppress the torque ripple, an iterative learning control (ILC) algorithm is used in addition to the former field-oriented control method. The results show the ILC algorithm can largely reduce the torque ripple.

  19. Magnetic ordering at low temperatures in some random superconducting and insulating compounds

    International Nuclear Information System (INIS)

    Hueser, D.

    1985-01-01

    This thesis presents the results of some investigations on the magnetic ordering phenomena in some random superconducting and insulating materials. The results are described of an investigation of the coexistence of superconductivity and random magnetic freezing in (Th,Nd)Ru 2 . On the basis of various measurements as function of temperature and external magnetic field the author found that spin glass-like freezing can occur far below the superconductivity and even that a sample may re-enter the superconducting state below a freezing temperature. Associated with the isothermal remanent magnetization of a random magnetic material he observed strong anomalies in the critical field versus temperature curves. Also a magnetic field memory effect has been found. (Auth.)

  20. Superconductivity and magnetism: Materials properties and developments

    International Nuclear Information System (INIS)

    Andersen, N.H.; Bay, N.; Grivel, J.C.

    2003-01-01

    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 c superconductivity, magnetic superconductors, MgB 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)

  1. High-resolution imaging of magnetic fields using scanning superconducting quantum interference device (SQUID) microscopy

    Science.gov (United States)

    Fong de Los Santos, Luis E.

    Development of a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with sub-millimeter resolution. The low-critical-temperature (Tc) niobium-based monolithic SQUID sensor is mounted in the tip of a sapphire rod and thermally anchored to the cryostat helium reservoir. A 25 mum sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows adjusting the sample-to-sensor spacing from the top of the Dewar. I have achieved a sensor-to-sample spacing of 100 mum, which could be maintained for periods of up to 4 weeks. Different SQUID sensor configurations are necessary to achieve the best combination of spatial resolution and field sensitivity for a given magnetic source. For imaging thin sections of geological samples, I used a custom-designed monolithic low-Tc niobium bare SQUID sensor, with an effective diameter of 80 mum, and achieved a field sensitivity of 1.5 pT/Hz1/2 and a magnetic moment sensitivity of 5.4 x 10-18 Am2/Hz1/2 at a sensor-to-sample spacing of 100 mum in the white noise region for frequencies above 100 Hz. Imaging action currents in cardiac tissue requires higher field sensitivity, which can only be achieved by compromising spatial resolution. I developed a monolithic low-Tc niobium multiloop SQUID sensor, with sensor sizes ranging from 250 mum to 1 mm, and achieved sensitivities of 480 - 180 fT/Hz1/2 in the white noise region for frequencies above 100 Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of

  2. Improved thermal isolation for superconducting magnet systems

    Science.gov (United States)

    Wiebe, E. R.

    1974-01-01

    Closed-cycle refrigerating system for superconductive magnet and maser is operated in vacuum environment. Each wire leading from external power source passes through cooling station which blocks heat conduction. In connection with these stations, switch with small incandescent light bulb, which generates heat, is used to stop superconduction.

  3. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    OpenAIRE

    Marchevsky, M.; Wang, X.; Sabbi, G.; Prestemon, S.

    2014-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01 [...

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

    International Nuclear Information System (INIS)

    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

  5. 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.

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

    Science.gov (United States)

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

    2009-02-01

    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.

  7. Experimental results of superconducting magnet behaviour during discharging into the external load

    Directory of Open Access Journals (Sweden)

    Ladislav Grega

    2008-12-01

    Full Text Available The basic part of every SMES (Superconducting magnetic energy storage system is a superconducting magnet. All eventsof electrical nature which happen during its charging,, bypassing and discharging are transient. The article deals with experimentalresults of the superconducting magnet behaviour, especially during the period of its discharging into the prepared external load.

  8. Theory of superconducting magnet suspension: main results survey

    International Nuclear Information System (INIS)

    Voevodskii, K.E.; Kochetkov, V.M.

    1981-01-01

    A survey is given of theoretical achievements on electro-dynamic suspension of high speed ground vehicles with superconducting magnets. The problems discussed, are calculation of lift and drag forces acting on a superconducting magnet, the latter moving above a guideway structure which may be of two different types (either conducting sheet or a series of discrete loops); influence of irregularities of the guideway structure; vertical and longitudinal stability of suspension. (author)

  9. High-T/sub c/ superconductor and its use in superconducting magnets

    International Nuclear Information System (INIS)

    Green, M.A.

    1988-02-01

    Many of the proposed uses for the high-T/sub c/ superconductor involve the creation of a magnetic field using superconducting coils. This report will assess what is known about the high-T/sub c/ superconductors and take a realistic look at their potential use in various kinds of superconducting magnets. Based on what is known about the high-T/sub c/ superconductors, one can make a ''wish list'' of things that will make such materials useful for magnets. Then, the following question is asked. If one had a high-T/sub c/ superconductor with the same properties as modern niobium-titanium superconductor, how would the superconductor work in a magnet environment? Finally, this report will show the potential impact of the ideal high-T/sub c/ superconductor on: 1) accelerator dipole and quadrupole magnets, 2) superconducting magnets for use in space, and 3) superconducting solenoids for magnetic resonance imaging. 78 refs., 11 tabs

  10. Safety issues for superconducting fusion magnets

    International Nuclear Information System (INIS)

    Hsieh, S.Y.; Reich, M.; Powell, J.R.

    1978-01-01

    Safety issues for future superconducting fusion magnet systems are examined. It is found that safety and failure experience with existing superconducting magnets is not very applicable to predictions as to the safety and reliability of fusion magnets. Such predictions will have to depend on analysis and judgement for many years to come, rather than on accumulated experience. A number of generic potential structural, thermal-hydraulic, and electrical safety problems are identified and analyzed. Prevention of quenches and non-uniform temperature distributions, if quenches should occur, is of great importance, since such events can trigger processes which lead to magnet damage or failure. Engineered safety features will be necessary for fusion magnets. Two of these, an energy dispersion system and external coil containment, appear capable of reducing the probability of coil disruption to very low levels. However, they do not prevent loss of function accidents which are of economic concern. Elaborate detector, temperature equalization, and energy removal systems will be required to minimize the chances of loss of function accidents

  11. Purification of condenser water in thermal power station by superconducting magnetic separation

    International Nuclear Information System (INIS)

    Ha, D.W.; Kwon, J.M.; Baik, S.K.; Lee, Y.J.; Han, K.S.; Ko, R.K.; Sohn, M.H.; Seong, K.C.

    2011-01-01

    Magnetic separation using cryo-cooled Nb-Ti superconducting magnet was applied for the purification of condenser water. Iron oxides in condenser water were effectively removed by superconducting magnetic separation. The effect of magnetic field strength and filter size was determined. Thermal power station is made up of a steam turbine and a steam condenser which need a lot of water. The water of steam condenser should be replaced, since scales consisting of iron oxide mainly are accumulated on the surface of condenser pipes as it goes. Superconducting high gradient magnetic separation (HGMS) system has merits to remove paramagnetic substance like iron oxides because it can generate higher magnetic field strength than electromagnet or permanent magnet. In this paper, cryo-cooled Nb-Ti superconducting magnet that can generate up to 6 T was used for HGMS systems. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The result of X-ray analysis showed contaminants were mostly α-Fe 2 O 3 (hematite) and γ-Fe 2 O 3 (maghemite). The higher magnetic field was applied up to 6 T, the more iron oxides were removed. As the wire diameter of magnetic filter decreased, the turbidity removal of the sample was enhanced.

  12. Superconductivity and magnetism: Materials properties and developments

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, N H; Bay, N; Grivel, J C [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)

  13. Energy of magnetic moment of superconducting current in magnetic field

    International Nuclear Information System (INIS)

    Gurtovoi, V.L.; Nikulov, A.V.

    2015-01-01

    Highlights: • Quantization effects observed in superconducting loops are considered. • The energy of magnetic moment in magnetic field can not be deduced from Hamiltonian. • This energy is deduced from a history of the current state in the classical case. • It can not be deduced directly in the quantum case. • Taking this energy into account demolishes agreement between theory and experiment. - Abstract: The energy of magnetic moment of the persistent current circulating in superconducting loop in an externally produced magnetic field is not taken into account in the theory of quantization effects because of identification of the Hamiltonian with the energy. This identification misleads if, in accordance with the conservation law, the energy of a state is the energy expended for its creation. The energy of magnetic moment is deduced from a creation history of the current state in magnetic field both in the classical and quantum case. But taking this energy into account demolishes the agreement between theory and experiment. Impartial consideration of this problem discovers the contradiction both in theory and experiment

  14. Applied superconductivity. Handbook on devices and applications. Vol. 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Paul (ed.) [Jena Univ. (Germany). Inst. fuer Festkoerperphysik, AG Tieftemperaturphysik

    2015-07-01

    The both volumes contain the following 12 chapters: 1. Fundamentals; 2. Superconducting Materials; 3. Technology, Preparation, and Characterization (bulk materials, thin films, multilayers, wires, tapes; cooling); 4, Superconducting Magnets; 5. Power Applications (superconducting cables, superconducting current leads, fault current limiters, transformers, SMES and flywheels; rotating machines; SmartGrids); 6. Superconductive Passive Devices (superconducting microwave components; cavities for accelerators; superconducting pickup coils; magnetic shields); 7. Applications in Quantum Metrology (superconducting hot electron bolometers; transition edge sensors; SIS Mixers; superconducting photon detectors; applications at Terahertz frequency; detector readout); 8. Superconducting Radiation and Particle Detectors; 9. Superconducting Quantum Interference (SQUIDs); 10. Superconductor Digital Electronics; 11. Other Applications (Josephson arrays as radiation sources. Tunable microwave devices) and 12. Summary and Outlook (of the superconducting devices).

  15. Applied superconductivity. Handbook on devices and applications. Vol. 1 and 2

    International Nuclear Information System (INIS)

    Seidel, Paul

    2015-01-01

    The both volumes contain the following 12 chapters: 1. Fundamentals; 2. Superconducting Materials; 3. Technology, Preparation, and Characterization (bulk materials, thin films, multilayers, wires, tapes; cooling); 4, Superconducting Magnets; 5. Power Applications (superconducting cables, superconducting current leads, fault current limiters, transformers, SMES and flywheels; rotating machines; SmartGrids); 6. Superconductive Passive Devices (superconducting microwave components; cavities for accelerators; superconducting pickup coils; magnetic shields); 7. Applications in Quantum Metrology (superconducting hot electron bolometers; transition edge sensors; SIS Mixers; superconducting photon detectors; applications at Terahertz frequency; detector readout); 8. Superconducting Radiation and Particle Detectors; 9. Superconducting Quantum Interference (SQUIDs); 10. Superconductor Digital Electronics; 11. Other Applications (Josephson arrays as radiation sources. Tunable microwave devices) and 12. Summary and Outlook (of the superconducting devices).

  16. Mechanical design and protection of superconducting magnets

    CERN Document Server

    Asner, Alfred M

    1978-01-01

    The principles of the mechanical design of superconducting magnets of concentric configuration, with iron low-temperature and room- temperature screening, are outlined. Measures for protection of such magnets against quench forces, are considered. (4 refs).

  17. 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 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.

  18. Advantages and disadvantages of contemporary magnetic resonance systems (resistive, permanent and superconductive)

    International Nuclear Information System (INIS)

    Krawczyk, R.; Matuszek, J.

    1994-01-01

    The purpose of the article is to assess the advantages and disadvantages of the operating MRI systems. There are 3 basic types of magnets useful for producing the B field: permanent magnet, resistive magnet and superconductive magnet. The authors compare basic features of those magnets including field strength, homogeneity, temporal stability and direction. The time of examination and the cost of exploitation was also discussed. In conclusions there are no significant differences between superconductive and resistive mid-field MRI systems. However the MRI spectroscopy and functional imaging requires high magnetic field which can be obtain only with superconductive magnet. (author)

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

    International Nuclear Information System (INIS)

    Wanderer, P.

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Wanderer, P.

    1993-01-01

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

  1. Superconducting magnets for ISABELLE

    International Nuclear Information System (INIS)

    Sampson, W.B.

    1976-01-01

    The application of superconducting magnet technology to high-energy accelerators has been studied at BNL for many years. Recently this effort has focused on the magnet system for the proposed Intersecting Storage Accelerator, ISABELLE. Several full-sized dipole and quadrupole magnets were fabricated and tested. A dipole was successfully operated using a high pressure forced circulation refrigeration system similar to that proposed for the accelerator. This magnet reached a maximum central field of 4.9 T, considerably above the design field of 3.9 T. A quadrupole of similar design was equally successful, achieving a gradient of 71 T/m compared to the design value of 53 T/m. A summary is given of the present status of the magnet development program, and the direction of future work is outlined

  2. Characteristics of a Bulk High-Critical Temperature Superconductor Fabricated by the Shock Compaction Method: Possible Use as a Highly Sensitive Magnetic Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H [Interdisci. Grad. School of Sci. and Engi., Grad. School of Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan); Maeji, Y [Interdisci. Grad. School of Sci. and Engi., Grad. School of Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan); Yamagata, K [Relia. Eval. Technol. Center, Nitto Denko Corp., Onomichi, Hiroshima 722-0212 (Japan); Itoh, M [Interdisci. Grad. School of Sci. and Engi., Grad. School of Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan); Kezuka, H [Faculty of Bionics, Tokyo University of Technol., Hachioji, Tokyo 192-0982 (Japan); Kikuchi, M [Kansen Fukushi Research Center, Tohoku Fukushi University Sendai, Miyagi 989-3201 (Japan); Atou, T [Insti. for Mate. Research, Tohoku University Sendai, Miyagi 980-8577 (Japan); Kawasaki, M [Insti. for Mate. Research, Tohoku University Sendai, Miyagi 980-8577 (Japan); Fukuoka, K [Insti. for Mate. Research, Tohoku University Sendai, Miyagi 980-8577 (Japan)

    2006-06-01

    A magnetic sensor, constructed of bulk Bi-Pb-Sr-Ca-Cu-O (BPSCCO), was fabricated by use of the shock compaction method, employing a propellant gun-system, and then sintered under through use of an electronic furnace. The specimen as a magnetic sensor was maintained in the superconducting state at 77.4 K, under a current density J of approximately 40 A/cm{sup 2} in the absence of an excitation magnetic field B{sub ex}. The superconducting state was then broken and the specimen exposed to a B{sub ex} value of 40x10{sup -4} T. That is, the resistance R{sub meas} of the specimen occurred when exposed to 40x10{sup -4} T under a constant J of 40 A/cm{sup 2}. The magnetic sensitivity S of the specimen was approximately 13 %/(10{sup -4} T) over the range of measurement of the magnetic field B{sub meas} from 0 to {+-}5x10{sup -4} T, under a constant 40x10{sup -4} T for the value of B{sub ex}, being approximately 13 times greater than that of a giant magnetoresistance (GMR) sensor. It was, consequently, determined that it was possible to apply the bulk BPSCCO specimen as a highly sensitive magnetic sensor.

  3. Characteristics of a Bulk High-Critical Temperature Superconductor Fabricated by the Shock Compaction Method: Possible Use as a Highly Sensitive Magnetic Sensor

    International Nuclear Information System (INIS)

    Fujita, H; Maeji, Y; Yamagata, K; Itoh, M; Kezuka, H; Kikuchi, M; Atou, T; Kawasaki, M; Fukuoka, K

    2006-01-01

    A magnetic sensor, constructed of bulk Bi-Pb-Sr-Ca-Cu-O (BPSCCO), was fabricated by use of the shock compaction method, employing a propellant gun-system, and then sintered under through use of an electronic furnace. The specimen as a magnetic sensor was maintained in the superconducting state at 77.4 K, under a current density J of approximately 40 A/cm 2 in the absence of an excitation magnetic field B ex . The superconducting state was then broken and the specimen exposed to a B ex value of 40x10 -4 T. That is, the resistance R meas of the specimen occurred when exposed to 40x10 -4 T under a constant J of 40 A/cm 2 . The magnetic sensitivity S of the specimen was approximately 13 %/(10 -4 T) over the range of measurement of the magnetic field B meas from 0 to ±5x10 -4 T, under a constant 40x10 -4 T for the value of B ex , being approximately 13 times greater than that of a giant magnetoresistance (GMR) sensor. It was, consequently, determined that it was possible to apply the bulk BPSCCO specimen as a highly sensitive magnetic sensor

  4. 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.

  5. Stability of superconducting cables for use in large magnet systems

    International Nuclear Information System (INIS)

    Tateishi, Hiroshi; Schmidt, C.

    1992-01-01

    The construction of large superconducting magnets requires the development of complicated conductor types, which can fulfill the specific requirements of different types of magnets. A rather hard boundary condition for large magnets is the presence of fast changing magnetic fields. In the Institute of Technical Physics of the Karlsruhe Nuclear Research Center, Germany, a superconducting cable was developed for use in poloidal field coils in Tokamak experiments. This 'POLO'-cable exhibits low losses in a magnetic ac-field and a high stability margin. In the present article the requirements on a superconducting cable are described, as well as the mechanisms of ac-losses and the calculation of the stability limit. Calculated values are compared with experimental data. Some unresolved problems concerning the stability of large magnets are discussed taking the example of the POLO-cable. (author)

  6. Heat Capacity and Thermal Conductance Measurements of a Superconducting-Normal Mixed State by Detection of Single 3 eV Photons 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.

    2015-01-01

    We report on measurements of the detected signal pulses in a molybdenum-gold Magnetic Penetration Thermometer (MPT) in response to absorption of one or more 3 eV photons. We designed and used this MPT sensor for x-ray microcalorimetry. In this device, the diamagnetic response of a superconducting MoAu bilayer is used to sense temperature changes in response to absorbed photons, and responsivity is enhanced by a Meissner transition in which the magnetic flux penetrating the sensor changes rapidly to minimize free energy in a mixed superconducting normal state. We have previously reported on use of our MPT to study a thermal phonon energy loss to the substrate when absorbing x-rays. We now describe results of extracting heat capacity C and thermal conductance G values from pulse height and decay time of MPT pulses generated by 3 eV photons. The variation in C and G at temperatures near the Meissner transition temperature (set by an internal magnetic bias field) allow us to probe the behavior in superconducting normal mixed state of the condensation energy and the electron cooling power resulting from quasi-particle recombination and phonon emission. The information gained on electron cooling power is also relevant to the operation of other superconducting detectors, such as Microwave Kinetic Inductance Detectors.

  7. Field quality of LHC superconducting dipole magnets

    International Nuclear Information System (INIS)

    Mishra, R.K.

    2003-01-01

    The author reports here the main results of field measurements performed so far on the LHC superconducting dipoles at superfluid helium temperature. The main field strength at injection, collision conditions and higher order multipoles are discussed. Superconducting magnets exhibit additional field imperfections due to diamagnetic properties of superconducting cables, apart from geometric error, saturation of iron yoke and eddy currents error. Dynamic effects on field harmonics, such as field decay at injection and subsequent snap back are also discussed. (author)

  8. A new approach to MgB2 superconducting magnet fabrication

    International Nuclear Information System (INIS)

    Miyazoe, A; Ando, T; Wada, H; Abe, H; Hirota, N; Sekino, M

    2008-01-01

    Fabrication of MgB 2 -based superconducting magnets has been attempted by a new approach using film coated on symmetric tubes. Superconducting MgB 2 films have been prepared on iron substrates by electroplating in molten electrolytes. The critical current (I c ) of the MgB 2 electroplating films at 4.2 K and at self-field was 15 A on the basis of 1 μV/cm of I c criterion. A model calculation has shown that MgB 2 -based superconducting magnets based on MgB 2 electroplating films have the potential to generate magnetic fields over 0.5 T

  9. Stability of high field superconducting dipole magnets

    International Nuclear Information System (INIS)

    Allinger, J.; Danby, G.; Foelsche, H.; Jackson, J.; Prodell, A.; Stevens, A.

    1977-01-01

    Superconducting dipole magnets of the window-frame type were constructed and operated successfully at Brookhaven National Laboratory. Examples of this type of magnet are the 6 T ''Model T'' magnet, and the 4 T 8 0 superconducting bending magnet. The latter magnet operated reliably since October 1973 as part of the proton beam transport to the north experimental area at the BNL AGS with intensities of typically 8 x 10 12 protons at 28.5 GeV/c passing through the magnet in a curved trajectory with the proton beam center only 2.0 cm from the beam pipe at both ends and the middle of each of the two units comprising the magnet. The energy in the beam is approximately 40 kJ per 3 μsec pulse. Targets were inserted in the beam at locations 2 m and 5.6 m upstream of the first magnet unit to observe the effects of radiation heating. The 8 0 magnet demonstrated ultrastability, surviving 3 μsec thermal pulses delivering up to 1 kJ into the cold magnet at repetition periods as short as 1.3 sec

  10. Magnetic signature of granular superconductivity in electrodeposited Pb nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Riminucci, Alberto, E-mail: a.riminucci@bo.ismn.cnr.it [CNR, Institute for Nanostructured Materials, Via Gobetti 101, 40129 Bologna (Italy); H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Schwarzacher, Walther [H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

    2014-06-14

    Nanocrystalline freestanding Pb nanowires ∼200 nm in diameter were fabricated by electrodeposition into track etched polycarbonate membranes in order to study their superconducting properties. Their superconducting critical temperature, as determined by measuring the Meissner effect, was the same as for bulk Pb, but their critical field was greatly enhanced up to ∼3000 Oe. By assuming the wires consisted of spherical superconducting grains, an estimated grain size r = 60 ± 25 nm was obtained from the magnetization measured as a function of the applied magnetic field at a fixed temperature. An independent estimate for r = 47 ± 12 nm, in good agreement with the previous one, was obtained from the magnetization measured as a function of temperature at a fixed applied magnetic field. Transmission electron microscopy was used to characterize grain size at the wire edges, where a grain size in agreement with the magnetic studies was observed.

  11. Electrical insulation for large multiaxis superconducting magnets

    International Nuclear Information System (INIS)

    Harvey, A.R.; Rinde, J.A.

    1975-01-01

    The selection of interturn and interlayer insulation for superconducting magnets is discussed. The magnet problems of the Baseball II device are described. Manufacture of the insulation and radiation damage are mentioned. A planned experimental program is outlined

  12. Conceptual design of the superconducting magnet for the 250 MeV proton cyclotron.

    Science.gov (United States)

    Ren, Yong; Liu, Xiaogang; Gao, Xiang

    2016-01-01

    The superconducting cyclotron is of great importance to treat cancer parts of the body. To reduce the operation costs, a superconducting magnet system for the 250 MeV proton cyclotron was designed to confirm the feasibility of the superconducting cyclotron. The superconducting magnet system consists of a pair of split coils, the cryostat and a pair of binary high temperature superconductor current leads. The superconducting magnet can reach a central magnetic field of about 1.155 T at 160 A. The three GM cryocooler with cooling capacities of 1.5 W at 4.5 K and 35 W at 50 K and one GM cryocooler of 100 W at 50 K were adopted to cool the superconducting magnet system through the thermosiphon technology. The four GM cryocoolers were used to cool the superconducting magnet to realize zero evaporation of the liquid helium.

  13. Magnetic Field Enhanced Superconductivity in Epitaxial Thin Film WTe2.

    Science.gov (United States)

    Asaba, Tomoya; Wang, Yongjie; Li, Gang; Xiang, Ziji; Tinsman, Colin; Chen, Lu; Zhou, Shangnan; Zhao, Songrui; Laleyan, David; Li, Yi; Mi, Zetian; Li, Lu

    2018-04-25

    In conventional superconductors an external magnetic field generally suppresses superconductivity. This results from a simple thermodynamic competition of the superconducting and magnetic free energies. In this study, we report the unconventional features in the superconducting epitaxial thin film tungsten telluride (WTe 2 ). Measuring the electrical transport properties of Molecular Beam Epitaxy (MBE) grown WTe 2 thin films with a high precision rotation stage, we map the upper critical field H c2 at different temperatures T. We observe the superconducting transition temperature T c is enhanced by in-plane magnetic fields. The upper critical field H c2 is observed to establish an unconventional non-monotonic dependence on temperature. We suggest that this unconventional feature is due to the lifting of inversion symmetry, which leads to the enhancement of H c2 in Ising superconductors.

  14. Shunt protection for superconducting Maglev magnets

    Energy Technology Data Exchange (ETDEWEB)

    Atherton, D L [Queen' s Univ., Kingston, Ontario (Canada). Dept. of Physics

    1979-09-01

    Closely coupled, short-circuited shunt coils are proposed for quench protection of superconducting Maglev magnets which use high resistance, matrix composite conductors. It is shown that, by suitable design, the shunts can reduce induced ac losses and that the changing currents during magnet energization or vehicle lift off and landing can be tolerated.

  15. Warm measurements of CBA superconducting magnets

    International Nuclear Information System (INIS)

    Engelmann, R.; Herrera, J.; Kahn, S.; Kirk, H.; Willen, E.; Yamin, P.

    1983-01-01

    We present results on magnetic field measurements of CBA dipole magnets in the warm (normal conductor) and cryogenic (superconducting) states. We apply two methods for the warm measurements, a dc and ac method. We find a good correlation between warm and cryogenic measurements which lends itself to a reliable diagnosis of magnet field errors using warm measurements early in the magnet assembly process. We further find good agreement between the two warm measurement methods, both done at low currents

  16. Magnetic fluctuations and heavy electron superconductivity

    International Nuclear Information System (INIS)

    Norman, M.R.

    1988-01-01

    A magnetic fluctuation self-energy based on neutron scattering data is used to calculate mass renormalizations, and superconducting critical temperatures and order parameters, for various heavy electron metals

  17. Full-switching FSF-type superconducting spin-triplet magnetic random access memory element

    Science.gov (United States)

    Lenk, D.; Morari, R.; Zdravkov, V. I.; Ullrich, A.; Khaydukov, Yu.; Obermeier, G.; Müller, C.; Sidorenko, A. S.; von Nidda, H.-A. Krug; Horn, S.; Tagirov, L. R.; Tidecks, R.

    2017-11-01

    In the present work a superconducting Co/CoOx/Cu41Ni59 /Nb/Cu41Ni59 nanoscale thin film heterostructure is investigated, which exhibits a superconducting transition temperature, Tc, depending on the history of magnetic field applied parallel to the film plane. In more detail, around zero applied field, Tc is lower when the field is changed from negative to positive polarity (with respect to the cooling field), compared to the opposite case. We interpret this finding as the result of the generation of the odd-in-frequency triplet component of superconductivity arising at noncollinear orientation of the magnetizations in the Cu41Ni59 layer adjacent to the CoOx layer. This interpretation is supported by superconducting quantum interference device magnetometry, which revealed a correlation between details of the magnetic structure and the observed superconducting spin-valve effects. Readout of information is possible at zero applied field and, thus, no permanent field is required to stabilize both states. Consequently, this system represents a superconducting magnetic random access memory element for superconducting electronics. By applying increased transport currents, the system can be driven to the full switching mode between the completely superconducting and the normal state.

  18. Measurement of AC electrical characteristics of SSC superconducting dipole magnets

    International Nuclear Information System (INIS)

    Smedley, K.M.; Shafer, R.E.

    1992-01-01

    Experiments were conducted to measure the AC electrical characteristics of SSC superconducting dipole magnets over the frequency range of 0.1 Hz to 10 kHz. A magnet equivalent circuit representing the magnet DC inductance, eddy current losses, coil-to-ground and turn-to-turn capacitance, was synthesized from the experimental data. This magnet equivalent circuit can be used to predict the current ripple distribution along the superconducting magnet string and can provide dynamic information for the design of the collider current regulation loop

  19. Superconducting magnet systems in EPR designs

    International Nuclear Information System (INIS)

    Knobloch, A.F.

    1976-10-01

    Tokamak experiments have reached a stage where large scale application of superconductors can be envisaged for machines becoming operational within the next decade. Existing designs for future devices already indicate some of the tasks and problems associated with large superconducting magnet systems. Using this information the coming magnet system requirements are summarized, some design considerations given and in conclusion a brief survey describes already existing Tokamak magnet development programs. (orig.) [de

  20. Electric vehicles, magnetic levitation and superconductive levitation in Japan

    International Nuclear Information System (INIS)

    Wyczalek, F.A.

    1988-01-01

    This is a technological assessment of electric automotive vehicles, high speed magnetic levitation trains and hyperspeed superconductive magnetic levitation trains in Japan. It includes conventional battery electric vehicles for the automotive application, conventional magnetic levitation trains with peak speeds of 300 km/h and superconductive levitation trains capable of speeds over 500 km/h in transcontinental service. These electric vehicles have been under development since 1971 and are now considered ready for introduction into intercity commercial service. Conventional magnetic levitation trains are targeted to connect New Chitose International Airport with Sapporo and shorter connections in LasVegas, Philadelphia and Miami. The first superconductive train is planned for the Osaka to Tokyo link by the year 2000, a distance of 515 km. The initial step has been taken with approval of funding for the first five year phase of construction beginning with the Kansai project near Osaka

  1. 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...

  2. Cryogenic techniques for large superconducting magnets in space

    Science.gov (United States)

    Green, M. A.

    1989-01-01

    A large superconducting magnet is proposed for use in a particle astrophysics experiment, ASTROMAG, which is to be mounted on the United States Space Station. This experiment will have a two-coil superconducting magnet with coils which are 1.3 to 1.7 meters in diameter. The two-coil magnet will have zero net magnetic dipole moment. The field 15 meters from the magnet will approach earth's field in low earth orbit. The issue of high Tc superconductor will be discussed in the paper. The reasons for using conventional niobium-titanium superconductor cooled with superfluid helium will be presented. Since the purpose of the magnet is to do particle astrophysics, the superconducting coils must be located close to the charged particle detectors. The trade off between the particle physics possible and the cryogenic insulation around the coils is discussed. As a result, the ASTROMAG magnet coils will be operated outside of the superfluid helium storage tank. The fountain effect pumping system which will be used to cool the coil is described in the report. Two methods for extending the operating life of the superfluid helium dewar are discussed. These include: operation with a third shield cooled to 90 K with a sterling cycle cryocooler, and a hybrid cryogenic system where there are three hydrogen-cooled shields and cryostat support heat intercept points.

  3. Shunt protection for superconducting Maglev magnets

    International Nuclear Information System (INIS)

    Atherton, D.L.

    1979-01-01

    Closely coupled, short-circuited shunt coils are proposed for quench protection of superconducting Maglev magnets which use high resistance, matrix composite conductors. It is shown that, by suitable design, the shunts can reduce induced ac losses and that the changing currents during magnet energization or vehicle lift off and landing can be tolerated. (author)

  4. Towards Computing Ratcheting and Training in Superconducting Magnets

    International Nuclear Information System (INIS)

    Ferracin, Paolo; Caspi, Shlomo; Lietzke, A.F.

    2007-01-01

    The Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL) has been developing 3D finite element models to predict the behavior of high field Nb 3 Sn superconducting magnets. The models track the coil response during assembly, cool-down, and excitation, with particular interest on displacements when frictional forces arise. As Lorentz forces were cycled, irreversible displacements were computed and compared with strain gauge measurements. Additional analysis was done on the local frictional energy released during magnet excitation, and the resulting temperature rise. Magnet quenching and training was correlated to the level of energy release during such mechanical displacements under frictional forces. We report in this paper the computational results of the ratcheting process, the impact of friction, and the path-dependent energy release leading to a computed magnet training curve

  5. The superconducting magnet system for the Tokamak Physics Experiment

    International Nuclear Information System (INIS)

    Lang, D.D.; Bulmer, R.J.; Chaplin, M.R.; O'Connor, T.G.; Slack, D.S.; Wong, R.L.; Zbasnik, J.P.; Schultz, J.H.; Diatchenko, N.; Montgomery, D.B.

    1994-01-01

    The superconducting magnet system for the Tokamak Physics eXperiment (TPX) will be the first all superconducting magnet system for a Tokamak, where the poloidal field coils, in addition to the toroidal field coils are superconducting. The magnet system is designed to operate in a steady state mode, and to initiate the plasma discharge ohmically. The toroidal field system provides a peak field of 4.0 Tesla on the plasma axis at a plasma major radius of 2.25 m. The peak field on the niobium 3-tin, cable-in-conduit (CIC) conductor is 8.4 Tesla for the 16 toroidal field coils. The toroidal field coils must absorb approximately 5 kW due to nuclear heating, eddy currents, and other sources. The poloidal field system provides a total of 18 volt seconds to initiate the plasma and drive a plasma current up to 2 MA. The poloidal field system consists of 14 individual coils which are arranged symmetrically above and below the horizontal mid plane. Four pairs of coils make up the central solenoid, and three pairs of poloidal ring coils complete the system. The poloidal field coils all use a cable-in-conduit conductor, using either niobium 3-tin (Nb 3 Sn) or niobium titanium (NbTi) superconducting strands depending on the operating conditions for that coil. All of the coils are cooled by flowing supercritical helium, with inlet and outlet connections made on each double pancake. The superconducting magnet system has gone through a conceptual design review, and is in preliminary design started by the LLNL/MIT/PPPL collaboration. A number of changes have been made in the design since the conceptual design review, and are described in this paper. The majority of the design and all fabrication of the superconducting magnet system will be ,accomplished by industry, which will shortly be taking over the preliminary design. The magnet system is expected to be completed in early 2000

  6. Magnetic field sensor for isotropically sensing an incident magnetic field in a sensor plane

    Science.gov (United States)

    Pant, Bharat B. (Inventor); Wan, Hong (Inventor)

    2001-01-01

    A magnetic field sensor that isotropically senses an incident magnetic field. This is preferably accomplished by providing a magnetic field sensor device that has one or more circular shaped magnetoresistive sensor elements for sensing the incident magnetic field. The magnetoresistive material used is preferably isotropic, and may be a CMR material or some form of a GMR material. Because the sensor elements are circular in shape, shape anisotropy is eliminated. Thus, the resulting magnetic field sensor device provides an output that is relatively independent of the direction of the incident magnetic field in the sensor plane.

  7. Radiation effects on superconducting fusion magnet components

    International Nuclear Information System (INIS)

    Weber, H.W.

    2011-01-01

    Nuclear fusion devices based on the magnetic confinement principle heavily rely on the existence and performance of superconducting magnets and have always significantly contributed to advancing superconductor and magnet technology to their limits. In view of the presently ongoing construction of the tokamak device ITER and the stellerator device Wendelstein 7X and their record breaking parameters concerning size, complexity of design, stored energy, amperage, mechanical and magnetic forces, critical current densities and stability requirements, it is deemed timely to review another critical parameter that is practically unique to these devices, namely the radiation response of all magnet components to the lifetime fluence of fast neutrons and gamma rays produced by the fusion reactions of deuterium and tritium. I will review these radiation effects in turn for the currently employed standard "technical" low temperature superconductors NbTi and Nb 3 Sn, the stabilizing material (Cu) as well as the magnet insulation materials and conclude by discussing the potential of high temperature superconducting materials for future generations of fusion devices, such as DEMO. (author)

  8. Development of partially-stabilized pulsed superconducting magnets

    International Nuclear Information System (INIS)

    Tateishi, Hiroshi; Onishi, Toshitada; Komuro, Kazuo; Koyama, Kenichi

    1987-01-01

    Two types of pulsed superconducting cables and four pulsed superconducting magnets have been developed in order to investigate basic problems in constructing ohmic heating coils of a tokamak-type fusion reactor. We found that a compacted cable is superior in mechanical rigidity and a braided cable is superior in cooling capacity as a conductor of a pulsed magnet. Stored energy and a maximum field of the magnets are 78 kJ and 6 T, 68 kJ and 4 T, 375 kJ and 6 T, and 363 kJ and 3 T, respectively. Some of these magnets quenched in pulsive operations due to excessive ac losses or macroscopic wire motions. Therefore, main conditions for operating pulsed magnets without quenching are (1) to make ac losses low enough to be cooled with liquid helium existing near at the conductor surface by reducing filament diameter to the order of 10 μm and utilizing CuNi as matrix effectively, and (2) to prevent macroscopic wire motions by partial solderfilling of a cable or winding a magnet with strong tension. (author)

  9. A commercial tokamak reactor using super high field superconducting magnets

    International Nuclear Information System (INIS)

    Schwartz, J.; Bromberg, L.; Cohn, D.R.; Williams, J.E.C.

    1988-01-01

    This paper explores the range of possibilities for producing super high fields with advanced superconducting magnets. Obtaining magnetic fields greater than about 18 T at the coil in a large superconducting magnet system will require advances in many areas of magnet technology. These needs are discussed and potential solutions (advanced superconductors, structural materials and design methods) evaluated. A point design for a commercial reactor with magnetic field at the coil of 24 T and fusion power of 1800 MW is presented. Critical issues and parameters for magnet design are identified. 20 refs., 9 figs., 4 tabs

  10. Superconducting super collider second generation dipole magnet cryostat design

    International Nuclear Information System (INIS)

    Niemann, R.C.; Bossert, R.C.; Carson, J.A.; Engler, N.H.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Ohmori, T.

    1988-12-01

    The Superconducting Super Collider, a planned colliding beam particle physics research facility, requires /approximately/10,000 superconducting devices for the control of high energy particle beams. The /approximately/7,500 collider ring superconducting dipole magnets require cryostats that are functional, cryogenically efficient, mass producible and cost effective. A second generation cryostat design has been developed utilizing the experiences gained during the construction, installation and operation of several full length first generation dipole magnet models. The nature of the cryostat improvements is presented. Considered are the connections between the magnet cold mass and its supports, cryogenic supports, cold mass axial anchor, thermal shields, insulation, vacuum vessel and interconnections. The details of the improvements are enumerated and the abstracted results of available component and system evaluations are presented. 8 refs., 11 figs

  11. Conceptual design of a superconducting solenoid for a magnetic SSC [Superconducting Super Collider] detector

    International Nuclear Information System (INIS)

    Fast, R.W.; Grimson, J.H.; Kephart, R.D.; Krebs, H.J.; Stone, M.E.; Theriot, D.; Wands, R.H.

    1988-07-01

    The conceptual design of a large superconducting solenoid suitable for a magnetic detector at the Superconducting Super Collider (SSC) has begun at Fermilab. The magnet will provide a magnetic field of 2 T over a volume 8 m in diameter by 16 m long. The particle-physics calorimetry will be inside the field volume and so the coil will be bath cooled and cryostable; the vessels will be stainless steel. Predictibility of performance and the ability to safely negotiate all probable failure modes, including a quench, are important items of the design philosophy. Although the magnet is considerably larger than existing solenoids of this type and although many issues of manufacturability, transportability and cost have not been completely addressed, our conceptual design has convinced us that this magnet is a reasonable extrapolation of present technology. 2 figs., 2 tabs

  12. Field-induced magnetic instability within a superconducting condensate

    DEFF Research Database (Denmark)

    Mazzone, Daniel Gabriel; Raymond, Stephane; Gavilano, Jorge Luis

    2017-01-01

    The application of magnetic fields, chemical substitution, or hydrostatic pressure to strongly correlated electron materials can stabilize electronic phases with different organizational principles. We present evidence for a fieldinduced quantum phase transition, in superconducting Nd0.05Ce0.95Co...... that the magnetic instability is not magnetically driven, and we propose that it is driven by a modification of superconducting condensate at H*.......In5, that separates two antiferromagnetic phases with identical magnetic symmetry. At zero field, we find a spin-density wave that is suppressed at the critical field mu H-0* = 8 T. For H > H*, a spin-density phase emerges and shares many properties with the Q phase in CeCoIn5. These results suggest...

  13. 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.

  14. SUPERCONDUCTING COMBINED FUNCTION MAGNET SYSTEM FOR J-PARC NEUTRINO EXPERIMENT

    International Nuclear Information System (INIS)

    2004-01-01

    The J-PARC Neutrino Experiment, the construction of which starts in JFY 2004, will use a superconducting magnet system for its primary proton beam line. The system, which bends the 50 GeV 0.75 MW proton beam by about 80 degrees, consists of 28 superconducting combined function magnets. The magnets utilize single layer left/right asymmetric coils that generate a dipole field of 2.6 T and a quadrupole field of 18.6 T/m with the operation current of about 7.35 kA. The system also contains a few conduction cooled superconducting corrector magnets that serve as vertical and horizontal steering magnets. All the magnets are designed to provide a physical beam aperture of 130 mm in order to achieve a large beam acceptance. Extensive care is also required to achieve safe operation with the high power proton beam. The paper summarizes the system design as well as some safety analysis results

  15. Lumped-Element Dynamic Electro-Thermal model of a superconducting magnet

    Science.gov (United States)

    Ravaioli, E.; Auchmann, B.; Maciejewski, M.; ten Kate, H. H. J.; Verweij, A. P.

    2016-12-01

    Modeling accurately electro-thermal transients occurring in a superconducting magnet is challenging. The behavior of the magnet is the result of complex phenomena occurring in distinct physical domains (electrical, magnetic and thermal) at very different spatial and time scales. Combined multi-domain effects significantly affect the dynamic behavior of the system and are to be taken into account in a coherent and consistent model. A new methodology for developing a Lumped-Element Dynamic Electro-Thermal (LEDET) model of a superconducting magnet is presented. This model includes non-linear dynamic effects such as the dependence of the magnet's differential self-inductance on the presence of inter-filament and inter-strand coupling currents in the conductor. These effects are usually not taken into account because superconducting magnets are primarily operated in stationary conditions. However, they often have significant impact on magnet performance, particularly when the magnet is subject to high ramp rates. Following the LEDET method, the complex interdependence between the electro-magnetic and thermal domains can be modeled with three sub-networks of lumped-elements, reproducing the electrical transient in the main magnet circuit, the thermal transient in the coil cross-section, and the electro-magnetic transient of the inter-filament and inter-strand coupling currents in the superconductor. The same simulation environment can simultaneously model macroscopic electrical transients and phenomena at the level of superconducting strands. The model developed is a very useful tool for reproducing and predicting the performance of conventional quench protection systems based on energy extraction and quench heaters, and of the innovative CLIQ protection system as well.

  16. 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

  17. Recent development of the superconducting magnet in Japan

    International Nuclear Information System (INIS)

    Umeda, M.; Aiyama, Y.

    1980-01-01

    The current R and D works on large-scale superconducting magnets in Japan are reviewed with special emphasis on those for fusion power and electric power storage. The contents include Nb-Ti and Nb 3 Sn magnets and pulsed magnets. (E.G.) [pt

  18. Superconducting permanent magnets for high-temperature operation

    Czech Academy of Sciences Publication Activity Database

    Jirsa, Miloš; Muralidhar, M.

    2004-01-01

    Roč. 54, Suppl. D (2004), D441-D444 ISSN 0011-4626. [Czech and Slovak Conference on Magnetism. Košice, 12.07.2004-15.07.2004] Institutional research plan: CEZ:AV0Z1010914 Keywords : superconducting magnets * ternary LRE-123 compounds * mesoscopic defects Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.292, year: 2004

  19. Cryogenic system for VECC K500 superconducting cyclotron

    CERN Document Server

    Pal, G; Bhattacharyya, T K; Bhandari, R K

    2009-01-01

    VEC Centre, Kolkata in India is at an advanced stage of commissioning a K500 superconducting cyclotron. The superconducting coil of the magnet for cyclotron is cooled by liquid helium. Three liquid helium cooled cryopanels, placed inside the Dees of the radiofrequency system, maintain the vacuum in the acceleration region of the superconducting cyclotron. The cryogenic system for magnet for cyclotron has been tested by cooling the coil and energizing the magnet. The cryogenic system for cryopanels has also been tested. Heater and temperature sensor were placed on the liquid helium cold head for cryopanel. The temperature of the cold head was observed to be below 20 K upto a heat load of 11.7 watt.

  20. Magnetic field measurements of superconducting magnets for the colliding beam accelerator

    International Nuclear Information System (INIS)

    Herrera, J.; Kirk, H.; Prodell, A.; Willen, E.

    1983-01-01

    An important aspect of the development and production of superconducting magnets for the Colliding Beam Accelerator is the measurement of the magnetic field in the aperture of these magnets. The measurements have the three-fold purpose of determining the field quality as compared to the lattice requirements of the CBA, of obtaining the survey data necessary to position the magnets in the CBA tunnel, and lastly, of characterizing the magnetic fields for use in initial and future orbit studies of the CBA proton beams. Since for a superconducting storage accelerator it is necessary to carry out these detailed measurements on many (approx. 1000) magnets and at many current values (approx. 1000), we have chosen, in agreement with previous experience, to develop a system which Fourier analyses the voltages induced in a number of rotating windings and thereby obtains the multipole field components. The important point is that such a measuring system can be fast and precise. It has been used for horizontal measurements of the CBA ring dipoles

  1. Tests of a 3 meter curved superconducting beam transport dipole magnet

    International Nuclear Information System (INIS)

    Allinger, J.E.; Carroll, A.S.; Danby, G.T.; DeVito, B.; Jackson, J.W.; Leonhardt, W.J.; Prodell, A.G.; Weisenbloom, J.

    1981-01-01

    Initial tests of one of the curved 3 m long superconducting dipole magnets intended to generate 6.0 T and produce a 20.4 0 bend in the primary proton beam to a new D-target station at the Brookhaven National Laboratory AGS have been completed. Although this magnet, whose window frame design generally follows that of the successful 8 0 and Model T superconducting dipoles, demonstrates many of the desirable characteristics of these earlier magnets such as excellent quench propagation and good ramping properties, it has only reached a disappointingly low magnetic field of 3.5 to 4.0 T. Because of the great interest in superconducting magnet technology, this report will describe the diagnostic tests performed and plans for future modifications

  2. Magnetic levitation and superconductivity

    International Nuclear Information System (INIS)

    Albrecht, C.

    1989-01-01

    The paper explains the impressive advances made in the development of superconducting magnets, in cryogenic engineering, and in the development of drive and vehicle concepts in Japan in the period following termination of West German development work for the electrodynamical system (MLU 001, MLU 002). The potentials engineering due to the development of high-Tc superconductors are discussed. (orig./MM) [de

  3. Commissioning of cryogen delivery system for superconducting cyclotron magnet

    International Nuclear Information System (INIS)

    Pal, G.; Nandi, C.; Bhattacharyya, T.K.; Chaudhuri, J.; Bhandari, R.K.

    2005-01-01

    A K-500 superconducting cyclotron is being constructed at VECC Kolkata. The cryogen delivery system distributes liquid helium and liquid nitrogen to the superconducting cyclotron. Liquid helium is required to cool the cyclotron magnet and cryopanels. Liquid nitrogen is used to reduce the capacity of the helium liquefier. This paper describes the system, the current status and the commissioning experiences of cryogen delivery system for cyclotron magnet. (author)

  4. Status of superconducting magnets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Schermer, R.I.

    1993-09-01

    The arc sections of the High Energy Booster and the two Collider Rings will need more than 10,000, very large, superconducting dipole and quadrupole magnets. Development work on these magnets was carried out at US/DOE laboratories in a program that began in the mid 1980's. In 1991-1992, the technology was transferred to industry and twenty, full-length, Collider dipoles were successfully fabricated and tested. This program, along with HERA and Tevatron experience, has provided industry a data base to use in formulating detailed designs for the prototypes of the accelerator magnets, with an eye to reducing cost and enhancing producibility. Several model magnets from this latest phase of the industrial program have already been tested. The excessive ramp-rate sensitivity of the magnets is understood and solutions are under investigation

  5. Status of superconducting magnets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Schermer, R.I.

    1994-01-01

    The arc sections of the High Energy Booster and the two Collider Rings will need more than 10,000, very large, superconducting dipole and quadrupole magnets. Development work on these magnets was carried out at US/DOE laboratories in a program that began in the mid 1980's. In 1991--92, the technology was transferred to industry and twenty, full-length, Collider dipoles were successfully fabricated and tested. This program, along with HERA and Tevatron experience, has provided industry a data base to use in formulating detailed designs for the prototypes of the accelerator magnets, with an eye to reducing cost and enhancing producibility. Several model magnets from this latest phase of the industrial program have already been tested. The excessive ramp-rate sensitivity of the magnets is understood and solutions are under investigation

  6. Origin and Reduction of 1 /f Magnetic Flux Noise in Superconducting Devices

    Science.gov (United States)

    Kumar, P.; Sendelbach, S.; Beck, M. A.; Freeland, J. W.; Wang, Zhe; Wang, Hui; Yu, Clare C.; Wu, R. Q.; Pappas, D. P.; McDermott, R.

    2016-10-01

    Magnetic flux noise is a dominant source of dephasing and energy relaxation in superconducting qubits. The noise power spectral density varies with frequency as 1 /fα, with α ≲1 , and spans 13 orders of magnitude. Recent work indicates that the noise is from unpaired magnetic defects on the surfaces of the superconducting devices. Here, we demonstrate that adsorbed molecular O2 is the dominant contributor to magnetism in superconducting thin films. We show that this magnetism can be reduced by appropriate surface treatment or improvement in the sample vacuum environment. We observe a suppression of static spin susceptibility by more than an order of magnitude and a suppression of 1 /f magnetic flux noise power spectral density of up to a factor of 5. These advances open the door to the realization of superconducting qubits with improved quantum coherence.

  7. 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%.

  8. Electronics and instrumentation for the SST-1 superconducting magnet system

    International Nuclear Information System (INIS)

    Khristi, Yohan; Pradhan, Subrata; Varmora, Pankaj; Banaudha, Moni; Praghi, Bhadresh R.; Prasad, Upendra

    2015-01-01

    Steady State Superconducting Tokamak-1 (SST-1) at Institute for Plasma Research (IPR), India is now in operation phase. The SST-1 magnet system consists of sixteen superconducting (SC), D-shaped Toroidal Field (TF) coils and nine superconducting Poloidal Field (PF) coils together with a pair of resistive PF coils, inside the vacuum vessel of SST-1. The magnets were cooled down to 4.5 K using either supercritical or two-phase helium, after which they were charged up to 10 kA of transport current. Precise quench detection system, cryogenic temperature, magnetic field, strain, displacement, flow and pressure measurements in the Superconducting (SC) magnet were mandatory. The Quench detection electronics required to protect the SC magnets from the magnet Quench therefore system must be reliable and prompt to detect the quench from the harsh tokamak environment and high magnetic field interference. A ∼200 channels of the quench detection system for the TF magnet are working satisfactorily with its design criteria. Over ∼150 channels Temperature measurement system was implemented for the several locations in the magnet and hydraulic circuits with required accuracy of 0.1K at bellow 30K cryogenic temperature. Whereas the field, strain and displacement measurements were carried out at few predefined locations on the magnet. More than 55 channels of Flow and pressure measurements are carried out to know the cooling condition and the mass flow of the liquid helium (LHe) coolant for the SC Magnet system. This report identifies the different in-house modular signal conditioning electronics and instrumentation systems, calibration at different levels and the outcomes for the SST-1 TF magnet system. (author)

  9. A novel superconducting toroidal field magnetic concept using advanced materials

    International Nuclear Information System (INIS)

    Schwartz, J.

    1991-01-01

    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. 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 rate, 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. 54 refs., 14 figs., 5 tabs

  10. 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...... and compete. A magnetic field can significantly enhance the magnetic scattering in the superconducting state, roughly doubling the Bragg intensity at 13.5 T. We perform a microscopic modelling of the data by use of a five-band Hamiltonian relevant to iron pnictides. In the superconducting state, vortices can...... slow down and freeze spin fluctuations locally. When such regions couple they result in a long-range ordered antiferromagnetic phase producing the enhanced magnetic elastic scattering in agreement with experiments....

  11. Identification of Plasma Parameters and Optimization of Magnetic Sensors in the Superconducting Steady-State Tokamak-1 Using Neural Networks

    International Nuclear Information System (INIS)

    Sengupta, A.; Ranjan, P.

    2001-01-01

    In this paper, we examine the possibility of using a multilayered feedforward neural network to extract tokamak plasma parameters from magnetic measurements as an improvement over the traditional methodology of function parametrization. It is also used to optimize the number and locations of the magnetic diagnostics designed for the tokamak. This work has been undertaken with the specific purpose of application of the neural network technique to the newly designed (and currently under fabrication) Superconducting Steady-State Tokamak-1 (SST-1). The magnetic measurements will be utilized to achieve real-time control of plasma shape, position, and some global profiles. A trained neural network is tested, and the results of parameter identification are compared with function parametrization. Both techniques appear well suited for the purpose, but a definite improvement with neural networks is observed. Although simulated measurements are used in this work, confidence regarding the network performance with actual experimental data is ensured by testing the network's noise tolerance with Gaussian noise of up to 10%. Finally, three possible methods of ranking the diagnostics in decreasing order of importance are suggested, and the neural network is used to optimize the number and locations of the magnetic sensors designed for SST-1. The results from the three methods are compared with one another and also with function parametrization. Magnetic probes within the plasma-facing side of the outboard limiter have been ranked high. Function parametrization and one of the neural network methods show a distinct tendency to favor the probes in the remote regions of the vacuum vessel, proving the importance of redundancy. Fault tolerance of the optimized network is tested. The results obtained should, in the long run, help in the decision regarding the final effective set of magnetic diagnostics to be used in SST-1 for reconstruction of the control parameters

  12. Cryogenic techniques for large superconducting magnets in space

    International Nuclear Information System (INIS)

    Green, M.A.

    1988-12-01

    A large superconducting magnet is proposed for use in a particle astrophysics experiment, ASTROMAG, which is to be mounted on the United States Space Station. This experiment will have a two-coil superconducting magnet with coils which are 1.3 to 1.7 meters in diameter. The two-coil magnet will have zero net magnetic dipole moment. The field 15 meters from the magnet will approach earth's field in low earth orbit. The issue of high Tc superconductor will be discussed in the paper. The reasons for using conventional niobium-titanium superconductor cooled with superfluid helium will be presented. Since the purpose of the magnet is to do particle astrophysics, the superconducting coils must be located close to the charged particle detectors. The trade off between the particle physics possible and the cryogenic insulation around the coils is discussed. As a result, the ASTROMAG magnet coils will be operated outside of the superfluid helium storage tank. The fountain effect pumping system which will be used to cool the coil is described in the report. Two methods for extending the operating life of the superfluid helium dewar are discussed. These include: operation with a third shield cooled to 90 K with a sterling cycle cryocooler, and a hybrid cryogenic system where there are three hydrogen-cooled shields and cryostat support heat intercept points. Both of these methods will extend the ASTROMAG cryogenic operating life from 2 years to almost 4 years. 14 refs., 8 figs., 4 tabs

  13. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    International Nuclear Information System (INIS)

    Marchevsky, M; Wang, X; Sabbi, G; Prestemon, S

    2013-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01, we show how acoustic data is connected with voltage instabilities measured simultaneously in the magnet windings during provoked extractions and current ramps to quench. Instrumentation and data analysis techniques for acoustic sensing are reviewed. (author)

  14. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    CERN Document Server

    Marchevsky, M.; Sabbi, G.; Prestemon, S.

    2013-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb$_{3}$Sn quadrupole HQ01 [1], we show how acoustic data is connected with voltage instabilities measured simultaneously in the magnet windings during provoked extractions and current ramps to quench. Instrumentation and data analysis techniques for acoustic sensing are reviewed.

  15. Development of superconducting magnets for the Canadian electrodynamic Maglev vehicle

    International Nuclear Information System (INIS)

    Fife, A.A.; Ensing, H.J.; Tillotson, M.; Westera, W.

    1986-01-01

    A review is presented on the current status of superconducting magnet developments for the Canadian electrodynamic Maglev transportation system. Various design aspects of the levitation and linear synchronous motor magnets, appropriate for the current vehicle concepts, are discussed. In addition, recent experimental work is outlined on the development of a suitable epoxy impregnation technology for the superconducting coils

  16. Decay and snapback in superconducting accelerator magnets

    NARCIS (Netherlands)

    Haverkamp, M.

    2003-01-01

    This thesis deals with the explanation and compensation of the effects ‘decay’ and ‘snapback’ in superconducting accelerator magnets, in particular in those used in the new Large Hardron Collider at CERN. During periods of constant magnet excitation, as for example during the injection of particles

  17. Superconducting magnets for toroidal fusion reactors

    International Nuclear Information System (INIS)

    Haubenreich, P.N.

    1980-01-01

    Fusion reactors will soon be employing superconducting magnets to confine plasma in which deuterium and tritium (D-T) are fused to produce usable energy. At present there is one small confinement experiment with superconducting toroidal field (TF) coils: Tokamak 7 (T-7), in the USSR, which operates at 4 T. By 1983, six different 2.5 x 3.5-m D-shaped coils from six manufacturers in four countries will be assembled in a toroidal array in the Large Coil Test Facility (LCTF) at Oak Ridge National Laboratory (ORNL) for testing at fields up to 8 T. Soon afterwards ELMO Bumpy Torus (EBT-P) will begin operation at Oak Ridge with superconducting TF coils. At the same time there will be tokamaks with superconducting TF coils 2 to 3 m in diameter in the USSR and France. Toroidal field strength in these machines will range from 6 to 9 T. NbTi and Nb 3 Sn, bath cooling and forced flow, cryostable and metastable - various designs are being tried in this period when this new application of superconductivity is growing and maturing

  18. Magnetic tunable confinement of the superconducting condensate in superconductor/ferromagnet hybrids

    International Nuclear Information System (INIS)

    Aladyshkin, A.Yu.; Gillijns, W.; Silhanek, A.V.; Moshchalkov, V.V.

    2008-01-01

    The effect of a nonuniform magnetic field induced by a ferromagnet on the magnetoresistance of thin-film superconductor/ferromagnet hybrid structures was investigated experimentally. Two different magnetic textures with out-of-plane magnetization were considered: a plain ferromagnetic film with bubble domains and a regular array of ferromagnetic dots. The stray fields of the structures are able to affect the spatial profile of the superconducting condensate, leading to a modification of the dependence of the critical temperature T c on an external magnetic field H. We showed how the standard linear T c (H) dependence with a single maximum at H=0 can be continuously transformed into so-called reentrant phase boundary with two T c peaks. We demonstrated that both domain-wall superconductivity and field-induced superconductivity are different manifestations of the magnetic confinement effect in various magnetic patterns

  19. The g-2 storage ring superconducting magnet system

    International Nuclear Information System (INIS)

    Green, M.A.

    1993-09-01

    The g-2 μ lepton (muon) storage ring is a single dipole magnet that is 44 meters in circumference. The storage ring dipole field is created by three large superconducting solenoid coils. A single outer solenoid, 15.1 meters in diameter, carries 254 kA. Two inner solenoids, 13.4 meters in diameter, carry 127 kA each in opposition to the current carried by the outer solenoid. A room temperature C shaped iron yoke returns the magnetic flux and shapes the magnetic field in a 180 mm gap where the stored muon beam circulates. The gap induction will be 1.47 T. This report describes the three large superconducting solenoids, the cryogenic system needed to keep them cold, the solenoid power supply and the magnet quench protection system

  20. Design and investigations of the superconducting magnet system for the multipurpose superconducting electron cyclotron resonance ion source.

    Science.gov (United States)

    Tinschert, K; Lang, R; Mäder, J; Rossbach, J; Spädtke, P; Komorowski, P; Meyer-Reumers, M; Krischel, D; Fischer, B; Ciavola, G; Gammino, S; Celona, L

    2012-02-01

    The production of intense beams of heavy ions with electron cyclotron resonance ion sources (ECRIS) is an important request at many accelerators. According to the ECR condition and considering semi-empirical scaling laws, it is essential to increase the microwave frequency together with the magnetic flux density of the ECRIS magnet system. A useful frequency of 28 GHz, therefore, requires magnetic flux densities above 2.2 T implying the use of superconducting magnets. A cooperation of European institutions initiated a project to build a multipurpose superconducting ECRIS (MS-ECRIS) in order to achieve an increase of the performances in the order of a factor of ten. After a first design of the superconducting magnet system for the MS-ECRIS, the respective cold testing of the built magnet system reveals a lack of mechanical performance due to the strong interaction of the magnetic field of the three solenoids with the sextupole field and the magnetization of the magnetic iron collar. Comprehensive structural analysis, magnetic field calculations, and calculations of the force pattern confirm thereafter these strong interactions, especially of the iron collar with the solenoidal fields. The investigations on the structural analysis as well as suggestions for a possible mechanical design solution are given.

  1. Power supply system for the superconducting outsert of the CHMFL hybrid magnet

    Science.gov (United States)

    Fang, Z.; Zhu, J.; Chen, W.; Jiang, D.; Huang, P.; Chen, Z.; Tan, Y.; Kuang, G.

    2017-12-01

    The construction of a new hybrid magnet, consisting of a 11 T superconducting outsert and a 34 T resistive insert magnet, has been finished at the Chinese High Magnetic Field Laboratory (CHMFL) in Hefei. With a room temperature bore of 800 mm in diameter, the hybrid magnet superconducting outsert is composed of four separate Nb3Sn-based Cable-in-Conduit Conductor (CICC) coils electrically connected in series and powered by a single power supply system. The power supply system for the superconducting outsert consists of a 16 kA DC power supply, a quench protection system, a pair of 16 kA High Temperature Superconducting (HTS) current leads, and two Low Temperature Superconducting bus-lines. The design and manufacturing of the power supply system have been completed at the CHMFL. This paper describes the design features of the power supply system as well as the current fabrication condition of its main components.

  2. Framework of collaboration investigation on neutron effect on superconducting magnet materials

    International Nuclear Information System (INIS)

    Nishimura, Arata; Takeuchi, Takao; Nishijima, Shigehiro; Izumi, Yoshinobu; Takakura, Kosuke; Ochiai, Kentaro; Henmi, Tsutomu; Nishijima, Gen; Watanabe, Kazuo; Sato, Isamu; Kurisita, Hiroaki; Narui, Minoru; Shikama, Tatsuo

    2009-01-01

    A fusion reactor will generate D-T neutron and the kinetic energy of the neutron will be converted to the thermal energy and electrical energy. The neutron has huge energy and will be able to penetrate a shielding blanket and stream out of ports for neutral beam injections. The penetrated and streamed out neutrons will reach superconducting magnets and make some damages on the magnet system. To investigate the neutron irradiation effects on the superconducting magnet materials, a collaborative network must be organized and the irradiation researches must be performed. This report will describe the framework of the collaboration investigation which has been established among neutronics, superconducting magnet and fusion system. After showing the collaboration scheme, some new results on 14 MeV neutron irradiation effect are presented. Then, a three years new project which was adopted as one of 'Nuclear basic infrastructure strategy study initiatives' by MEXT will be introduced as an example of collaborative program among superconducting materials, fission reactor and high magnetic field technology. (author)

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

    International Nuclear Information System (INIS)

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

    1998-01-01

    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 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 c2 . This negates the conventional thinking that superconductivity and magnetic fields are antagonistic

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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 "1"2C"6"+ 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Wook; Kang, Joonsun, E-mail: genuinei@kirams.re.kr; 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 {sup 12}C{sup 6+} 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.

  6. Experience with overcooling and refilling of large superconducting magnets

    Directory of Open Access Journals (Sweden)

    Peter Trojan

    2008-11-01

    Full Text Available Cooling process of big superconducting magnets from temperature of surrounding to the critical temperature is a verycomplicated process from economical as well as from technical view. In case when cryostat containing experimental device overcoolitself from normal temperature directly with liquid helium the consumption would be considerably higher than in case that we use liquidnitrogen for first overcool. Thus whole process of overcooling would be considerably nonprofitable. The article describes experiencewith overflowing of superconducting magnets installed in laboratory at the Technical University in Kosice, where the research projectfor the electric energy in the magnetic field storage takes place.

  7. SCMAG series of programs for calculating superconducting dipole and quadrupole magnets

    International Nuclear Information System (INIS)

    Green, M.A.

    1974-10-01

    Programs SCMAG1, SCMAG2, SCMAG3, and SCMAG4 are a group of programs used to design and calculate the characteristics of conductor dominated superconducting dipole and quadrupole magnets. These magnets are used to bend and focus beams of high energy particles and are being used to design the superconducting magnets for the LBL ESCAR accelerator. The four programs are briefly described. (TFD)

  8. SCMAG series of programs for calculating superconducting dipole and quadrupole magnets

    International Nuclear Information System (INIS)

    Green, M.A.

    1974-01-01

    A general description is given of four computer programs for calculating the characteristics of superconducting magnets used in the bending and focusing of high-energy particle beams. The programs are being used in the design of magnets for the LBL ESCAR (Experimental Superconducting Accelerator Ring) accelerator. (U.S.)

  9. Superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    Rogers, J.D.; Boenig, H.J.

    1978-01-01

    Superconducting inductors provide a compact and efficient means of storing electrical energy without an intermediate conversion process. Energy storage inductors are under development for diurnal load leveling and transmission line stabilization in electric utility systems and for driving magnetic confinement and plasma heating coils in fusion energy systems. Fluctuating electric power demands force the electric utility industry to have more installed generating capacity than the average load requires. Energy storage can increase the utilization of base-load fossil and nuclear power plants for electric utilities. Superconducting magnetic energy storage (SMES) systems, which will store and deliver electrical energy for load leveling, peak shaving, and the stabilization of electric utility networks are being developed. In the fusion area, inductive energy transfer and storage is also being developed by LASL. Both 1-ms fast-discharge theta-pinch and 1-to-2-s slow tokamak energy transfer systems have been demonstrated. The major components and the method of operation of an SMES unit are described, and potential applications of different size SMES systems in electric power grids are presented. Results are given for a 1-GWh reference design load-leveling unit, for a 30-MJ coil proposed stabilization unit, and for tests with a small-scale, 100-kJ magnetic energy storage system. The results of the fusion energy storage and transfer tests are also presented. The common technology base for the systems is discussed

  10. BNL Direct Wind Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  11. Design prospect of remountable high-temperature superconducting magnet

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Hidetoshi, E-mail: hidetoshi.hashizume@qse.tohoku.ac.jp; Ito, Satoshi

    2014-10-15

    The remountable (mountable and demountable repeatedly) high-temperature superconducting (HTS) magnet has been proposed for huge and complex superconducting magnets in future fusion reactors to fabricate and repair easily the magnet and access inner structural components. This paper summarizes progress in R and D activities of mechanical joints of HTS conductors in terms of the electrical resistance and heat transfer performance at the joint region. The latest experimental results show the low joint resistance, 4 nΩ under 70 kA current condition using REBCO HTS conductor with mechanical lap joint system, and for the cooling system the maximum heat flux of 0.4 MW/m{sup 2} is removed by using bronze sintered porous media with sub-cooled liquid nitrogen. These values indicate that there is large possibility to design the remountable HTS magnet for fusion reactors.

  12. Mechanical disturbances in superconducting magnets

    International Nuclear Information System (INIS)

    Sugimoto, Makoto

    1990-03-01

    The stress distribution in a small epoxy-impregnated Nb 3 Sn coil was calculated by the finite element method. Mechanical disturbances due to the electromagnetic force in the magnet are discussed. The coil stability in relation with the stress distribution is also discussed by using the experimental results. To evaluate such stresses, a calculation model was investigated. It was found that the model, which removed the internal bore element in the model magnet, gave a reasonable condition to estimate to stress. A quench mechanism due to mechanical disturbances in superconducting magnets is discussed. According to this mechanism, an internal slit was assumed as the reason for the mechanical disturbance. The internal slit is generated at the boundary between the superconductor and the bore element by the thermally induced stress. When charging a magnet, the induced electromagnetic force results in a stress concentration at the slit, and hence to an enlargement of it. During the enlargement of the internal slit, heat is generated at the top of it. Such heat generation from a mechanical disturbance can induce a quench. Through these investigations, the following coil manufacturing method can be proposed to reduce such stresses: the magnet should be manufactured to separate the bore element from the superconductor and this separation technique can reduce the boundary stress during cool-down. Actually, a thin teflon film at the boundary between the superconductor and the bore element can be used as a separator. Another separation technique is a teflon coating on the internal bore element. The separation technique should result in a stable epoxy-impregnated superconducting magnet. (J.P.N.)

  13. A large channel count multi client data acquisition system for superconducting magnet system of SST-1

    International Nuclear Information System (INIS)

    Doshi, K.; Pradhan, S.; Masand, H.; Khristi, Y.; Dhongde, J.; Sharma, A.; Parghi, B.; Varmora, P.; Prasad, U.; Patel, D.

    2012-01-01

    The magnet system of the Steady-state Superconducting Tokamak-1 at the Institute for Plasma Research, Gandhinagar, India, consists of sixteen Toroidal field and nine Poloidal field Superconducting coils together with a pair of resistive PF coils, an air core ohmic transformer and a pair of vertical field coils. These coils are instrumented with various cryogenic grade sensors and voltage taps to monitor its operating status and health during different operational scenarios. A VME based data acquisition system with remote system architecture is implemented for data acquisition and control of the complete magnet operation. Client-Server based architecture is implemented with remote hardware configuration and continuous online/offline monitoring. A JAVA based platform independent client application is developed for data analysis and data plotting. The server has multiple data pipeline architecture to send data to storage database, online plotting application, numerical display screen, and run time calculation. This paper describes software architecture, design and implementation of the data acquisition system. (author)

  14. Superconducting magnetic energy storage for asynchronous electrical systems

    Science.gov (United States)

    Boenig, Heinrich J.

    1986-01-01

    A superconducting magnetic energy storage coil connected in parallel between converters of two or more ac power systems provides load leveling and stability improvement to any or all of the ac systems. Control is provided to direct the charging and independently the discharging of the superconducting coil to at least a selected one of the ac power systems.

  15. 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.

  16. 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.

  17. Development of Experimental Superconducting Magnet for the Collector Ring of FAIR Project

    International Nuclear Information System (INIS)

    Zhu Yinfeng; Wu Weiyue; Wu Songtao; Liu Changle; Xu Houchang

    2010-01-01

    A pool cooled experimental magnet based on the copper stabilized NbTi superconducting wire was designed, fabricated and tested, in order to evaluate the engineering design of the dipole superconducting magnet for the collector ring (CR) of the facility for antiproton and ion research (FAIR) project. In this paper, the experimental setup including quench protection system was presented. Performance of the liquid helium pool cooled test was introduced. All of the results indicate both the performance of conductor and the experimental superconducting magnet under low temperature is stable, which suggests the engineering design are feasible for the formal magnet in CR of the FAIR project.

  18. Potential damage to dc superconducting magnets due to high frequency electromagnetic waves

    Science.gov (United States)

    Gabriel, G. J.; Burkhart, J. A.

    1977-01-01

    Studies of a d.c. superconducting magnet coil indicate that the large coil behaves as a straight waveguide structure. Voltages between layers within the coil sometimes exceeded those recorded at terminals where protective resistors are located. Protection of magnet coils against these excessive voltages could be accomplished by impedance matching throughout the coil system. The wave phenomenon associated with superconducting magnetic coils may create an instability capable of converting the energy of a quiescent d.c. superconducting coil into dissipative a.c. energy, even in cases when dielectric breakdown does not take place.

  19. A monitoring of superconducting magnets by acoustic emission

    International Nuclear Information System (INIS)

    Nomura, Harehiko; Tateishi, Hiroshi; Onishi, Toshitada

    1990-01-01

    Since superconducting magnets (SCM) are going to be indispensable to magnetic levitated train, nuclear fusion, magnetic resonating imaging, rotational machines, etc., they must be placed great reliance on its repetitional operations. But without appropriate evaluating methods, these promising techniques must remain still in science levels and hard to be transferable to real human technologies. SCM, being used under dynamical operation with linking other electro-magnetic systems as said above, induce high voltage from which monitoring superconducting to normal transitional voltage is difficult to distinguish. To solve this problem, monitoring SCM by Acoustic Emission (AE) from themselves, have been found effective, in particular, during the dynamical energizing of them. As for a demonstration, this paper will report mainly how to monitor 3 MJ-SCM and a few results of the experiments aquired both by counting and locational mode of AE in pulsed and repeated operations of the magnet. Some discussions on the AE monitorings are also made along the main issues to be solved in future. (author)

  20. 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

  1. Pair-breaking effects by parallel magnetic field in electric-field-induced surface superconductivity

    International Nuclear Information System (INIS)

    Nabeta, Masahiro; Tanaka, Kenta K.; Onari, Seiichiro; Ichioka, Masanori

    2016-01-01

    Highlights: • Zeeman effect shifts superconducting gaps of sub-band system, towards pair-breaking. • Higher-level sub-bands become normal-state-like electronic states by magnetic fields. • Magnetic field dependence of zero-energy DOS reflects multi-gap superconductivity. - Abstract: We study paramagnetic pair-breaking in electric-field-induced surface superconductivity, when magnetic field is applied parallel to the surface. The calculation is performed by Bogoliubov-de Gennes theory with s-wave pairing, including the screening effect of electric fields by the induced carriers near the surface. Due to the Zeeman shift by applied fields, electronic states at higher-level sub-bands become normal-state-like. Therefore, the magnetic field dependence of Fermi-energy density of states reflects the multi-gap structure in the surface superconductivity.

  2. Superconducting (radiation hardened) magnets for mirror fusion devices

    International Nuclear Information System (INIS)

    Henning, C.D.; Dalder, E.N.C.; Miller, J.R.; Perkins, J.R.

    1983-01-01

    Superconducting magnets for mirror fusion have evolved considerably since the Baseball II magnet in 1970. Recently, the Mirror Fusion Test Facility (MFTF-B) yin-yang has been tested to a full field of 7.7 T with radial dimensions representative of a full scale reactor. Now the emphasis has turned to the manufacture of very high field solenoids (choke coils) that are placed between the tandem mirror central cell and the yin-yang anchor-plug set. For MFTF-B the choke coil field reaches 12 T, while in future devices like the MFTF-Upgrade, Fusion Power Demonstration and Mirror Advanced Reactor Study (MARS) reactor the fields are doubled. Besides developing high fields, the magnets must be radiation hardened. Otherwise, thick neutron shields increase the magnet size to an unacceptable weight and cost. Neutron fluences in superconducting magnets must be increased by an order of magnitude or more. Insulators must withstand 10 10 to 10 11 rads, while magnet stability must be retained after the copper has been exposed to fluence above 10 19 neutrons/cm 2

  3. Superconducting magnet and cryostat for a space application

    Science.gov (United States)

    Pope, W. L.; Smoot, G. F.; Smith, L. H.; Taylor, C. E.

    1975-01-01

    The paper describes the design concepts, development, and testing of a superconducting coil and cryostat for an orbiting superconducting magnetic spectrometer. Several coils were subject to overall thermal performance and coil charging tests. The coils have low but persistent currents and have proven themselves to be rugged and reliable for mobile balloon flights. Satellite experiments will be conducted on a new, similar design.

  4. Magnetic actuators and sensors

    CERN Document Server

    Brauer, John R

    2014-01-01

    An accessible, comprehensive guide on magnetic actuators and sensors, this fully updated second edition of Magnetic Actuators and Sensors includes the latest advances, numerous worked calculations, illustrations, and real-life applications. Covering magnetics, actuators, sensors, and systems, with updates of new technologies and techniques, this exemplary learning tool emphasizes computer-aided design techniques, especially magnetic finite element analysis, commonly used by today's engineers. Detailed calculations, numerous illustrations, and discussions of discrepancies make this text an inva

  5. 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.

  6. Superconducting magnets in nuclear and high energy physics

    International Nuclear Information System (INIS)

    Hamelin, J.; Parain, J.; Perot, J.; Lesmond, C.

    1976-01-01

    A few examples of superconducting magnets developped at Saclay for high energy physics are presented. The OGA doublet is a large acceptance optical system consisting of two quadrupoles with maximum field gradients of 35 and 23 teslas per meter giving an increase of the beam acceptance by a factor 4. The ALEC dipole is a synchrotron magnet with a length of 1.5 meter and a field of 5 teslas, operating in pulse made at a frequency of 0.1 Hertz and entirely constructed in industry. The ECO project is a demonstration of electrical energy saving by means of superconductors. It consists in the replacement of conventional copper of a classical beam transport magnet by superconducting windings. The use of superconductors for polarized target magnets allows a large variety of configurations to be obtained in order to satisfy the acceptance and space requirements to the detectors around the targets [fr

  7. Superconductive magnetic-field-trapping device

    Science.gov (United States)

    Hildebrandt, A. F.; Elleman, D. D.; Whitmore, F. C. (Inventor)

    1965-01-01

    An apparatus which enables the establishment of a magnetic field in air that has the same intensity as the ones in ferromagnetic materials is described. The apparatus is comprised of a core of ferromagnetic material and is surrounded by a cylinder made of a material that has superconducting properties when cooled below a critical temperature. A method is provided for producing a magnetic field through the ferromagnetic core. The core can also be split and pulled apart when it is required that the center of the cavity be left empty.

  8. 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 regenerator and desiredinternal magnetic field. It is shown that to produce a 1 T internal field in theregenerator a permanent magnet of hundreds of kilograms is needed or an area ofsuperconducting tape of tens of square meters. The cost of cooling the SC solenoidis shown to be a small fraction of the cost...... of the SC tape. Assuming a cost ofthe SC tape of 6000 $/m2 and a price of the permanent magnet of 100 $/kg, thesuperconducting solenoid is shown to be a factor of 0.3-3 times more expensive thanthe permanent magnet, for a desired field from 0.5-1.75 T and the geometrical aspectratio of the regenerator...

  9. [The discussion of superconducting MRI magnet transformation without LHe].

    Science.gov (United States)

    Yu, Huixian

    2014-01-01

    In this paper, from the current situation of the domestic use of superconducting MRI, on liquid helium supply and demand crisis in the market, the significance of the transformation without LHe of the superconducting MRI magnet was explained, and according to the enterprise's production process, a number of operating without liquid helium transformation practice and ideas were raised, important value orientation for the domestic manufacture and use of superconducting MRI was provided.

  10. Superconducting dipole magnet for the UTSI MHD facility

    International Nuclear Information System (INIS)

    Wang, S.T.; Niemann, R.C.; Turner, L.R.

    1978-01-01

    The Argonne National Laboratory is designing and will build a large superconducting dipole magnet system for use in the Coal Fired Flow MHD Research Facility at the University of Tennessee Space Institute (UTSI). Presented in detail are the conceptual design of the magnet geometry, conductor design, cryostability evaluation, magnetic pressure computation, structural design, cryostat design, the cryogenics system design, and magnet instrumentations and control

  11. Two phase cooling for superconducting magnets

    International Nuclear Information System (INIS)

    Eberhard, P.H.; Gibson, G.A.; Green, M.A.; Ross, R.R.; Smits, R.G.

    1986-01-01

    Comments on the use of two phase helium in a closed circuit tubular cooling system and some results obtained with the TPC superconducting magnet are given. Theoretical arguments and experimental evidence are given against a previously suggested method to determine helium two phase flow regimes. Two methods to reduce pressure in the magnet cooling tubes during quenches are discussed; 1) lowering the density of helium in the magnet cooling tubes and 2) proper location of pressure relief valves. Some techniques used to protect the refrigerator from too much cold return gas are also mentioned

  12. Design principles for prototype and production magnetic measurements of superconducting magnets

    International Nuclear Information System (INIS)

    Brown, B.C.

    1989-02-01

    The magnetic field strength and shape for SSC superconducting magnets will determine critical properties of the accelerator systems. This paper will enumerate the relations between magnetic field properties and magnet material selection and assembly techniques. Magnitudes of various field errors will be explored along with operating parameters which can affect them. Magnetic field quality requirements will be compared to available measuring techniques and the relation between magnetic field measurements and other quality control efforts will be discussed. This will provide a framework for designing a complete magnet measurement plan for the SSC project. 17 refs., 1 fig., 5 tabs

  13. Connections between magnetism and superconductivity in UBe13 doped with thorium or boron

    International Nuclear Information System (INIS)

    Heffner, R.H.; Ott, H.R.; Schenck, A.; Mydosh, J.A.; MacLaughlin, D.E.

    1991-06-01

    Magnetism and superconductivity appear to be intimately connected in the heavy electron (HE) superconductors. For example, it has been conjectured but not proven that the exchange of antiferromagnetic spin fluctuations are responsible for pairing in HE superconductors. In this paper we review recent results in U 1-x Th x Be 13 , where specific heat, lower critical field and zero-field μSR measurements reveal another second-order phase transition to a state which possesses small-moment magnetic correlations for 0.019 ≤ x ≤ 0.043. We present a new phase diagram for (U,Th)Be 13 which indicates that the superconducting and magnetic order parameters are closely coupled. A discussion of the nature of the lower phase is presented, including the consideration of a possible magnetic superconducting state. When UBe 13 is doped with B (UBe 12.97 B 0.03 ) the Kondo temperature is decreased and the specific heat jump at the superconducting transition temperature is significantly enhanced. However, μSR measurements reveal no magnetic signature in UBe 12.97 B 0.03 , unlike the case for Th doping. The correlation between changes in the Kondo temperature and changes in the superconducting properties induced by B doping provide evidence for the importance of magnetic excitations in the superconducting pairing interaction in UBe 13

  14. 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).

  15. Forced two phase helium cooling of large superconducting magnets

    International Nuclear Information System (INIS)

    Green, M.A.; Burns, W.A.; Taylor, J.D.

    1979-08-01

    A major problem shared by all large superconducting magnets is the cryogenic cooling system. Most large magnets are cooled by some variation of the helium bath. Helium bath cooling becomes more and more troublesome as the size of the magnet grows and as geometric constraints come into play. An alternative approach to cooling large magnet systems is the forced flow, two phase helium system. The advantages of two phase cooling in many magnet systems are shown. The design of a two phase helium system, with its control dewar, is presented. The paper discusses pressure drop of a two phase system, stability of a two phase system and the method of cool down of a two phase system. The results of experimental measurements at LBL are discussed. Included are the results of cool down and operation of superconducting solenoids

  16. Application of an analytical method for the field calculation in superconducting magnets

    International Nuclear Information System (INIS)

    Martinelli, G.; Morini, A.

    1983-01-01

    Superconducting magnets are taking on ever-growing importance due to their increasing prospects of utilization in electrical machines, nuclear fusion, MHD conversion and high-energy physics. These magnets are generally composed of cylindrical or saddle coils, while a ferromagnetic shield is generally situated outside them. This paper uses an analytical method for calculating the magnetic field at every point in a superconducting magnet composed of cylindrical or saddle coils. The method takes into account the real lengths and finite thickness of the coils as well as their radial and axial ferromagnetic shields, if present. The values and distribution of the flux density for some superconducting magnets of high dimensions and high magnetic field, composed of cylindrical or saddle coils, are also given. The results obtained with analytical method are compared with those obtained using numerical methods

  17. Investigation of the chain of 5T full-scale superconducting magnets

    International Nuclear Information System (INIS)

    Ageev, A.I.; Aleksandrov, G.M.; Aleksandrov, A.G.

    1987-01-01

    Bench investigations of the chain of dipoles with warm magnetic screen, connected in series, are being conducted in the framework of the IHEP program of the UNK superconducting magnet simulation. At the given stage conditions of accidental magnet transition to the normal state are being investigated. The study of processes of propagation of the normal phase, temperature fields and pressure growth dynamics, processes of energy and helium evacuation from magnet chain is given. Results of measuring electric and nonstationary processes in the chain during transition of one of superconducting magnets to the normal state are presented

  18. Ideal of the perfect magnet-superconducting systems

    International Nuclear Information System (INIS)

    Shoaee, H.; Spencer, J.E.

    1983-04-01

    In this report, we study an iron-free, superconducting, elliptical coil quadrupole which has been proposed by General Atomics for use in the SLC final focus system. Beth has shown that such coils might provide a pure quadrupole field ignoring 3-D effects. Similarly, recent studies of rare earth permanent magnets have shown that, at least in principle, these magnets can also be made arbitrarily pure. Since similar claims can be made for conventional iron-core electromagnets either by demanding pure hyperbolic pole contours or using tricks, it is interesting to consider just how wide the gulf between principle and practice really is for each type of magnet and what it takes to bridge it (and where one is most likely to fall off). Here we consider only the superconducting option because its greater strength, variability and linearity make it potentially useful for the SLC and the low-beta insertions of the high energy storage rings such as PEP

  19. CERN-LHC accelerator superconducting magnet. Development and international cooperation

    International Nuclear Information System (INIS)

    Yamamoto, Akira; Nakamoto, Tatsushi; Sasaki, Ken-ichi

    2009-01-01

    CERN-LHC accelerator superconducting magnets and a cooperative work for interaction region quadrupole magnets are introduced. The accelerator commissioning and the incident happened during the commissioning in 2008 is also briefly discussed. (author)

  20. 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.

  1. 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)

  2. Superconductivity and magnetism: From antagonism to mutual interplay

    International Nuclear Information System (INIS)

    Steglich, Frank

    2007-01-01

    In this paper, a brief survey is given on a number of research activities devoted to exploring the relationship between superconductivity and magnetism in f-electron systems. The starting point for these activities has been the pioneering work of 1958 by Matthias and coworkers illustrating the antagonistic nature of the two phenomena. Subsequent efforts concerned the investigation of Kondo superconductors and Kondo-lattice systems (in the 1970s), heavy-fermion metals (in the 1980s and 90s) and quantum critical materials (in the last decade). The latter systems are especially interesting as they promise a deeper insight into the mutual interplay between unconventional superconductivity and magnetism

  3. Construction of Superconducting Magnet System for the J-PARC Neutrino Beam Line

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, T.; Wanderer, P.; Sasaki, K.; Ajima, Y.; Araoka, O.; Fujii, Y.; Hastings, N.; Higashi, N.; Iida, M.; Ishii, T.; Kimura, N.; Kobayashi, T.; Makida, Y.; Nakadaira, T.; Ogitsu, T.; Ohhata, H.; Okamura, T.; Sakashita, K.; Sugawara, S.; Suzuki, S.; Tanaka, K.; Tomaru, T.; Terashima, A.; Yamamoto, A.; Ichikawa, A.; Kakuno, H.; Anerella, M.; Escallier, J.; Ganetis, G.; gupta, R.; Jain, A.; Muratore, J.; Parker, B.; Boussuge, T.; Charrier, J.-P.; Arakawa, M.; Ichihara, T.; Minato, T.; Okada, Y.; Itou, A.; Kumaki, T.; Nagami, M.; Takahashi, T.

    2009-10-18

    Following success of a prototype R&D, construction of a superconducting magnet system for J-PARC neutrino beam line has been carried out since 2005. A new conceptual beam line with the superconducting combined function magnets demonstrated the successful beam transport to the neutrino production target.

  4. Cryogenic magnet case and distributed structural materials for high-field superconducting magnets

    International Nuclear Information System (INIS)

    Summers, L.T.; Miller, J.R.; Kerns, J.A.; Myall, J.O.

    1987-01-01

    The superconducting magnets of the Tokamak Ignition/Burn Experimental Reactor (TIBER II) will generate high magnetic fields over large bores. The resulting electromagnetic forces require the use of large volumes of distributed steel and thick magnet case for structural support. Here we review the design allowables, calculated loads and forces, and structural materials selection for TIBER II. 7 refs., 2 figs., 3 tabs

  5. Superconducting superferric dipole magnet with cold iron core for the VLHC

    CERN Document Server

    Foster, G W

    2002-01-01

    Magnetic system of the stage I Very Large Hadron Collider (VLHC) is based on 2 Tesla superconducting magnets with combined functions. These magnets have a room temperature iron yoke with two 20 mm air gaps. Magnetic field in both horizontally separated air gaps is generated by a single, 100 kA superconducting transmission line. An alternative design with a cold iron yoke, horizontally or vertically separated air gaps is under investigation. The cold iron option with horizontally separated air gaps reduces the amount of iron, which is one of the major cost drivers for the 233-km magnet system of future accelerator. The vertical beam separation decreases the superconductor volume, heat load from the synchrotron radiation and eliminates fringe field from the return bus. Nevertheless, the horizontal beam separation provides lowest volume of the iron yoke and, therefore, smaller heat load on the cryogenic system during cooling down. All these options are discussed and compared in the paper. Superconducting correct...

  6. Design study of an indirect cooling superconducting magnet for a fusion device

    International Nuclear Information System (INIS)

    Mito, Toshiyuki; Hemmi, Tsutomu

    2009-01-01

    The design study of superconducting magnets adapting a new coil winding scheme of an indirect cooling method is reported. The superconducting magnet system for the spherical tokamak (ST), which is proposed to study the steady state plasma experiment with Q - equiv-1, requires high performances with a high current density compared to the ordinal magnet design because of its tight spatial restriction. The superconducting magnet system for the fusion device has been used in the condition of high magnetic field, high electromagnetic force, and high heat load. The pool boiling liquid helium cooling outside of the conductor or the forced flow of supercritical helium cooling inside of the conductor, such as cable-in-conduit conductors, were used so far for the cooling method of the superconducting magnet for a fusion application. The pool cooling magnet has the disadvantages of low mechanical rigidities and low withstand voltages of the coil windings. The forced flow cooling magnet with cable-in-conduit conductors has the disadvantages of the restriction of the coil design because of the path of the electric current must be the same as that of the cooling channel for refrigerant. The path of the electric current and that of the cooling channel for refrigerant can be independently designed by adopting the indirect cooling method that inserts the independent cooling panel in the coil windings and cools the conductor from the outside. Therefore the optimization of the coil windings structure can be attempted. It was shown that the superconducting magnet design of the high current density became possible by the indirect cooling method compared with those of the conventional cooling scheme. (author)

  7. Downhole Applications of Magnetic Sensors.

    Science.gov (United States)

    Gooneratne, Chinthaka P; Li, Bodong; Moellendick, Timothy E

    2017-10-19

    In this paper we present a review of the application of two types of magnetic sensors-fluxgate magnetometers and nuclear magnetic resonance (NMR) sensors-in the oil/gas industry. These magnetic sensors play a critical role in drilling wells safely, accurately and efficiently into a target reservoir zone by providing directional data of the well and acquiring information about the surrounding geological formations. Research into magnetic sensors for oil/gas drilling has not been explored by researchers to the same extent as other applications, such as biomedical, magnetic storage and automotive/aerospace applications. Therefore, this paper aims to serve as an opportunity for researchers to truly understand how magnetic sensors can be used in a downhole environment and to provide fertile ground for research and development in this area. A look ahead, discussing other magnetic sensor technologies that can potentially be used in the oil/gas industry is presented, and what is still needed in order deploy them in the field is also addressed.

  8. Theoretical study of in-plane response of magnetic field sensor to magnetic beads magnetized by the sensor self-field

    DEFF Research Database (Denmark)

    Hansen, Troels Borum Grave; Damsgaard, Christian Danvad; Dalslet, Bjarke Thomas

    2010-01-01

    We present a theoretical study of the spatially averaged in-plane magnetic field on square and rectangular magnetic field sensors from a single magnetic bead, a monolayer of magnetic beads, and a half-space filled with magnetic beads being magnetized by the magnetic self-field due to the applied...... bias current through the sensor. The analysis of the single bead response shows that beads always contribute positively to the average magnetic field as opposed to the case for an applied homogeneous magnetic field where the sign of the signal depends on the bead position. General expressions...... and analytical approximations are derived for the sensor response to beads as function of the bead distribution, the bias current, the geometry and size of the sensor, and the bead characteristics. Consequences for the sensor design are exemplified and it is described how the contribution from the self...

  9. Magnetic Resonance Sensors

    Directory of Open Access Journals (Sweden)

    Robert H. Morris

    2014-11-01

    Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...

  10. A chopper circuit for energy transfer between superconducting magnets

    International Nuclear Information System (INIS)

    Onishi, Toshitada; Tateishi, Hiroshi; Takeda, Masatoshi; Matsuura, Toshiaki; Nakatani, Toshio.

    1986-01-01

    It has been suggested that superconducting magnets could provide a medium for storing energy and supplying the large energy pulses needed by experimental nuclear-fusion equipment and similar loads. Based on this concept, tests on energy transfer between superconducting magnets are currently being conducted at the Agency of Industrial Science and Technology's Electrotechnical Laboratory. Mitsubishi Electric has pioneered the world's first chopper circuit for this application. The circuit has the advantages of being simple and permitting high-speed, bipolar energy transfer. The article describes this circuit and its testing. (author)

  11. Superconducting magnetic energy storage, possibilities and limitations

    International Nuclear Information System (INIS)

    Bace, M.; Knapp, V.

    1981-01-01

    Energy storage is of great importance for the exploitation of new energy sources as well as for the better utilisation of conventional ones. Several proposals in recent years have suggested that superconducting magnets could be used as energy storage in large electricity networks. It is a purpose of this note to point out that the requirements which have to be met by energy storage in a large electricity network place serious limitation on the possible use of superconducting energy storage. (author)

  12. Development of a superconducting position sensor for the Satellite Test of the Equivalence Principle

    Science.gov (United States)

    Clavier, Odile Helene

    The Satellite Test of the Equivalence Principle (STEP) is a joint NASA/ESA mission that proposes to measure the differential acceleration of two cylindrical test masses orbiting the earth in a drag-free satellite to a precision of 10-18 g. Such an experiment would conceptually reproduce Galileo's tower of Pisa experiment with a much longer time of fall and greatly reduced disturbances. The superconducting test masses are constrained in all degrees of freedom except their axial direction (the sensitive axis) using superconducting bearings. The STEP accelerometer measures the differential position of the masses in their sensitive direction using superconducting inductive pickup coils coupled to an extremely sensitive magnetometer called a DC-SQUID (Superconducting Quantum Interference Device). Position sensor development involves the design, manufacture and calibration of pickup coils that will meet the acceleration sensitivity requirement. Acceleration sensitivity depends on both the displacement sensitivity and stiffness of the position sensor. The stiffness must kept small while maintaining stability of the accelerometer. Using a model for the inductance of the pickup coils versus displacement of the test masses, a computer simulation calculates the sensitivity and stiffness of the accelerometer in its axial direction. This simulation produced a design of pickup coils for the four STEP accelerometers. Manufacture of the pickup coils involves standard photolithography techniques modified for superconducting thin-films. A single-turn pickup coil was manufactured and produced a successful superconducting coil using thin-film Niobium. A low-temperature apparatus was developed with a precision position sensor to measure the displacement of a superconducting plate (acting as a mock test mass) facing the coil. The position sensor was designed to detect five degrees of freedom so that coupling could be taken into account when measuring the translation of the plate

  13. Compact high-field superconducting quadrupole magnet with holmium poles

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, D.B.; Kraus, R.H. Jr.; Lobb, C.T.; Menzel, M.T. (Los Alamos National Lab., NM (United States)); Walstrom, P.L. (Grumman Space Systems, Los Alamos, NM (United States))

    1992-03-15

    A compact high-field superconducting quadrupole magnet was designed and built with poles made of the rare-earth metal holmium. The magnet is intended for use in superconducting coupled-cavity linear accelerators where compact high-field quadrupoles are needed, but where the use of permanent magnets is ruled out because of trapped-flux losses. The magnet has a clear bore diameter of 1.8 cm, outside diameter of 11 cm, length of 11 cm, and pole tip length of 6 cm. The effect of using holmium, a material with a higher saturation field than iron, was investigated by replacing poles made of iron with identical poles made of holmium. The magnet was operated at a temperature of 4.2 K and reached a peak quadrupole field gradient of 355 T/m, a 10% increase over the same magnet with iron poles. This increase in performance is consistent with calculations based on B-H curves that were measured for holmium at 4.2 K. (orig.).

  14. SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS

    International Nuclear Information System (INIS)

    WILLEN, E.; ANERELLA, M.; COZZOLINO, J.; GANETIS, G.; GHOSH, A.; GUPTA, R.; HARRISON, M.; JAIN, A.; MARONE, A.; MURATORE, J.; PLATE, S.; SCHMALZLE, J.; WANDERER, P.; WU, K.C.

    2000-01-01

    Dipole bending magnets are required to change the horizontal separation of the two beams in the LHC. In Intersection Regions (IR) 1, 2, 5, and 8, the beams are brought into collision for the experiments located there. In IR4, the separation of the beams is increased to accommodate the machine's particle acceleration hardware. As part of the US contribution to the LHC Project, BNL is building the required superconducting magnets. Designs have been developed featuring a single aperture cold mass in a single cryostat, two single aperture cold masses in a single cryostat, and a dual aperture cold mass in a single cryostat. All configurations feature the 80 mm diameter, 10 m long superconducting coil design used in the main bending magnets of the Relativistic Heavy Ion Collider recently completed at Brookhaven. The magnets for the LHC, to be built at Brookhaven, are described and results from the program to build two dual aperture prototypes are presented

  15. Magnetic sensor device

    NARCIS (Netherlands)

    2009-01-01

    The present invention provides a sensor device and a method for detg. the presence and/or amt. of target moieties in a sample fluid, the target moieties being labeled with magnetic or magnetizable objects. The sensor device comprises a magnetic field generating means adapted for applying a retention

  16. High-field superconducting window-frame beam-transport magnets

    International Nuclear Information System (INIS)

    Allinger, J.; Carroll, A.; Danby, G.; DeVito, B.; Jackson, J.; Leonhardt, W.; Prodell, A.; Skarita, J.

    1982-01-01

    The window-frame design for high-field superconducting beam-transport magnets was first applied to two, 2-m-long, 4-T modules of an 8 0 bending magent which has operated for nine years in the primary proton beam line at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). The design of two 1.5-m long, 7.6-cm cold-bore superconducting windowframe magnets, described in this paper, intended for the external proton beam transport system at the AGS incorporated evolutionary changes. These magnets generated a maximum aperture field of 6.8 T with a peak field in the dipole coil of 7.1 T. Measured fields are very accurate and are compared to values calculated using the computer programs LINDA and POISSON. Results of quench-propagation studies demonstrate the excellent thermal stability of the magnets. The magnets quench safely without energy extraction at a maximum current density, J = 130 kA/cm 2 in the superconductor, corresponding to J = 57.6 kA/cm 2 overall the conductor at B = 6.7 T

  17. Cryotribological applications in superconducting magnets

    International Nuclear Information System (INIS)

    Michael, P.C.; Iwasa, Y.; Rabinowicz, E.

    1993-01-01

    The authors have previously advocated the development of materials selection guidelines for high-performance superconducting magnets on the basis of steady-state sliding stability. Theoretical and experimental evidence suggests that inherently stable friction materials may be physically impossible at cryogenic temperatures. The authors propose an alternate strategy for improving low-temperature sliding stability within the framework of available material behaviors

  18. Young's moduli of cables for high field superconductive dipole magnet

    International Nuclear Information System (INIS)

    Yamada, Shunji; Shintomi, Takakazu.

    1983-01-01

    Superconductive dipole magnets for big accelerators are subjected to enormous electro-magnetic force, when they are operated with high field such as 10 Tesla. They should be constructed by means of superconductive cables, which have high Young's modulus, to obtain good performance. To develop such cables we measured the Young's moduli of cables for practical use of accelerator magnets. They are monolithic and compacted strand cables. We measured also Young's moduli of monolithic copper and brass cables for comparison. The obtained data showed the Young's moduli of 35 and 15 GPa for the monolithic and compacted strand cables, respectively. (author)

  19. Progress on the superconducting magnet for the time projection chamber experiment (TPC) at PEP

    International Nuclear Information System (INIS)

    Green, M.A.; Eberhard, P.H.; Burns, W.A.

    1980-01-01

    The TPC (Time Projection Chamber) experiment at PEP will have a two meter inside diameter superconducting magnet which creatests a 1.5 T uniform solenoidal field for the TPC. The superconducting magnet coil, cryostat, cooling system, and the TPC gas pressure vessel (which operatests at 11 atm) were designed to be about two thirds of a radiation length thick. As a result, a high current density coil design was chosen. The magnet is cooled by forced flow two phase helium. The TPC magnet is the largest adiabatically stable superconducting magnet built to date. The paper presents the parameters of the TPC thin solenoid and its subsystems. Tests results from the Spring 1980 cryogenic tes are presented. The topics to be dealt with in the paper are cryogenic services and the tests of magnet subsystems such as the folded current leads. Large thin superconducting magnet technology will be important to large detectors to be used on LEP

  20. Radiation Shielding Utilizing A High Temperature Superconducting Magnet

    Data.gov (United States)

    National Aeronautics and Space Administration — Project objective is to evaluate human radiation protection and architecture utilizing existing superconducting magnet technology while attempting to significantly...

  1. Hofstadter's Butterfly and Phase Transition of Checkerboard Superconducting Network in a Magnetic Field

    International Nuclear Information System (INIS)

    Hou Jingmin; Tian, Li-Jim

    2010-01-01

    We study the magnetic effect of the checkerboard superconducting wire network. Based on the de Gennes-Alexader theory, we obtain difference equations for superconducting order parameter in the wire network. Through solving these difference equations, we obtain the eigenvalues, linked to the coherence length, as a function of magnetic field. The diagram of eigenvalues shows a fractal structure, being so-called Hofstadter's butterfly. We also calculate and discuss the dependence of the transition temperature of the checkerboard superconducting wire network on the applied magnetic field, which is related to up-edge of the Hofstadter's butterfly spectrum. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  2. Two phase cooling for superconducting magnets

    International Nuclear Information System (INIS)

    Eberhard, P.H.; Gibson, G.A.; Green, M.A.; Ross, R.R.; Smits, R.G.; Taylor, J.D.; Watt, R.D.

    1986-01-01

    Comments on the use of two phase helium in a closed circuit tubular cooling system and some results obtained with the TPC superconducting magnet are given. Theoretical arguments and experimental evidence are given against a previously suggested method to determine helium two phase flow regimes. Two methods to reduce pressure in the magnet cooling tubes during quenches are discussed; (1) lowering the density of helium in the magnet cooling tubes and (2) proper location of pressure relief valves. Some techniques used to protect the refrigerator from too much cold return gas are also mentioned. 10 refs., 1 fig., 5 tabs

  3. Development of a superconducting bulk magnet for NMR and MRI.

    Science.gov (United States)

    Nakamura, Takashi; Tamada, Daiki; Yanagi, Yousuke; Itoh, Yoshitaka; Nemoto, Takahiro; Utumi, Hiroaki; Kose, Katsumi

    2015-10-01

    A superconducting bulk magnet composed of six vertically stacked annular single-domain c-axis-oriented Eu-Ba-Cu-O crystals was energized to 4.74 T using a conventional superconducting magnet for high-resolution NMR spectroscopy. Shim coils, gradient coils, and radio frequency coils for high resolution NMR and MRI were installed in the 23 mm-diameter room-temperature bore of the bulk magnet. A 6.9 ppm peak-to-peak homogeneous region suitable for MRI was achieved in the central cylindrical region (6.2 mm diameter, 9.1 mm length) of the bulk magnet by using a single layer shim coil. A 21 Hz spectral resolution that can be used for high resolution NMR spectroscopy was obtained in the central cylindrical region (1.3 mm diameter, 4 mm length) of the bulk magnet by using a multichannel shim coil. A clear 3D MR image dataset of a chemically fixed mouse fetus with (50 μm)(3) voxel resolution was obtained in 5.5 h. We therefore concluded that the cryogen-free superconducting bulk magnet developed in this study is useful for high-resolution desktop NMR, MRI and mobile NMR device. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Superconducting electromagnets for large wind tunnel magnetic suspension and balance systems

    International Nuclear Information System (INIS)

    Boom, R.W.; Abdelsalam, M.K.; Bakerek, K.

    1985-01-01

    This paper presents a new design study of a Magnetic Suspension and Balance System (MSBS) for airplane models in a large 8 ft x 8 ft wind tunnel. New developments in the design include: use of a superconducting solenoid as a model core instead of magnetized iron; combination of permanent magnet material in the model wings along with four race-track coils to produce the required roll torque; and mounting of all the magnets in an integral cold structure instead of in separate cryostats. Design of superconducting solenoid model cores and practical experience with a small-scale prototype are discussed

  5. Study of superconducting magnetic bearing applicable to the flywheel energy storage system that consist of HTS-bulks and superconducting-coils

    International Nuclear Information System (INIS)

    Seino, Hiroshi; Nagashima, Ken; Tanaka, Yoshichika; Nakauchi, Masahiko

    2010-01-01

    The Railway Technical Research Institute conducted a study to develop a superconducting magnetic bearing applicable to the flywheel energy-storage system for railways. In the first step of the study, the thrust rolling bearing was selected for application, and adopted liquid-nitrogen-cooled HTS-bulk as a rotor, and adopted superconducting coil as a stator for the superconducting magnetic bearing. Load capacity of superconducting magnetic bearing was verified up to 10 kN in the static load test. After that, rotation test of that approximately 5 kN thrust load added was performed with maximum rotation of 3000rpm. In the results of bearing rotation test, it was confirmed that position in levitation is able to maintain with stability during the rotation. Heat transfer properties by radiation in vacuum and conductivity by tenuous gas were basically studied by experiment by the reason of confirmation of rotor cooling method. The experimental result demonstrates that the optimal gas pressure is able to obtain without generating windage drag. In the second stage of the development, thrust load capacity of the bearing will be improved aiming at the achievement of the energy capacity of a practical scale. In the static load test of the new superconducting magnetic bearing, stable 20kN-levitation force was obtained.

  6. Mechanical characterization of journal superconducting magnetic bearings: stiffness, hysteresis and force relaxation

    International Nuclear Information System (INIS)

    Cristache, Cristian; Valiente-Blanco, Ignacio; Diez-Jimenez, Efren; Alvarez-Valenzuela, Marco Antonio; Perez-Diaz, Jose Luis; Pato, Nelson

    2014-01-01

    Superconducting magnetic bearings (SMBs) can provide stable levitation without direct contact between them and a magnetic source (typically a permanent magnet). In this context, superconducting magnetic levitation provides a new tool for mechanical engineers to design non-contact mechanisms solving the tribological problems associated with contact at very low temperatures. In the last years, different mechanisms have been proposed taking advantage of superconducting magnetic levitation. Flywheels, conveyors or mechanisms for high-precision positioning. In this work the mechanical stiffness of a journal SMBs have been experimentally studied. Both radial and axial stiffness have been considered. The influence of the size and shape of the permanent magnets (PM), the size and shape of the HTS, the polarization and poles configuration of PMs of the journal SMB have been studied experimentally. Additionally, in this work hysteresis behavior and force relaxation are considered because they are essential for mechanical engineer when designing bearings that hold levitating axles.

  7. Magnetic nanocomposite sensor

    KAUST Repository

    Alfadhel, Ahmed

    2016-05-06

    A magnetic nanocomposite device is described herein for a wide range of sensing applications. The device utilizes the permanent magnetic behavior of the nanowires to allow operation without the application of an additional magnetic field to magnetize the nanowires, which simplifies miniaturization and integration into microsystems. In5 addition, the nanocomposite benefits from the high elasticity and easy patterning of the polymer-based material, leading to a corrosion-resistant, flexible material that can be used to realize extreme sensitivity. In combination with magnetic sensor elements patterned underneath the nanocomposite, the nanocomposite device realizes highly sensitive and power efficient flexible artificial cilia sensors for flow measurement or tactile sensing.

  8. Synergy of exchange bias with superconductivity in ferromagnetic-superconducting layered hybrids: the influence of in-plane and out-of-plane magnetic order on superconductivity

    International Nuclear Information System (INIS)

    Stamopoulos, D; Manios, E; Pissas, M

    2007-01-01

    It is generally believed that superconductivity and magnetism are two antagonistic long-range phenomena. However, as was preliminarily highlighted in Stamopoulos et al (2007 Phys. Rev. B 75 014501), and extensively studied in this work, under specific circumstances these phenomena instead of being detrimental to each other may even become cooperative so that their synergy may promote the superconducting properties of a hybrid structure. Here, we have studied systematically the magnetic and transport behavior of such exchange biased hybrids that are comprised of ferromagnetic (FM) Ni 80 Fe 20 and low-T c superconducting (SC) Nb for the case where the magnetic field is applied parallel to the specimens. Two structures have been studied: FM-SC-FM trilayers (TLs) and FM-SC bilayers (BLs). Detailed magnetization data on the longitudinal and transverse magnetic components are presented for both the normal and superconducting states. These data are compared to systematic transport measurements including I-V characteristics. The comparison of the exchange biased BLs and TLs that are studied here with the plain ones studied in Stamopoulos et al (2007 Phys. Rev. B 75 184504) enable us to reveal an underlying parameter that may falsify the interpretation of the transport properties of relevant FM-SC-FM TLs and FM-SC BLs investigated in the recent literature: the underlying mechanism motivating the extreme magnetoresistance peaks in the TLs relates to the suppression of superconductivity mainly due to the magnetic coupling of the two FM layers as the out-of-plane rotation of their magnetizations takes place across the coercive field where stray fields emerge in their whole surface owing to the multidomain magnetic state that they acquire. The relative in-plane magnetization configuration of the outer FM layers exerts a secondary contribution on the SC interlayer. Since the exchange bias directly controls the in-plane magnetic order it also controls the out-of-plane rotation of

  9. Superconducting energy storage magnet

    Science.gov (United States)

    Boom, Roger W. (Inventor); Eyssa, Yehia M. (Inventor); Abdelsalam, Mostafa K. (Inventor); Huang, Xianrui (Inventor)

    1993-01-01

    A superconducting magnet is formed having composite conductors arrayed in coils having turns which lie on a surface defining substantially a frustum of a cone. The conical angle with respect to the central axis is preferably selected such that the magnetic pressure on the coil at the widest portion of the cone is substantially zero. The magnet structure is adapted for use as an energy storage magnet mounted in an earthen trench or tunnel where the strength the surrounding soil is lower at the top of the trench or tunnel than at the bottom. The composite conductor may be formed having a ripple shape to minimize stresses during charge up and discharge and has a shape for each ripple selected such that the conductor undergoes a minimum amount of bending during the charge and discharge cycle. By minimizing bending, the working of the normal conductor in the composite conductor is minimized, thereby reducing the increase in resistance of the normal conductor that occurs over time as the conductor undergoes bending during numerous charge and discharge cycles.

  10. Magnetic anomaly in superconducting TmRh4B4

    International Nuclear Information System (INIS)

    Smith, J.L.; Huang, C.Y.; Tsou, J.J.; Ho, J.C.

    1978-01-01

    The magnetic and superconducting properties of TmRh 4 B 4 (which becomes superconducting at 9.6 K) by means of ac and dc magnetic susceptibility and specific heat measurements are investigated. At 10.7 K, an ac susceptibility peak similar to those found in spin glasses has been observed. In addition, a pronounced specific heat peak has been observed at 11.4 K. The susceptibility peak is essentially unaffected by substitution of 1% Lu or Er for the Tm, but it diminishes when much larger amounts of Er are substituted. The physical origin of this anomalous peak will be discussed

  11. Tools to Study Interfaces for Superconducting, Thermoelectric, and Magnetic Materials at the University of Houston

    Science.gov (United States)

    2016-09-01

    AFRL-AFOSR-VA-TR-2016-0303 Tools to Study Interfaces for Superconducting ,Thermoelectric, and Magnetic Materials Paul C. W. Chu UNIVERSITY OF HOUSTON...8/28/2014 - 8/27/2016 Title: Tools to Study Interfaces for Superconducting , Thermoelectric, and Magnetic Materials at the University of Houston...effort. Tools to Study Interfaces for Superconducting , Thermoelectric, and Magnetic Materials at the University of Houston Grant/Contract Number AFOSR

  12. Random errors in the magnetic field coefficients of superconducting quadrupole magnets

    International Nuclear Information System (INIS)

    Herrera, J.; Hogue, R.; Prodell, A.; Thompson, P.; Wanderer, P.; Willen, E.

    1987-01-01

    The random multipole errors of superconducting quadrupoles are studied. For analyzing the multipoles which arise due to random variations in the size and locations of the current blocks, a model is outlined which gives the fractional field coefficients from the current distributions. With this approach, based on the symmetries of the quadrupole magnet, estimates are obtained of the random multipole errors for the arc quadrupoles envisioned for the Relativistic Heavy Ion Collider and for a single-layer quadrupole proposed for the Superconducting Super Collider

  13. Cryogenic system for production testing and measurement of Fermilab energy saver superconducting magnets

    International Nuclear Information System (INIS)

    Cooper, W.E.; Barger, R.K.; Bianchi, A.J.; Cooper, W.E.; Johnson, F.B.; McGuire, K.J.; Pinyan, K.D.; Wilson, F.R.

    1983-01-01

    The cryogenic system of the Fermilab Magnet Test Facility has been used to provide cooling for the testing of approximately 1200 Energy Saver superconducting magnets. The system provides liquid helium, liquid nitrogen, gas purification, and vacuum support for six magnet test stands. It provides for simultaneous high current testing of two superconducting magnets and nonhigh current cold testing of two additional magnets. The cryogenic system has been in operation for about 32000 hours. The 1200 magnets have taken slightly more than three years to test

  14. Cryogenic system for production testing and measurement of Fermilab energy saver superconducting magnets

    International Nuclear Information System (INIS)

    Cooper, W.E.; Bianchi, A.J.; Barger, R.K.; Johnson, F.B.; McGuire, K.J.; Pinyan, K.D.; Wilson, F.R.

    1983-03-01

    The cryogenic system of the Fermilab Magnet Test Facility has been used to provide cooling for the testing of approximately 1200 Energy Saver superconducting magnets. The system provides liquid helium, liquid nitrogen, gas purification, and vacuum support for six magnet test stands. It provides for simultaneous high current testing of two superconducting magnets and non-high current cold testing of two additional magnets. The cryogenic system has been in operation for about 32000 hours. The 1200 magnets have taken slightly more than three years to test

  15. Alternating-gradient canted cosine theta superconducting magnets for future compact proton gantries

    Directory of Open Access Journals (Sweden)

    Weishi Wan

    2015-10-01

    Full Text Available We present a design of superconducting magnets, optimized for application in a gantry for proton therapy. We have introduced a new magnet design concept, called an alternating-gradient canted cosine theta (AG-CCT concept, which is compatible with an achromatic layout. This layout allows a large momentum acceptance. The 15 cm radius of the bore aperture enables the application of pencil beam scanning in front of the SC-magnet. The optical and dynamic performance of a gantry based on these magnets has been analyzed using the fields derived (via Biot-Savart law from the actual windings of the AG-CCT combined with the full equations of motion. The results show that with appropriate higher order correction, a large 3D volume can be rapidly scanned with little beam shape distortion. A very big advantage is that all this can be done while keeping the AG-CCT fields fixed. This reduces the need for fast field ramping of the superconducting magnets between the successive beam energies used for the scanning in depth and it is important for medical application since this reduces the technical risk (e.g., a quench associated with fast field changes in superconducting magnets. For proton gantries the corresponding superconducting magnet system holds promise of dramatic reduction in weight. For heavier ion gantries there may furthermore be a significant reduction in size.

  16. Magnetic and superconducting properties of Ir-doped EuFe2As2

    International Nuclear Information System (INIS)

    B Paramanik, U; Hossain, Z; L Paulose, P; Ramakrishnan, S; K Nigam, A; Geibel, C

    2014-01-01

    The magnetic and superconducting properties of 14% Ir-doped EuFe 2 As 2 are studied by means of dc and ac magnetic susceptibilities, electrical resistivity, specific heat and 151 Eu and 57 Fe Mössbauer spectroscopy (MS) measurements. Doping of Ir in EuFe 2 As 2 suppresses the Fe spin density wave transition and in turn gives rise to high temperature superconductivity below 22.5 K with a reentrant feature at lower temperature. Magnetization and 151 Eu Mössbauer data indicate that the Eu 2+ spins order magnetically below 18 K. 57 Fe MS studies show a line broadening in the absorption spectra below 18 K due to transferred hyperfine field from the magnetically ordered Eu sublattices. A pronounced λ-shape peak in the specific heat supports a second-order phase transition of Eu 2+ magnetic ordering with a strong ferromagnetic component, as confirmed by the magnetic field dependences of the transition. For a single crystal, the in-plane resistivity (ρ ab ) and out-of-plane susceptibility (χ c ) show superconducting transitions with zero resistance and diamagnetism, respectively. But the in-plane susceptibility (χ ab ) does not show any diamagnetic shielding against external fields. The observed non-zero resistance in the temperature range 10–17.5 K, below the superconducting transition temperature, suggests the possible existence of a spontaneous vortex state in this superconductor. (papers)

  17. Superconducting levitation applications to bearings and magnetic transportation

    CERN Document Server

    Moon, Francis C

    1994-01-01

    Presents the fundamental principles governing levitation of material bodies by magnetic fields without too much formal theory. Defines the technology of magnetic bearings, especially those based on superconductivity, and demonstrates the key roles that magnetics, mechanics and dynamics play in the complete understanding of magnetic levitation and its bearings. Features extensive figures and photos of Mag-Lev devices and summarizes recent U.S. research studies in an effort to regain the lead in Mag-Lev technologies

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

    International Nuclear Information System (INIS)

    Schwerg, Juljan Nikolai

    2010-01-01

    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 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

  19. 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

  20. Superconducting magnet and fabrication method

    Science.gov (United States)

    Israelsson, Ulf E. (Inventor); Strayer, Donald M. (Inventor)

    1994-01-01

    A method of trapping a field in a block of superconductor material, includes providing (i) a block of material defining a bore, (ii) a high permeability core within the bore that defines a low reluctance path through the bore, (iii) a high permeability external structure on the exterior of the block of material that defines a low reluctance path between opposite ends of the core, and (iv) an electromagnet configured to apply a magnetic field around the high permeability core. The method proceeds by energizing the electromagnet to produce an applied magnetic field around the high permeability core, cooling the block of material sufficiently to render the block of material superconducting, de-energizing the electromagnet to result in a trapped magnetic field, and at least partially removing the low reluctance path defined by the core and the external structure in order to increase the magnetic flux density of the trapped magnetic field.

  1. 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...

  2. Levitation properties of superconducting magnetic bearings using superconducting coils and bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Yuuki; Seino, Hiroshi; Nagashima, Ken [Railway Technical Research Institute, 2-8-38 Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan)

    2010-11-15

    We have been developing a flywheel energy storage system (FESS) with 36 MJ energy capacity for a railway system with superconducting magnetic bearings (SMBs). We prepared two kinds of models using superconducting coils and bulk superconductors (SCs). One model demonstrated SMB load capacity of 20 kN and the other model proved non-contact stable levitation and non-contact rotation with SMBs. Combining these results, the feasibility of a 36 MJ energy capacity FESS with SMBs completely inside a cryostat has been confirmed. In this paper, we report the levitation properties of SMBs in these models.

  3. Levitation properties of superconducting magnetic bearings using superconducting coils and bulk superconductors

    International Nuclear Information System (INIS)

    Arai, Yuuki; Seino, Hiroshi; Nagashima, Ken

    2010-01-01

    We have been developing a flywheel energy storage system (FESS) with 36 MJ energy capacity for a railway system with superconducting magnetic bearings (SMBs). We prepared two kinds of models using superconducting coils and bulk superconductors (SCs). One model demonstrated SMB load capacity of 20 kN and the other model proved non-contact stable levitation and non-contact rotation with SMBs. Combining these results, the feasibility of a 36 MJ energy capacity FESS with SMBs completely inside a cryostat has been confirmed. In this paper, we report the levitation properties of SMBs in these models.

  4. 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...

  5. DEALS: a maintainable superconducting magnet system for tokamak fusion reactors

    International Nuclear Information System (INIS)

    Hseih, S.Y.; Danby, G.; Powell, J.R.

    1979-01-01

    The feasibility of demountable superconducting magnet systems has been examined in a design study of a DEALS [Demountable Externally Anchored Low Stress] TF magnet for an HFITR [High Field Ignition Test Reactor] Tokamak device. All parts of the system appear feasible, including the demountable superconducting joints. Measurements on small scale prototype joints indicate that movable pressure contact joints exhibit acceptable electrical, mechanical, and cryogenic performance. Such joints permit a relatively simple support structure and are readily demountable. Assembly and disassembly sequences are described whereby any failed portion of the magnet, or any part of the reactor inside the TF coils can be removed and replaced if necessary

  6. A facility to test short superconducting accelerator magnets at Fermilab

    International Nuclear Information System (INIS)

    Lamm, M.J.; Hess, C.; Lewis, D.; Jaffery, T.; Kinney, W.; Ozelis, J.P.; Strait, J.; Butteris, J.; McInturff, A.D.; Coulter, K.J.

    1992-10-01

    During the past four years the Superconducting Magnet R ampersand D facility at Fermilab (Lab 2) has successfully tested superconducting dipole, quadrupole, and correction coil magnets less than 2 meters in length for the SSC project and the Tevatron D0/B0 Low-β Insertion. During this time several improvements have been made to the facility that have greatly enhanced its magnet testing capabilities. Among the upgrades have been a new rotating coil and data acquisition system for measuring magnetic fields, a controlled flow liquid helium transfer line using an electronically actuated cryo valve, and stand-alone systems for measuring AC loss and training low current Tevatron correction coil packages. A description of the Lab 2 facilities is presented

  7. Magnetic and superconducting phase diagram of Nb/Gd/Nb trilayers

    Science.gov (United States)

    Khaydukov, Yu. N.; Vasenko, A. S.; Kravtsov, E. A.; Progliado, V. V.; Zhaketov, V. D.; Csik, A.; Nikitenko, Yu. V.; Petrenko, A. V.; Keller, T.; Golubov, A. A.; Kupriyanov, M. Yu.; Ustinov, V. V.; Aksenov, V. L.; Keimer, B.

    2018-04-01

    We report on a study of the structural, magnetic, and superconducting properties of Nb (25 nm ) /Gd (df) /Nb (25 nm ) hybrid structures of a superconductor/ ferromagnet (S/F) type. The structural characterization of the samples, including careful determination of the layer thickness, was performed using neutron and x-ray scattering with the aid of depth-sensitive mass spectrometry. The magnetization of the samples was determined by superconducting quantum interference device magnetometry and polarized neutron reflectometry, and the presence of magnetic ordering for all samples down to the thinnest Gd(0.8 nm) layer was shown. The analysis of the neutron spin asymmetry allowed us to prove the absence of magnetically dead layers in junctions with Gd interlayer thickness larger than one monolayer. The measured dependence of the superconducting transition temperature Tc(df) has a damped oscillatory behavior with well-defined positions of the minimum at df=3 nm and the following maximum at df=4 nm, in qualitative agreement with prior work [J. S. Jiang et al., Phys. Rev. B 54, 6119 (1996), 10.1103/PhysRevB.54.6119]. We use a theoretical approach based on the Usadel equations to analyze the experimental Tc(df) dependence. The analysis shows that the observed minimum at df=3 nm can be described by the so-called zero to π phase transitions of highly transparent S/F interfaces with a superconducting correlation length ξf≈4 nm in Gd. This penetration length is several times higher than for strong ferromagnets like Fe, Co, and Ni, thus simplifying the preparation of S/F structures with df˜ξf which are of topical interest in superconducting spintronics.

  8. Technologies pioneered by LHC. Superconducting magnet and radiation-tolerant tracking detector

    International Nuclear Information System (INIS)

    Yamamoto, Akira; Unno, Yoshinobu

    2007-01-01

    In the LHC project of proton-proton collisions exploring the energy frontier, superconducting magnets and radiation-tolerant tracking detector play fundamental roles as key technologies. The superconducting magnets contribute to bending and focusing particle beam by using high magnetic field created with the NbTi superconductor cooled to the superfluid temperature of He (1.9 K). In order to overcome the unprecedented radiation damage and to capture the particles emerging with high energy and high density, the large area and highly radiation-tolerant silicon semiconductor tracking detector has been developed for the LHC experiment. (author)

  9. Computer simulations of quench properties of thin, large superconducting solenoid magnets

    International Nuclear Information System (INIS)

    Kishimoto, Takeshi; Mori, Shigeki; Noguchi, Masaharu

    1983-01-01

    Measured quench data of a 1 m diameter x 1 m thin superconducting solenoid magnet with a single layer aluminum-stabilized NbTi/Cu superconductor of 269 turns were fitted by computer simulations using the one-dimensional approximation. Parameters obtained were used to study quench properties of a 3 m diameter x 5 m (1.5 Tesla) thin superconducting solenoid magnet with a stored magnetic energy of 30 x 10 6 J. Conductor dimensions with which the solenoid could be built substantially safe for the full field quench were optimized. (author)

  10. 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.

  11. Criteria of the efficiency for radiation protection of tokamak reactor superconducting magnet coils

    International Nuclear Information System (INIS)

    Zimin, S.A.

    1988-01-01

    Factors determining serviceability of the main elements (superconductor, stabilizing conductor, insulation) of superconducting magnet coils for tokamak reactors are discussed. It is suggested that the limiting values of total and specific energy release in the material of superconducting coils, increase in electric resistance of the stabilizing conductor, decrease in the superconductor critical current and damage of the superconducting magnet insulation should be used as criteria of the reactor internal radiation protection efficiency. The conclusion is made that neutron fluence in the magnet coil components considered can be used as a generalized criterion of the first approximation for the evaluation of the protection efficiency

  12. 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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. (paper)

  14. Mechanical stresses and strains in superconducting dipole magnets for high energy accelerators

    International Nuclear Information System (INIS)

    Greben, L.I.; Mironov, E.S.; Moustafin, H.H.

    1979-01-01

    Stress and strain distributions in superconducting dipole magnets were investigated numerically. A finite element computer program was developed to calculate stresses and displacements due to thermal stress, electromagnetic forces and prestressing of structural elements. Real mechanical and thermal properties of superconducting dipole elements are taken into account. Numerical results of stress and strain patterns in dipole magnets are presented

  15. Pulsed energy conversion with a dc superconducting magnet

    International Nuclear Information System (INIS)

    Cowan, M.; Cnare, E.C.; Leisher, W.B.; Tucker, W.K.; Wessenberg, D.L.

    1976-01-01

    A generator system for pulsed power is described which employs a dc superconducting magnet in a magnetic flux compression scheme. Experience with a small-scale generator together with projections of numerical models indicate potential applications to fusion research and commercial power generation. When the system is large enough pulse energy can exceed that stored in the magnet and pulse rise time can range from several microseconds to tens of milliseconds. (author)

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

    International Nuclear Information System (INIS)

    Asai, Y.

    1995-01-01

    We have studied the superconducting, magnetic, and charge correlation functions and the spin excitation spectrum in the doped two-chain Hubbard model by projector Monte Carlo and Lanczos diagonalization methods. The exponent of the interchain singlet superconducting correlation function, γ, is found to be close to 2.0 as long as two distinct noninteracting bands cross the Fermi level. Magnetic and charge correlation functions decay more rapidly than or as fast as the interchain singlet superconducting correlation function along the chains. The superconducting correlation in the doped two-chain Hubbard model is the most long-range correlation studied here. Implications of the results for the possible universality class of the doped two-chain Hubbard model are discussed

  17. Liquid helium-free 15 T superconducting magnet at 4 K

    International Nuclear Information System (INIS)

    Sakuraba, J.; Mikami, Y.; Watazawa, K.; Watanabe, K.; Awaji, S.

    2000-01-01

    We have successfully demonstrated a 15.1 T liquid helium-free superconducting magnet with a room-temperature bore of 52 mm using a Nb 3 Sn/NbTi hybrid coil, Bi2223 current leads and two Gifford-McMahon cryocoolers. The magnet has 830 mm outside diameter, 1221 mm height and 720 kg weight. The magnet was cooled to 3.6 K in 114 h. A central magnetic field of 15.1 T was achieved in 38 min. The temperature of the coil increased to 5.7 K due to ac losses during the excitation, but it decreased to 4.0 K before reaching 15.1 T. The temperature of the coil remained at a constant value of 3.8 K over the 24 h of operation. The demonstration indicated the usefulness of a liquid helium-free superconducting magnet to generate high magnetic fields up to 15 T. (author)

  18. Up gradation of VME based data acquisition for SST-1 superconducting magnets

    International Nuclear Information System (INIS)

    Varmora, Pankaj; Parghi, Bhadresh; Banaudha, Moni; Prasad, Upendra

    2017-01-01

    SST-1 magnet system consists of sixteen Toroidal Field (TF) coils and nine Poloidal Field (PF) superconducting coils along with a pair of vertical field coils and air core ohmic transformer. These magnets are instrumented with various cryogenic compatible sensors and voltage taps for its monitoring, operation, protection, and control during different machine operational scenarios like cryogenic cool down, current charging cycles including ramp up, flat top, plasma breakdown, dumping/ramp down and warm up. A VME hardware based data acquisition system has been developed for data monitoring, acquisition and control of magnet operation. A java platform based client and server utility has been developed for this data acquisition system. Upgradation of this java software utility has been carried out with enhance features, fast operating performance and new tools additions. Upgradation features includes larger data file sizes, highlights of critical data indicators, new file generation, online mass flow calculations etc. This poster describes basis hardware details, upgradation of previous software utility, testing and troubleshooting during software development. (author)

  19. 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

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

    Science.gov (United States)

    Hull, John R.

    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.

  1. Switching Magnetism and Superconductivity with Spin-Polarized Current in Iron-Based Superconductor.

    Science.gov (United States)

    Choi, Seokhwan; Choi, Hyoung Joon; Ok, Jong Mok; Lee, Yeonghoon; Jang, Won-Jun; Lee, Alex Taekyung; Kuk, Young; Lee, SungBin; Heinrich, Andreas J; Cheong, Sang-Wook; Bang, Yunkyu; Johnston, Steven; Kim, Jun Sung; Lee, Jhinhwan

    2017-12-01

    We explore a new mechanism for switching magnetism and superconductivity in a magnetically frustrated iron-based superconductor using spin-polarized scanning tunneling microscopy (SPSTM). Our SPSTM study on single-crystal Sr_{2}VO_{3}FeAs shows that a spin-polarized tunneling current can switch the Fe-layer magnetism into a nontrivial C_{4} (2×2) order, which cannot be achieved by thermal excitation with an unpolarized current. Our tunneling spectroscopy study shows that the induced C_{4} (2×2) order has characteristics of plaquette antiferromagnetic order in the Fe layer and strongly suppresses superconductivity. Also, thermal agitation beyond the bulk Fe spin ordering temperature erases the C_{4} state. These results suggest a new possibility of switching local superconductivity by changing the symmetry of magnetic order with spin-polarized and unpolarized tunneling currents in iron-based superconductors.

  2. Magnetism and superconductivity in a heavy-fermion superconductor, CePt3Si

    International Nuclear Information System (INIS)

    Takeuchi, T; Hashimoto, S; Yasuda, T; Shishido, H; Ueda, T; Yamada, M; Obiraki, Y; Shiimoto, M; Kohara, H; Yamamoto, T; Sugiyama, K; Kindo, K; Matsuda, T D; Haga, Y; Aoki, Y; Sato, H; Settai, R; Onuki, Y

    2004-01-01

    We have studied the magnetic and thermal properties of a single crystal of CePt 3 Si, which is a recently reported heavy-fermion superconductor with a superconducting transition temperature T c = 0.75 K and a Neel temperature T N = 2.2 K. The overall experimental data are principally explained on the basis of the crystalline electric field (CEF) scheme. Even in the antiferromagnetic state, the CEF model applies well to the characteristic features in the magnetization curve. These results indicate the existence of a localized magnetic moment at the Ce site, with a considerably reduced ordered moment of 0.16 μ B /Ce, and the strongly correlated conduction electrons are condensed into the superconducting state. We have also constructed the magnetic phase diagram including the superconducting phase for H parallel [110] and [001]. (letter to the editor)

  3. Stress relaxation technique of high magnetic field superconducting magnet for the nuclear fusion

    International Nuclear Information System (INIS)

    Kamimoto, Masayuki; Tateishi, Hiroshi; Agatsuma, Ko; Arai, Kazuaki; Umeda, Masaichi

    1999-01-01

    Here were attempted not only to prove effectiveness of a stress self-supporting type wire material for magnet constituting technique, but also to develop a fiber reinforcing type superconducting wire material used by materials with excellent strain resistance to expand usable range of the stress self-supporting type with material. In 1997 fiscal year, superconductive features of the wire material produced by using composite processing method were evaluated, actual applicability for superconducting wire material was inspected, and investigation on manufacturing parameter of NbN thin films on trial production at present apparatus was conducted. (G.K.)

  4. Superconducting magnetic shields production. Realisation d'ecrans magnetiques supraconducteurs

    Energy Technology Data Exchange (ETDEWEB)

    Lainee, F; Kormann, R [Thomson-CSF, Domaine de Corbeville, 91 - Orsay (FR); Lainee, F [Ecole des Mines de Paris, 91 - Evry (FR)

    1992-02-01

    Low fields and low frequency shielding properties of YBCO magnetic shields are measured at 77 K. They compare favourably with shielding properties of mumetal shields. Therefore high-T{sub c} superconducting magnetic shields can already be used to shield small volumes. The case of magnetic shields for large volumes is also discussed. 3 refs; 6 figs; 4 tabs.

  5. Progress on axicell MFTF-B superconducting magnet systems

    International Nuclear Information System (INIS)

    Wang, S.T.; Kozman, T.A.; Hanson, C.L.; Shimer, D.W.; VanSant, J.H.; Zbasnik, J.

    1983-01-01

    Since the entire Mirror Fusion Test Facility (MFTF-B) Magnet System was reconfigured from the original A-cell to an axicell design, much progress has been made on the design, fabrication, and installation planning. The axicell MFTF-B magnet array consists of a total of 26 large superconducting main coils. This paper provides an engineering overview of the progress of these coils. Recent studies on the effects of field errors on the plasma at the recircularizing region (transition coils) show that small field errors will generate large displacements of the field lines. These field errors might enhance radial electron heat transport and deteriorate the plasma confinement. Therefore, 16 superconducting trim coils have been designed to correct the coil misalignments. Progress of the trim coils are reported also

  6. 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.

  7. Superconductive magnet having shim coils and quench protection circuits

    International Nuclear Information System (INIS)

    Schwall, R.E.

    1987-01-01

    A superconductive magnet is described comprising: a first persistent current loop comprising a first superconductor and a main coil connected to the first superconductor, the main coil being operative in response to superconduction therein to generate a primary magnetic field; a second persistent current loop comprising a second superconductor and a shim coil connected thereto, the shim coil being operative in response to superconduction therein to generate a corrective field for correcting aberrations in a predetermined gradient in the primary magnetic field, the shim coil having fewer turns than the main coil and being inductively coupled therewith whereby small changes in the current in the main coil cause much greater changes in the current in the shim coil. The magnet is characterized by an improvement which consists of: a first heater connected across the second persistent loop in parallel with the shim coil, the first heater being normally inoperative to carry current while the shim coil and the second superconductor are superconducting, the first heater being operative in response to current therein to heat the shim coil to a resistive state; and protective circuit means comprising a second heater connected to the main coil for carrying current from the main coil upon quenching of the main coil, the second heater being disposed in thermal contact with the second superconductor to heat the second superconductor to a resistive state in response to the current from the main coil to thereby divert current in the second persistent loop through the second heater causing it to heat the shim coil to a resistive state and resistively dissipate energy therein

  8. 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...

  9. Conceptual design of the superconducting magnet system for the helical fusion reactor

    International Nuclear Information System (INIS)

    Yanagi, Nagato; Hamaguchi, Shinji; Takahata, Kazuya; Natsume, Kyohei

    2013-01-01

    Current status of conceptual design of superconducting magnet system and low temperature system for the helical fusion reactor are introduced. There are three kinds of candidates of superconducting magnets such as Cable-in-conduit (CIC), Low-Temperature Superconductor (LTS) and High-Temperature Superconductor (HTS). Their characteristic properties, coil designs and cooling systems are stated. The freezer and low temperature distribution system, bus line and current lead, and excitation power source for superconducting coil are reported. The various elements of superconducting magnet system of FFHR-d1, partial cross section of FFHR helical coil using CIC, conceptual diagram of helical coil winding method of FFHR using CIC, relation among mass flow of supercritical helium supplied into CIC conductor and temperature increasing and pressure loss, cross section structure of LTS indirect-cooling conductor at 100 kA, cross section of 100-kA HTS conductor, connection method of helical coil segment and YBCO conductor are illustrated. (S.Y.)

  10. Control of the superconducting magnet power supply for SECRAL

    International Nuclear Information System (INIS)

    Zhou Wenxiong; Wang Yanyu; Zhou Detai; Lu Wang; Feng Yucheng; Su Jianjun

    2014-01-01

    The control of the superconducting magnet power supply (SMPS) is very important for Superconducting Electron Cyclotron Resonance Ion source with Advanced design in Lanzhou (SECRAL). In order to improve the safety and the reliability of the SMPS, a remote control system was designed and implemented. There are four power supplies needed to be controlled with suitable strategy to avoid the quench of the superconducting magnet. These four power supplies are used to supply four superconducting solenoids. Because the value and the changing rates of the current for these four solenoids are different, the power supplies must be operated synchronously to keep the current of the solenoids balanced. In this paper, we provide a detailed description for the control strategy of the four power supplies and the architecture of the hardware and the software. A serial switch is used for protocol conversion between TCP/IP and RS232 in firmware. And the software is implemented using VC++. The system can operate the four power supplies automatically after it is triggered. With the help of the control system, operation of the SMPS gets easier and safer. (authors)

  11. Magnetic Nanocomposite Cilia Sensors

    KAUST Repository

    Alfadhel, Ahmed

    2016-07-19

    Recent progress in the development of artificial skin concepts is a result of the increased demand for providing environment perception such as touch and flow sensing to robots, prosthetics and surgical tools. Tactile sensors are the essential components of artificial skins and attracted considerable attention that led to the development of different technologies for mimicking the complex sense of touch in humans. This dissertation work is devoted to the development of a bioinspired tactile sensing technology that imitates the extremely sensitive hair-like cilia receptors found in nature. The artificial cilia are fabricated from permanent magnetic, biocompatible and highly elastic nanocomposite material, and integrated on a giant magneto-impedance magnetic sensor to measure the stray field. A force that bends the cilia changes the stray field and is therefore detected with the magnetic sensor, providing high performance in terms of sensitivity, power consumption and versatility. The nanocomposite is made of Fe nanowires (NWs) incorporated into polydimethylsiloxane (PDMS). Fe NWs have a high remanent magnetization, due the shape anisotropy; thus, they are acting as permanent nano-magnets. This allows remote device operation and avoids the need for a magnetic field to magnetize the NWs, benefiting miniaturization and the possible range of applications. The magnetic properties of the nanocomposite can be easily tuned by modifying the NWs concentration or by aligning the NWs to define a magnetic anisotropy. Tactile sensors are realized on flexible and rigid substrates that can detect flow, vertical and shear forces statically and dynamically, with a high resolution and wide operating range. The advantage to operate the sensors in liquids and air has been utilized to measure flows in different fluids in a microfluidic channel. Various dynamic studies were conducted with the tactile sensor demonstrating the detection of moving objects or the texture of objects. Overall

  12. Coupling between magnetic and superconducting order parameters and evidence for the spin excitation gap in the superconducting state of a heavy fermion superconductor UPd2Al3

    International Nuclear Information System (INIS)

    Metoki, Naoto; Haga, Yoshinori; Koike, Yoshihiro; Aso, Naofumi; Onuki, Yoshichika

    1997-01-01

    Neutron scattering experiments have been carried out in order to study the interplay between magnetism and superconductivity in a heavy fermion superconductor, UPd 2 Al 3 . We have observed 1% suppression of the (0 0 0.5) magnetic peak intensity below the superconducting transition temperature T c . This is direct evidence for the coupling of the magnetic order parameter with the superconducting one. Furthermore, we have observed a spin excitation gap associated with superconductivity. The gap energy ΔE g increases continuously from ΔE g =0 to 0.4 meV with decreasing temperature from T c to 0.4 K. This gap energy corresponds to 2k B T c , which is smaller than the superconducting gap expected from the BCS theory (3.5k B T c ). These results are indicative of the strong interplay between magnetism and superconductivity. (author)

  13. Harmonic current layer method for the design of superconducting quadrupole magnetic field

    International Nuclear Information System (INIS)

    Zizek, F.

    1977-01-01

    The magnetic field of a superconducting quadrupole is investigated by the method of harmonic current layers of cylindrical shape. The superconducting winding is replaced by a system of thin current layers with a harmonically distributed density of the surface current along the circumference. The effect of the outer ferromagnetic circuit with an arbitrary constant permeability over the cross section is replaced analogically. The resultant magnetic field is then given by the superposition of the contributions from the individual current layers. The calculation method can be modified for the selection of the geometry of the winding for the latter to meet the demand for the high homogeneity of the gradient of magnetic induction in the working space of the superconducting quadrupole. (author)

  14. Superconductivity, magnetics, cryogenics, and vacuum coating

    International Nuclear Information System (INIS)

    Akin, J.E.; Ballou, J.K.; Beaver, R.J.

    1975-01-01

    The Engineering Sciences Department continued to provide consultation, design, and experiment to support the plasma physics activities of the Division while inaugurating a comprehensive program to develop superconducting magnets for toroidal fusion devices. This newly funded program is aimed at producing toroidal superconducting magnets for an experimental power reactor by the mid 1980's. Other superconducting work, such as the 14-T niobium tin solenoid designed last year for use in Moessbauer experiments, has been fabricated, successfully tested, and delivered to the Physics Division. This coil, which used a 1.27-cm wide Nb 3 Sn conductor operating at 14 T with a coil current density of 11,000 A/cm, represents an advance in the state-of-the-art. The conceptual design was provided for a subcooler to extend the ORMAK operating temperature to 70 0 K and thus allow operation at fields up to 25 kG with the present generators. The detailed design, fabrication, installation supervision, and acceptance testing of the subcooler were provided by the UCCND engineering organization. Further support to the ORMAK program was provided by the vacuum-coating activity through an investigation of sputtering erosion of the ORMAK liner. In addition, a program was undertaken to develop a variety of refractory surfaces of metals, alloys, and intermetallic compounds on stainless steel for use as first walls in future fusion devices. Adherent thick-film metallic and compound coatings deposited in vacuum by several mechanisms were produced and tested. (U.S.)

  15. A new hybrid protection system for high-field superconducting magnets

    CERN Document Server

    Ravaioli, E; Kirby, G; ten Kate, H H J; Verweij, A P

    2014-01-01

    The new generation of high-field superconducting accelerator magnets poses a challenge concerning the protection of the magnet coil in the case of a quench. The very high stored energy per unit volume requires a fast and efficient quench heating system in order to avoid damage due to overheating. A new protection system for superconducting magnets is presented, comprising a combination of a novel coupling-loss induced quench (CLIQ) system and conventional quench heaters. CLIQ can provoke a very fast transition to the normal state in coil windings by introducing coupling loss and thus heat in the coil's conductor. The advantage of the hybrid protection system is a global transition, resulting in a much faster current decay, a significantly lower hot-spot temperature, and a more homogeneous temperature distribution in the magnet's coil.

  16. Magnetic levitation using high temperature superconducting pancake coils as composite bulk cylinders

    International Nuclear Information System (INIS)

    Patel, A; Hopkins, S C; Baskys, A; Glowacki, B A; Kalitka, V; Molodyk, A

    2015-01-01

    Stacks of superconducting tape can be used as composite bulk superconductors for both trapped field magnets and for magnetic levitation. Little previous work has been done on quantifying the levitation force behavior between stacks of tape and permanent magnets. This paper reports the axial levitation force properties of superconducting tape wound into pancake coils to act as a composite bulk cylinder, showing that similar stable forces to those expected from a uniform bulk cylinder are possible. Force creep was also measured and simulated for the system. The geometry tested is a possible candidate for a rotary superconducting bearing. Detailed finite element modeling in COMSOL Multiphysics was also performed including a full critical state model for induced currents, with temperature and field dependent properties and 3D levitation force models. This work represents one of the most complete levitation force modeling frameworks yet reported using the H-formulation and helps explain why the coil-like stacks of tape are able to sustain levitation forces. The flexibility of geometry and consistency of superconducting properties offered by stacks of tapes, make them attractive for superconducting levitation applications. (paper)

  17. Superconducting, magnetic and magnetotransport properties of FeTe1-xSex single crystals

    Science.gov (United States)

    Kumar, Rohit; Sudesh, Varma, G. D.

    2018-05-01

    The single crystalline samples with compositions FeTe1-xSex (0.25 ≤ x ≤ 0.50) have been prepared via self-flux method and the superconducting, magnetic and magnetotransport properties of the grown crystals were investigated. The superconducting onset temperatures have been determined from the measurements of zero field cooled magnetization and resistance with temperatures. In the present case, highest superconducting transition temperature TC (onset) ˜ 15 K has been obtained for x=0.5. The HC2 (T=0 K) values have been estimated by fitting the experimental HC2 - T plots with WHH model. The highest HC2(0) has been obtained for x=0.5. The activation energy of the thermally activated flux flow has been found from the broadening of superconducting transition in an applied magnetic field using the Arrhenius law. Our results show that the activation energy (U0) decreases with the increasing magnetic field. Furthermore, the magnetization measurements for x=0.4 and 0.5 samples have been performed at T=5 K in the magnetic field range ±7 T to estimate critical current density at different applied magnetic fields using Bean formula. We see that the sample x=0.5 has higher values of JC as compared to that of x=0.4 at all magnetic fields. This is in conformity with the behavior of U0-H plots.

  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. Enhancement of magnetic flux distribution in a DC superconducting electric motor

    International Nuclear Information System (INIS)

    Hamid, N A; Ewe, L S; Chin, K M

    2013-01-01

    Most motor designs require an air gap between the rotor and stator to enable the armature to rotate freely. The interaction of magnetic flux from rotor and stator within the air gap will provide the thrust for rotational motion. Thus, the understanding of magnetic flux in the vicinity of the air gap is very important to mathematically calculate the magnetic flux generated in the area. In this work, a finite element analysis was employed to study the behavior of the magnetic flux in view of designing a synchronous DC superconducting electric motor. The analysis provides an ideal magnetic flux distribution within the components of the motor. From the flux plot analysis, it indicates that flux losses are mainly in the forms of leakage and fringe effect. The analysis also shows that the flux density is high at the area around the air gap and the rotor. The high flux density will provide a high force area that enables the rotor to rotate. In contrast, the other parts of the motor body do not show high flux density indicating low distribution of flux. Consequently, a bench top model of a DC superconducting motor was developed where by motor with a 2-pole type winding was chosen. Each field coil was designed with a racetrack-shaped double pancake wound using DI-BSCCO Bi-2223 superconducting tapes. The performance and energy efficiency of the superconducting motor was superior when compared to the conventional motor with similar capacity.

  20. Magnetic and superconducting order in some random pseudobinary compounds

    International Nuclear Information System (INIS)

    Dongen, J.C.M. van.

    1982-01-01

    This thesis presents the results of a study on the magnetic and superconducting ordering phenomena in some random pseudobinary compounds. In the investigations ternary systems are utilised in which two of the elements form a binary intermetallic compound, e.g. PdH, GdCu and YCo 2 . A third element is then randomly substituted into one of the sublattices without changing the basic intermetallic compound structure. In chapter II a study is presented on the Kondo effect and spin-glass freezing of the magnetic impurities Cr, Mn, and Fe in superconducting palladium hydride. Chapter III contains a study on crystal structure transformations and magnetic ordering phenomena in GdCusub(1-x)Gasub(x) and related pseudobinary compounds. In Chapter IV experiments on the magnetic properties and the electrical resistivity of the transition metal Laves phase compounds Y(Cosub(1-x)Fesub(x)) 2 , Y(Irsub(1-x)Fesub(x)) 2 and Hf(Cosub(1-x)Fesub(x)) 2 are described. (Auth.)

  1. Globally optimal superconducting magnets part II: symmetric MSE coil arrangement.

    Science.gov (United States)

    Tieng, Quang M; Vegh, Viktor; Brereton, Ian M

    2009-01-01

    A globally optimal superconducting magnet coil design procedure based on the Minimum Stored Energy (MSE) current density map is outlined. The method has the ability to arrange coils in a manner that generates a strong and homogeneous axial magnetic field over a predefined region, and ensures the stray field external to the assembly and peak magnetic field at the wires are in acceptable ranges. The outlined strategy of allocating coils within a given domain suggests that coils should be placed around the perimeter of the domain with adjacent coils possessing alternating winding directions for optimum performance. The underlying current density maps from which the coils themselves are derived are unique, and optimized to possess minimal stored energy. Therefore, the method produces magnet designs with the lowest possible overall stored energy. Optimal coil layouts are provided for unshielded and shielded short bore symmetric superconducting magnets.

  2. Performance of the Superconducting Corrector Magnet Circuits during the Commissioning of the LHC

    International Nuclear Information System (INIS)

    Venturini Delsolaro, W.; Baggiolini, V.; Ballarino, A.; Bellesia, B.; Bordry, F.; Cantone, A.; Casas Lino, M.P.; CastilloTrello, C.; Catalan-Lasheras, N.; Charifoulline, Zinour; Charrondiere, C.; CERN; Madrid, CIEMAT; Fermilab

    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, focusing on the quench behavior 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 compared to the test results obtained at the reception of the individual magnets

  3. Calculation of persistent currents in superconducting magnets

    Directory of Open Access Journals (Sweden)

    C. Völlinger

    2000-12-01

    Full Text Available This paper describes a semianalytical hysteresis model for hard superconductors. The model is based on the critical state model considering the dependency of the critical current density on the varying local field in the superconducting filaments. By combining this hysteresis model with numerical field computation methods, it is possible to calculate the persistent current multipole errors in the magnet taking local saturation effects in the magnetic iron parts into consideration. As an application of the method, the use of soft magnetic iron sheets (coil protection sheets mounted between the coils and the collars for partial compensation of the multipole errors during the ramping of the magnets is investigated.

  4. Magnetic Tactile Sensor for Braille Reading

    KAUST Repository

    Alfadhel, Ahmed

    2016-04-27

    We report a biomimetic magnetic tactile sensor for Braille characters reading. The sensor consists of magnetic nanocomposite artificial cilia implemented on magnetic micro sensors. The nanocomposite is produced from the highly elastic polydimethylsiloxane and iron nanowires that exhibit a permanent magnetic behavior. This design enables remote operation and does not require an additional magnetic field to magnetize the nanowires. The highly elastic nanocomposite is easy to pattern, corrosion resistant and thermally stable. The tactile sensors can detect vertical and shear forces, which allows recognizing small changes in surface texture, as in the case of Braille dots. The 6 dots of a braille cell are read from top to bottom with a tactile sensor array consisting of 4 elements and 1 mm long nanocomposite cilia.

  5. Magnetic Tactile Sensor for Braille Reading

    KAUST Repository

    Alfadhel, Ahmed; Khan, Mohammed; Cardoso, Susana; Kosel, Jü rgen

    2016-01-01

    We report a biomimetic magnetic tactile sensor for Braille characters reading. The sensor consists of magnetic nanocomposite artificial cilia implemented on magnetic micro sensors. The nanocomposite is produced from the highly elastic polydimethylsiloxane and iron nanowires that exhibit a permanent magnetic behavior. This design enables remote operation and does not require an additional magnetic field to magnetize the nanowires. The highly elastic nanocomposite is easy to pattern, corrosion resistant and thermally stable. The tactile sensors can detect vertical and shear forces, which allows recognizing small changes in surface texture, as in the case of Braille dots. The 6 dots of a braille cell are read from top to bottom with a tactile sensor array consisting of 4 elements and 1 mm long nanocomposite cilia.

  6. Magnetic Parameters Of A NB3SN Superconducting Magnet For A 56 HGz ECR Ion Source

    International Nuclear Information System (INIS)

    Ferracin, P.; Caspi, S.; Felice, H.; Leitner, D.; Lyneis, C.M.; Prestemon, S.; Sabbi, G.L.; Todd, D.S.

    2009-01-01

    Third generation Electron Cyclotron Resonance (ECR) ion sources operate at microwave frequencies between 20 and 30 GHz and employ NbTi superconducting magnets with a conductor peak field of 6-7 T. A significant gain in performance can be achieved by replacing NbTi with Nb 3 Sn, allowing solenoids and sextupole coils to reach a field of 15 T in the windings. In this paper we describe the design of a Nb 3 Sn superconducting magnet for a fourth generation ECR source operating at a microwave frequency of 56 GHz. The magnet design features a configuration with an internal sextupole magnet surrounded by three solenoids. A finite element magnetic model has been used to investigate conductor peak fields and the operational margins. Results of the numerical analysis are presented and discussed.

  7. MAGNETIC PARAMETERS OF A NB3SN SUPERCONDUCTING MAGNET FOR A 56 HGz ECR ION SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Ferracin, P.; Caspi, S.; Felice, H.; Leitner, D.; Lyneis, C. M.; Prestemon, S.; Sabbi, G. L.; Todd, D. S.

    2009-05-04

    Third generation Electron Cyclotron Resonance (ECR) ion sources operate at microwave frequencies between 20 and 30 GHz and employ NbTi superconducting magnets with a conductor peak field of 6-7 T. A significant gain in performance can be achieved by replacing NbTi with Nb{sub 3}Sn, allowing solenoids and sextupole coils to reach a field of 15 T in the windings. In this paper we describe the design of a Nb{sub 3}Sn superconducting magnet for a fourth generation ECR source operating at a microwave frequency of 56 GHz. The magnet design features a configuration with an internal sextupole magnet surrounded by three solenoids. A finite element magnetic model has been used to investigate conductor peak fields and the operational margins. Results of the numerical analysis are presented and discussed.

  8. Lattice parameters guide superconductivity in iron-arsenides

    Science.gov (United States)

    Konzen, Lance M. N.; Sefat, Athena S.

    2017-03-01

    The discovery of superconducting materials has led to their use in technological marvels such as magnetic-field sensors in MRI machines, powerful research magnets, short transmission cables, and high-speed trains. Despite such applications, the uses of superconductors are not widespread because they function much below room-temperature, hence the costly cooling. Since the discovery of Cu- and Fe-based high-temperature superconductors (HTS), much intense effort has tried to explain and understand the superconducting phenomenon. While no exact explanations are given, several trends are reported in relation to the materials basis in magnetism and spin excitations. In fact, most HTS have antiferromagnetic undoped ‘parent’ materials that undergo a superconducting transition upon small chemical substitutions in them. As it is currently unclear which ‘dopants’ can favor superconductivity, this manuscript investigates crystal structure changes upon chemical substitutions, to find clues in lattice parameters for the superconducting occurrence. We review the chemical substitution effects on the crystal lattice of iron-arsenide-based crystals (2008 to present). We note that (a) HTS compounds have nearly tetragonal structures with a-lattice parameter close to 4 Å, and (b) superconductivity can depend strongly on the c-lattice parameter changes with chemical substitution. For example, a decrease in c-lattice parameter is required to induce ‘in-plane’ superconductivity. The review of lattice parameter trends in iron-arsenides presented here should guide synthesis of new materials and provoke theoretical input, giving clues for HTS.

  9. Logic of quench protection assembly for BEPC II interaction region superconducting magnet

    International Nuclear Information System (INIS)

    Chen Fusan; Cheng Jian

    2006-01-01

    Two superconducting magnet complexes are used in BEPC II interaction region. The corresponding quench protection system divides all related faults into two classes and takes different protection actions according to the urgency degree. Since BEPC II has two operating modes and the superconducting magnets use different power supplies in different operating modes, the quench protection system must take the mode switching into consideration. (authors)

  10. Downhole Applications of Magnetic Sensors

    Directory of Open Access Journals (Sweden)

    Chinthaka P. Gooneratne

    2017-10-01

    Full Text Available In this paper we present a review of the application of two types of magnetic sensors—fluxgate magnetometers and nuclear magnetic resonance (NMR sensors—in the oil/gas industry. These magnetic sensors play a critical role in drilling wells safely, accurately and efficiently into a target reservoir zone by providing directional data of the well and acquiring information about the surrounding geological formations. Research into magnetic sensors for oil/gas drilling has not been explored by researchers to the same extent as other applications, such as biomedical, magnetic storage and automotive/aerospace applications. Therefore, this paper aims to serve as an opportunity for researchers to truly understand how magnetic sensors can be used in a downhole environment and to provide fertile ground for research and development in this area. A look ahead, discussing other magnetic sensor technologies that can potentially be used in the oil/gas industry is presented, and what is still needed in order deploy them in the field is also addressed.

  11. Redundant cryorefrigerator system for a refrigerated superconductive magnet

    International Nuclear Information System (INIS)

    Ackermann, R.A.

    1992-01-01

    This patent describes a cryorefrigerator system for a refrigerated superconductive magnet. It comprises a mounting means rigidly attached to the magnet; at least two cryorefrigerator means mounted on the mounting means such that the cryorefrigerator means moves on the mounting means and at least one of the two cryorefrigerator means being substantially out of contact with the magnet; and an adjustment means rigidly attached to the cryorefrigerator means for moving the at least one of the cryorefrigerator means

  12. 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.

  13. Superconducting magnet safety

    International Nuclear Information System (INIS)

    Arendt, F.; Komarek, P.

    1983-01-01

    One of the major components in a fusion reactor for which a safety analysis must be carried out is the magnet system. Most of the possible disturbances influencing the operation of superconducting magnets lead only to a quench, defined as an ''abnormal operating condition'' which causes just a temporary shut down of the magnet system without damage, if the system is well designed. More unlikely are accidental events which are associated with the generation of high power arcs. In these cases, single current arcs, e.g. at broken current leads, will lead to moderate damage only, but with the necessity of a longer shut down period for repair or replacing. Severe damage can only occur if in a multiple current arcing, starting by broken conductors, a wide-spread rupture of the winding occurs and the final high power arc burns through the coil case damaging other coils and reactor components. In a very hypothetical event the simultaneous rupture of the complete winding at two locations at least 1 m apart leads to missile generation due to the electromagnetic forces in the background field. The kinetic energy which the flying piece can get will be less than the values assumed for airplane crashes with the containment of modern fission power plants. (author)

  14. Countermeasure for the magnetic drag force in guideway structure of superconducting magnetic levitation Vehicle system (MAGLEV); Chodendo jiki fujoshiki tetsudo no kozobutsu ni okeru denjiki taisaku

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, A [JR Railway Technical Research Inst., Tokyo (Japan)

    1995-02-15

    As for the levitation vehicle system, the vehicle is equipped with superconducting magnets and is levitated about 10cm by the electromagnetic force that works between the push coil and levitation guide coil laid on the ground and it runs 500km an hour. But, the running resistance and energy loss called as magnetic resistance caused by the electromagnet phenomenon that generates between the superconducting magnets and structures (steel products) generate. In this paper, the magnet resistance generated in guideway structure of superconducting magnetic levitation vehicle system and its countermeasures therefor are introduced. The main countermeasures against the magnetic resistance are as follows. The steel products have to be as arranged as separated from the superconducting magnets as far as possible in the permissible design limit. Based on the analysis results the low magnetic steel would be used in an area within 1.5m from the strand of the superconducting magnet. The contact resistance of the joints part of loop-shaped components would be bigger so as to do not cause the loop current. And the big component would be divided into small parts when it is used near to the superconducting magnets. 5 refs., 10 figs.

  15. Safety analysis of the UTSI-CFFF superconducting magnet

    International Nuclear Information System (INIS)

    Turner, L.R.; Wang, S.T.; Smith, R.P.; VanderArend, P.C.; Hsu, Y.H.

    1979-01-01

    In designing a large superconducting magnet such as the UTSI-CFFF dipole, great attention must be devoted to the safety of the magnet and personnel. The conductor for the UTSI-CFFF magnet incorporates much copper stabilizer, which both insures its cryostability, and contributes to the magnet safety. The quench analysis and the cryostat fault condition analysis are presented. Two analyses of exposed turns follow; the first shows that gas cooling protects uncovered turns; the second, that the cryostat pressure relief system protects them. Finally the failure mode and safety analysis is presented

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

    Energy Technology Data Exchange (ETDEWEB)

    Bhunia, Uttam, E-mail: ubhunia@vecc.gov.in; Saha, Subimal; Chakrabarti, Alok

    2014-10-15

    Highlights: • The optimization approach minimizes both the magnet size and necessary cable length of a sectored toroidal SMES unit. • Design approach is suitable for low temperature superconducting cable suitable for medium size SMES unit. • It investigates coil parameters with respect to practical engineering aspects. - Abstract: 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.

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

    International Nuclear Information System (INIS)

    Bhunia, Uttam; Saha, Subimal; Chakrabarti, Alok

    2014-01-01

    Highlights: • The optimization approach minimizes both the magnet size and necessary cable length of a sectored toroidal SMES unit. • Design approach is suitable for low temperature superconducting cable suitable for medium size SMES unit. • It investigates coil parameters with respect to practical engineering aspects. - Abstract: 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

  18. Superconducting spin valves controlled by spiral re-orientation in B20-family magnets

    Science.gov (United States)

    Pugach, N. G.; Safonchik, M.; Champel, T.; Zhitomirsky, M. E.; Lähderanta, E.; Eschrig, M.; Lacroix, C.

    2017-10-01

    We propose a superconducting spin-triplet valve, which consists of a superconductor and an itinerant magnetic material, with the magnet showing an intrinsic non-collinear order characterized by a wave vector that may be aligned in a few equivalent preferred directions under the control of a weak external magnetic field. Re-orienting the spiral direction allows one to controllably modify long-range spin-triplet superconducting correlations, leading to spin-valve switching behavior. Our results indicate that the spin-valve effect may be noticeable. This bilayer may be used as a magnetic memory element for cryogenic nanoelectronics. It has the following advantages in comparison to superconducting spin valves proposed previously: (i) it contains only one magnetic layer, which may be more easily fabricated and controlled; (ii) its ground states are separated by a potential barrier, which solves the "half-select" problem of the addressed switch of memory elements.

  19. Beam heating studies on an early model is a superconducting cosine theta magnet

    International Nuclear Information System (INIS)

    Bozoki, G.; Bunce, G.; Danby, G.; Foelsche, H.; Jackson, J.; Prodell, A.; Soukas, A.; Stevens, A.; Stoehr, R.; Weisenbloom, J.

    1980-01-01

    Superconducting magnets for accelerators can be accidentally quenched by heat resulting from beam losses in the magnet. The threshold for such quenches is determined by the time structure of the beam loss and by details of the magnet application, construction and cooling. A 4.25 m long superconducting cosine theta dipole magnet, MARK VI, constructed during the research and development phase of the ISABELLE Project at BNL was installed in the 28.5 GeV/c primary proton beam line from the AGS. By energizing the magnet, the proton beam could be deflected into the magnet. The beam intensity required to quench the magnet was observed for different beam sizes and at several values of magnet current up to 2400 A or approximately 70% of the highest magnet operating current. The maximum current was limited by the gas-cooled power lead flow available using pool-boiling helium rather than single phase forced-flow helium at 5 atm for which the magnet system was designed. Details of the experimental setup including the magnet and cryogenic system, the beam-monitoring equipment and instrumentation are described. The measurements are discussed and compared with beam heating measurements made on another superconducting magnet and interpreted using the Cascade Simulation Program, CASIM

  20. Superconducting Cable Development for Future High Energy Physics Detector Magnets

    Science.gov (United States)

    Horvath, I. L.

    1995-11-01

    Under the leadership of the Swiss Federal Institute of Technology (ETHZ) an international ad hoc collaboration for superconducting cables developed an aluminium stabilised superconducting cable for future detector magnets. With the financial support of the Swiss government, this R&D work was carried out for the European Organisation for Nuclear Research (CERN). In this report the manufacturing process is described and results of the quality control measurements are summarised. These tests showed that the industrial manufacturing of an aluminium stabilised superconducting cable is feasible.

  1. Bipolar programmable current supply for superconducting nuclear magnetic resonance magnets

    Science.gov (United States)

    Koivuniemi, Jaakko; Luusalo, Reeta; Hakonen, Pertti

    1998-09-01

    In high resolution continuous-wave nuclear magnetic resonance (NMR) work well-reproducible, linear sweeps of current are needed. We have developed a microcontroller based programmable current supply, tested with superconducting magnets with inductance of 10 mH and 10 H. We achieved a resolution and noise of 4 ppm. The supply has an internal sweep with programmable ramping rate and a possibility for remote operation from a computer with either GPIB or RS232 interface. It is based on an 18-bit D/A converter. The maximum output current is ±10 A, the sweep rate can be set between 1 μA/s-140 mA/s, and the maximum output voltage is ±2.5 V. In work at ultralow temperatures, especially in superconducting quantum interference device NMR, all rf interference to the experiment should be avoided. One of the sources of this kind of unwanted input is the digital switching noise of fast logic devices. We discuss this problem in the context of our design.

  2. Studies of the Superconducting Transition in the Mo/Au-Bilayer Thin Films

    Science.gov (United States)

    Sadleir, John; Smith, Stephen; Iyomoto, naoko; Bandler, Simon; Chervenak, Jay; Brown, Ari; Brekowsky, Regis; Kilbourne, Caroline; Robinson, Ian

    2007-01-01

    At NASA Goddard, microcalorimeter arrays using superconducting transition edge sensor thermometers (TESs) are under development for high energy resolution X-ray astrophysics applications. We report on our studies of the superconducting transition in our Mo/Au-bilayer TES films including: low current measurements of the superconducting bilayer's resistance transition versus temperature on pixels with different normal metal absorber attachment designs and measured temperature scaling of the critical current and critical magnetic field.

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

    International Nuclear Information System (INIS)

    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.

    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)

  4. 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)

  5. Studies of quench propagation in a superconducting window frame magnet

    International Nuclear Information System (INIS)

    Allinger, J.; Carroll, A.; Danby, G.; DeVito, B.; Jackson, J.; Leonhardt, M.; Prodell, A.; Stoehr, R.

    1981-01-01

    During the testing of a meter long, superconducting window frame magnet, information from many spontaneously generated quenches have been recorded by an on-line computer system. Nearly every layer in an eleven layer dipole had a voltage tap and for some layers this subdivided into two halves. This allowed us to study development of the quenches in some detail. Knowledge of the resistances throughout the magnet also allowed the temperature distributions in the superconducting windings to be determined. A qualitative picture of the quench was developed and quantitative values of quench propagation velocities were compared to heat transfer calculations

  6. ESCAR, tests of superconducting bending magnets at the accelerator site

    International Nuclear Information System (INIS)

    Gilbert, W.S.; Lambertson, G.R.; Meuser, R.B.; Rechen, J.B.

    1979-03-01

    ESCAR (Experimental Superconducting Accelerator Ring) was conceived as a project in accelerator technology development which would provide data and experience to insure that planning for larger superconducting synchrotrons would proceed in a knowledgeable and responsible manner. It was to consist of the fabrication and operation of a relatively small proton synchrotron and storage ring with superconducting magnet elements for all of the main ring. The project was funded and design work began in July 1974. During the next two years it became increasingly apparent that the funding rate was directly limiting the rate of completion of ESCAR and that an intermediate goal, a test of the unconventional aspects of the project, was desirable. To that end, twelve dipole bending magnets, one-half of those required for the total ring, were installed at the site along with the 1500 watt helium refrigerator, cryogenic distribution system, electrical power supplies, vacuum systems, and necessary instrumentation. This truncated system was put through an extended series of tests which were completed in June 1978 at which time the ESCAR Project was terminated. ESCAR, and the dipole magnets have been described previously. The results of the systems tests have also been reported. The tests involving the dipole magnets are described

  7. A burnout safety condition for superconducting magnets and some of its applications

    International Nuclear Information System (INIS)

    Eberhard, P.H.; Alston-Garnjost, M.; Green, M.A.; Lecomte, P.; Smits, R.G.; Taylor, J.D.; Vuillemin, V.

    1979-01-01

    From the time evolution of the current in a superconducting coil during a quench, an upper limit can be computed for the temperature reached anywhere in the coil. A condition under which the danger of burnout is eliminated is derived here. It is used to show how the tests of superconducting magnets can be made safe against burnout and it provides constraints for the design of some type of magnets. (Auth.)

  8. Development of magnetic jxB sensor

    International Nuclear Information System (INIS)

    Kasai, Satoshi; Ishitsuka, Etsuo

    2001-12-01

    The improved mechanical sensor, i.e. magnetic jxB sensor (a mechanical sensor and a part of the steady state hybrid-type magnetic sensor) has been designed. The basic structure of the sensor is similar to the previously developed sensor (old sensor) in EDA phase. In this design, the neutron resistant materials are selected for the load cell (strain gauge and sensor beam) and sensing coil/frame. In order to reduce temperature drift of the sensor signal, four strain gauges with the same electrical property and geometrical size are bonded on the sensor beam by using Al 2 O 3 plasma spraying process, i.e., a couple of strain gauges is bonded on one side of the beam and another couple of gauges is bonded on the other side. These four strain gauges form an electrical bridge circuit. The zero-level drift of the output of the load cell used in the magnetic jxB sensor was reduced to about 1/20 compared with the old sensor. The temperature dependence of the output of the load cell is small. The linearity of the output of the load cell against weight was obtained. A non-linearity was observed in the sensitivity of the magnetic jxB sensor. The deviation of sensitivity from the fitting line was less than 7% in the high magnetic field region. The neutron irradiation effect on sensitivity of the sensor was investigated. The sensitivity of the sensor was gradually decreased by ∼30% at neutron fluence of (1.8-2.8)x10 23 n/m 2 in the high magnetic field. During irradiation, the non-linearity was observed in the sensitivity. (author)

  9. Mechanical behavior of the mirror fusion test Facility superconducting magnet coils

    International Nuclear Information System (INIS)

    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

  10. Sensor for detecting a quench in a superconductor using an optical coupling

    International Nuclear Information System (INIS)

    Mallick, G.T. Jr.; Logan, J.R.; Marschik, D.

    1991-01-01

    This patent describes a sensor for detecting a quench in a superconducting coil. It comprises a readout coil located in a magnetic field produced by the superconducting coil that will move in response to a current flow between two potential leads connected to voltage taps on the superconducting coil caused by the presence of a quench in the superconducting coil; at least one light source; at least one light sensor aligned with the light source; an optical encoder integrally attached to the readout and capable of interrupting light emitted by the light source and impinging on the light sensor; a means of biasing the readout coil to return it to an original position when a quench is not present in the superconducting coil; and a means of remotely decoding the transmitted and interrupted light received by the light sensor to indicate the presence of a quench in the superconducting coil

  11. Structural materials for large superconducting magnets for tokamaks

    International Nuclear Information System (INIS)

    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

  12. Analysis of persistent current in the superconducting magnets on an EDS Maglev vehicle for high-speed passenger transport

    Energy Technology Data Exchange (ETDEWEB)

    Azukizawa, Teruo [R and D Center, Toshiba Corp. (Japan)

    1996-12-31

    In an electrodynamic suspension system using superconducting magnets, an air core system is employed to effectively use strong magnetic fields produced by the superconducting magnets. This paper proposes an analysis method for the fluctuating persistent current in an superconducting soil, considering electromagnetic effects of the conductive cryostat. (HW)

  13. Two phase cooling for superconducting magnets

    International Nuclear Information System (INIS)

    Eberhard, P.H.; Gibson, G.A.; Green, M.A.; Ross, R.R.; Smits, R.G.; Taylor, J.D.; Watt, R.D.

    1985-08-01

    A closed circuit tubular cooling system for superconducting magnets offers advantages of limiting boiloff and containing high pressures during quenches. Proper location of automatic valves to lower pressures and protect the refrigerator in the event of quenches is described. Theoretical arguments and exprimental evidence are given against a previously suggested method to determine He two phase flow regimes. If loss of flow occurs due to some types of refrigeration failure and transfer lines have enough heat leak to warm up, quenches are induced when the flow is restored. Examples are taken from experience with the TPC magnet

  14. Design and analysis of the SSC [Superconducting Super Collider] dipole magnet suspension system

    International Nuclear Information System (INIS)

    Nicol, T.H.; Niemann, R.C.; Gonczy, J.D.

    1989-03-01

    The design of the suspension system for Superconducting Super Collider (SSC) dipole magnets has been driven by rigorous thermal and structural requirements. The current system, designed to meet those requirements, represents a significant departure from previous superconducting magnet suspension system designs. This paper will present a summary of the design and analysis of the vertical and lateral suspension as well as the axial anchor system employed in SSC dipole magnets. 5 refs., 9 figs., 4 tabs

  15. Real-World Sorting of RHIC Superconducting Magnets

    International Nuclear Information System (INIS)

    Wei, J.; Gupta, R.; Harrison, M.; Jain, A.; Peggs, S.; Thompson, P.; Trbojevic, D.; Wanderer, P.

    1999-01-01

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

  16. Development of heat-resistant magnetic sensor

    International Nuclear Information System (INIS)

    Takaya, Shigeru; Arakawa, Hisashi; Keyakida, Satoshi

    2013-01-01

    A heat-resistant flux gate magnetic sensor has been developed. Permendur, which has high Curie point, is employed as the magnetic core material and the detection method of the external magnetic field is modified. The characteristics of the developed magnetic sensor up to 500degC were evaluated. The sensor output increased linearly with the external magnetic field in the range of ±5 G and the standard deviation at 500degC was about 0.85G. (author)

  17. Magnetic sensor for steady state tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Neyatani, Yuzuru; Mori, Katsuharu; Oguri, Shigeru; Kikuchi, Mitsuru [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1996-06-01

    A new type of magnetic sensor has been developed for the measurement of steady state magnetic fields without DC-drift such as integration circuit. The electromagnetic force induced to the current which leads to the sensor was used for the measurement. For the high frequency component which exceeds higher than the vibration frequency of sensor, pick-up coil was used through the high pass filter. From the results using tokamak discharges, this sensor can measure the magnetic field in the tokamak discharge. During {approx}2 hours measurement, no DC drift was observed. The sensor can respond {approx}10ms of fast change of magnetic field during disruptions. We confirm the extension of measured range to control the current which leads to the sensor. (author).

  18. Superconducting magnetic energy storage unit; Supraleitender magnetischer Energiespeicher

    Energy Technology Data Exchange (ETDEWEB)

    Kleimaier, M [RWE Energie AG, Essen (Germany); Prescher, K [Siemens AG, Muehlheim an der Ruhr (Germany); Radtke, U [PreussenElektra AG, Hannover (Germany); Voelzke, R [Siemens AG, Erlangen (Germany)

    1995-07-01

    Superconducting magnetic power storage units are a low-cost alternative to turbine throttling as a means of ensuring active power seconds-range reserve. Advantages are fuel savings, emission reduction and a better utilisation of the available power plant park. With the aid of network simulations, the authors investigate the application conditions of superconducting magnetic power storage units in combination with preheater shut-off for the example of a 10 GW subgrid of the European interconnected grid. (orig.) [Deutsch] Supraleitende magnetische Energiespeicher (SMES) koennten einem Lastverteiler neue Moeglichkeiten bieten, Sekundenreserveleistung kostenguenstig vorzuhalten. Anstelle der heute vorherrschenden Androsselung der Turbinenventile sind bei Ersatz durch einen SMES Brennstoffeinsparungen, Emissionsminderungen und eine hoehere Ausnutzung des bestehenden Kraftwerksparks zu erwarten. Untersucht werden mit Hilfe von Netzsimulationsrechnungen am Beispiel eines 10-GW-Teilnetzes im westeuropaeischen Verbundnetz die Einsatzbedingungen dieser SMES in Kombination mit der Vorwaermeabschaltung. (orig.)

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

    International Nuclear Information System (INIS)

    Peng, Quanling; Xu, Fengyu; Wang, Ting; Yang, Xiangchen; Chen, Anbin; Wei, Xiaotao; Gao, Yao; Hou, Zhenhua; Wang, Bing; Chen, Yuan; Chen, Haoshu

    2014-01-01

    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. Optimal design of a 7 T highly homogeneous superconducting magnet for a Penning trap

    International Nuclear Information System (INIS)

    Wu Wei; He Yuan; Ma Lizhen; Huang Wenxue; Xia Jiawen

    2010-01-01

    A Penning trap system called Lanzhou Penning Trap (LPT) is now being developed for precise mass measurements at the Institute of Modern Physics(IMP). One of the key components is a 7 T actively shielded superconducting magnet with a clear warm bore of 156 mm. The required field homogeneity is 3 x 10 -7 over two 1 cubic centimeter volumes lying 220 mm apart along the magnet axis. We introduce a two-step method which combines linear programming and a nonlinear optimization algorithm for designing the multi-section superconducting magnet. This method is fast and flexible for handling arbitrary shaped homogeneous volumes and coils. With the help of this method an optimal design for the LPT superconducting magnet has been obtained. (authors)

  1. High magnetic field uniformity superconducting magnet for a movable polarized target

    International Nuclear Information System (INIS)

    Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

    1998-01-01

    The superconducting polarizing magnet was constructed for movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat with 'warm' aperture diameter of 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements using a NMR-magnetometer are given. The MPT set-up is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the Synchrophasotron of the Laboratory of High Energies (LHE), JINR, Dubna

  2. Cooper pairs' magnetic moment in MCFL color superconductivity

    International Nuclear Information System (INIS)

    Feng Bo; Ferrer, Efrain J.; Incera, Vivian de la

    2011-01-01

    We investigate the effect of the alignment of the magnetic moments of Cooper pairs of charged quarks that form at high density in three-flavor quark matter. The high-density phase of this matter in the presence of a magnetic field is known to be the Magnetic Color-Flavor-Locked (MCFL) phase of color superconductivity. We derive the Fierz identities of the theory and show how the explicit breaking of the rotational symmetry by the uniform magnetic field opens new channels of interactions and allows the formation of a new diquark condensate. The new order parameter is a spin-1 condensate proportional to the component in the field direction of the average magnetic moment of the pairs of charged quarks. The magnitude of the spin-1 condensate becomes comparable to the larger of the two scalar gaps in the region of large fields. The existence of the spin-1 condensate is unavoidable, as in the presence of a magnetic field there is no solution of the gap equations with nonzero scalar gaps and zero magnetic moment condensate. This is consistent with the fact that the extra condensate does not break any symmetry that has not already been broken by the known MCFL gaps. The spin-1 condensate enhances the condensation energy of pairs formed by charged quarks and the magnetization of the system. We discuss the possible consequences of the new order parameter on the issue of the chromomagnetic instability that appears in color superconductivity at moderate density.

  3. Theory of superconductivity

    International Nuclear Information System (INIS)

    Crisan, M.

    1988-01-01

    This book discusses the most important aspects of the theory. The phenomenological model is followed by the microscopic theory of superconductivity, in which modern formalism of the many-body theory is used to treat most important problems such as superconducting alloys, coexistence of superconductivity with the magnetic order, and superconductivity in quasi-one-dimensional systems. It concludes with a discussion on models for exotic and high temperature superconductivity. Its main aim is to review, as complete as possible, the theory of superconductivity from classical models and methods up to the 1987 results on high temperature superconductivity. Contents: Phenomenological Theory of Superconductivity; Microscopic Theory of Superconductivity; Theory of Superconducting Alloys; Superconductors in a Magnetic Field; Superconductivity and Magnetic Order; Superconductivity in Quasi-One-Dimensional Systems; and Non-Conventional Superconductivity

  4. Corrosion detection of nanowires by magnetic sensors

    KAUST Repository

    Kosel, Jü rgen; Amara, Selma; Ivanov, Iurii; Blanco, Mario

    2017-01-01

    Disclosed are various embodiments related to a corrosion detection device for detecting corrosive environments. A corrosion detection device comprises a magnetic sensor and at least one magnetic nanowire disposed on the magnetic sensor. The magnetic sensor is configured to detect corrosion of the one or more magnetic nanowires based at least in part on a magnetic field of the one or more magnetic nanowires.

  5. Corrosion detection of nanowires by magnetic sensors

    KAUST Repository

    Kosel, Jürgen

    2017-10-05

    Disclosed are various embodiments related to a corrosion detection device for detecting corrosive environments. A corrosion detection device comprises a magnetic sensor and at least one magnetic nanowire disposed on the magnetic sensor. The magnetic sensor is configured to detect corrosion of the one or more magnetic nanowires based at least in part on a magnetic field of the one or more magnetic nanowires.

  6. Magnetic field measurement and correction of VECC K500 superconducting cyclotron

    International Nuclear Information System (INIS)

    Dey, M.K.; Debnath, J.; Bhunia, U.; Pradhan, J.; Rashid, H.; Paul, S.; Dutta, A.; Naser, Z.A.; Singh, V.; Pal, G.; Nandi, C.; Dasgupta, S.; Bhattacharya, S.; Pal, S.; Roy, A.; Bhattacharya, T.; Bhole, R.B.; Bhale, D.; Chatterjee, M.; Prasad, R.; Nabhiraj, P.Y.; Hazra, D.P.; Mallik, C.; Bhandari, R.K.

    2006-01-01

    The VECC K500 superconducting cyclotron magnet is commissioned and magnetic field measurement and correction program was successfully completed in March 2006. Here we report the analysis of the measured field data and subsequent correction of the magnet to improve the field quality. (author)

  7. Three computer codes for safety and stability of large superconducting magnets

    International Nuclear Information System (INIS)

    Turner, L.R.

    1985-01-01

    For analyzing the safety and stability of large superconducting magnets, three computer codes TASS, SHORTURN, and SSICC have been developed, applicable to bath-cooled magnets, bath-cooled magnets with shorted turns, and magnets with internally cooled conductors respectively. The TASS code is described, and the use of the three codes is reviewed

  8. Feeding helium to superconducting magnets

    CERN Multimedia

    CERN PhotoLab

    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.

  9. Change in properties of superconducting magnet materials by fusion neutron irradiation

    International Nuclear Information System (INIS)

    Nishimura, Arata; Nishijima, Shigehiro; Takeuchi, Takao; Nishitani, Takeo

    2007-01-01

    A fusion reactor will generate a lot of high energy neutron and much energy will be taken out of the neutrons by a blanket system. Since some neutrons will stream out of a plasma vacuum vessel through neutral beam injection ports and penetrate a blanket system, a superconducting magnet system, which provides high magnetic field to confirm high energy particles, will be irradiated by a certain amount of neutrons. By developing the new NBI system or by reducing the penetration, the neutron fluence to the superconducting magnet will be able to be reduced. However, it is not easy to achieve the lower streaming and penetration at the present. Therefore, investigations on irradiation behavior of superconducting magnet materials are desired and some novel researches have been performed from 1970s. In general, the critical current of the superconducting wire increases under fast neutron environment comparing with that of the non-irradiated wire, and then decreased to almost zero as an increase of neutron fluence. On the other hand, the critical temperature of the wire starts to get down around 10 22 n/m 2 of neutron fluence and the temperature margin will be decreased during the operation by the neutron irradiation. In this paper, some aspects of irradiated materials will be overviewed and general tendency will be discussed focussing on knock-on effect of fast neutron and long range ordering of A15 compounds

  10. Shimming a superconducting nuclear-magnetic-resonance imaging magnet with steel

    International Nuclear Information System (INIS)

    Hoult, D.I.; Lee, D.

    1985-01-01

    Using a recently published paper as a basis, the magnetic field produced by steel bars inserted in a superconducting NMR imaging magnet is analyzed in a spherically harmonic basis set. A description is then given of how such bars were used to improve the homogeneity of the field within the magnet's imaging volume from 1.2 parts per thousand to about 10 ppm. The poor homogeneity was caused by the magnet's being placed in a steel-laden environment, a situation normally shunned by investigators, and it is the author's contention that the results obtained abrogate the main objection to NMR equipment's being installed in an ordinary hospital building. To facilitate the latter, the equations developed may also be used to estimate, prior to installation, the effects of the proposed environment on field homogeneity

  11. Organic magnetic field sensor

    Energy Technology Data Exchange (ETDEWEB)

    McCamey, Dane; Boehme, Christoph

    2017-01-24

    An organic, spin-dependent magnetic field sensor (10) includes an active stack (12) having an organic material with a spin-dependence. The sensor (10) also includes a back electrical contact (14) electrically coupled to a back of the active stack (12) and a front electrical contact (16) electrically coupled to a front of the active stack (12). A magnetic field generator (18) is oriented so as to provide an oscillating magnetic field which penetrates the active stack (12).

  12. Superconducting magnetic energy storage (SMES) program, January 1-December 31, 1981

    International Nuclear Information System (INIS)

    Rogers, J.D.

    1982-02-01

    Work reported is on the development of a 30 MJ superconducting magnetic energy storage (SMES) unit for use by the Bonneville Power Administration (BPA) to stabilize power oscillations on their Pacific AC Intertie. The 30 MJ superconducting coil manufacture was completed. Design of the seismic mounting of the coil to the nonconducting dewar lid and a concrete foundation is complete. The superconducting application VAR (SAVAR) control study indicated a low economic advantage and the SAVAR program was terminated. An economic and technological evaluation of superconducting fault current limiter (SFCL) was completed and the results are reported

  13. DESY: All superconducting magnets in place for HERA

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    On 19 September the last of the 646 superconducting magnets for the proton ring of the HERA electron-proton collider was placed in position in the 6.4 kilometre tunnel at the German DESY Laboratory in Hamburg. The different sections of the cryogenic ring are being cooled down, and all magnet connections should be complete by 8 November for the official ceremony marking the end of HERA construction and installation

  14. Conductive-cooled superconducting magnets and their applications; Chodendo wo mijikanishita reitoki chokurei hoshiki no chodendo jishaku

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, T.; Sasaki, T.; Urata, M. [Toshiba Corp., Tokyo (Japan)

    1998-01-01

    This paper describes an outline of conductive-cooled superconducting magnets, magnetic regenerator materials, and their applications. This magnet is composed of a 4K cryocooler, superconducting current lead, heat shield plate, support, and vacuum vessel. Cooling of the conductive coil is initiated by the operation of 4K cryocooler. It takes two days to one week for the cooling-down time from room temperature to the given temperature. During that time, users need to do nothing for the superconducting magnet. When the superconducting coil is cooled to the given temperature, current is applied to the coil for excitation. Thus, magnetic field is formed. Paying attention to the magnetic anomaly specific heat accompanied with magnetic phase transition of magnetic substance at the extremely low temperature, Toshiba has developed a 4K cryocooler using magnetic regenerator material by utilizing magnetic specific heat. Oxide superconductor is adopted for the current lead which is used at the temperature level below 80K. Inflow of the heat can be suppressed in one-tenth of the conventional current lead. As a result, a small size device having easy operability without using liquid helium has been developed. 6 refs., 4 figs.

  15. Magnetic field simulation and shimming analysis of 3.0T superconducting MRI system

    Science.gov (United States)

    Yue, Z. K.; Liu, Z. Z.; Tang, G. S.; Zhang, X. C.; Duan, L. J.; Liu, W. C.

    2018-04-01

    3.0T superconducting magnetic resonance imaging (MRI) system has become the mainstream of modern clinical MRI system because of its high field intensity and high degree of uniformity and stability. It has broad prospects in scientific research and other fields. We analyze the principle of magnet designing in this paper. We also perform the magnetic field simulation and shimming analysis of the first 3.0T/850 superconducting MRI system in the world using the Ansoft Maxwell simulation software. We guide the production and optimization of the prototype based on the results of simulation analysis. Thus the magnetic field strength, magnetic field uniformity and magnetic field stability of the prototype is guided to achieve the expected target.

  16. 1999 Review of superconducting dipole and quadrupole magnets for particle accelerators

    International Nuclear Information System (INIS)

    Devred, A.

    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 cosθ and cos 2 θ 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 conductor positioning

  17. 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

  18. Effect of coupling currents on the dynamic inductance during fast transient in superconducting magnets

    Directory of Open Access Journals (Sweden)

    V. Marinozzi

    2015-03-01

    Full Text Available We present electromagnetic models aiming to calculate the variation of the inductance in a magnet due to dynamic effects such as the variation of magnetization or the coupling with eddy currents. The models are studied with special regard to the calculation of the inductance in superconducting magnets which are affected by interfilament coupling currents. The developed models have been compared with experimental data coming from tests of prototype Nb_{3}Sn magnets designed for the new generation of accelerators. This work is relevant for the quench protection study of superconducting magnets: quench is an unwanted event, when part of the magnet becomes resistive; in these cases, the current should be discharged as fast as possible, in order to maintain the resistive zone temperature under a safe limit. The magnet inductance is therefore a relevant term for the description of the current discharge, especially for the high-field new generation superconducting magnets for accelerators, and this work shows how to calculate the correct value during rapid current changes, providing a mean for simulations of the reached temperature.

  19. Time variations of fields in superconducting magnets and their effects on accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Herrup, D.A.; Syphers, M.J.; Johnson, D.E.; Johnson, R.P.; Tollestrup, A.V.; Hanft, R.W.; Brown, B.C.; Lamm, M.J.; Kuchnir, M.; McInturff, A.D.

    1988-08-22

    A report on the time dependence of magnetic fields in the superconducting magnets of the Fermilab Tevatron has been published. A field variation of order 1 gauss at the aperture radius is observed. Studies on both full sized Tevatron, dipoles and prototype magnets have been used to elucidate these effects. Explanations based on eddy currents in the coil matrix or on flux creep in the superconducting filaments are explored with these tests. Measurement results and techniques for controlling the effect based on new laboratory tests and the latest accelerator operation are presented. 9 refs., 4 figs.

  20. Time variations of fields in superconducting magnets and their effects on accelerators

    International Nuclear Information System (INIS)

    Herrup, D.A.; Syphers, M.J.; Johnson, D.E.

    1988-01-01

    A report on the time dependence of magnetic fields in the superconducting magnets of the Fermilab Tevatron has been published. A field variation of order 1 gauss at the aperture radius is observed. Studies on both full sized Tevatron, dipoles and prototype magnets have been used to elucidate these effects. Explanations based on eddy currents in the coil matrix or on flux creep in the superconducting filaments are explored with these tests. Measurement results and techniques for controlling the effect based on new laboratory tests and the latest accelerator operation are presented. 9 refs., 4 figs