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Sample records for cooling superconducting magnet

  1. 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

  2. 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

  3. A small refrigerator system for cooling thermal shield of a large superconducting magnet

    International Nuclear Information System (INIS)

    Kitami, T.; Hasegawa, T.; Hashimoto, O.

    1993-02-01

    A commercial small refrigerator system has been integrated to a large superconducting spectrometer magnet to cool its thermal shield and anchors. It has been in operation for more than 10,000 hours without major troubles. The refrigerator has cooling power of 60 W for thermal shield at 80 K and 6 W for anchors at 20 K. The magnet is kept below the liquid nitrogen temperature even when the main refrigerator system is turned off, and the cool-down time of the large superconducting magnet is considerably shortened. Operation of the large superconducting magnet has become much easier thanks to the small refrigerator system. (author)

  4. Operation of a forced two phase cooling system on a large superconducting magnet

    International Nuclear Information System (INIS)

    Green, M.A.; Burns, W.A.; Eberhard, P.H.; Gibson, G.H.; Pripstein, M.; Ross, R.R.; Smits, R.G.; Taylor, J.D.; Van Slyke, H.

    1980-05-01

    This paper describes the operation of a forced two phase cooling system on a two meter diameter superconducting solenoid. The magnet is a thin high current density superconducting solenoid which is cooled by forced two phase helium in tubes around the coil. The magnet, which is 2.18 meters in diameter and 3.4 meters long, has a cold mass of 1700 kg. The two phase cooling system contains less than 300 liters of liquid helium, most of which is contained in a control dewar. This paper describes the operating characteristics of the LBL two phase forced cooling system during cooldown and warm up. The paper presents experimental data on operations of the magnet using either a helium pump or the refrigerator compressor to circulate two phase helium through the superconducting coil cooling tubes

  5. Conduction cooled high temperature superconducting dipole magnet for accelerator applications

    DEFF Research Database (Denmark)

    Zangenberg, N.; Nielsen, G.; Hauge, N.

    2012-01-01

    A 3T proof-of-principle dipole magnet for accelerator applications, based on 2nd generation high temperature superconducting tape was designed, built, and tested by a consortium under the lead of Danfysik. The magnet was designed to have a straight, circular bore with a good field region of radius...... = 25 mm, and a magnetic length of 250 mm. A total length of 2.5 km YBCO-based copper stabilized conductor supplied by SuperPower Inc., NY, USA, was isolated with 0.025 mm of epoxy and subsequently wound into 14 saddle coils and 4 racetrack coils with a cosine theta like configuration. The coils were......-liquid free operation of an HTS accelerator magnet was demonstrated. The cold mass support design permits magnet orientation under arbitrary angles. Careful choice of materials in terms of magnetic, heat conducting and mechanical properties resulted in a robust and compact solution which opens up...

  6. Liquid helium cooling of the MFTF superconducting magnets

    International Nuclear Information System (INIS)

    VanSant, J.H.; Zbasnik, J.P.

    1986-09-01

    During acceptance testing of the Mirror Fusion Test Facility (MFTF), we measured these tests: liquid helium heat loads and flow rates in selected magnets. We used the data from these tests to estimate helium vapor quality in the magnets so that we could determine if adequate conductor cooling conditions had occurred. We compared the measured quality and flow with estimates from a theoretical model developed for the MFTF magnets. The comparison is reasonably good, considering influences that can greatly affect these values. This paper describes the methods employed in making the measurements and developing the theoretical estimates. It also describes the helium system that maintained the magnets at required operating conditions

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  8. Feasibility of Using Conductively Cooled Magnets in Cryomidules of Superconducting Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Terechkine, I. [Fermilab; Cheban, Cheban,S. [Fermilab; Nicol. T., Nicol. T. [Fermilab; Poloubotko, V. [Fermilab; Sergatskov, D. [Fermilab

    2013-09-01

    As part of a search for optimal ways to configure cryomodules of the low-beta section of a high-current, high-power superconducting linac, an option of using conductively cooled superconducting focusing lenses was evaluated. Superconducting magnet was installed inside existing test cryostat, which was modified by adding current feed-throughs and two conductively cooled current leads. Each lead was equipped with heat sinks at the temperatures of liquid nitrogen and liquid helium. The magnet was mounted inside the cryostat on an individual heat sink plate, and thermometers were installed on the leads, heat sinks, and on the magnet. In this report we provide some details of the test setup and analyse results of the temperature measurements.

  9. Thermal conductance of heat transfer interfaces for conductively cooled superconducting magnets

    International Nuclear Information System (INIS)

    Cooper, T.L.; Walters, J.D.; Fikse, T.H.

    1996-01-01

    Minimizing thermal resistances across interfaces is critical for efficient thermal performance of conductively cooled superconducting magnet systems. Thermal conductance measurements have been made for a flexible thermal coupling, designed to accommodate magnet-to-cryocooler and cryocooler-to-shield relative motion, and an interface incorporating Multilam designed as a sliding thermal connector for cryocoolers. Temperature changes were measured across each interface as a function of heat input. Thermal conductances have been calculated for each interface, and the impact of each interface on conductively cooled magnet systems will be discussed

  10. Stability and fast heat removal with He-II cooling for pulsed superconductive magnets

    International Nuclear Information System (INIS)

    Desportes, H.

    1979-01-01

    The use of pressurized superfluid helium between 1.6 K and 1.8 K is being considered for a number of superconducting magnet applications. This type of cooling is particularly interesting in the case of pulsed field magnets where large heat fluxes need to be evacuated in a short time. This paper reviews a few recent experiments on heat transport properties and stability in He-II, which contribute to evaluating its potential use for such an application. Present technology is illustrated by the description of a large test facility recently operated at Saclay

  11. 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

  12. Experimental study of gas-cooled current leads for superconducting magnets

    International Nuclear Information System (INIS)

    Warren, R.P.

    1978-04-01

    Design details and experimental test results from several design variations of the gas-cooled, copper current leads used in conjunction with the superconducting dipole magnets for ESCAR (Experimental Superconducting Accelerator Ring) are reported. Thermal acoustic oscillations, which were experienced with an initial design, were eliminated in subsequent designs by a reduction of the hydraulic diameter. The occurrence of these oscillations is in general agreement with the stability analysis of Rott but the observed gas flow dependence is not in agreement with some other recently reported results for leads operated supercritical phase coolant. An empirically determined correlation was obtained by plotting lead resistance vs. enthalpy gain of the coolant gas. The resulting family of curves can be reduced to a single line on a plot of effective resistivity vs. the product of current and cross-sectional area divided by the product of the square of the mass flow of the coolant and the lead length. This correlation, which should be applicable to other designs of copper current leads in which ideal heat transfer to the coolant gas is approached, predicts that the enthalpy gain of the coolant, and therefore the peak lead temperature, is proportional to the cube of the ratio of current to coolant mass flow. The effective value of the strongly temperature-dependent kinematic viscosity of the coolant gas was found to vary linearly with the effective resistivity of the lead

  13. Non-linear Model Predictive Control for cooling strings of superconducting magnets using superfluid helium

    CERN Document Server

    AUTHOR|(SzGeCERN)673023; Blanco Viñuela, Enrique

    In each of eight arcs of the 27 km circumference Large Hadron Collider (LHC), 2.5 km long strings of super-conducting magnets are cooled with superfluid Helium II at 1.9 K. The temperature stabilisation is a challenging control problem due to complex non-linear dynamics of the magnets temperature and presence of multiple operational constraints. Strong nonlinearities and variable dead-times of the dynamics originate at strongly heat-flux dependent effective heat conductivity of superfluid that varies three orders of magnitude over the range of possible operational conditions. In order to improve the temperature stabilisation, a proof of concept on-line economic output-feedback Non-linear Model Predictive Controller (NMPC) is presented in this thesis. The controller is based on a novel complex first-principles distributed parameters numerical model of the temperature dynamics over a 214 m long sub-sector of the LHC that is characterized by very low computational cost of simulation needed in real-time optimizat...

  14. 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...

  15. Residual gas analysis of a cryostat vacuum chamber during the cool down of SST - 1 superconducting magnet field coil

    International Nuclear Information System (INIS)

    Semwal, P.; Joshi, K.S.; Thankey, P.L.; Pathan, F.S.; Raval, D.C.; Patel, R.J.; Pathak, H.A.

    2005-01-01

    One of the most important feature of Steady state Superconducting Tokamak -1 (SST-l) is the Nb-Ti superconducting magnet field coils. The coils will be kept in a high vacuum chamber (Cryostat) and liquid Helium will be flown through it to cool it down to its critical temperature of 4.5K. The coil along with its hydraulics has four types of joints (1) Stainless Steel (S.S.) to Copper (Cu) weld joints (2) S. S. to S. S. weld joints (3) Cu to Cu brazed joints and (4) G-10 to S. S. joints with Sti-cast as the binding material. The joints were leak tested with a Helium mass spectrometer leak detector in vacuum as well as in sniffer mode. However during the cool-down of the coil, these joints may develop leaks. This would deteriorate the vacuum inside the cryostat and coil cool-down would subsequently become more difficult. To study the effect of cooling on the vacuum condition of the Cryostat, a dummy Cryostat chamber was fabricated and a toroidal Field (TF) magnet was kept inside this chamber and cooled down to 4.5 K.A residual gas analyzer (RGA) was connected to the Cryostat chamber to study the behaviour of major gases inside this chamber with temperature. An analysis of the RGA data acquired during the coo-down has been presented in this chamber. (author)

  16. Investigation, modelling and control of the 1.9 K cooling loop for superconducting magnets for the Large Hadron Collider

    CERN Document Server

    Flemsæter, Bjorn

    2000-01-01

    The temperature of the superconducting magnets for the 27 km LHC particle accelerator under construction at CERN is a control parameter with strict operating constraints imposed by (a) the maximum temperature at which the magnets can operate, (b) the cooling capacity of the cryogenic system, (c) the variability of applied heat loads and (d) the accuracy of the instrumentation. A pilot plant for studying aspects beyond single magnet testing has been constructed. This magnet test string is a 35-m full-scale model if the LHC and consists of four superconducting cryogmagnets operating in a static bath of He II at 1.9 K. An experimental investigation of the properties dynamic characteristics of the 1.9 K cooling loop of the magnet test string has been carried out. A first principle model of the system has been created. A series of experiments designed for system identification purposes have been carried out, and black box models of the system have been created on the basis on the recorded data. A Model Predictive ...

  17. Superconductors for superconducting magnets

    Science.gov (United States)

    Larbalestier, David

    2011-03-01

    Even in 1913 Kamerlingh Onnes envisioned the use of superconductors to create powerful magnetic fields well beyond the capability provided by cooling normal metals with liquid helium. Only some ``bad places'' in his Hg and Pb wires seemed to impede his first attempts at this dream, one that he imagined would be resolved in a few weeks of effort. In fact, of course, resolution required another 50 years and development of both a true understanding of the difference between type I and type II superconductors and the discovery of compounds such as Nb 3 Sn that could remain superconducting to fields as high as 30 T. And then indeed, starting in the 1960s, Onnes's dreams were comfortably surpassed. In the last 45 years virtually all superconducting magnets have been made from just two Nb-base materials, Nb-Ti and Nb 3 Sn. Now it seems that a new generation of magnets based on cuprate high temperature superconductors with fields well above 30 T are possible using Bi-Sr-Ca-Cu-O and the RE-Ba-Cu-O compounds. We hope that a first demonstration of this possibility will be an all-superconducting 32 T magnet with RE-Ba-Cu-O insert that we are building for NHMFL users. The magnet application potential of this new generation of superconducting conductors will be discussed.

  18. Superconducting Magnets

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Starting from the beam requirements for accelerator magnets, we will outline the main issues and the physical limitations for producing strong and pure magnetic fields with superconductors. The seminar will mainly focus on the magnets for the accelerator, and give some hints on the magnets for the experiments. Prerequisite knowledge: Basic knowledge of Maxwell equations, and linear optics for particle accelerators (FODO cell, beta functions).

  19. Development of the active magnetic regenerative refrigerator operating between 77 K and 20 K with the conduction cooled high temperature superconducting magnet

    Science.gov (United States)

    Park, Inmyong; Jeong, Sangkwon

    2017-12-01

    The experimental investigation of an active magnetic regenerative refrigerator (AMRR) operating between 77 K and 20 K is discussed in this paper, with detailed energy transfer analysis. A multi-layered active magnetic regenerator (AMR) is used, which consists of four different rare earth intermetallic compounds in the form of irregular powder. Numerical simulation confirms that the AMR can attain its target operating temperature range. Magnetic field alternation throughout the AMR is generated by a high temperature superconducting (HTS) magnet. The HTS magnet is cooled by a two stage Gifford-McMahon (GM) cryocooler. Helium gas was employed as a working fluid and its oscillating flow in the AMR is controlled in accordance with the magnetic field variation. The AMR is divided into two stages and each stage has a different mass flow rate as needed to achieve the desired cooling performance. The temperature variation of the AMR during the experiment is monitored by temperature sensors installed inside the AMR. The experimental results show that the AMRR is capable of achieving no-load temperature of 25.4 K while the warm end temperature is 77 K. The performance of the AMRR is analyzed by observing internal temperature variations at cyclic steady state. Furthermore, numerical estimation of the cooling capacity and the temperature variation of the AMR are examined and compared with the experimental results.

  20. 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

  1. Large superconducting magnets

    CERN Document Server

    Pérot, J

    1981-01-01

    Discusses the use of large superconducting magnets in the areas of particle physics, thermonuclear fusion, and magnetohydrodynamics. In addition to considering the physics of the superconducting state, the article considers machines such as BEBC (Big European Bubble Chamber) at CERN, the LINAC at SLAC and possible Tokamak applications. The future application of superconductors to high speed trains is discussed. (0 refs).

  2. 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...

  3. 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

  4. Superconducting magnets and cryogenics

    International Nuclear Information System (INIS)

    Purcell, J.R.

    1975-01-01

    Several significant superconducting beam line magnet systems are being constructed in the U. S. These will demonstrate the practicability of superconductors in beam lines. It is now time to consider some of the more subtle engineering problems associated with these magnets in order to assure a ''next generation'' of highly usable magnets. This paper presents some engineering approaches to better magnets for the future. (U.S.)

  5. The polyimide-alumina: a performant insulator used in a superconducting magnet cooled with superfluid helium

    International Nuclear Information System (INIS)

    Libeyre, M.

    1987-03-01

    Thermal insulation between the coils of the toroidal magnet of Tore Supra and the ''box'' including it able to transmit mechanical efforts is necessary. To require to the specifications a new material has been developed; industrial production of this material has also been realized [fr

  6. 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.

  7. Fracture behavior analysis of EuBaCuO superconducting ring bulk reinforced by a stainless steel ring during field-cooled magnetization

    Science.gov (United States)

    Takahashi, K.; Fujishiro, H.; Naito, T.; Yanagi, Y.; Itoh, Y.; Nakamura, T.

    2017-11-01

    We have magnetized the EuBaCuO ring bulk reinforced by a stainless steel ring during field-cooled magnetization (FCM) at 50 K under the magnetic fields from 6.3, 7.3 or 8.3 T, in which the ring bulk was broken at the intermediate step of FCM from 8.3 T. To discuss the fracture behavior of the bulk, we have performed the numerical simulation using a three dimensional finite element method for the bulk with realistic superconducting characteristics, and obtained both the electromagnetic hoop stress, {{σ }θ }{{FCM}}, during FCM and thermal hoop stress, {{σ }θ }{{cool}}, under cooling from 300 to 50 K. The difference of the thermal contraction coefficient between the bulk and the stainless steel ring caused an inhomogeneous {{σ }θ }{{cool}} profile with a tensile stress at the outermost edge on the bulk surface under cooling process. The maximum of the total hoop stress, {{σ }θ }{{total}} (={{σ }θ }{{FCM}}+{{σ }θ }{{cool}}), was estimated to be +50 MPa and +59 MPa during FCM from 7.3 T and 8.3 T, respectively. These results suggest that the actual fracture strength of the present ring bulk is between 50 and 59 MPa. The {{σ }θ }{{total}} value should be reduced as low as possible in the whole area of the bulk to avoid the fracture behavior during FCM.

  8. 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 ...

  9. 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

  10. 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.

  11. Development of portable superconducting bulk magnet system

    International Nuclear Information System (INIS)

    Saho, N.; Nishijima, N.; Tanaka, H.; Sasaki, A.

    2009-01-01

    Recently a magnetic drug delivery system (MDDS) has been developing to navigate magnetic seeded drugs around diseased parts of the human body. To improve the magnetic drug delivery performance, a portable high temperature superconducting (HTS) bulk magnet system with high magnetic fields has been developed. This magnet system mainly consists of small bulk high temperature superconductors and a compact cryocooler. The materials of the high temperature superconductor are rare earth 123 single domain compounds (Gd-Ba-Cu-O). The bulk magnet was activated successfully using field-cooling magnetization under the superconducting solenoid magnet. The magnetic flux densities at the surface of the vacuum chambers that contain bulk magnets reached 5.07 T and 6.76 T using the static magnetic fields of 6 T and 10 T superconducting solenoid magnets, respectively. A cryocooler cooled them to 38.1 K and 39.1 K. It was clarified that the magnetic gradient was approximately 10 T/m at a position located 50 mm from the surface of the vacuum chambers.

  12. 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

  13. Design, modification and test of the conduction cooled high-current current leads for the superconducting magnet

    Science.gov (United States)

    Peng, Quanling; Cheng, Da; Xu, Fengyu; Yang, Xiangchen; Wang, Ting; Wei, Xiaotao

    2017-09-01

    Conduction cooled current leads, which bring the current from the room temperature terminal down to the cryogenic environment, were used in common recently in large scale superconducting accelerators for its low cost, sample design and low heat load. In practice, the current lead is designed contained in a stainless steel tube. The heat load can be incepted in steps by thermal anchors, where one end is attached to the stainless steel tube, while the other end is connected with the cold shield of the cryomodule. Since the limitation of the welding technique, a thicker stainless steel tube needs to be used, and hence the thermal anchors cannot provide enough pressure to deform the tube enough to be in direct contact with the current lead, which may lead to temperature instability and bring extra heat load to the cryogenic system. An excellent option of epoxy filled current lead can realize the fully contact and reduce the heat load effectively. This paper will present the process of the current lead design, optimization, numerical simulation and cryogenic test, the test results show that the current lead can keep in a stable operation and low heat load.

  14. 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.

  15. Superconducting materials suitable for magnets

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    The range of materials available for superconducting magnets is steadily expanding, even as the choice of material becomes potentially more complex. When virtually all magnets were cooled by helium at ~2-5 K it was easy to separate the domain of Nb-Ti from those of Nb$_{3}$Sn applications and very little surprise that more than 90% of all magnets are still made from Nb-Ti. But the development of useful conductors of the Bi-Sr-Ca-Cu-O and YBa2Cu3Ox high temperature superconductors, coupled to the recent discovery of the 39 K superconductor MgB2 and the developing availability of cryocoolers suggests that new classes of higher temperature, medium field magnets based on other than Nb-based conductors could become available in the next 5-10 years. My talks will discuss the essential physics and materials science of these 5 classes of material - Nb-Ti, Nb$_{3}$Sn, MgB2, Bi-Sr-Ca-Cu-O and YBa2Cu3Ox - in the context of those aspects of their science, properties and fabrication properties, which circumscribe their ap...

  16. Superconducting materials suitable for magnets

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2002-01-01

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

  17. 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)

  18. The integration of cryogenic cooling systems with superconducting electronic systems

    International Nuclear Information System (INIS)

    Green, Michael A.

    2003-01-01

    The need for cryogenic cooling has been critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of the superconducting circuit is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a disadvantage. This report will talk about the various methods for refrigerating superconducting devices. Cryocooler types will be compared for vibration, efficiency, and cost. Some solutions to specific problems of integrating cryocoolers to superconducting devices are presented.

  19. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-15

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

  1. Superconducting magnets for fusion reactors

    International Nuclear Information System (INIS)

    Haubenreich, P.N.

    1978-01-01

    Superconducting magnets for fusion reactor applications are being developed in the U.S., Europe, Japan and the USSR. A substantial technological base already exists, but magnets for fusion face special problems and strong incentives for higher performance. In the U.S. high-field magnets for mirrors are being addressed by construction of the superconducting (NbTi) MFTF and by Nb 3 Sn conductor development. Large toroidal field magnets for tokamaks are being developed through the Large Coil Program, which involves design and construction of NbTi and Nb 3 Sn coils by six industrial teams, three in the U.S. and three in other countries

  2. Improved superconducting magnet wire

    Science.gov (United States)

    Schuller, I.K.; Ketterson, J.B.

    1983-08-16

    This invention is directed to a superconducting tape or wire composed of alternating layers of copper and a niobium-containing superconductor such as niobium of NbTi, Nb/sub 3/Sn or Nb/sub 3/Ge. In general, each layer of the niobium-containing superconductor has a thickness in the range of about 0.05 to 1.5 times its coherence length (which for Nb/sub 3/Si is 41 A) with each copper layer having a thickness in the range of about 170 to 600 A. With the use of very thin layers of the niobium composition having a thickness within the desired range, the critical field (H/sub c/) may be increased by factors of 2 to 4. Also, the thin layers of the superconductor permit the resulting tape or wire to exhibit suitable ductility for winding on a magnet core. These compositions are also characterized by relatively high values of critical temperature and therefore will exhibit a combination of useful properties as superconductors.

  3. Superconducting cyclotron magnet coil short

    International Nuclear Information System (INIS)

    Mallory, M.L.; Blosser, H.G.; Clark, D.J.; Launer, H.; Lawton, D.; Miller, P.; Resmini, F.

    1982-01-01

    In February 1981, a short circuit appeared in the superconducting coil of the K500 cyclotron. The short is resistive in character and therefore has no effect on steady state operation of the magnet. The resistance of the short varies, sometimes being below threshold of detection as a heat load on the cooling system and sometimes being significant. The resistance under certain conditions shows approximately cyclic phenomena with time constants in the range of seconds and other approximately cyclic phenomena which correlate with gross operating parameters of the magnet (shifting current from one coil to another at high field and lowering and raising the liquid helium level). A number of diagnostic studies of the short have been made, using 1) an array of flux sensing loops to sense the magnetic effect of the short, 2) voltage comparisons between upper and lower sections of the coil, 3) comparisons of forces in the nine member coil support system and 4) the effect of the short on the thermal charactersitics of the coil. Insulation failure or a metal chip shorting out turns have been explored in some detail but a convincing determination of the exact cause of the short may never be available, (even the extreme step of unwinding the coil having a significant probability that an imperfection with the observed characteristics would pass unnoticed). Analysis of the characteristics of the short indicated that the most serious consequence would be failure of the coils mechanical support system in the event that the magnet was quickly discharged, as in a dump or quench. To deal with this hazard, the support system has been modified by installing solid supports which prevent the coil from moving by an amount sufficient to damage the support system. We have also reexamined the data and calculations used in the original coil design and have made some additional measurements of the properties of the materials (yield strength, friction coefficient, Young's modulus) used in the

  4. Forced flow cooling of ISABELLE dipole magnets

    International Nuclear Information System (INIS)

    Bamberger, J.A.; Aggus, J.; Brown, D.P.; Kassner, D.A.; Sondericker, J.H.; Strobridge, T.R.

    1976-01-01

    The superconducting magnets for ISABELLE will use a forced flow supercritical helium cooling system. In order to evaluate this cooling scheme, two individual dipole magnets were first tested in conventional dewars using pool boiling helium. These magnets were then modified for forced flow cooling and retested with the identical magnet coils. The first evaluation test used a l m-long ISA model dipole magnet whose pool boiling performance had been established. The same magnet was then retested with forced flow cooling, energizing it at various operating temperatures until quench occurred. The magnet performance with forced flow cooling was consistent with data from the previous pool boiling tests. The next step in the program was a full-scale ISABELLE dipole ring magnet, 4.25 m long, whose performance was first evaluated with pool boiling. For the forced flow test the magnet was shrunk-fit into an unsplit laminated core encased in a stainless steel cylinder. The high pressure gas is cooled below 4 K by a helium bath which is pumped below atmospheric pressure with an ejector nozzle. The performance of the full-scale dipole magnet in the new configuration with forced flow cooling, showed a 10 percent increase in the attainable maximum current as compared to the pool boiling data

  5. 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).

  6. Superconducting magnets. B. Superconducting magnet systems in EPR designs

    International Nuclear Information System (INIS)

    Knobloch, A.F.

    1978-01-01

    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

  7. Development of a 4K/80K multiple operating type of GM refrigeration system for the superconducting magnet in maglev use. Cooling characteristics of the nitrogen self-circulated cooling-type radiation shield plate; Fujoshiki tetsudoyo chodendojishaku no 4K/80K ryoyo GM reito sisutemu no kaihatsu. Chisso shizen junkanhoshiki netsu shirudo no reikyaku tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Hiroyuki; Takahashi, Masahiko; Sanada, Yoshinao; Yamashita, Tomohiro; Yamaji, Mutsuhiko [Toshiba Corp., Tokyo (Japan); Terai, Motoaki [Central Japan Railway Corp., Tokyo (Japan); Igarashi, Motohiro; Yamaguchi, Mitsugu [Niigata Unviersity, Niigata (Japan)

    1999-02-25

    An onboard refrigeration system is one of the most important components in the superconducting magnetically levitated system (Maglev system). In the superconducting magnet, liquid helium and nitrogen are used to cool the superconducting coils and the radiation shields. At the Yamanashi Maglev Test Line, the operation of the superconducting magnet without a supplement of liquid helium has been achieved by the onboard 4 K Gifford-McMahon/Joule-Thomson (GM/JT) refrigerators- . As for the liquid nitrogen, it is supplied to the radiation shields periodically. Our final target for an onboard refrigeration system for commercial use is to operate magnets with no supplementation of cryogen. That is the operations of magnets should not depend on a helium liquefaction plant or a liquid nitrogen supplying system in the train depot, except for occasions of the magnet's precooling or when the vehicle is being overhauled. To meet these requirements, we have been developing a new type of onboard GM refrigeration (GM refrigerator application) system that features a combination of a 4K/80K multiple-operating type of GM refrigerator and a self-circulated cooling-type radiation shield. The nitrogen self-circulated cooling-type radiation shield plate was demonstrated by using the radiation shield plate mock-up. (author)

  8. Magnets for Muon 6D Cooling Channels

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland [Muons, Inc.; Flanagan, Gene [Muons, Inc.

    2014-09-10

    The Helical Cooling Channel (HCC), an innovative technique for six-dimensional (6D) cooling of muon beams using a continuous absorber inside superconducting magnets, has shown considerable promise based on analytic and simulation studies. The implementation of this revolutionary method of muon cooling requires high field superconducting magnets that provide superimposed solenoid, helical dipole, and helical quadrupole fields. Novel magnet design concepts are required to provide HCC magnet systems with the desired fields for 6D muon beam cooling. New designs feature simple coil configurations that produce these complex fields with the required characteristics, where new high field conductor materials are particularly advantageous. The object of the program was to develop designs and construction methods for HCC magnets and design a magnet system for a 6D muon beam cooling channel. If successful the program would develop the magnet technologies needed to create bright muon beams for many applications ranging from scientific accelerators and storage rings to beams to study material properties and new sources of energy. Examples of these applications include energy frontier muon colliders, Higgs and neutrino factories, stopping muon beams for studies of rare fundamental interactions and muon catalyzed fusion, and muon sources for cargo screening for homeland security.

  9. Superconducting niobium cavity with cooling fins

    International Nuclear Information System (INIS)

    Isagawa, Shigeru.

    1978-04-01

    Cooling efficiency of a superconducting cavity is shown to be improved by applying a fin structure. Internal heating can be suppressed in a certain degree and the higher rf field is expected to be reached on surfaces of the cavity which is immersed in superfluid He 4 liquid. The rf measurements were made on a C-band niobium cavity with cylindrical and circular fins around the wall. Fields of 39 mT and 25 MV/m were attained for TM 010 mode cavity after surface treatments including high temperature annealing in a UHV furnace. (auth.)

  10. The cryogenic operation of the superconducting magnet system in the HERA proton storage ring: Cool down, steady state operation, quench recovery processes

    International Nuclear Information System (INIS)

    Horlitz, G.; Clausen, M.; Lierl, H.; Lange, R.; Herzog, H.

    1991-01-01

    The 6.4 km long superconducting proton storage ring of HERA was completed in 1990. In October the first halfring was cooled, in December the second one. Steady state operation could be established after about 200 hours. The authors report on the cryogenic operation of the system during cooldown and steady state operation and give values for thermal losses. One octant was excited up to values exceeding the design current. Some results of quench tests in this octant are presented

  11. Superconducting magnets for high energy storage rings

    International Nuclear Information System (INIS)

    Sampson, W.B.

    1977-01-01

    Superconducting dipole and quadrupole magnets were developed for the proton-proton intersecting storage accelerator ISABELLE. Full size prototypes of both kinds of magnets were constructed and successfully tested. The coils are fabricated from a single layer of wide braided superconductor and employ a low temperature iron core. This method of construction leads to two significant performance advantages; little or no training, and the ability of the coil to absorb its total magnetic stored energy without damage. A high pressure (15 atm) helium gas system is used for cooling. Measurements of the random field errors are compared with the expected field distribution. Three magnets (two dipoles and one quadrupole) were assembled into a segment of the accelerator ring structure (half cell). The performance of this magnet array, which is coupled in series both electrically and cryogenically, is also summarized

  12. 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.

  13. Possible circuits for superconducting coil cooling by superfluid helium

    International Nuclear Information System (INIS)

    Shaposhnikov, V.A.; Volkova, N.M.

    1984-01-01

    Investigation results on heat transfer in heated channels under conditions of internal and forced He-2 convection are presented in order to obtain estimated dependences allowing to design cryostatting system for superconducting magnetic systems (SMS). Different cryostatting schemes are considered, and results of their calculations are presented. It is shown that in cryostatting system designing it is necessary to prefer the scheme, in which heat exchager is put into a bath with superfluid helium. One cryostatting scheme is presented; cooling of the heat release object in it is performed under conditions of forced motion. It is sown that the process of forced convection enlarges the heat exchange efficiency

  14. 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.

  15. 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...

  16. Superconductivity from magnetic elements under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Katsuya [KYOKUGEN, Research Center for Materials Science at Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)]. E-mail: shimizu@rcem.osaka-u.ac.jp; Amaya, Kiichi [Toyota Physical and Chemical Research Institute, Aichi 480-1192 (Japan); Suzuki, Naoshi [Graduate School of Engineering Science, Osaka University, Osaka 560-8531 (Japan); Onuki, Yoshichika [Graduate School of Science, Osaka University, Osaka 560-0043 (Japan)

    2006-05-01

    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.

  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. Study of heat transfer in superconducting cable electrical insulation of accelerator magnet cooled by superfluid helium; Etude des transferts de chaleur dans les isolations electriques de cables supraconducteurs d'aimant d'accelerateur refroidi par helium superfluide

    Energy Technology Data Exchange (ETDEWEB)

    Baudouy, B

    1996-10-04

    Heat transfer studies of electrical cable insulation in superconducting winding are of major importance for stability studies in superconducting magnets. This work presents an experimental heat transfer study in superconducting cables of Large Hadron Collider dipoles cooled by superfluid helium and submitted to volume heat dissipation due to beam losses. For NbTi magnets cooled by superfluid helium the most severe heat barrier comes from the electrical insulation of the cables. Heat behaviour of a winding is approached through an experimental model in which insulation characteristics can be modified. Different tests on insulation patterns show that heat transfer is influenced by superfluid helium contained in insulation even for small volume of helium (2 % of cable volume). Electrical insulation can be considered as a composite material made of a solid matrix with a helium channels network which cannot be modelled easily. This network is characterised by another experimental apparatus which allows to study transverse and steady-state heat transfer through an elementary insulation pattern. Measurements in Landau regime ({delta}T{approx}10{sup -5} to 10{sup -3} K) and in Gorter-Mellink regime ({delta}T>10{sup -3} K) and using assumptions that helium thermal paths and conduction in the insulation are decoupled allow to determine an equivalent channel area (10{sup -6} m{sup 2}) and an equivalent channel diameter (25 {mu}). (author)

  19. 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

  20. Cooling of superconducting devices by liquid storage and refrigeration unit

    Science.gov (United States)

    Laskaris, Evangelos Trifon; Urbahn, John Arthur; Steinbach, Albert Eugene

    2013-08-20

    A system is disclosed for cooling superconducting devices. The system includes a cryogen cooling system configured to be coupled to the superconducting device and to supply cryogen to the device. The system also includes a cryogen storage system configured to supply cryogen to the device. The system further includes flow control valving configured to selectively isolate the cryogen cooling system from the device, thereby directing a flow of cryogen to the device from the cryogen storage system.

  1. Superconducting bulk magnets for magnetic levitation systems

    Science.gov (United States)

    Fujimoto, H.; Kamijo, H.

    2000-06-01

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

  2. Cool-down performance of CICC superconducting coils for the CHMFL

    Science.gov (United States)

    Xie, Y.; Li, J.; Ouyang, Z. R.

    2017-10-01

    A hybrid magnet composed of a water-cooled magnet and a superconducting magnet was developed at the High Magnetic Field Laboratory of the Chinese Academy of Sciences. The superconducting coils made of Nb3Sn CICC were cooled by the forced flow of supercritical helium at 4.5 K. The paper presents the cryogenic system framework, and reports the characteristics of the supercritical helium in a cable-in-conduit conductor (CICC), including the friction factor change during the cooling process, the heat transfer coefficient from 4.6 K to 6.8 K, and the helium mass flow rate distribution. After the 23-day cooling process, the temperature reached 4.5 K. The operation process was introduced in the paper.

  3. Superconducting hexapole magnet

    International Nuclear Information System (INIS)

    Coupland, J.H.; Stovold, R.V.

    1977-08-01

    This metre long magnet, intended for polarising and focusing a beam of cold neutrons, has been tested to 1.1 x 10 4 T m -2 , or 90% of the design value. It showed considerable training to this level with every indication that it would have continued further upwards had more liquid helium been available. Field measurements indicate an eighteen pole harmonic of 1.2% at the full bore radius of 25 mm. (author)

  4. Superconducting hexapole magnet

    International Nuclear Information System (INIS)

    Coupland, J.H.; Stovold, R.V.

    1978-01-01

    One metre long magnet, intended for polarising and focusing a beam of cold neutrons, has been tested to 1.1x10 4 T.m -2 , or 90% of the design value. It showed considerable training to this level with every indication that it would have continued further upwards had more liquid helium been available. Field measurements indicate an eighteen pole harmonic of 1.2% at the full bore radius of 25 mm. (author)

  5. High-temperature superconducting quantum interference device with cooled LC resonant circuit for measuring alternating magnetic fields with improved signal-to-noise ratio.

    Science.gov (United States)

    Qiu, Longqing; Zhang, Yi; Krause, Hans-Joachim; Braginski, Alex I; Usoskin, Alexander

    2007-05-01

    Certain applications of superconducting quantum interference devices (SQUIDs) require a magnetic field measurement only in a very narrow frequency range. In order to selectively improve the alternating-current (ac) magnetic field sensitivity of a high-temperature superconductor SQUID for a distinct frequency, a single-coil LC resonant circuit has been used. Within the liquid nitrogen bath, the coil surrounds the SQUID and couples to it inductively. Copper coils with different numbers of windings were used to cover the frequency range from circuit, the signal-to-noise ratio of measurements could be improved typically by one order of magnitude or more in a narrow frequency band around the resonance frequency exceeding a few kilohertz. The best attained equivalent magnetic field resolution was 2.5 fT/radicalHz at 88 kHz. The experimental findings are in good agreement with mathematical analysis of the circuit with copper coil.

  6. 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

  7. Superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    Rogers, J.D.

    1976-01-01

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

  8. 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

  9. Fiber Bragg Grating Cryo-Sensors for Superconducting Accelerator Magnets

    CERN Document Server

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

    2014-01-01

    The design, fabrication and tests of the new generation of superconducting magnets for the High Luminosity upgrade of the Large Hadron Collider (HL - LHC) require the support of an adequate sensing technology able to assure the integrity of the strain sensitive and brittle superconducting cables through the whole service life of the magnet: assembly up to 150 MPa, cool down to 1.9 K and powering up to about 16 kA. A precise temperature monitoring is also needed in order to guarantee the safe working condition of the superconducting cables in the power transmission lines (SC - Link) designed to feed the magnet over long distance. Temperature and strain FBGs based monitoring systems have been implemented in the first SC-Link prototype and in two subscale dipole magnets and tested in the cryogenic test facility at CERN at 30 K, 77 K and 1.9 K.

  10. Search for superconductivity of magnetic metals

    Energy Technology Data Exchange (ETDEWEB)

    Amaya, K [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Furomoto, S [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Kimura, T [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Shimizu, K [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Onuki, Y [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan)

    2002-11-11

    A search for superconductivity of magnetic elemental metals is performed. A successful discovery of the onset of superconductivity is reported in the case of iron under pressure. By electrical resistance measurement, a maximum value of the superconducting transition temperature T{sub c} of 2 K and the upper critical magnetic field H{sub c} of 0.2 T are observed under pressure of 20 GPa where iron is in the crystallographic hcp phase and non-magnetic. Further confirmation of the superconducting transition of hcp iron was obtained by the detection of the diamagnetic signal due to the Meissner effect in accordance with the results of the electrical resistance measurements.

  11. Search for superconductivity of magnetic metals

    CERN Document Server

    Amaya, K; Kimura, T; Shimizu, K; Onuki, Y

    2002-01-01

    A search for superconductivity of magnetic elemental metals is performed. A successful discovery of the onset of superconductivity is reported in the case of iron under pressure. By electrical resistance measurement, a maximum value of the superconducting transition temperature T sub c of 2 K and the upper critical magnetic field H sub c of 0.2 T are observed under pressure of 20 GPa where iron is in the crystallographic hcp phase and non-magnetic. Further confirmation of the superconducting transition of hcp iron was obtained by the detection of the diamagnetic signal due to the Meissner effect in accordance with the results of the electrical resistance measurements.

  12. 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.

  13. Superconducting magnets for energy buncher at FAIR

    International Nuclear Information System (INIS)

    Bhandari, R.K.; Ahammed, M.; Bhattacharya, P.; Bhattacharya, S.; Chattopadhyay, S.; Bhattacharya, T.K.; Bhunia, U.; Chaudhuri, J.; Dey, M.K.; Dutta, A.; DuttaGupta, A.; Mallik, C.; Mandal, B.; Manna, B.; Nandi, C.; Pal, G.; Roy, S.; Saha, S.; Sarma, P.R.

    2011-01-01

    A set of large superconducting magnets have been designed for the Low Energy Buncher (LEB) of the Superconducting Fragment Separator (Super-FRS) for FAIR. The set of magnets will include dipoles and multipoles (sextupole and quadrupole) of stringent quality criteria. Details of design and expected performance have been discussed. (author)

  14. 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

  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. 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

  17. 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.

  18. 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

  19. 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.

  20. Quench protection in superconducting magnets

    International Nuclear Information System (INIS)

    Shajii, A.; Freidberg, J.P.

    1993-01-01

    The purpose of this obviously non-plasma physics research is to demonstrate that many of the powerful and sophisticated theoretical techniques widely used by the plasma physics community can be applied to engineering problems of direct interest to the magnetic fusion program. Quench protection is such a problem. If a sudden pulse of energy is delivered (usually by accident) to a small section of a superconducting magnet, it may go normal. Under such conditions, the magnet current flows in the surrounding copper matrix, which is essentially in parallel with the superconductor. Although the copper is a good conductor, it still dissipates ohmic power, further adding to the energy input. It is important to detect the quench as early as possible in order to shut off the current, thereby preventing irreversible damage to the conductor. This a non-trivial problem since the cables comprising a coil can be as long as one kilometer. The theory presented here starts with a set of multi-dimensional Navier-Stokes and heat transport equations for the coupled system of helium coolant, superconducting/copper cable, and surrounding jacket. A combination of multiple time scale expansions and asymptotic analysis reduces the problem to a nonlinear fourth order system of 1-D plus time equations. A code has been written whose numerical results are in excellent agreement with more complex engineering codes. There is at least an order of magnitude savings in CPU over the existing codes where a typical run requires one hour Cray CPU. By investigating a number of different cases the authors have been able to introduce further analytic approximations which reduce the problem to quasi-analytic form, a set of three ODE's in time. The results here too are in excellent agreement with the engineering code and requires only several seconds of CPU time. More important, the critical dimensionless parameters have been identified, as well as practical scaling information for the magnet design

  1. 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.

  2. 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

  3. 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

  4. Durability Evaluation of Superconducting Magnets

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  5. 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.

  6. 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

  7. 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

  8. Neutron star cooling constraints for color superconductivity in hybrid stars

    International Nuclear Information System (INIS)

    Popov, S.; Grigoryan, Kh.; Blaschke, D.

    2005-01-01

    We apply the recently developed LogN-LogS test of compact star cooling theories for the first time to hybrid stars with a color superconducting quark matter core. While there is not yet a microscopically founded superconducting quark matter phase which would fulfill constraints from cooling phenomenology, we explore the hypothetical 2SC+X phase and show that the magnitude and density-dependence of the X-gap can be chosen to satisfy a set of tests: temperature-age (T-t), the brightness constraint, LogN-LogS, and the mass spectrum constraint. The latter test appears as a new conjecture from the present investigation

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

    NARCIS (Netherlands)

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

    1992-01-01

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

  10. Cryogen free superconducting splittable quadrupole magnet for linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab

    2011-09-01

    A new superconducting quadrupole magnet for linear accelerators was fabricated at Fermilab. The magnet is designed to work inside a cryomodule in the space between SCRF cavities. SCRF cavities must be installed inside a very clean room adding issues to the magnet design, and fabrication. The designed magnet has a splittable along the vertical plane configuration and could be installed outside of the clean room around the beam pipe previously connected to neighboring cavities. For more convenient assembly and replacement a 'superferric' magnet configuration with four racetrack type coils was chosen. The magnet does not have a helium vessel and is conductively cooled from the cryomodule LHe supply pipe and a helium gas return pipe. The quadrupole generates 36 T integrated magnetic field gradient, has 600 mm effective length, and the peak gradient is 54 T/m. In this paper the quadrupole magnetic, mechanical, and thermal designs are presented, along with the magnet fabrication overview and first test results.

  11. The helium cryogenic plant for the CMS superconducting magnet

    CERN Document Server

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

    2002-01-01

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

  12. Trial manufacture of liquid nitrogen cooling High Temperature Superconductivity Motor

    International Nuclear Information System (INIS)

    Sugimoto, H; Nishikawa, T; Tsuda, T; Hondou, Y; Akita, Y; Takeda, T; Okazaki, T; Ohashi, S; Yoshida, Y

    2006-01-01

    We present a new high temperature superconductivity (HTS) synchronous motor using the liquid nitrogen as the refrigerant in this paper. This motor is designed to be used as the propulsion motor in ship. Because we use the liquid nitrogen as the refrigerant, it is possible to simplify the cooling equipments in the motor. And in our design, we apply the axial flux type of motor to simplify the cryostat of the HTS wires used to make the field coils. Here, the fields using the bismuth HTS wire for the HTS coils are fixed. Moreover, the cores used in the fields are separated from cryostat, and the armature applies the core-less structure. According to various the electromagnetic field analysis results, the new motor was designed and produced. The diameter of the motor is 650mm, and the width of the motor is 360mm. The motor's rated output is 8.8kW at 100rpm, while the overload output is 44kW, and the maximum efficiency is 97.7%. Also, in order to further miniaturize the motor, other magnetic field analysis have been done when the high-current-density type HTS wire was used and the permendur was used instead of magnetic steel plates. In this case, the motor's rated output is 12kW, and the overload output is 60kW

  13. 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

  14. 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

  15. Superconducting magnet radiation effects in fusion reactors

    International Nuclear Information System (INIS)

    Sawan, M.E.; Walstrom, P.L.

    1986-01-01

    Radiation effects in superconducting magnets of fusion reactors are analyzed and experimental data reviewed. The interaction between the different radiation effects and impact on reactor design is discussed. The need for experimental data with higher irradiation levels is assessed

  16. 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

  17. Liquid Hydrogen Recirculation System for Forced Flow Cooling Test of Superconducting Conductors

    Science.gov (United States)

    Shirai, Y.; Kainuma, T.; Shigeta, H.; Shiotsu, M.; Tatsumoto, H.; Naruo, Y.; Kobayashi, H.; Nonaka, S.; Inatani, Y.; Yoshinaga, S.

    2017-12-01

    The knowledge of forced flow heat transfer characteristics of liquid hydrogen (LH2) is important and necessary for design and cooling analysis of high critical temperature superconducting devices. However, there are few test facilities available for LH2 forced flow cooling for superconductors. A test system to provide a LH2 forced flow (∼10 m/s) of a short period (less than 100 s) has been developed. The test system was composed of two LH2 tanks connected by a transfer line with a controllable valve, in which the forced flow rate and its period were limited by the storage capacity of tanks. In this paper, a liquid hydrogen recirculation system, which was designed and fabricated in order to study characteristics of superconducting cables in a stable forced flow of liquid hydrogen for longer period, was described. This LH2 loop system consists of a centrifugal pump with dynamic gas bearings, a heat exchanger which is immersed in a liquid hydrogen tank, and a buffer tank where a test section (superconducting wires or cables) is set. The buffer tank has LHe cooled superconducting magnet which can produce an external magnetic field (up to 7T) at the test section. A performance test was conducted. The maximum flow rate was 43.7 g/s. The lowest temperature was 22.5 K. It was confirmed that the liquid hydrogen can stably circulate for 7 hours.

  18. 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

  19. Forced-circulation cooling system for the Argonne superconducting heavy-ion linac

    International Nuclear Information System (INIS)

    Nixon, J.M.; Bollinger, L.M.

    1980-01-01

    The Argonne superconducting heavy-ion linac is a prototype heavy-ion accelerator used to increase the energy of an ion beam from a tandem electrostatic accelerator. The accelerating elements are split-ring-type resonators with hollow niobium drift tubes mounted in cylindrical housings. The housings are made of explosively bonded niobium clad copper. The resonators, along with superconducting solenoid focusing magnets are positioned axially in cryostats on support structures which also serve as helium supply and return manifolds. The resonators and magnets are cooled by a continuous forced-flow circulation of liquid helium directly from a refrigerator. The colling system consists of the refrigerator, a 1000-liter dewar with built-in heat exchanger coil, a 46-m 3 helium gas storage tank, three distribution boxes with valves, heat exchangers, and transfer line ports, connected by a 20-m-long, liquid-nitrogen-shielded, coaxial distribution line. Design and operation of the cooling system are described

  20. Cooling of Compact Stars with Nucleon Superfluidity and Quark Superconductivity

    Science.gov (United States)

    Noda, Tsuneo; Hashimoto, Masa-aki; Yasutake, Nobutoshi; Maruyama, Toshiki; Tatsumi, Toshitaka

    We show a cooling scenario of compact stars to satisfy recent observations of compact stars. The central density of compact stars can exceed the nuclear density, and it is considered that many hadronic phases appear at such a density. It is discussed that neutron superfluidity (1S0 for lower density, and 3P2 for higher density) and proton superfluidity/superconductivity (1S0) appears in all compact stars. And some "Exotic" states are considered to appear in compact stars, such as meson condensation, hyperon mixing, deconfinement of quarks and quark colour superconductivity. These exotic states appear at the density region above the threshold densities of each state. We demonstrate the thermal evolution of isolated compact stars, adopting the effects of nucleon superfluidity and quark colour superconductivity. We assume large gap energy (Δ > 10 MeV) for colour superconducting quark phase, and include the effects of nucleon superfluidity with parametrised models. We simulate the cooling history of compact stars, and shows that the heavier star does not always cool faster than lighter one, which is determined by the parameters of neutron 3P2 superfluidity.

  1. Rotational decay torques of superconducting magnetic bearing

    International Nuclear Information System (INIS)

    Takahata, R.; Yotsuya, T.

    1991-01-01

    This paper proposes a superconducting magnetic bearing as one of application of a high critical temperature (Tc) oxide superconducting material. The authors have assembled new models of bearing with free rotation axis. In these models, superconductor, YBa 2 Cu 3 O X , prepared by the quench and melt growth (QMG) method was applied to the bearing section and a permanent magnet was used for a rotor. This development originated from the knowledge that YBa 2 Cu 3 O X prepared by QMG method had a stronger pinning force of magnetic flux than that of conventional superconductors

  2. 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

  3. 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)

  4. 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.

  5. 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

  6. 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)

  7. Magnetic entropy and cooling

    DEFF Research Database (Denmark)

    Hansen, Britt Rosendahl; Kuhn, Luise Theil; Bahl, Christian Robert Haffenden

    2010-01-01

    the eect: the isothermal magnetic entropy change and the adiabatic temperature change. Some of the manifestations and utilizations of the MCE will be touched upon in a general way and nally I will talk about the results I have obtained on a sample of Gadolinium Iron Garnet (GdIG, Gd3Fe5O12), which...

  8. Central magnetic cooling and refrigeration machines (chiller) and their assessment. A feasibility study - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Egolf, P. W.; Gonin, C. [University of Applied Sciences of Western Switzerland, HEIG-VD, Yverdon-les Bains (Switzerland); Kitanovski, A. [University of Ljubljana, Ljubljana (Slovenia)

    2010-03-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a feasibility study made concerning magnetic cooling and refrigeration machines. This report presents a comprehensive thermodynamic and economic analysis of applications of rotary magnetic chillers. The study deals with magnetic chillers based on permanent magnets and superconducting magnets, respectively. The numerical design of permanent magnet assemblies with different magnetic flux densities is discussed. The authors note that superconducting magnetic chillers are feasible only in large-scale applications with over 1 MW of cooling power. This report describes new ideas for magnetic refrigeration technologies, which go beyond the state of the art. They show potential for a substantial reduction of costs and further improvements in efficiency. Rotary magnetic liquid chillers with 'wavy' structures and using micro tubes are discussed, as are superconducting magnetic chillers and future magneto-caloric technologies.

  9. 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

  10. Cooling cycle test of DC superconducting power transmission cable

    Energy Technology Data Exchange (ETDEWEB)

    Hamabe, M; Watanabe, H; Kawahara, T; Yamaguchi, S [Center of Applied Superconductivity and Sustainable Energy Research, Chubu University, Kasugai, Aichi, 487-8501 (Japan); Fujii, T; Sugino, M; Sasaki, A; Sugimoto, T [Department of Electric Engineering, Chubu University, Kasugai, Aichi, 487-8501 (Japan); Ishiguro, Y [JFE Steel Co., Chita, Aichi, 475-8611 (Japan); Kawamura, K, E-mail: hamabe@isc.chubu.ac.j [Mayekawa M.F.G. Co Ltd., Moriya, Ibaraki, 302-0118 (Japan)

    2010-06-01

    We constructed a test stand of a 20 m DC superconducting power transmission cable in Chubu University in 2006. The cable uses thirty-nine Bi-2223 tapes. Four cycles of a cooling and current-feeding test have been carried out after the construction of the test stand. The cable suffered rapid temperature decrease of 20 K/hour at the daytime during the cooling process by cold nitrogen gas and liquid to the liquid nitrogen temperature. Nineteen HTS tapes in the cable are electrically isolated from each other, and the superconducting characteristics of these HTS tapes can be measured separately. At every cooling cycle, critical current of these isolated HTS tapes were measured. Consequently, no reduction of the critical current characteristics was observed through the 4 cooling cycles. We considered that this endurance of the cable against the cooling cycle is due to unfixed cable end structure of the cable, and that the cable was free from the mechanical stress in spite of the 6 cm shrinkage of the cable length under the low temperature.

  11. Superconductivity and magnetism: Materials properties and developments

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  12. 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.)

  13. 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)

  14. 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

  15. 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

  16. 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

  17. Manufacturing and Testing of Accelerator Superconducting Magnets

    CERN Document Server

    Rossi, L

    2014-01-01

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

  18. Continuous magnetic trapping of laser cooled atoms

    International Nuclear Information System (INIS)

    Bagnato, V.S.; Lafyatis, G.; Martin, A.G.; Raab, E.L.; Landry, J.; Ahmad-Bitar, R.N.; Pritchard, D.E.

    1987-01-01

    The authors present here initial results of the deceleration of a thermal atomic beam from -- 1000 to -- 100 m/s. The experiment was conducted in the 1.4-m long vertical superconducting solenoid which produced the slowing field. The fluorescence of the slowed atomic beam has been studied as a function of laser frequency. Figure 2 is a 12-GHz scan showing the fluorescence at a position 150 cm from the beginning of the solenoid. The wide peak corresponds to unslowed atoms with generally the initial velocity distribution. The second, narrower, peak corresponds to slowed atoms with a velocity of -- 150 m/s. Similar spectra have been obtained for various positions along the magnetic slower and trap. These data should allow better understanding of the cooling process and will be compared to computer models

  19. Operation and design selection of high temperature superconducting magnetic bearings

    International Nuclear Information System (INIS)

    Werfel, F N; Floegel-Delor, U; Riedel, T; Rothfeld, R; Wippich, D; Goebel, B

    2004-01-01

    Axial and radial high temperature superconducting (HTS) magnetic bearings are evaluated by their parameters. Journal bearings possess advantages over thrust bearings. High magnetic gradients in a multi-pole permanent magnet (PM) configuration, the surrounding melt textured YBCO stator and adequate designs are the key features for increasing the overall bearing stiffness. The gap distance between rotor and stator determines the specific forces and has a strong impact on the PM rotor design. We report on the designing, building and measuring of a 200 mm prototype 100 kg HTS bearing with an encapsulated and thermally insulated melt textured YBCO ring stator. The encapsulation requires a magnetically large-gap (4-5 mm) operation but reduces the cryogenic effort substantially. The bearing requires 3 l of LN 2 for cooling down, and about 0.2 l LN 2 h -1 under operation. This is a dramatic improvement of the efficiency and in the practical usage of HTS magnetic bearings

  20. Air-cooled fast discharge resistors for ITER magnets

    International Nuclear Information System (INIS)

    Tanchuk, Victor; Grigoriev, Sergey; Lokiev, Vladimir; Roshal, Alexander; Song, Inho; Buzykin, Oleg

    2011-01-01

    The ITER superconducting magnets will store up to 50 GJ of magnetic energy per operation cycle. In case of coil quench the energy stored in the coils must be extracted rapidly with a time constant from 7.5 to 14 s. It will be achieved by fast discharge resistors (FDR) normally bridged by circuit breakers and inserted in series with the superconducting coils. The fast discharge of the coils results practically in adiabatic heating of the resistive elements up to 200-300 deg. C. The resistors need to be cooled to the initial temperature over 6-8 h. Natural air circulation is proposed as a cooling method. In order to simulate the temperature response of the resistors to energy released in the resistive plates and to demonstrate their cooling capability within the required time by natural air circulation the numerical model of the resistor cooling circuit has been developed. As the calculations have shown, the developed FDR cooling system based on cooling by natural air circulation is capable of providing the required temperature operation regime of FDRs, but the supply channels are to be optimized so that the cooling time does not exceed the permissible one.

  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. 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)

  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. Calculation of Persistent Currents in Superconducting Magnets

    CERN Document Server

    Völlinger, Christine; Russenschuck, Stephan

    2000-01-01

    The paper describes a semi-analytical 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 the part compensation of the multipole errors during the ramping of the magnets is investigated.

  5. 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

  6. 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)

  7. Superconducting vortex pinning with artificial magnetic nanostructures.

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-01

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

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

    Science.gov (United States)

    Fujimoto, Hiroyuki

    2000-06-01

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

  9. Po Superconducting Magnet:detail of the windings

    CERN Multimedia

    1982-01-01

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

  10. Superconducting magnets for isochronous cyclotrons

    International Nuclear Information System (INIS)

    Martin, E.R.

    1979-01-01

    Different approaches using superconductivity for isochronous cyclotrons and examination of advantages and disadvantages of each of them are considered. The discussion is focused on isochronous cyclotrons designed for heavy particle acceleration up to kinetic energies of approximately 0.5 times the rest energy of the accelerated ion. A quantitative solution for the influence of the field edges and for the various values of the valley fields are given. The Indiana University cyclotron is considered where both the coil and the associated pole tip material operate at a cryogenic temperature. Offered are advantages for the design which provide reduction in size and impivement in terms of beam dynamics

  11. Optimization of the cooling power distribution in a superconducting linac

    International Nuclear Information System (INIS)

    Wendl, C.M.; Noe, J.W.

    1996-01-01

    The benefits of setting the resonators in a superconducting heavy-ion linac to a certain optimum distribution of cooling power have been evaluated in terms of the total acceleration such a distribution may produce, compared to a distribution in which each resonator dissipates power equally. The optimum power distribution can be expressed in closed form in certain simplified cases, but the general case is solved by equalizing the 'marginal power cost' of the resonators by iteration in a computer simulation. For the Stony Brook linac an additional possible acceleration of several percent is thus predicted for typical beams. (author)

  12. Preliminary study of superconducting bulk magnets for Maglev

    Science.gov (United States)

    Fujimoto, Hiroyuki; Kamijo, Hiroki

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

  13. Peltier current lead experiment and their applications for superconducting magnets

    Science.gov (United States)

    Yamaguchi, Satarou; Yamaguchi, Takayuki; Nakamura, Kenji; Hasegawa, Yasuhiro; Okumura, Haruhiko; Sato, Ken

    2004-01-01

    Many applications of superconductivity are studied because they are basically nondissipative systems; however, electric power is spent to keep them at low temperature. If heat leakage is high, the advantage of the superconductivity will be reduced or disappear, and therefore we must reduce the heat leakage as much as we can in the actual system. The Peltier current lead (PCL) was proposed to reduce heat leakage from the electric circuit of the superconducting magnet system. PCL is composed of thermoelectric semiconductors, metal leads, and high temperature superconducting (HTS) leads. Bismuth-tellurium alloys (BiTe) are used as the thermoelectric semiconductors in the experiment, and these are placed on the room temperature side. Optimum design of the PCL is conducted to solve a heat leakage equation, and depends on the transport parameters such as thermal conductivity, electric resistivity, and Seebeck coefficient of the materials of the PCL. The thermal conductivity of the BiTe is about 0.4% of the copper's, and we can expect the Peltier cooling by using this material. Therefore, we can expect the large temperature difference of the BiTe and reduce the heat leakage. The experiment has been done and the cold-end temperature of the thermoelectric BiTe is around 200 K both in the experiment and the numerical calculation. The temperature difference of 4 mm thickness of the BiTe exceeds 70 K for 150 A in both the experiment and the calculation. Therefore, the principle was proven in the experiments, and the reduction of the heat leakage is up to 35% for the current lead included in the HTS current lead. Here, we also mentioned and proposed the various types of the PCL for the different kinds of superconducting magnet systems in this article.

  14. 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.

  15. 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

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

    CERN Document Server

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

    2006-01-01

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

  17. How the Performance of a Superconducting Magnet is affected by the Connection between a small cooler and the Magnet

    International Nuclear Information System (INIS)

    Green, Michael A.

    2005-01-01

    As low temperature cryocoolers become more frequently used to cool superconducting magnets, it becomes increasingly apparent that the connection between the cooler and the magnet has an effect on the design and performance of the magnet. In general, the use of small coolers can be considered in two different temperature ranges; (1) from 3.8 to 4.8 K for magnet fabricated with LTS conductor and (2) from 18 to 35 K for magnets fabricated using HTS conductor. In general, both temperature ranges call for the use of a two-stage cooler. The best method for connecting a cooler to the magnet depends on a number of factors. The factors include: (1) whether the cooler must be used to cool down the magnet from room temperature, (2) whether the magnet must have one or more reservoirs of liquid cryogen to keep the magnet cold during a loss of cooling, and (3) constraints on the distance from the cooler cold heads and the magnet and its shield. Two methods for connecting low temperature coolers to superconducting magnets have been studied. The first method uses a cold strap to connect the cold heads directly to the loads. This method is commonly used for cryogen-free magnets. The second method uses a thermal siphon and liquid cryogens to make the connection between the load being cooled and the cold head. The two methods of transferring heat from the magnet to the cooler low temperature cold head are compared for the two temperature ranges given above

  18. Radiation Effects on Superconducting Fusion Magnet Components

    Science.gov (United States)

    Weber, Harald W.

    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 Nb3Sn, 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.

  19. Inductive voltage compensation in superconducting magnet systems

    International Nuclear Information System (INIS)

    Yeh, H.T.; Goddard, J.S.; Shen, S.S.

    1979-01-01

    This paper details several techniques of inductive voltage compensation developed for quench detection in superconducting magnet systems with multiple coils and power supplies, with particular application for the Large Coil Test Facility (LCTF). Sources of noise, their magnitudes, and the sensitivity required for normal zone detection to avoid damage to the magnets are discussed. Two passive compensation schemes (second difference and central difference) are introduced and illustrated by parameters of LCTF; these take advantage of coil symmetries and other system characteristics. An active compensation scheme based on current rate input fom pickup coils and utilizing theory on ac loss voltage for calibration was tested, and the experimental setup and test results are discussed

  20. Superconducting niobium in high rf magnetic fields

    International Nuclear Information System (INIS)

    Mueller, G.

    1988-01-01

    The benefit of superconducting cavities for accelerator applications depends on the field and Q/sub 0/ levels which can be achieved reliably in mass producible multicell accelerating structures. The presently observed field and Q/sub 0/ limitations are caused by anomalous loss mechanisms which are not correlated with the intrinsic properties of the pure superconductor but rather due to defects or contaminants on the superconducting surface. The ultimate performance levels of clean superconducting cavities built from pure Nb will be given by the rf critical field and the surface resistance of the superconductor. In the first part of this paper a short survey is given of the maximum surface magnetic fields achieved in single-cell cavities. The results of model calculations for the thermal breakdown induced by very small defects and for the transition to the defect free case is discussed in part 2. In the last chapter, a discussion is given for the rf critical field of Nb on the basis of the Ginzburg-Landau Theory. It is shown that not only purity but also the homogeneity of the material should become important for the performance of superconducting Nb cavities at field levels beyond 100mT. Measurement results of the upper critical field for different grades of commercially available Nb sheet materials are given. 58 references, 20 figures, 1 table

  1. SMES: Superconducting Magnetic Energy Storage

    Science.gov (United States)

    1993-01-01

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

  2. 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

  3. Development of large high current density superconducting solenoid magnets for use in high energy physics experiments

    International Nuclear Information System (INIS)

    Green, M.A.

    1977-05-01

    The development of a unique type of large superconducting solenoid magnet, characterized by very high current density windings and a two-phase helium tubular cooling system is described. The development of the magnet's conceptual design and the construction of two test solenoids are described. The successful test of the superconducting coil and its tubular cooling refrigeration system is presented. The safety, environmental and economic impacts of the test program on future developments in high energy physics are shown. Large solid angle particle detectors for colliding beam physics will analyze both charged and neutral particles. In many cases, these detectors will require neutral particles, such as gamma rays, to pass through the magnet coil with minimum interaction. The magnet coils must be as thin as possible. The use of superconducting windings allows one to minimize radiation thickness, while at the same time maximizing charged particle momentum resolution and saving substantial quantities of electrical energy. The results of the experimental measurements show that large high current density solenoid magnets can be made to operate at high stored energies. The superconducting magnet development described has a positive safety and environmental impact. The use of large high current density thin superconducting solenoids has been proposed in two high energy physics experiments to be conducted at the Stanford Linear Accelerator Center and Cornell University as a result of the successful experiments described

  4. A superconducting magnet upgrade of the ATF2 final focus

    CERN Document Server

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

    2010-01-01

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

  5. Superconducting magnets for fusion applications

    International Nuclear Information System (INIS)

    Henning, C.D.

    1987-01-01

    Fusion magnet technology has made spectacular advances in the past decade; to wit, the Mirror Fusion Test Facility and the Large Coil Project. However, further advances are still required for advanced economical fusion reactors. Higher fields to 14 T and radiation-hardened superconductors and insulators will be necessary. Coupled with high rates of nuclear heating and pulsed losses, the next-generation magnets will need still higher current density, better stability and quench protection. Cable-in-conduit conductors coupled with polyimide insulations and better steels seem to be the appropriate path. Neutron fluences up to 10 19 neutrons/cm 2 in niobium tin are achievable. In the future, other amorphous superconductors could raise these limits further to extend reactor life or decrease the neutron shielding and corresponding reactor size

  6. 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…

  7. 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...

  8. 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...

  9. 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

  10. New Bridge Temperature Sensor for Superconducting Magnets and other Cryogenic Applications

    NARCIS (Netherlands)

    Dudarev, Alexey; Bremer, J.; Mulder, T.; Mentink, M.; ter Harmsel, J.; ten Kate, H. H.J.

    A few hundred temperature sensors are used to monitor the temperature behavior of the gigantic ATLAS toroid superconducting magnet system during cool down and normal operation. In order to guarantee good sensitivity of temperature measurements in the range from liquid helium to room temperature, two

  11. Superconducting flat tape cable magnet

    Science.gov (United States)

    Takayasu, Makoto

    2015-08-11

    A method for winding a coil magnet with the stacked tape cables, and a coil so wound. The winding process is controlled and various shape coils can be wound by twisting about the longitudinal axis of the cable and bending following the easy bend direction during winding, so that sharp local bending can be obtained by adjusting the twist pitch. Stack-tape cable is twisted while being wound, instead of being twisted in a straight configuration and then wound. In certain embodiments, the straight length should be half of the cable twist-pitch or a multiple of it.

  12. 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

  13. 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)

  14. Construction and Performance of Superconducting Magnets for Synchrotron Radiation

    CERN Document Server

    Hwang, Ching-Shiang; Chang, Cheng-Kuo; Chang, Ho-Ping; Chen Chien Te; Chen Hui Huang; Chen, Jenny; Chen June Rong; Chien, Yuan-Chen; Fan, Tai-Ching; Hsiung, Gao-Yu; Hsu, Kuo-Tung; Hsu, Shen-Nung; Huang, Ming-Hsiung; Kuo, Chin-Cheng; Lin, Fu-Yuan

    2005-01-01

    Two superconducting magnets, one wavelength shifter (SWLS) with a field of 5 T and one wiggler (SW6) with a field of 3.2 T, were constructed and routinely operated at NSRRC for generating synchrotron x-rays. In addition, three multipole wigglers (IASW) with fields of 3.1 T will be constructed and installed each in the three achromatic short straight sections. A warm beam duct of 20 mm inner gap and a 1.5 W GM type cryo-cooler were chosen for the SWLS to achieve cryogen-free operation. For the SW6, a cold beam duct of 11 mm inner gap was kept at 100 K temperature and no trim coil compensation is necessary for its operation. Meanwhile, no beam loss was observed when the SW6 was quenched. A cryogenic plant with cooling power of 450 W was constructed to supply the liquid helium for the four superconducting wigglers. The design concept, magnetic field quality, the commissioning results, and the operation performance of these magnets will be presented.

  15. Cryogenic Characteristics of the ATLAS Barrel Toroid Superconducting Magnet

    CERN Document Server

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

    2008-01-01

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

  16. 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

  17. SUPERCONDUCTING HELICAL SNAKE MAGNETS: CONSTRUCTION AND MEASUREMENTS

    International Nuclear Information System (INIS)

    Mackay, W.W.; Anerella, M.; Courant, E.

    1999-01-01

    In order to collide polarized protons, the RHIC project will have two snakes in each ring and four rotators around each of two interaction regions. Two snakes on opposite sides of each ring can minimize depolarization during acceleration by keeping the spin tune at a half. Since the spin direction is normally along the vertical direction in a flat ring, spin rotators must be used around an interaction point to have longitudinal polarization in a collider experiment. Each snake or rotator will be composed of four helical dipoles to provide the required rotation of spin with minimal transverse orbit excursions in a compact length of 10m. The basic helical dipole is a superconducting magnet producing a transverse dipole field which is twisted about the magnet axis through 360 o in a length of 2.4 m. The design and construction of the magnets is described in this paper

  18. SSC [Superconducting Super Collider] magnet technology

    International Nuclear Information System (INIS)

    Taylor, C.

    1987-09-01

    To minimize cost of the SSC facility, small-bore high field dipole magnets have been developed;some of the new technology that has been developed at several U.S. national laboratories and in industry is summarized. Superconducting wire with high J/sub c/ and filaments as small as 5μm diameter is not produced iwht mechanical properties suitable for reliable cable production. A variety of collar designs of both aluminum and stainless steel have been used in model magnets. A low-heat leak post-type cryostat support system is used and a system for accurate alignment of coil-collar-yoke in the cryostat has been developed. Model magnets of 1-m, 1.8 m, 4.5 m, and 17 m lengths have been build during the past two years. 23 refs., 5 figs., 2 tabs

  19. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system

    International Nuclear Information System (INIS)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2014-01-01

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems

  20. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system.

    Science.gov (United States)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2014-09-01

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems.

  1. 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.

  2. High-Field Superconducting Magnets Supporting PTOLEMY

    Science.gov (United States)

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

    2013-10-01

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

  3. Imaging the Statics and Dynamics of Superconducting Vortices and Antivortices Induced by Magnetic Microdisks

    Directory of Open Access Journals (Sweden)

    R. B. G. Kramer

    2011-10-01

    Full Text Available If a magnet of microscopic dimensions is brought in close proximity to a superconductor, the quantized nature of their interaction due to the creation of flux quanta in the superconducting system becomes noticeable. Herein, we directly image, via scanning Hall microscopy, the vortex-antivortex pairs in a superconducting film created by micromagnets. The number of antivortices at equilibrium conditions can be changed either by tuning the magnetic moment of the magnets or by annihilation with externally induced vortices. We demonstrate that small ac field excitations shake the antivortices sitting next to the micromagnets whereas no sizable motion is observed for the vortices sitting on top of the magnets, clearly revealing the different mobility of these two vortex species. A metastable state, which is obtained by applying a field after the system has been cooled down below the superconducting transition, shows a complex graded distribution of coexisting vortices and antivortices forming an intertwined critical state.

  4. 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

  5. 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...

  6. Superconducting solenoids for an international muon cooling experiment

    International Nuclear Information System (INIS)

    Green, M.A.; Rey, J.M.

    2002-01-01

    The international muon ionization cooling experiment MICE will consist of two focusing cooling cells and a pair of uniform field solenoids used for particle identification and emittance measurements. The 2.75-meter long cooling cells have a pair of field flip coils and a coupling coil. The 0.52-meter diameter field flip coils surround an absorber that removes transverse and longitudinal momentum from the muons to be cooled. The beam in the absorber is at a minimum beta point so that scattering of the muons is minimized. The 1.7-meter diameter coupling coils are outside of conventional 201.25 MHz RF cavities that accelerate the muons putting longitudinal momentum into the muons without putting back the transverse momentum into the beam. A third set of flip coils helps the muon beam transition from and to the experimental solenoids. The 0.6-meter diameter experimental solenoids have a uniform field region (good to about 1 part in 1000) that is 1.3-meters long. The MICE experiment magnets must operate as a single unit so that the field profile will produce the maximum muon cooling

  7. 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

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

    International Nuclear Information System (INIS)

    Deng, Z.; Zheng, J.; Li, J.; Ma, G.; Lu, Y.; Zhang, Y.; Wang, S.; Wang, J.

    2008-01-01

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

  9. Superconducting Helical Snake Magnet for the AGS

    CERN Document Server

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

    2005-01-01

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

  10. Improved cable insulation for superconducting magnets

    International Nuclear Information System (INIS)

    Anerella, M.; Ghosh, A.K.; Kelly, E.; Schmalzle, J.; Willen, E.; Fraivillig, J.; Ochsner, J.; Parish, D.J.

    1993-01-01

    Several years ago, Brookhaven joined with DuPont in a cooperative effort to develop improved cable insulation for SSC superconducting dipole magnets. The effort was supported by the SSC Central Design Group and later the SSC Laboratory. It was undertaken because turn-to-turn and midplane shorts were routinely being experienced during the assembly of magnets with coils made of the existing Kapton/Fiberglass (K/FG) system of Kapton film overwrapped with epoxy-impregnated fiberglass tape. Dissection of failed magnets showed that insulation disruption and punch-through was occurring near the inner edges of turns close to the magnet midplane. Coil pressures of greater than 17 kpsi were sufficient to disrupt the insulation at local high spots where wires in neighboring turns crossed one another and where the cable had been strongly compacted in the keystoning operation during cable manufacture. In the joint development program, numerous combinations of polyimide films manufactured by DuPont with varying configurations and properties (including thickness) were subjected to tests at Brookhaven. Early tests were bench trials using wrapped cable samples. The most promising candidates were used in coils and many of these assembled and tested as magnets in both the SSC and RHIC magnet programs currently underway. The Kapton CI (CI) system that has been adopted represents a suitable compromise of numerous competing factors. It exhibits improved performance in the critical parameter of compressive punch-through resistance as well as other advantages over the K/FG system

  11. Last LHC superconducting main magnet completes the suite at CERN

    CERN Multimedia

    2006-01-01

    "CERN took delivery of the last superconducting main magnet for the Large Hadron Collider (LHC) on 27 November. This completes the full set of 1624 main magnets required to build the world's largest and most powerful particle accelerator." (1 page)

  12. 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.

  13. 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

  14. Brittle superconducting magnets: an equivilent strain model

    International Nuclear Information System (INIS)

    Barzi, E.; Danuso, M.

    2010-01-01

    To exceed fields of 10 T in accelerator magnets, brittle superconductors like A15 Nb 3 Sn and Nb 3 Al or ceramic High Temperature Superconductors have to be used. For such brittle superconductors it is not their maximum tensile yield stress that limits their structural resistance as much as strain values that provoke deformations in their delicate lattice, which in turn affect their superconducting properties. Work on the sensitivity of Nb 3 Sn cables to strain has been conducted in a number of stress states, including uniaxial and multi-axial, producing usually different results. This has made the need of a constituent design criterion imperative for magnet builders. In conventional structural problems an equivalent stress model is typically used to verify mechanical soundness. In the superconducting community a simple scalar equivalent strain to be used in place of an equivalent stress would be an extremely useful tool. As is well known in fundamental mechanics, there is not one single way to reduce a multiaxial strain state as represented by a 2nd order tensor to a scalar. The conceptual experiment proposed here will help determine the best scalar representation to use in the identification of an equivalent strain model.

  15. Brittle superconducting magnets: an equivilent strain model

    Energy Technology Data Exchange (ETDEWEB)

    Barzi, E.; /Fermilab; Danuso, M.

    2010-08-01

    To exceed fields of 10 T in accelerator magnets, brittle superconductors like A15 Nb{sub 3}Sn and Nb{sub 3}Al or ceramic High Temperature Superconductors have to be used. For such brittle superconductors it is not their maximum tensile yield stress that limits their structural resistance as much as strain values that provoke deformations in their delicate lattice, which in turn affect their superconducting properties. Work on the sensitivity of Nb{sub 3}Sn cables to strain has been conducted in a number of stress states, including uniaxial and multi-axial, producing usually different results. This has made the need of a constituent design criterion imperative for magnet builders. In conventional structural problems an equivalent stress model is typically used to verify mechanical soundness. In the superconducting community a simple scalar equivalent strain to be used in place of an equivalent stress would be an extremely useful tool. As is well known in fundamental mechanics, there is not one single way to reduce a multiaxial strain state as represented by a 2nd order tensor to a scalar. The conceptual experiment proposed here will help determine the best scalar representation to use in the identification of an equivalent strain model.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    1996-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    1997-01-01

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

  18. First Cryogenic Testing of the ATLAS Superconducting Prototype Magnets

    CERN Document Server

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

    2002-01-01

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

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

    CERN Multimedia

    Maximilien Brice

    2012-01-01

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

  20. Cryogenic commissioning, cool down and first magnet operation of Wendelstein 7-X

    Science.gov (United States)

    Nagel, M.; Dhard, C. P.; Bau, H.; Bosch, H.-S.; Meyer, U.; Raatz, S.; Risse, K.; Rummel, T.

    2017-02-01

    The construction of the stellarator fusion experiment Wendelstein 7-X (W7-X) was accomplished in 2014. Commissioning of cryogenic system, first cool down of W7-X cryostat and operation of the magnet system was achieved. First plasma operation was accomplished 10th of December 2015. W7-X consists of a magnet system with 70 superconducting coils inside a cryostat. The cold mass of 456 tons is cooled with a helium plant with an equivalent refrigeration power of 7 kW at 4.5 K. The paper presents the commissioning of the cryogenic system, the cool down of the cryostat and first steady state operation with currents up to 12.8 kA. Helium temperatures, mass flow rates and pressure drops inside W7-X cooling circuits are as expected allowing safe magnet operation. Heat loads on the thermal shield and on the superconducting coils are lower than specified for the cryostat design.

  1. CFD Analyses on LHe Cooling for SCQ Magnets in BEPCII Upgrade

    International Nuclear Information System (INIS)

    He, Z.H.; Wang, L.; Tang, H.M.; Zhang, X.B.; Jia, L.X.

    2004-01-01

    A pair of superconducting interaction region quadrupole magnets in Beijing Electron-Positron Collider Upgrade (BEPCII) are to be cooled by supercritical helium in order to eliminate the flow instabilities in the constrained cooling channels. The fluid flow is simulated by the commercial computational dynamics fluid software. The heat loads to the superconducting quadrupole (SCQ) magnets from the radiation shields at 80 K and from the thermal conduction of mechanical supports are considered. The temperature distribution of the fluid in the liquid helium cooling channels, and the heat transfer in the SCQ magnet and by its supports are presented. The influence of mass flow rate on pressure drop in the cooling passage is analyzed

  2. CFD ANALYSES ON THE COOLING FOR SCQ MAGNETS IN BEPC II UPGRADE

    International Nuclear Information System (INIS)

    HE, Z.H.; WANG, L.; TANK, H.M.; ZHANG, X.B.; JIA, L.X.

    2003-01-01

    A pair of superconducting interaction region quadrupole magnets in Beijing Electron-Positron Collider Upgrade (BEPCII) are to be cooled by supercritical helium in order to eliminate the flow instabilities in the constrained cooling channels. The fluid flow is simulated by the commercial computational dynamics fluid software. The heat loads to the superconducting quadrupole (SCQ) magnets from the radiation shields at 80 K and from the thermal conduction of mechanical supports are considered. The temperature distribution of the fluid in the liquid helium cooling channels, and the heat transfer in the SCQ magnet and by its supports are presented. The influence of mass flow rate on pressure drop in the cooling passage is analyzed

  3. 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)

  4. Superconducting poloidal field magnet engineering for the ARIES-ST

    International Nuclear Information System (INIS)

    Bromberg, Leslie; Pourrahimi, S.; Schultz, J.H.; Titus, P.; Jardin, S.; Kessel, C.; Reiersen, W.

    2003-01-01

    The critical issues of the poloidal systems for the ARIES-ST design have been presented in this paper. Because of the large plasma current and the need of highly shaped plasmas, the poloidal field (PF) coils should be located inside the toroidal field in order to reduce their current. Even then, the divertor coils carry large currents. The ARIES-ST PF coils are superconducting using the internally cooled cable-in-conduit conductor. The peak self field in the divertor coils is about 15 T and the highest field in the non-divertor coils is about 6 T. The PF magnets have built-in margins that are sufficient to survive disruptions without quenching. The costing study indicates that the specific cost of the PF system is $80/kg. Detailed design and trade-off studies of ARIES-ST are presented and remaining R and D issues are identified

  5. 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

  6. Magnetic measurements on the ISR superconducting quadrupoles

    International Nuclear Information System (INIS)

    Walckiers, L.

    1981-01-01

    The eight superconducting quadrupoles of the ISR high luminosity insertion were measured by the rotating coil method. This method allows an analysis of all harmonic components of the field. In order to achieve magnetic measurements precise enough to check the quality of the magnet, a study of the errors inherent in such a measuring system was made. This paper described how the measurement of the different harmonics of the field is affected by imperfections of the mechanical or electronic components of the measuring system. The relative errors of the gradient are measured within 0.2 10/sup -3/ in the useful aperture, the absolute value of the quadrupole term is known within 0.5 10/sup -3/ as a function of current, and the magnetic axis is determined within 20 microns. By using the dodecapole correction winding, the relative error of the gradient integrated along the axis can be kept within the tolerance of 1% in the useful aperture of the magnets. 2 refs

  7. Magnetic flux trapping in superconducting niobium

    CERN Document Server

    Benvenuti, Cristoforo; Campisi, I E; Darriulat, Pierre; Durand, C; Peck, M A; Russo, R; Valente, A M

    1997-01-01

    In a systematic study of the RF response of superconducting niobium cavities operated in their fundamental TM010 mode at 1.5 GHz, magnetic flux trapping has been used as a tool to diagnose the presenc e of pinning centres. In addition to bulk niobium cavities the study covers copper cavities, the inner walls of which are coated with 1.5 µm thick niobium films grown by magnetron sputtering in a nobl e gas atmosphere. The use of different gases (Xe, Kr, Ar and Ne) or gas mixtures has made it possible to vary the concentration of noble gas atoms in the films. Film contamination is characterised by an electron mean free path l calculated from the results of systematic measurements of the penetration depth at T = 0 K, l0, and from RRR measurements made on samples prepared under similar conditions as the cavity films.

  8. International team successfully launches world's largest superconducting magnet

    CERN Multimedia

    2006-01-01

    "The world's largest superconducting magnet was successfully brought online recently as part of CERN's Large Hadron Collider (LHC), the new particle accelerator scheduled for full scale use in November 2007. The magnet charged and operated successfully on its first attempt. The magnet, called Barrel Toroid, provides the powerful magnetic fiedl for ATLAS, one of the major particle detectors for LHC." (2/3 page)

  9. 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

  10. Cryogenic equipment to test models of superconducting magnets for accelerating-storage unit (ASU)

    International Nuclear Information System (INIS)

    Bondarenko, V.I.; Vasiliev, V.N.; Dinaburg, L.B.; Kalinin, V.V.; Katasonov, N.N.; Semenov, S.V.; Fokoeev, V.F.; Khrushchev, V.N.

    1986-01-01

    The paper describes the testing results of the cryogenic equipment to investigate 2-m models of ASU superconducting magnets in subcooled forces and pool-boiling cooling regimes. A special cryostat with radial helium bath supports is used for pool-boiling testing of 2-m models without magnetic screen. For forced flow testing of dipole models a cooling loop with a centrifugal helium pump is used providing the consumption up to 110 g/s and the head of 0.01 + 0.015 MPa with loop pressure 0.25 + 0.6 MPa and temperature 4.4 K

  11. 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

  12. Magnetization Modeling of Twisted Superconducting Filaments

    CERN Document Server

    Satiramatekul, T; Devred, Arnaud; Leroy, Daniel

    2007-01-01

    This paper presents a new Finite Element numerical method to analyze the coupling between twisted filaments in a superconducting multifilament composite wire. To avoid the large number of elements required by a 3D code, the proposed method makes use of the energy balance principle in a 2D code. The relationship between superconductor critical current density and local magnetic flux density is implemented in the program for the Bean and modified Kim models. The modeled wire is made up of six filaments twisted together and embedded in a lowresistivity matrix. Computations of magnetization cycle and of the electric field pattern have been performed for various twist pitch values in the case of a pure copper matrix. The results confirm that the maximum magnetization depends on the matrix conductivity, the superconductor critical current density, the applied field frequency, and the filament twist pitch. The simulations also lead to a practical criterion for wire design that can be used to assess whether or not th...

  13. Safety aspects of superconducting magnets for Super-FRS

    CERN Multimedia

    CERN. Geneva

    2016-01-01

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

  14. Efficient Room-Temperature Cooling with Magnets

    NARCIS (Netherlands)

    Boeije, M.F.J.; Roy, P.; Guillou, F.; Yibole, Hargen; Miao, X.F.; Caron, L.; Banerjee, D.; van Dijk, N.H.; de Groot, R.M.; Brück, E.H.

    2016-01-01

    Magnetic cooling is a highly efficient refrigeration technique with the potential to replace the traditional vapor compression cycle. It is based on the magnetocaloric effect, which is associated with the temperature change of a material when placed in a magnetic field. We present experimental

  15. Radiation Shielding Utilizing A High Temperature Superconducting Magnet Project

    Data.gov (United States)

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

  16. 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)

  17. Superconducting film magnetic flux transformer with micro- and nanosized branches

    Directory of Open Access Journals (Sweden)

    Levan Ichkitidze

    2013-06-01

    Full Text Available The object of the study is a superconducting film magnetic flux transformer comprising two square shaped loops with the tapering active strips and a magnetosensitive film element between them. It is shown that splitting of the active strips into parallel micro- and nanosized superconducting branches and slits increases the gain factor of the transformer, i. e., the concentration of an external magnetic field on the magnetosensitive element, by a factor of more than four.

  18. Effect of Anderson magnetic impurities on superconducting alloys

    International Nuclear Information System (INIS)

    Ahmed, M.; Rashid, R.I.M.A.

    1983-06-01

    A model which consists of a BCS Hamiltonian and a periodic Anderson Hamiltonian for a lattice of magnetic ions is studied using the Green functions equation of motion method. It is found that the Cooper pairing on the site-localized magnetic electrons with antiferromagnetic coupling is capable of destroying superconductivity at a lower critical temperature and thus predicting a reentrant behaviour of the superconducting transition temperature. (author)

  19. Magnetic cooling at Risoe DTU

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Bjørk, Rasmus; Jensen, Jesper Buch

    2009-01-01

    Magnetic refrigeration at room temperature is of great interest due to a long-term goal of making refrigeration more energy-efficient, less noisy and free of any environmentally hostile materials. A refrigerator utilizing an active magnetic regenerator (AMR) is based on the magnetocaloric effect......, which manifests itself as a temperature change in magnetic materials when subjected to a varying magnetic field. In this work we present the current state of magnetic refrigeration research at Risoe DTU with emphasis on the numerical modeling of an existing AMR test machine. A 2D numerical heat......-transfer and fluid-flow model that represents the experimental setup is presented. Experimental data of both no-heat load and heat load situations are compared to the model. Moreover, results from the numerical modeling of the permanent magnet design used in the system are presented....

  20. 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.)

  1. 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

  2. Quench performance analysis on spare superconducting cryo-magnets

    CERN Document Server

    Warych, Agata

    2014-01-01

    The main purpose of this project was to organise and analyse the data, in particular quench performance for superconducting spare magnets considering relation of the magnets to assemblies and families. As a result of analysis an Excel file was created, which consists of quench measurements and charts for spare cryo-magnets.

  3. Superconductivity in an Organic Insulator at Very High Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Balicas, L.; Brooks, J. S.; Storr, K.; Uji, S.; Tokumoto, M.; Tanaka, H.; Kobayashi, H.; Kobayashi, A.; Barzykin, V.; Gor' kov, L. P.

    2001-08-06

    We investigate by electrical transport the field-induced superconducting state (FISC) in the organic conductor {lambda}-(BETS){sub 2}FeCl{sub 4} . Below 4K, antiferromagnetic-insulator, metallic, and eventually superconducting (FISC) ground states are observed with increasing in-plane magnetic field. The FISC state survives between 18 and 41T and can be interpreted in terms of the Jaccarino-Peter effect, where the external magnetic field compensates the exchange field of aligned Fe{sup 3+} ions. We further argue that the Fe{sup 3+} moments are essential to stabilize the resulting singlet, two-dimensional superconducting state.

  4. Superconductivity in an organic insulator at very high magnetic fields.

    Science.gov (United States)

    Balicas, L; Brooks, J S; Storr, K; Uji, S; Tokumoto, M; Tanaka, H; Kobayashi, H; Kobayashi, A; Barzykin, V; Gor'kov, L P

    2001-08-06

    We investigate by electrical transport the field-induced superconducting state (FISC) in the organic conductor lambda-(BETS)2FeCl4. Below 4 K, antiferromagnetic-insulator, metallic, and eventually superconducting (FISC) ground states are observed with increasing in-plane magnetic field. The FISC state survives between 18 and 41 T and can be interpreted in terms of the Jaccarino-Peter effect, where the external magnetic field compensates the exchange field of aligned Fe3+ ions. We further argue that the Fe3+ moments are essential to stabilize the resulting singlet, two-dimensional superconducting state.

  5. 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

  6. Protection of the Superconducting Corrector Magnets for the LHC

    CERN Document Server

    Schmidt, R; Hilaire, A; Ijspeert, Albert; Rodríguez-Mateos, F; Sonnemann, F

    2000-01-01

    n the LHC about 6500 superconducting corrector magnets will be powered either in stand-alone mode or in electrical circuits of up to 154 magnets. Single corrector magnets are designed to be self-protected in case of a quench. The protection scheme of magnets powered in series depends on the energy stored in the magnet and on the number of magnets in the circuit. A quench is detected by measuring the resistive voltage of the circuit. The power converter is switched off, and for most circuits part of the energy is extracted with a resistor. Some magnets may require a resistor or possibly a diode parallel to the magnet in order to avoid overheating of the superconducting wire or an unacceptable voltage level. Experiments have been performed to understand quenching of prototype corrector magnets. In order to determine the adequate protection schemes for the magnet circuits the results have been used as input for simulations to extrapolate to the LHC conditions.

  7. A Method to Measure Thermal Deformation of Superconducting Magnet Cross Sections

    OpenAIRE

    Grau-Carles, A; García-Tabarés, L; Todesco, Ezio; Tommasini, D; Siegel, N

    1999-01-01

    The precision measurement of the cable positioning in superconducting coils is of great interest both at room and liquid nitrogen temperatures because mechanical and thermal deformations affect the quality of the magnetic field. The paper describes a new two-coordinate measuring device, which is able to obtain scanned images of flat composite samples at liquid nitrogen temperature. The sample is cooled at 77 K into a flat quartz tray to permit the optical access to the sample from the bottom....

  8. Superconducting magnetic Wollaston prism for neutron spin encoding.

    Science.gov (United States)

    Li, F; Parnell, S R; Hamilton, W A; Maranville, B B; Wang, T; Semerad, R; Baxter, D V; Cremer, J T; Pynn, R

    2014-05-01

    A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ~30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ~98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 μm. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

  9. Superconducting magnetic Wollaston prism for neutron spin encoding

    Energy Technology Data Exchange (ETDEWEB)

    Li, F., E-mail: fankli@indiana.edu; Parnell, S. R.; Wang, T.; Baxter, D. V. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Hamilton, W. A. [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Maranville, B. B. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Semerad, R. [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany); Cremer, J. T. [Adelphi Technology Inc., Redwood City, California 94063 (United States); Pynn, R. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

    2014-05-15

    A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ∼30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ∼98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 μm. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

  10. 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.

  11. Fiber Bragg Grating Sensor as Valuable Technological Platform for New Generation of Superconducting Magnets

    CERN Document Server

    Chiuchiolo, A; Cusano, A; Bajko, M; Perez, J C; Bajas, H; Viret, P; Giordano, M; Breglio, G

    2014-01-01

    New generation of superconducting magnets for high energy applications designed, manufactured and tested at the European Organization for Nuclear Research (CERN) require the implementation of reliable sensors able to monitor the mechanical stresses affecting the winding from fabrication to operation in magnetic field of 13 T. This work deals with the embedding of Fiber Bragg Grating sensors in a short model Nb3Sn 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 perspectives for the replacement of standard strain gauges.

  12. Construction and tests of a heart scanner based on superconducting sensors cooled by small stirling cryocoolers

    NARCIS (Netherlands)

    Rijpma, A.P.; Blom, C.J.H.A.; Blom, Cock; Balena, A.P.; de Vries, E.; Holland, Herman J.; ter Brake, Hermanus J.M.; Rogalla, Horst

    2001-01-01

    At the University of Twente, a heart scanner has been designed and constructed that uses superconducting devices (superconducting quantum interference devices (SQUIDs)) to measure the magnetic field of the heart. A key feature is the elimination of liquid cryogens by incorporating cryocoolers. In

  13. Nematicity, magnetism and superconductivity in FeSe

    Science.gov (United States)

    Böhmer, Anna E.; Kreisel, Andreas

    2018-01-01

    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.

  14. 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.

  15. 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.

  16. 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.

  17. 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....

  18. A "cool" set of magnets

    CERN Multimedia

    2003-01-01

    The first Short Straight Section for the LHC arcs, containing the first Main Quadrupole and two packages of corrector magnets, was fully assembled and successfully cold tested at CERN end of September.

  19. Contribution to the development of dry R and W MgB2 superconducting magnets

    International Nuclear Information System (INIS)

    Pasquet, Raphael

    2015-01-01

    Currently, the majority of superconducting magnets, including MRI, are cooled by a bath of liquid helium at atmospheric pressure. Nevertheless, this type of cooling is expensive and imposes significant security constraints for large volumes. For these reasons, the cooling of superconducting magnets is desirable without liquid helium. Cryo-cooler provides dry cooling to 4 K without any liquid helium. However, the power available is low and dry cooling is difficult. In these conditions, it is complicate to use NbTi with dry cooling. But if we increase the operating temperature to 10 K, the power of cryo-cooler increases by a factor of ten. Nevertheless in this case, it is necessary to use of a high critical temperature superconductor. We choose to use MgB 2 R and W conductors because it is relatively low cost but it has the handicap to be sensible at mechanical stress. It is therefore necessary to be careful during their winding to not degrade their superconducting performance. As part of this thesis, we have developed a dry test facility to measure the critical current of MgB 2 R and W conductors as well as mock-ups. To do this, a new type of thermal contact based on aluminum nitride has been developed. In addition to this development, we designed two MgB 2 R and W magnet mock-ups: a solenoid and a double pancake. The double pancake was manufactured (with a new patented winding method) and it has been successfully tested. (author) [fr

  20. The Effect of Temperature Dependence of AC Losses in a Bi-2223/Ag Insert of an 8-T Superconducting Magnet

    DEFF Research Database (Denmark)

    Wang, Lei; Wang, Qiuliang; Wang, Hui

    2016-01-01

    A conduction-cooled split-gap superconducting magnet system with a center field of 8 T has been designed and fabricated in the Institute of Electrical Engineering, Chinese Academy of Sciences. The system consists of two Bi-2223/Ag coils and six NbTi coils. Due to a large aspect ratio of the high......-temperature superconducting tape, there will be large ac losses when the magnet is ramped up and down. An accurate estimation of the total ac losses in the high-temperature superconducting coils is essential for the cryogenic system design. In the Bi-2223/Ag coils, the total ac losses mainly originate from two parts: One...... is transport loss caused by the variation of transport current with respect to time, and the other is magnetization loss due to alternating external magnetic field. In this paper, the effect of temperature variation on ac losses generated in the Bi-2223/Ag coils is studied. The magnetic field and temperature...

  1. 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 12 C 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.

  2. Calculation of mechanical stresses and deformations in superconducting magnets of the accelerating-storage complex

    International Nuclear Information System (INIS)

    Dajkovskij, A.G.; Larin, V.N.; Portugalov, Yu.I.; Sytnik, V.V.

    1981-01-01

    To provide working capacity of superconducting magnets, mechanical stresses and deformations in the superconducting coil and tyre under conditions maximally approaching the practical ones are calculated. Calculations are carried out for the following processes: construction deformation under the effect of ponderomotive forces corresponding to the 50 kGs magnetic field in the centre; coil compression by a press; welding in points; magnet cooling till helium tempe-- rature. It is shown that the tyre thickness should be not less than 2.5 cm to prevent changes in the coil shape. The maximum press loading should be 3150 kg/cm 2 . The numerical values of deviations of coordinates of some boundary points of the coil from the optimum values at additional press compression are given [ru

  3. Exotic Magnetic Orders and Their Interplay with Superconductivity

    DEFF Research Database (Denmark)

    Christensen, Morten Holm

    Superconductivity represents one of the most important scientific discoveries of the 20th century. The practical applications are numerous ranging from clean energy storage and MRI machines to quantum computers. However, the low temperatures required for superconductivity prohibits many practical...... applications. The more recent discovery of high-temperature superconductors, with superconducting transition temperatures above 100~K, has led to the hope that superconductivity at room-temperature might be achievable, although a complete theoretical understanding of the high-temperature superconductors...... is currently lacking. In this talk I will review the properties of a specific family of high-temperature superconductors, namely the iron-based materials. While the specific mechanism responsible for the formation of superconducting ground state is unknown, it is believed to be magnetic in nature. Thus...

  4. Optimization of the protective energy removal parameters for tokamak HT7-U superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Khvostenko, P.P.; Chudnovsky, A.N.; Posadsky, I.A. [RRC ' Kurchatov Inst.' , Nuclear Fusion Inst., Moscow (Russian Federation); Bi, Y.F.; Cheng, S.M.; He, Y.X. [Academia Sinica, Hefei, Anhui (China). Inst. of Plasma Physics

    1998-07-01

    The design of the HT-7U superconducting tokamak is in progress now. The design incorporates superconducting magnets of the toroidal field and poloidal field systems. Toroidal field system consists of 16 D-shape coils and poloidal field system consists of 12 coils. All coils will be use NbTi/Cu cable-in-conduit conductor cooled with forced-flow supercritical helium at 4.5 K, 4 Bar. Quench in the superconducting magnets is accompanied byconversion of the stored magnetic field energy into a thermal one which is spent on heating of both the coil part which made transition into a normal state and dump resistors. A non-uniform heating of the coil part results in the emergence of thermomechanical stresses which can cause its destruction. The protective removal of a current is realized to prevent the coil destruction at the emergence of the quench. In that case, the faster the current removal occurs, the less the coil heating is. On the other hand, the current removal rate should not be too high in order to avoid an electric breakdown by the excited inductive voltage. Optimization of the protective energy removal parameters both for TF and PF superconducting magnets is presented. (author)

  5. Optimization of the protective energy removal parameters for tokamak HT7-U superconducting magnets

    International Nuclear Information System (INIS)

    Khvostenko, P.P.; Chudnovsky, A.N.; Posadsky, I.A.; Bi, Y.F.; Cheng, S.M.; He, Y.X.

    1998-01-01

    The design of the HT-7U superconducting tokamak is in progress now. The design incorporates superconducting magnets of the toroidal field and poloidal field systems. Toroidal field system consists of 16 D-shape coils and poloidal field system consists of 12 coils. All coils will be use NbTi/Cu cable-in-conduit conductor cooled with forced-flow supercritical helium at 4.5 K, 4 Bar. Quench in the superconducting magnets is accompanied by conversion of the stored magnetic field energy into a thermal one which is spent on heating of both the coil part which made transition into a normal state and dump resistors. A non-uniform heating of the coil part results in the emergence of thermomechanical stresses which can cause its destruction. The protective removal of a current is realized to prevent the coil destruction at the emergence of the quench. In that case, the faster the current removal occurs, the less the coil heating is. On the other hand, the current removal rate should not be too high in order to avoid an electric breakdown by the excited inductive voltage. Optimization of the protective energy removal parameters both for TF and PF superconducting magnets is presented. (author)

  6. 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

  7. 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

  8. 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)

  9. 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

  10. 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...

  11. Progress on Design and Construction of a MuCool Coupling Solenoid Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L.; Liu, Xiao Kun; Xu, FengYu; Li, S.; Pan, Heng; Wu, Hong; Guo, Xinglong; Zheng, ShiXian; Li, Derun; Virostek, Steve; Zisman, Mike; Green, M.A.

    2010-06-28

    The MuCool program undertaken by the US Neutrino Factory and Muon Collider Collaboration is to study the behavior of muon ionization cooling channel components. A single superconducting coupling solenoid magnet is necessary to pursue the research and development work on the performance of high gradient, large size RF cavities immersed in magnetic field, which is one of the main challenges in the practical realization of ionization cooling of muons. The MuCool coupling magnet is to be built using commercial copper based niobium titanium conductors and cooled by two cryo-coolers with each cooling capacity of 1.5 W at 4.2 K. The solenoid magnet will be powered by using a single 300A power supply through a single pair of binary leads that are designed to carry a maximum current of 210A. The magnet is to be passively protected by cold diodes and resistors across sections of the coil and by quench back from the 6061 Al mandrel in order to lower the quench voltage and the hot spot temperature. The magnet is currently under construction. This paper presents the updated design and fabrication progress on the MuCool coupling magnet.

  12. Possible coexistence of superconductivity and magnetic order in ...

    Indian Academy of Sciences (India)

    Abstract. Coexistence of superconductivity and magnetic order has been one of the exciting as- pects of the quaternary borocarbide superconductors. So far, RNi2B2C (R= Tm, Er, Ho and Dy) are the only known magnetic superconductors in this family. Here, we present our resistivity, mag- netization and heat capacity ...

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bleile, Alexander

    2016-01-06

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

  15. Development of remountable joints and heat removable techniques for high-temperature superconducting magnets

    Science.gov (United States)

    Hashizume, H.; Ito, S.; Yanagi, N.; Tamura, H.; Sagara, A.

    2018-02-01

    Segment fabrication is now a candidate for the design of superconducting helical magnets in the helical fusion reactor FFHR-d1, which adopts the joint winding of high-temperature superconducting (HTS) helical coils as a primary option and the ‘remountable’ HTS helical coil as an advanced option. This paper reports on recent progress in two key technologies: the mechanical joints (remountable joints) of the HTS conductors and the metal porous media inserted into the cooling channel for segment fabrication. Through our research activities it has been revealed that heat treatment during fabrication of the joint can reduce joint resistance and its dispersion, which can shorten the fabrication process and be applied to bent conductor joints. Also, heat transfer correlations of the cooling channel were established to evaluate heat transfer performance with various cryogenic coolants based on the correlations to analyze the thermal stability of the joint.

  16. Operational experience with superconducting synchrotron magnets

    International Nuclear Information System (INIS)

    Martin, P.S.

    1987-03-01

    The operational experience with the Fermilab Tevatron is presented, with emphasis on reliability and failure modes. Comprisons are made between the operating efficiencies for the superconducting machine and for he conventional Main Ring

  17. Superconducting magnet coils protection schemes and apparatus

    International Nuclear Information System (INIS)

    Kuchinski, V.; Bulgakov, S.; Larionov, B.; Mikhailov, N.; Silin, V.

    1995-01-01

    The circuitry of the superconducting coils protection system of the large fusion installations is analyzed. The requirements to the switches and several options of the circuit breakers and making switches with the data of their experimental study are discussed. (orig.)

  18. Recovery Characteristics of GdBCO Superconducting Tape With Cooling Fins and Teflon Coating for Resistive Fault Current Limiter

    OpenAIRE

    Shirai, Yasuyuki; Yoneda, Kazuya; Higa, Daisuke; Shiotsu, Masahiro; Honda, Yoshihiro; Isojima, Shigeki

    2016-01-01

    Recovery time, which is defined as the time during which the superconducting component recovers to its initial condition after the current-limiting operation, is very important to design an SFCL. In this paper, the cooling properties of GdBCO superconducting tape with various types of fins or PTFE (polytetrafluoroethylene:Teflon) coating were investigated. Superconducting tape was heated by current, which was larger than its critical current, in liquid nitrogen. The cooling down speed after t...

  19. 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

  20. 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...

  1. Stability of Superconducting Rutherford Cables For accelerator magnets

    CERN Document Server

    Willering, GP; Verweij, A P

    2009-01-01

    The stability of superconducting magnets has a high priority for particle accelerators, since the operational time and operational collision energy depend strongly on it. Local heat dissipation due to beam loss and conductor movement is inevitable, causing local hot spots in the conductor, possibly leading to magnet quench. For stability against local and transient energy deposition, the cable is the most important unit to investigate. Most superconducting accelerator magnets are wound from Rutherford cables with a flat cable layout, consisting of twisted strands. The mechanisms of normal zone propagation in Rutherford cables have been described in detail with experimental and modeling data. The onset of a local normal zone forces current to redistribute in adjacent neighboring superconducting strands, reducing the longitudinal normal zone propagation. Transversal normal zone propagation in adjacent and crossing strands is caused by the redistribution of current and by heat exchange. The mechanism of normal z...

  2. 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...

  3. 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

  4. Magnetic design of large-bore superconducting quadrupoles for the AHF

    Energy Technology Data Exchange (ETDEWEB)

    Vladimir S Kashikhin et al.

    2002-08-13

    The Advanced Hydrotest Facility (AHF), under study by LANL, utilizes large-bore superconducting quadrupole magnets to image protons for radiography of fast events. In this concept, 50-GeV proton bunches pass through a thick object and are imaged by a lens system that analyzes the scattered beam to determine object details. Twelve simultaneous views of the object are obtained using multiple beam lines. The lens system uses two types of quadrupoles: a large bore (48-cm beam aperture) for wide field of view imaging and a smaller bore (23 cm aperture) for higher resolution images. The gradients of the magnets are 10.14 T/m and 18.58 T/m with magnetic lengths of 4.3 m and 3.0 m, respectively. The magnets are sufficiently novel to present a design challenge. Evaluation and comparisons were made for various types of magnet design: shell and racetrack coils, cold and warm iron, as well as an active superconducting screen. Nb{sub 3}Sn cable was also considered as an alternative to avoid quenching under high beam-scattering conditions. The superconducting shield concept eliminates the iron core and greatly lessens the cryogenic energy needed for cool down. Several options are discussed and comparisons are made.

  5. Heat transfer between the superconducting cables of the LHC accelerator magnets and the superfluid helium bath

    CERN Document Server

    Granieri, Pier Paolo; Tommasini, D

    In this thesis work we investigate the heat transfer through the electrical insulation of superconducting cables cooled by superfluid helium. The cable insulation constitutes the most severe barrier for heat extraction from the superconducting magnets of the CERN Large Hadron Collider (LHC). We performed an experimental analysis, a theoretical modeling and a fundamental research to characterize the present LHC insulation and to develop new ideas of thermally enhanced insulations. The outcome of these studies allowed to determine the thermal stability of the magnets for the LHC and its future upgrades. An innovative measurement technique was developed to experimentally analyze the heat transfer between the cables and the superfluid helium bath. It allowed to describe the LHC coil behavior using the real cable structure, an appropriate thermometry and controlling the applied pressure. We developed a new thermally enhanced insulation scheme based on an increased porosity to superfluid helium. It aims at withstan...

  6. Magnetic preferential orientation of metal oxide superconducting materials

    Science.gov (United States)

    Capone, Donald W.; Dunlap, Bobby D.; Veal, Boyd W.

    1990-01-01

    A superconductor comprised of a polycrystalline metal oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-X (where 0material permits the use of an applied magnetic field to orient the individual crystals when in the superconducting state to substantially increase current transport between adjacent grains. In another embodiment, the anisotropic paramagnetic susceptibility of rare-earth ions substituted into the oxide material is made use of as an applied magnetic field orients the particles in a preferential direction. This latter operation can be performed with the material in the normal (non-superconducting) state.

  7. 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

  8. 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

  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. Theoretical and experimental investigations of superconductivity. Amorphous semiconductors, superconductivity and magnetism

    Science.gov (United States)

    Cohen, M. H.

    1973-01-01

    The research activities from 1 March 1963 to 28 February 1973 are summarized. Major lectures are listed along with publications on superconductivity, superfluidity, electronic structures and Fermi surfaces of metals, optical spectra of solids, electronic structure of insulators and semiconductors, theory of magnetic metals, physics of surfaces, structures of metals, and molecular physics.

  11. 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.

  12. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  14. 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

  15. Performance of a conduction-cooled high-temperature superconducting bearing

    International Nuclear Information System (INIS)

    Strasik, M.; Hull, J.R.; Johnson, P.E.; Mittleider, J.; McCrary, K.E.; McIver, C.R.; Day, A.C.

    2008-01-01

    We report rotational loss measurements for a high-temperature superconducting (HTS) bearing whose cooling consists of a thermal conduction path to the cold head of a cryocooler. Losses have been measured for rotational rates up to 14,500 rpm at different HTS temperatures. The rotational losses decrease with decreasing HTS temperature. For temperatures that can be obtained in a liquid-nitrogen thermosiphon system, at a given speed and gap, the loss of the conduction-cooled HTS bearing is not significantly higher than the loss of a nearly identical HTS bearing cooled by flowing nitrogen from the thermosiphon

  16. Study on the flow reduction of forced flow superconducting magnet and its stable operation condition

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Makoto [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-03-01

    The forced flow superconducting coil especially made from a Cable-in-Conduit Conductor (CICC) is applied for large-scale devices such as fusion magnets and superconducting magnet energy storage (SMES) because it has high mechanical and electrical performance potential. The flow reduction phenomena caused by AC loss generation due to the pulsed operation was found based on the experimental results of three forced flow superconducting coils. And relation between the AC loss generation and flow reduction was defined from viewpoint of the engineering design and operation of the coils. Also the mechanism of flow reduction was investigated and stable operation condition under the flow reduction was clarified for forced flow superconducting coils. First, experiments of three different large-scale superconducting coils were carried out and experimental database of the flow reduction by AC loss generation was established. It was found experimentally that the flow reduction depends on the AC loss generation (W/m{sup 3}) in all of coils. It means the stable operation condition is defined not only the electro magnetism of superconducting coil but also flow condition. Mechanism of the flow reduction was investigated based on the experimental database. Hydraulics was applied to supercritical helium as a coolant. Also performances of the cryogenic pump by which coolant are supplied to the coil and friction of the superconductor as cooling path is considered for hydraulic estimation. The flow reduction of the coil is clarified and predictable by the equations of continuity, momentum and energy balance. Also total mass flow rate of coolant was discussed. The estimation method in the design phase was developed for total mass flow rate which are required under the flow reduction by AC losses. The friction of the superconductor and performance of cryogenic pump should be required for precise prediction of flow reduction. These values were obtained by the experiment data of coil and

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

    CERN Multimedia

    2012-01-01

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

  18. Possible coexistence of superconductivity and magnetic order in ...

    Indian Academy of Sciences (India)

    Dd; 65.40.+g; 75.50.-y. 1. Introduction. One of the attractions of quaternary borocarbide superconductors [1–3] is the coexistence of superconductivity and magnetism found in some of the members at relatively elevated. (. > ∼ 5 K) temperatures ...

  19. Stability of superconducting Rutherford cables for accelerator magnets

    NARCIS (Netherlands)

    Willering, G.P.

    2009-01-01

    The stability of superconducting magnets has a high priority for particle accelerators, since the operational time and operational collision energy depend strongly on it. Local heat dissipation due to beam loss and conductor movement is inevitable, causing local hot spots in the conductor, possibly

  20. Nucleation of bulk superconductivity close to critical magnetic fields

    DEFF Research Database (Denmark)

    Fournais, Søren; Kachmar, Ayman

    2011-01-01

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

  1. Survey of high field superconducting material for accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-05-01

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

  2. Safety of superconducting fusion magnets: twelve problem areas

    Energy Technology Data Exchange (ETDEWEB)

    Turner, L. R.

    1979-01-01

    Twelve problem areas of superconducting magnets for fusion reaction are described. These are: Quench Detection and Energy Dump, Stationary Normal Region of Conductor, Current Leads, Electrical Arcing, Electrical Shorts, Conductor Joints, Forces from Unequal Currents, Eddy Current Effects, Cryostat Rupture, Vacuum Failure, Fringing Field and Instrumentation for Safety. Priorities among these areas are suggested.

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

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-01

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

  4. Superconductive combinational logic circuit using magnetically coupled SQUID array

    Science.gov (United States)

    Yamanashi, Y.; Umeda, K.; Sai, K.

    2010-11-01

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

  5. 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

  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. 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...

  8. Evidence of magnetic mechanism for cuprate superconductivity

    Science.gov (United States)

    Keren, Amit

    2009-06-01

    A proper understanding of the mechanism for cuprate superconductivity can emerge only by comparing materials in which physical parameters vary one at a time. Here, we present a variety of bulk, resonance and scattering measurements on the (CaxLa1-x) (Ba1.75-xLa0.25+x) Cu3Oy high temperature superconductors, in which this can be done. We determine the superconducting, Néel, glass and pseudopage critical temperatures. In addition, we clarify which physical parameter varies, and, equally important, which does not, with each chemical modification. This allows us to demonstrate that a single energy scale, set by the superexchange interaction J, controls all the critical temperatures of the system. J, in turn, is determined by the in plane Cu-O-Cu buckling angle.

  9. Structural materials for large superconducting magnets for tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Long, C.J.

    1976-12-01

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

  10. 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

  11. Magnetic profiles in ferromagnetic/superconducting superlattices.

    Energy Technology Data Exchange (ETDEWEB)

    te Velthuis, S. G. E.; Hoffmann, A.; Santamaria, J.; Materials Science Division; Univ. Complutense de Madrid

    2007-02-28

    The interplay between ferromagnetism and superconductivity has been of longstanding fundamental research interest to scientists, as the competition between these generally mutually exclusive types of long-range order gives rise to a rich variety of physical phenomena. A method of studying these exciting effects is by investigating artificially layered systems, i.e. alternating deposition of superconducting and ferromagnetic thin films on a substrate, which enables a straight-forward combination of the two types of long-range order and allows the study of how they compete at the interface over nanometer length scales. While originally studies focused on low temperature superconductors interchanged with metallic ferromagnets, in recent years the scope has broadened to include superlattices of high T{sub c} superconductors and colossal magnetoresistance oxides. Creating films where both the superconducting as well as the ferromagnetic layers are complex oxide materials with similar crystal structures (Figure 1), allows the creation of epitaxial superlattices, with potentially atomically flat and ordered interfaces.

  12. Numerical and experimental investigations of coupled electromagnetic and thermal fields in superconducting accelerator magnets

    International Nuclear Information System (INIS)

    Mierau, Anna

    2013-01-01

    and its individual components, which occur during acceleration cycles. The study and analysis of these physical characteristics of the superconducting magnets and the relation between thermal und magnetic fields are subject of this PhD thesis. The object of investigation was the first SIS100 full size fast ramped superconducting dipole magnet prototype. Due to the complex design of accelerator magnets numerical simulations as well as measurements on test models are commonly used methods to determine the characteristics of the electromagnetic and thermal fields of such magnets. In the frame of this work both methods have been used to study the properties of the static magnetic field in the aperture of the dipole magnet. The dynamic heat losses in the magnet and its vacuum chamber were measured using the calorimetrical method. The knowledge gained in this work has contributed to the development of superconducting dipole magnets which will satisfy the operational conditions of the SIS100 beam guiding magnets. Furthermore, the knowledge of the dynamic heat loads in individual dipole units is important for developing a reliable cooling system for the superconducting magnets in the accelerator ring and thus for the stable operation of the SIS100 heavy ion synchrotron.

  13. The Role of Superconducting Magnets for High Energy Physics

    CERN Document Server

    CERN. Geneva

    2012-01-01

    Superconducting Magnets have played a crucial role for the particle physics energy frontier. From Tevatron to LHC, passing through HERA and RHIC, they have defined the last 30 years of hadron colliders. The talk will review the successful projects and mention the reasons and learning from the ill-fated projects, Isabelle and SSC. Technology spin-off will be discussed, together with the development of the next generation magnets; the high field ones, aimed at passing the 10 Tesla frontier in collider quality magnets, and the fast cycled ones, aimed at enabling field ramp rates of 1 to 4 Tesla per second in synchrotron quality magnets.

  14. Superconducting magnet for gyrotron tube with 4 mm wave length

    International Nuclear Information System (INIS)

    Zhu Xuewu; Pu Men; Chen Jian; Liu Jianmin; Shi Qingju

    1988-03-01

    In this paper a superconducting magnet for gyrotron tube with 4mm wave length is described. It can provide a uniform magnetic field (B 0 ) of 3T in resonant cavity area. Its uniform area width is 6 cm and uniformity is better than ±0.16%. The uniform magnetic field can also to be adjusted into a gradient field and ΔB/B 0 ≥8.5%. The uniform area width of magnetic field (B k ) in the cathode area is 4 cm. Its uniformity is ±(1.0∼1.8)%. B k /B 0 can be adjusted in the region of 1/6∼1/15. The magnet is energized by four power sources. As optimum form of the magnetic field has been adjusted, the magnet can operate closely. The magnet will coordinate with the gyrotron tube to do ECRH physical experiment on the HL-1 Tokamak

  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. On analogy between the magnetic field of pulsars and that of magnetized superconducting sphere

    International Nuclear Information System (INIS)

    Mkrtchyan, G.S.; Sedraksyan, D.M.

    1984-01-01

    The field is calculated, which is induced by a superconducting sphere homogeneously magnetized over the volume. It is assumed that such a field is generated within a neutron star due to an entrainment of superfluid protons by neutrons

  17. Design study of superconducting magnets for tokamak experimental fusion reactor, (1)

    International Nuclear Information System (INIS)

    1980-03-01

    Design study has been made of superconducting magnets for a Tokamak experimental fusion reactor: toroidal field magnet design, poloidal field magnet design, refrigeration system design, magnet safety analysis, and magnet assembling and disassembling system design. A maximum toroidal field in the coil is 11.0 T, providing 5.5 T at plasma center. Nb 3 Sn superconducting cable is used to attain the toroidal field of 11 T. The coil bore is 7.3 x 11.2 m, and the coil shape is deformed constant-tension D-shape. The magnetomotive force is 185.6 MAT, and the operational current is 25.9 kA. In poloidal field magnet design, the coil is pancake-wound Nb 3 Sn conductor. The conductor is enclosed in Ti-alloy sheath, which serves also as helium containment vessel. The conductor is cooled by forced flow supercritical helium of 7 atm and 4.6 K, and the operational current is 25 -- 27 kA. (author)

  18. Superconducting magnetic separation of ground steel slag powder for recovery of resources

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, H. W.; Kim, J. J.; Kim, Young Hun [Andong National University, Andong (Korea, Republic of); Ha, D. W. [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of); Choi, J. H. [Dept. of Environmental Engineering, Catholic University of Pusan, Pusan (Korea, Republic of)

    2017-03-15

    Steel slag has been considered as an industrial waste. A huge amount of slag is produced as a byproduct and the steel slag usually has been dumped in a landfill site. However the steel slag contains valuable resources such as iron, copper, manganese, and magnesium. Superconducting magnetic separation has been applied on recovery of the valuable resources from the steel slag and this process also has intended to reduce the waste to be dumped. Cryo-cooled Nb-Ti superconducting magnet with 100 mm bore and 600 mm of height was used as the magnetic separator. The separating efficiency was evaluated in the function of magnetic field. A steel slag was ground and analyzed for the composition. Iron containing minerals were successfully concentrated from less iron containing portion. The separation efficiency was highly dependent on the particle size giving higher separating efficiency with finer particle. The magnetic field also effects on the separation ratio. Current study showed that an appropriate grinding of slag and magnetic separation lead to the recovery of metal resources from steel slag waste rather than dumping all of the volume.

  19. A Method to Measure Thermal Deformation of Superconducting Magnet Cross Sections

    CERN Document Server

    Grau-Carles, A; Todesco, Ezio; Tommasini, D; Siegel, N

    1999-01-01

    The precision measurement of the cable positioning in superconducting coils is of great interest both at room and liquid nitrogen temperatures because mechanical and thermal deformations affect the quality of the magnetic field. The paper describes a new two-coordinate measuring device, which is able to obtain scanned images of flat composite samples at liquid nitrogen temperature. The sample is cooled at 77 K into a flat quartz tray to permit the optical access to the sample from the bottom. The comparison of the images taken at room and liquid nitrogen temperatures by a high-resolution flatbed scanner gives the thermal contraction of the components.

  20. 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

  1. High resolution neutron Larmor diffraction using superconducting magnetic Wollaston prisms.

    Science.gov (United States)

    Li, Fankang; Feng, Hao; Thaler, Alexander N; Parnell, Steven R; Hamilton, William A; Crow, Lowell; Yang, Wencao; Jones, Amy B; Bai, Hongyu; Matsuda, Masaaki; Baxter, David V; Keller, Thomas; Fernandez-Baca, Jaime A; Pynn, Roger

    2017-04-13

    The neutron Larmor diffraction technique has been implemented using superconducting magnetic Wollaston prisms in both single-arm and double-arm configurations. Successful measurements of the coefficient of thermal expansion of a single-crystal copper sample demonstrates that the method works as expected. The experiment involves a new method of tuning by varying the magnetic field configurations in the device and the tuning results agree well with previous measurements. The difference between single-arm and double-arm configurations has been investigated experimentally. We conclude that this measurement benchmarks the applications of magnetic Wollaston prisms in Larmor diffraction and shows in principle that the setup can be used for inelastic phonon line-width measurements. The achievable resolution for Larmor diffraction is comparable to that using Neutron Resonance Spin Echo (NRSE) coils. The use of superconducting materials in the prisms allows high neutron polarization and transmission efficiency to be achieved.

  2. Device for delivering cryogen to rotary super-conducting winding of cryogen-cooled electrical machine

    International Nuclear Information System (INIS)

    Filippov, I.F.; Gorbunov, G.S.; Khutoretsky, G.M.; Popov, J.S.; Skachkov, J.V.; Vinokurov, A.A.

    1980-01-01

    A device is disclosed for delivering cryogen to a superconducting winding of a cryogen-cooled electrical machine comprising a pipe articulated along the axis of the electrical machine and intended to deliver cryogen. One end of said pipe is located in a rotary chamber which communicates through channels with the space of the electrical machine, and said space accommodating its superconducting winding. The said chamber accommodates a needle installed along the chamber axis, and the length of said needle is of sufficient length such that in the advanced position of said cryogen delivering pipe said needle reaches the end of the pipe. The layout of the electrical machine increases the reliability and effectiveness of the device for delivering cryogen to the superconducting winding, simplifies the design of the device and raises the efficiency of the electrical machine

  3. 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

  4. Design Optimization for Superconducting Bending Magnets using Pareto Front Curve

    Science.gov (United States)

    Murata, Yukihiro; Abe, Mitsushi; Ando, Ryuya

    2017-09-01

    A novel limit design method for superconducting magnets is presented. It is particularly suitable for ion core magnets such as those used in accelerator magnets. In general, a stochastic optimization whose objective functions consist of values, e.g., the magnetic field, experience field of superconducting coils, current density, and multipole field integral, is often used. However, it is well known that the obtained solution strongly depends on the initial one. Furthermore, once the calculation model is fixed, the range of solutions is also fixed, i.e., there are times when it may be impossible to find the global optimum solution even with a lot of parameter sweeps. In this study, we draw the Pareto front curve to obtain the range and infer whether the solution is an optimum one. In addition, the Pareto front curve indicates the neighborhood solution that is substituted for the initial one. After this process a stochastic optimization is implemented with its initial design parameters. To confirm the validity, we designed a superconducting bending magnet, and it showed that this method works well.

  5. High field septum magnet using a superconducting shield for the Future Circular Collider

    CERN Document Server

    AUTHOR|(CDS)2069375

    2017-01-01

    A zero-field cooled superconducting shield is proposed to realize a high-field (3–4 T) septum magnet for the Future Circular Collider hadron-hadron (FCC-hh) ring. Three planned prototypes using different materials and technical solutions are presented, which will be used to evaluate the feasibility of this idea as a part of the FCC study. The numerical simulation methods are described to calculate the field patterns around such a shield. A specific excitation current configuration is presented that maintains a fairly homogeneous field outside of a rectangular shield in a wide range of field levels from 0 to 3 Tesla. It is shown that a massless septum configuration (with an opening in the shield) is also possible and gives satisfactory field quality with realistic superconducting material properties.

  6. High field septum magnet using a superconducting shield for the Future Circular Collider

    Directory of Open Access Journals (Sweden)

    Dániel Barna

    2017-04-01

    Full Text Available A zero-field cooled superconducting shield is proposed to realize a high-field (3–4 T septum magnet for the Future Circular Collider hadron-hadron (FCC-hh ring. Three planned prototypes using different materials and technical solutions are presented, which will be used to evaluate the feasibility of this idea as a part of the FCC study. The numerical simulation methods are described to calculate the field patterns around such a shield. A specific excitation current configuration is presented that maintains a fairly homogeneous field outside of a rectangular shield in a wide range of field levels from 0 to 3 Tesla. It is shown that a massless septum configuration (with an opening in the shield is also possible and gives satisfactory field quality with realistic superconducting material properties.

  7. Design and construction of superconducting quadrupole magnets at Karlsruhe

    CERN Document Server

    Arendt, F; Turowski, P

    1977-01-01

    Two types of superconducting quadrupole magnets have been developed: 6 extremely short doublets with a quadrupole length of nearly 11 cm as beam focusing elements in the Karlsruhe superconducting proton linac; 2 quadrupoles of about 1 m length for use in the hyperon experiments at the CERN SPS. The concept for these quadrupoles is a one current block winding per pole, calculated with respect to minimum field errors. Special mechanical and winding techniques have been developed to get the high geometric accuracy required for such air coils. The short doublets must be operated in persistent current mode with a thermal superconducting switch and a required time constant of tau >10 /sup 4/ hours. The hyperon beam quadrupoles must operate reliably for a long time in an inaccessible concrete shielding. (2 refs).

  8. 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

  9. Mobile refrigeration system for precool and warm up of superconducting magnets

    Science.gov (United States)

    Gandla, S. K.; Longsworth, R. C.

    2017-12-01

    Conservation of helium has become more important in recent years due to global shortages in supply. Magnetic resonance imaging (MRI) superconducting magnets use approximately 20% of the world’s helium reserves in liquid form to cool down and maintain operating temperatures at 4 K. This paper describes a mobile cryogenic refrigeration system, which has been developed by Sumitomo (SHI) Cryogenics of America, Inc. to conserve helium by shipping MRI magnets warm and cooling them down or servicing them on site at a medical facility. The system can cool a typical magnet from room temperature to below 40K in less than a week. The system consists of four single stage Displex®-type Gifford-McMahon (GM) expanders in a cryostat with heat exchangers integrated on the cold ends that cool the helium gas, which is circulated in a closed-loop system through the magnet by a cryogenic fan. The system is configured with heaters on the heat exchangers to effectively warm up a magnet. The system includes a scroll vacuum pump, which is used to evacuate the helium circuit with or without the magnet and turbo pump to evacuate the cryostat. Vacuum-jacketed transfer lines connect the cryostat to the magnet. The system is designed with its own controller for continuous operation of precool, warm up and evacuation processes with automatic and manual controls. The cryostat, pumps and gas controls are mounted on a dewar cart. One compressor and the system controller are mounted on a compressor and control cart, and the other three compressors are mounted on separate carts.

  10. Design of mass flow rate measurement system for SST-1 superconducting magnet system

    International Nuclear Information System (INIS)

    Varmora, P.; Sharma, A.N.; Khristi, Y.; Prasad, U.; Patel, D.; Doshi, K.; Pradhan, S.

    2016-01-01

    Highlights: • Design of Venturi meter for SST-1 magnet system. • Details of Helium mass flow measurement system used in SST-1. • Instruments and measurement techniques for flow measurement. • VME based data acquisition system details and flow calculation and results from SST-1 campaigns. - Abstract: Superconducting Magnet System (SCMS) of Steady State Superconducting Tokamak – 1 (SST-1) is forced-flow cooled by a closed cycle 1.3 kW (at 4.5 K) class Helium Refrigerator cum Liquefier (HRL) system. An accurate measurement of helium mass flow rate in different coils is required to ensure the uniform cooling of the cold mass in the entire range of operating temperature (300 K to 4.5 K) and pressure (0.9–0.4 MPa). To meet this requirement, indigenously designed and fabricated venturi meters are installed on 27 different coils of SST-1 SCMS. A VME based Data Acquisition System (DAS) has been developed and used to acquire the flow measurement data from different flowmeters. The details of the design of venturi meter, its different measurement and signal conditioning components, the data acquisition system and the mass flow rate calculation method are described in this paper. The mass flow rate measurement data from cryogenic acceptance and SST-1 magnet commissioning experiments are also presented and discussed in this paper.

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

    CERN Document Server

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

    2014-01-01

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

  12. 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.

  13. Superconducting Magnet Technology for the Upgrade

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-01

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

  14. Models for large superconducting toroidal magnet systems

    International Nuclear Information System (INIS)

    Arendt, F.; Brechna, H.; Erb, J.; Komarek, P.; Krauth, H.; Maurer, W.

    1976-01-01

    Prior to the design of large GJ toroidal magnet systems it is appropriate to procure small scale models, which can simulate their pertinent properties and allow to investigate their relevant phenomena. The important feature of the model is to show under which circumstances the system performance can be extrapolated to large magnets. Based on parameters such as the maximum magnetic field and the current density, the maximum tolerable magneto-mechanical stresses, a simple method of designing model magnets is presented. It is shown how pertinent design parameters are changed when the toroidal dimensions are altered. In addition some conductor cost estimations are given based on reactor power output and wall loading

  15. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid

    International Nuclear Information System (INIS)

    Dunand, J.J.

    1970-01-01

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author) [fr

  16. Mechanical alignment of particles for use in fabricating superconducting and permanent magnetic materials

    Science.gov (United States)

    Nellis, William J.; Maple, M. Brian

    1992-01-01

    A method for mechanically aligning oriented superconducting or permanently magnetic materials for further processing into constructs. This pretreatment optimizes the final crystallographic orientation and, thus, properties in these constructs. Such materials as superconducting fibers, needles and platelets are utilized.

  17. Cooling unit for a superconducting power cable. Two years successful operation

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Friedhelm [Messer Group GmbH, Krefeld (Germany); Kutz, Thomas [Messer Industriegase GmbH, Bad Soden (Germany); Stemmle, Mark [Nexans Deutschland GmbH, Hannover (Germany); Kugel, Torsten [Westnetz GmbH, Essen (Germany)

    2016-07-01

    High temperature super conductors (HTS) can efficiently be cooled with liquid nitrogen down to a temperature of 64 K (-209 C). Lower temperatures are not practical, because nitrogen becomes solid at 63 K (-210 C). To achieve this temperature level the coolant has to be vaporized below atmospheric pressure. Messer has developed a cooling unit with an adequate vacuum subcooler, a liquid nitrogen circulation system, and a storage vessel for cooling an HTS power cable. The cooling unit was delivered in 2013 for the German AmpaCity project of RWE Deutschland AG, Nexans and Karlsruhe Institute of Technology. Within this project RWE and Nexans installed the worldwide longest superconducting power cable in the city of Essen, Germany. The cable is in operation since March 10th, 2014.

  18. 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

  19. Magnetic Fields Boosted by Gluon Vortices in Color Superconductivity

    International Nuclear Information System (INIS)

    Ferrer, Efrain J.; Incera, Vivian de la

    2006-01-01

    We investigate the effects of an external magnetic field in the gluon dynamics of a color superconductor with three massless quark flavors. In the framework of gluon mean-field theory at asymptotic densities, we show that the long-range component H(tilde sign) of the external magnetic field that penetrates the color-flavor locked phase produces an instability when its strength becomes larger than the Meissner mass of the charged gluons. As a consequence, the magnetic field causes the formation of a vortex state characterized by the condensation of charged gluons and the creation of magnetic flux tubes. Inside the flux tubes, the magnetic field is stronger than the applied one. This antiscreening effect is connected to the anomalous magnetic moment of the gluon field. We suggest how this same mechanism could serve to remove the chromomagnetic instabilities existing in gapless color superconductivity

  20. Superconducting HTS coil made from round cable cooled by liquid nitrogen flow

    Science.gov (United States)

    Šouc, J.; Gömöry, F.; Vojenčiak, M.; Solovyov, M.; Seiler, E.; Kováč, J.; Frolek, L.

    2017-10-01

    The concept of simple cooling arrangement for superconducting coil made from a round cable based on high-temperature superconductor tapes is demonstrated. The cable architecture is similar to the Conductor on Round Core (CORC®) concept: it consists of eight superconducting tapes wound in two layers on a copper tube core in a helical manner. Such a Conductor on Round Tube hand-made cable 4 m long was used to wind the coil with eight turns on 14 cm diameter. Layers of commercial aerogel and polyurethane foam were applied to the coil to provide vacuum-less thermal insulation at its cooling by the flow of liquid nitrogen (LN) in the cable tube. The temperature of superconducting tapes was around 1 K above the coolant temperature in these conditions, causing about 16% reduction of the critical current compared to the LN bath cooling. Electromagnetic performance of the coil was calculated by the model based on the finite element method and the results compared with experimental observations.

  1. Modular transportable superconducting magnetic Energy Systems

    International Nuclear Information System (INIS)

    Lieurance, D.; Kimball, F.; Rix, C.

    1994-01-01

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

  2. Straight ends for superconducting dipole magnet using constant perimeter geometry

    International Nuclear Information System (INIS)

    Royet, J.

    1989-01-01

    The ends of the SSC Dipole magnets are a very critical aspect of the superconducting cable windings needed for this large project. The internal coils, where the radius at the pole is as small as 3/10 of an inch for the first turn, are difficult to form with the very stiff cable, and a high tension is needed. The curing operation on the coils is performed in a heated forming press which applies an important additional stress on the superconducting wire and insulation. A new design of this sensitive region of the magnets was performed at LBL, and several prototypes were built and tested. In this paper the construction method used to solve some of the most critical problems is exposed along with a description of the experimental work in progress. 3 refs., 2 figs

  3. Magnetic properties of electrospun non-woven superconducting fabrics

    Science.gov (United States)

    Koblischka, Michael R.; Zeng, Xian Lin; Karwoth, Thomas; Hauet, Thomas; Hartmann, Uwe

    2016-03-01

    Non-woven superconducting fabrics were prepared by the electrospinning technique, consisting of Bi2Sr2CaCuO8 (Bi-2212) nanowires. The individual nanowires have a diameter of ˜150-200 nm and lengths of up to 100 μm. A non-woven fabric forming a network with a large number of interconnects results, which enables the flow of transport currents through the entire network. We present here magnetization data [M(T) and M(H)-loops] of this new class of superconducting material. The magnetic properties of these nanowire networks are discussed including the irreversibility line and effects of different field sweep rates, regarding the microstructure of the nanowire networks investigated by electron microscopy.

  4. 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

  5. Magnetic properties of electrospun non-woven superconducting fabrics

    International Nuclear Information System (INIS)

    Koblischka, Michael R.; Zeng, Xian Lin; Karwoth, Thomas; Hartmann, Uwe; Hauet, Thomas

    2016-01-01

    Non-woven superconducting fabrics were prepared by the electrospinning technique, consisting of Bi 2 Sr 2 CaCuO 8 (Bi-2212) nanowires. The individual nanowires have a diameter of ∼150-200 nm and lengths of up to 100 μm. A non-woven fabric forming a network with a large number of interconnects results, which enables the flow of transport currents through the entire network. We present here magnetization data [M(T) and M(H)-loops] of this new class of superconducting material. The magnetic properties of these nanowire networks are discussed including the irreversibility line and effects of different field sweep rates, regarding the microstructure of the nanowire networks investigated by electron microscopy.

  6. Magnetic properties of electrospun non-woven superconducting fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Koblischka, Michael R.; Zeng, Xian Lin; Karwoth, Thomas; Hartmann, Uwe [Institute of Experimental Physics, Saarland University, Campus C 6 3, 66123 Saarbrücken (Germany); Hauet, Thomas [Institute Jean Lamour, UMR CNRS-Université de Lorraine, Vandoevre-lès-Nancy (France)

    2016-03-15

    Non-woven superconducting fabrics were prepared by the electrospinning technique, consisting of Bi{sub 2}Sr{sub 2}CaCuO{sub 8} (Bi-2212) nanowires. The individual nanowires have a diameter of ∼150-200 nm and lengths of up to 100 μm. A non-woven fabric forming a network with a large number of interconnects results, which enables the flow of transport currents through the entire network. We present here magnetization data [M(T) and M(H)-loops] of this new class of superconducting material. The magnetic properties of these nanowire networks are discussed including the irreversibility line and effects of different field sweep rates, regarding the microstructure of the nanowire networks investigated by electron microscopy.

  7. 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.

  8. Development of superconducting braid for accelerator magnets

    International Nuclear Information System (INIS)

    Sampson, W.B.

    1976-01-01

    Superconductors for use in the magnets of high energy particle accelerators have been under development at BNL since 1962. The first wide braided conductor was made in 1968 from single core NbTi wire. The conductor now used in the prototype ISABELLE magnets is a more sophisticated version of these early conductors. The large aspect ratio attainable with flat braids makes it possible to construct dipole and quadrupole magnets from a single layer of conductor, considerably simplifying their design. Magnets made from this type of conductor have performed excellently, exhibiting very little training and demonstrating a remarkable ability to quench without sustaining damage. The fabrication steps for braided conductor are described. Contracts have been negotiated for the industrial production of braided conductor and the first shipments of finished conductor are scheduled for delivery early in 1977. A multifilamentary Nb 3 Sn version of the conductor is also being developed and is described briefly

  9. 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)

  10. Superconducting beam bending magnets at CERN

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    The photo shows Gerhard Kesseler with the cyogenic vessels for one of the 10.8 Tesla-metre beam bending magnets. The magnet itself (not visible) is sitting inside the superinsukated helium vessel (white). The next larger shell and the biggest tubular structure (with the largest part behind the person) is the insulation vacuum tank. See CERN Courier 1970 pp. 228-229 CERN Courier 1973 pp. 144-145 Yellow Report CERN 78-03, 1978

  11. Superconducting magnets for future particle accelerators

    International Nuclear Information System (INIS)

    Devred, A.

    2000-05-01

    LHC magnet R and D programs shows that the limit for NbTi at 1.9 K could be between 9 and 10 T. Encouraging results have been obtained on a few Nb 3 Sn magnet models, opening the 10 and 15 T range. Given that LHC will have taken nearly 25 years to builds, it is already time to think of the future. (author)

  12. Contribution to the study of the thermal and hydrodynamical properties of a two-phase natural circulation flow of normal helium (He I) for the cooling of superconducting magnets; Contribution a l'etude des proprietes thermiques et hydrodynamiques d'un ecoulement d'helium normal (He I) diphasique en circulation naturelle pour le refroidissement des aimants supraconducteurs

    Energy Technology Data Exchange (ETDEWEB)

    Benkheira, L

    2007-06-15

    The method of cooling based on the thermosyphon principle is of great interest because of its simplicity, its passivity and its low cost. It is adopted to cool down to 4,5 K the superconducting magnet of the CMS particles detector of the Large Hadron Collider (LHC) experiment under construction at CERN, Geneva. This work studies heat and mass transfer characteristics of two phase He I in a natural circulation loop. The experimental set-up consists of a thermosyphon single branch loop mainly composed of a phase separator, a downward tube, and a test section. The experiments were conducted with varying several parameters such as the diameter of the test section (10 mm or 14 mm) and the applied heat flux up to the appearance of the boiling crisis. These experiments have permitted to determine the laws of evolution of the various parameters characterizing the flow (circulation mass flow rate, vapour mass flow rate, vapour quality, friction coefficient, two phase heat transfer coefficient and the critical heat flux) as a function of the applied heat flux. On the base of the obtained results, we discuss the validity of the various existing models in the literature. We show that the homogeneous model is the best model to predict the hydrodynamical properties of this type of flow in the vapour quality range 0{<=}x{<=}30%. Moreover, we propose two models for the prediction of the two phase heat transfer coefficient and the density of the critical heat flux. The first one considers that the effects of the forced convection and nucleate boiling act simultaneously and contribute to heat transfer. The second one correlates the measured critical heat flux density with the ratio altitude to diameter. (author)

  13. Structural design of superconducting magnets for the large coil program

    International Nuclear Information System (INIS)

    Gray, W.H.; Long, C.J.; Stoddart, W.C.T.

    1979-09-01

    The Large Coil Program (LCP) is a research, development, and demonstration effort specifically for the advancement of the technologies involved in the production of large superconducting magnets. This paper presents a review of the status of the structural designs, analysis methods, and verification tests being performed by the participating LCP design teams in the USA, Switzerland, Japan, and the Federal Republic of Germany. The significant structural mechanics concerns that are being investigated with the LCP are presented

  14. 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

  15. Magnetic flux dynamics in superconducting materials

    International Nuclear Information System (INIS)

    Hernandez Nieves, Alexander

    2004-01-01

    The magnetization curves, the Bean-Livingston barrier in type I and type II superconductors, the ac magnetic response, the effects of thermal fluctuations on the magnetic behavior and the different dissipation mechanism at microwave frequencies are investigated in mesoscopic superconductors.For small mesoscopic samples we study the peaks and discontinuous jumps found in the magnetization as a function of magnetic field.To interpret these jumps we consider that vortices located inside the sample induce a reinforcement of the Bean- Livingston surface barrier at fields greater than the first penetration field Hp1.This leads to multiple penetration fields Hpi Hp1;Hp2;Hp3;... for vortex entrance in mesoscopic samples.For low-T c mesoscopic superconductors we found that the meta-stable states due to the surface barrier have a large half-life time, which leads to the hysteresis in the magnetization curves as observed experimentally.A very different behavior appears for high-T c mesoscopic superconductors where thermally activated vortex entrance/exit through surface barriers is frequent.This leads to a reduction of the magnetization and a non-integer average number of flux quanta penetrating the superconductor.At microwave frequencies we found that each vortex penetration event produces a significant suppression of the ac losses since the imaginary part of the ac susceptibility X ( H d c) as a function of the magnetic field (Hdc) increases before the penetration of vortices and then it decreases abruptly after vortices have entered into the sample.We show that nascent vortices (vortices that are partly inside the sample and nucleated at the surface) play an important role in the dynamic behavior of mesoscopic samples. In type I macroscopic superconductors with first-principles simulations of the TDGL equations we have been able to reproduce several features of the intermediate state observed in experiments.Particularly, droplet and striped patterns are obtained depending

  16. 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

  17. Field flattening in superconducting beam transport magnets

    International Nuclear Information System (INIS)

    Morgan, G.H.

    1994-01-01

    Dipoles in which the beam traverses the midplane well away from tie magnet axis may benefit from flattening of the vertical field on the midplane. A procedure is described for doing so, making use of Chebyshev polynomials. In the case of the large aperture ''DX'' magnets located immediately on each side of the six intersection regions of the Relativistic Heavy Ion Powder (RHIC), a comparison is made of the field of coils optimized in this way and of coils optimized in the more common way by minimizing the leading coefficients of the Fourier expansion about the magnet axis. The comparison is of the integrated Fourier coefficients of the field expanded locally along the beam trajectory

  18. Design concepts for a mechanically refrigerated 13 K superconducting magnet system

    International Nuclear Information System (INIS)

    Hoenig, M.

    1983-01-01

    The construction of small superconducting magnets operating in the 12 to 14 K temperature range without use of supplemental cryogenic fluids is of interest for a number of applications. This requirement can be satisfied for peak fields of up to 3.3 T using Nb 3 Sn superconductor and cooling by means of a close-coupled two stage refrigerator. In order to reduce lead losses, the current must be minimized. Conduction-cooled leads, heat stationed at 14, 70 and 300 K have been designed. Operating at 40 A, they impose 5 and 1 W heat loads (respectively) on the first and second stages of the CTI1020 refrigerator capable of absorbing 30 and 2.5 W (respectively) at the 70 and 13 K heat stations. The refrigerator is a relatively inexpensive ''off-the-shelf'' item

  19. Superconductivity

    International Nuclear Information System (INIS)

    2007-01-01

    During 2007, a large amount of the work was centred on the ITER project and related tasks. The activities based on low-temperature superconducting (LTS) materials included the manufacture and qualification of ITER full-size conductors under relevant operating conditions, the design of conductors and magnets for the JT-60SA tokamak and the manufacture of the conductors for the European dipole facility. A preliminary study was also performed to develop a new test facility at ENEA in order to test long-length ITER or DEMO full-size conductors. Several studies on different superconducting materials were also started to create a more complete database of superconductor properties, and also for use in magnet design. In this context, an extensive measurement campaign on transport and magnetic properties was carried out on commercially available NbTi strands. Work was started on characterising MgB 2 wire and bulk samples to optimise their performance. In addition, an intense experimental study was started to clarify the effect of mechanical loads on the transport properties of multi-filamentary Nb 3 Sn strands with twisted or untwisted superconducting filaments. The experimental activity on high-temperature superconducting (HTS) materials was mainly focussed on the development and characterisation of YBa 2 Cu 3 O 7-X (YBCO) based coated conductors. Several characteristics regarding YBCO deposition, current transport performance and tape manufacture were investigated. In the framework of chemical approaches for YBCO film growth, a new method, developed in collaboration with the Technical University of Cluj-Napoca (TUCN), Romania, was studied to obtain YBCO film via chemical solution deposition, which modifies the well-assessed metallic organic deposition trifluoroacetate (MOD-TFA) approach. The results are promising in terms of critical current and film thickness values. YBCO properties in films with artificially added pinning sites were characterised in collaboration with

  20. Helium release rates and ODH calculations from RHIC magnet cooling line failure

    Energy Technology Data Exchange (ETDEWEB)

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28

    A catastrophic failure of the magnet cooling lines, similar to the LHC superconducting bus failure incident, could discharge cold helium into the RHIC tunnel and cause an Oxygen Deficiency Hazard (ODH) problem. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the insulating vacuum volumes and discharging via the reliefs into the RHIC tunnel, had been developed. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces are included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Results, including helium discharge rates, helium inventory loss, and the resulting oxygen concentration in the RHIC tunnel area, are reported. Good agreement had been achieved when comparing the simulation results, a RHIC sector depressurization test measurement, and some simple analytical calculations.

  1. Safety of superconducting fusion magnets: twelve problem areas

    Energy Technology Data Exchange (ETDEWEB)

    Turner, L.R.

    1979-05-01

    Twelve problem areas of superconducting magnets for fusion reaction are described. These are: Quench Detection and Energy Dump, Stationary Normal Region of Conductor, Current Leads, Electrical Arcing, Electrical Shorts, Conductor Joints, Forces from Unequal Currents, Eddy Current Effects, Cryostat Rupture, Vacuum Failure, Fringing Field and Instrumentation for Safety. Each is described under the five categories: Identification and Definition, Possible Safety Effects, Current Practice, Adequacy of Current Practice for Fusion Magnets and Areas Requiring Further Analytical and Experimental Study. Priorities among these areas are suggested; application is made to the Large Coil Project at Oak Ridge National Laboratory.

  2. 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

  3. Status of the SSC superconducting magnet program

    International Nuclear Information System (INIS)

    Peoples, J.

    1988-09-01

    The work that has been done on the SSC dipole over the past year is summarized in this paper, which is divided into four sections: cable development and production, cryostat design, cold mass design, and model magnet testing. 13 refs., 2 figs., 7 tabs

  4. Precision transport of LHC superconducting magnet

    CERN Multimedia

    Maximilien Brice

    2003-01-01

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

  5. Quench behavior of a superconducting accelerator magnet

    International Nuclear Information System (INIS)

    McInturff, A.D.; Sampson, W.B.; Garber, M.; Dahl, P.F.

    1980-01-01

    Data are presented on the minimum energy required to cause quenches to propagate in an accelerator dipole magnet. The amount of stored energy dissipated into the magnet was measured as a function of dipole excitation current. This in turn determines the maximum coil temperature reached in a given magnet. Quench velocities in the longitudinal direction of the conductor were as high as 11m/sec. The azimuthal velocities or turn to turn velocities were found to be a function of the number of fiberglass layers of insulation that the quench had to cross and were on the order of a few tens of centimeters/sec. The field shape of a given magnet was found to be unchanged for more than 100 quenches. The coil to coil connection and inter-coil splice resistances were found to be less than a namo-ohm and therefore of litle consequence in the cryogenic load considerations. No definitive answers were found on how to decrease the rate of training (130 Gauss/Quench average) required from 4.OT to 5.1T

  6. Design report for an indirectly cooled 3-m diameter superconducting solenoid for the Fermilab Collider Detector Facility

    International Nuclear Information System (INIS)

    Fast, R.; Grimson, J.; Kephart, R.

    1982-01-01

    The Fermilab Collider Detector Facility (CDF) is a large detector system designed to study anti pp collisions at very high center of mass energies. The central detector for the CDF shown employs a large axial magnetic field volume instrumented with a central tracking chamber composed of multiple layers of cylindrical drift chambers and a pair of intermediate tracking chambers. The purpose of this system is to determine the trajectories, sign of electric charge, and momenta of charged particles produced with polar angles between 10 and 170 degrees. The magnetic field volume required for tracking is approximately 3.5 m long an 3 m in diameter. To provide the desired δp/sub T/p/sub T/ less than or equal to 1.5% at 50 GeV/c using drift chambers with approx. 200μ resolution the field inside this volume should be 1.5 T. The field should be as uniform as is practical to simplify both track finding and the reconstruction of particle trajectories with the drift chambers. Such a field can be produced by a cylindrical current sheet solenoid with a uniform current density of 1.2 x 10 6 A/m (1200 A/mm) surrounded by an iron return yoke. For practical coils and return yokes, both central electromagnetic and central hadronic calorimetry must be located outside the coil of the magnet. This geometry requires that the coil and the cryostat be thin both in physical thickness and in radiation and absorption lengths. This dual requirement of high linear current density and minimal coil thickness can only be satisfied using superconducting technology. In this report we describe the design for an indirectly cooled superconducting solenoid to meet the requirements of the Fermilab CDF. The components of the magnet system are discussed in the following chapters, with a summary of parameters listed in Appendix A

  7. Performance of cold compressors in a cooling system of an R and D superconducting coil cooled with subcooled helium

    International Nuclear Information System (INIS)

    Hamaguchi, S.; Imagawa, S.; Yanagi, N.; Takahata, K.; Maekawa, R.; Mito, T.

    2006-01-01

    The helical coils of large helical device (LHD) have been operated in saturated helium at 4.4 K and plasma experiments have been carried out at magnetic fields lower than 3 T for 8 years. Now, it is considered that the cooling system of helical coils will be improved to enhance magnetic fields in 2006. In the improvement, the helical coils will be cooled with subcooled helium and the operating temperature of helical coils will be lowered to achieve the designed field of 3 T and enhance cryogenic stabilities. Two cold compressors will be used in the cooling system of helical coils to generate subcooled helium. In the present study, the performance of cold compressors has been investigated, using a cooling system of R and D coil, to apply cold compressors to the cooling system of helical coils. Actual surge lines of cold compressors were observed and the stable operation area was obtained. Automatic operations were also performed within the area. In the automatic operations, the suitable pressure of a saturated helium bath, calculated from the rotation speed of the 1st cold compressor, was regulated by bypass valve. From these results, stable operations will be expected in the cooling system of helical coils

  8. 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.)

  9. LHC prototype magnet

    CERN Multimedia

    1991-01-01

    1.5 metre superconducting magnet. This prototype magnet for the LHC was cooled to a few degrees above absolute zero, which allowed it to obtain the world record for the highest magnetic field for an accelerator magnet in 1991.

  10. 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)

  11. Precise Thermometry for Next Generation LHC Superconducting Magnet Prototypes

    CERN Document Server

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

    2013-01-01

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

  12. The design and the manufacturing process of the superconducting toroidal field magnet system for EAST device

    International Nuclear Information System (INIS)

    Chen Wenge; Pan Yannian; Chen Zuoming; Wei Jin

    2008-01-01

    The toroidal field (TF) magnet system of EAST (HT-7U), which consists of 16 superconducting coils enclosed in steel cases, has been manufactured to generate the magnetic field of 3.5 T at the plasma center to maintain plasma in a tokamak configuration with a current up to 1 MA. The TF coils have an approximately D-shape geometry of 2.6 m wide and 4.0 m high, and operate at a maximum field of 5.8 T. The conductor used in the TF coil is NbTi/Cu cable-in conduit (CIC) conductor, and its operating current is 14.3 kA. In March 2006, the first cooling down of the EAST device has been carried out successfully. The total of TF magnet system has been cooled down from room temperature to 4.5 K, and the TF system has been energized up to 8.2 kA with 5 A/s ramp rate. In September 2006, full performances of the TF magnet system have been reached, and the device of EAST has delivered its first plasma. In addition, the TF magnet system has been routinely operated with a current maintained constant on a whole day basis, for a preliminary program of more than 500 shots. In this paper, the main parts of the design, developmental tests, and the fabrication and assembly of TF coils are described in detail

  13. Cooling profiles of laser induced temperature fields for superconducting vanadium nitrate products

    Science.gov (United States)

    Emetere, Moses Eterigho

    2016-01-01

    The flexibility of vanadium nitrate makes it a good constituent for emerging superconductors. Its thermal instability engenders a disordered structure when doped by insulating constituents. The physics of the heat source i.e. the probe laser was theoretical derived to avoid deficiency of the superconducting material at low laser energy density. The mathematical experimentation was accomplished by queering the energy balance and heat conductivity of the individual constituents of the reagent. In-depth analysis of the layered distribution of laser induced temperature fields was carried out by cooling the compound via the forced convective cooling technique to about 150 °C. The material was gradual heated via the laser probe to its superconducting state. The structural defect which explained different state of the thermal outcomes were explained and proven to correspond with experimental outcomes. The temperature distribution under the irradiating laser intensity (0.45 W) shows an effective decay rate probability density function which is peculiar to the concept of photoluminescence. The dynamics of the electronic structure of thermally-excited superconducting materials is hinged on the complementary stoichiometry signatures, thermal properties amongst others. The maximum possible critical temperatures of the inter-layer were calculated to be about 206 K.

  14. 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

  15. Thermal studies of a high gradient quadrupole magnet cooled with pressurized, stagnant superfluid

    CERN Document Server

    Chiesa, L; Kerby, J S; Lamm, M J; Novitski, I; Orris, D; Ozelis, J P; Peterson, Thomas J; Tartaglia, M; Zlobin, A V

    2001-01-01

    A 2-m long superconducting model of an LHC Interaction Region quadrupole magnet was wound with stabrite coated cable. The resulting low interstrand resistance and high AC losses presented the opportunity to measure magnet quench performance in superfluid as a function of helium temperature and heat deposition in the coil. Our motivation was to duplicate the high radiation heat loads predicted for the inner triplet quadrupoles at LHC and study the coil cooling conditions in the magnet. At the Magnet Test Facility in Fermilab's Technical Division, the magnet quench performance was tested as a function of bulk helium temperature and current ramp rate near the planned high luminosity interaction region field gradient of 205 T/m. AC loss measurements provided a correlation between current ramp rate and heat deposition in the coil. Analysis indicates that the results are consistent with there being little participation of superfluid helium in the small channels inside the inner layer in the heat removal from the co...

  16. Superconducting dipole magnet for the CBM experiment at FAIR

    Directory of Open Access Journals (Sweden)

    Kurilkin P.

    2017-01-01

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

  17. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-01

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

  19. Evaluation of magnetic field distribution of superconducting bulk magnets with the same pole arrangement

    International Nuclear Information System (INIS)

    Yokoyama, K.; Oka, T.; Noto, K.

    2008-01-01

    We study on the construction of superconducting permanent magnets by RE123 bulk materials and the investigation of these industrial applications such as a magnetic separation. The bulk magnets can generate strong magnetic field in comparison with common permanent magnets and iron-cored electromagnets. In order to propagate an industrial application of bulk magnet in the feature, it is necessary to form various shape of magnetic field, as well as its strength is enlarged. In this paper, the strong magnetic field in the radial direction has been constructed by a pair of bulk magnets. Two Gd123 bulk materials are magnetized by the IMRA method and these are arranged face-to-face with the same pole facing each other. When the radial component of magnetic fields, B x , is measured in the open space between the magnetic poles with a gap of 50 mm, the area of |B x | > 0.5 T increases to 148% compared with the single pole

  20. Superconductivity

    CERN Document Server

    Poole, Charles P; Farach, Horacio A

    1995-01-01

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

  1. Design Studies of Magnet Systems for Muon Helical Cooling Channels

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V.; Kashikhin, V.S.; Lamm, M.J.; Lopes, M.L.; Zlobin, A.V.; /Fermilab; Alsharo' a, M.; Johnson, R.P.; Kahn, Stephen A.; /MUONS Inc., Batavia

    2008-06-25

    Helical cooling channels with superimposed solenoid and helical dipole and quadrupole coils, and a pressurized gas absorber in the aperture offer high efficiency of 6D muon beam cooling. In this paper, we continue design studies and comparison of two basic concepts of magnet system proposed for a helical cooling channel focusing on the high field sections. The results of magnetic analysis and Lorentz force calculations as well as the superconductor choice are presented and discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gehlot, Mona, E-mail: mona_gehlot@yahoo.com [Insertion Device Development Laboratory, School of Physics, Devi Ahilya University, Indore 452001, MP (India); Mishra, G. [Insertion Device Development Laboratory, School of Physics, Devi Ahilya University, Indore 452001, MP (India); Institute of Engineering, UNAM (Mexico); Soleil, Paris (France); Trillaud, Frederic [Institute of Engineering, UNAM (Mexico); Sharma, Geetanjali [Soleil, Paris (France)

    2017-02-21

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

  3. Multi-layered Chalcogenides with potential for magnetism and superconductivity

    Science.gov (United States)

    Li, Li; Parker, David S.; dela Cruz, Clarina R.; Sefat, Athena S.

    2016-12-01

    Layered thallium copper chalcogenides can form single, double, or triple layers of Cu-Ch separated by Tl sheets. Here we report on the preparation and properties of Tl-based materials of TlCu2Se2, TlCu4S3, TlCu4Se3 and TlCu6S4. Having no long-range magnetism for these materials is quite surprising considering the possibilities of inter- and intra-layer exchange interactions through Cu 3d, and we measure by magnetic susceptibility and confirm by neutron diffraction. First principles density-functional theory calculations for both the single-layer TlCu2Se2 (isostructural to the '122' iron-based superconductors) and the double-layer TlCu4Se3 suggest a lack of Fermi-level spectral weight that is needed to drive a magnetic or superconducting instability. However, for multiple structural layers with Fe, there is much greater likelihood for magnetism and superconductivity.

  4. 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.)

  5. Optimization of operating parameters of internally cooled superconducting cables; Optimale Betriebsparameter fuer intern gekuehlte Supraleiterkabel

    Energy Technology Data Exchange (ETDEWEB)

    Katheder, H. [Max-Planck-Inst. fuer Plasmaphysik, Garching (Germany). NET Team

    1995-12-31

    Large superconducting coils such as are used for fusion experiments (Tokamak or Stellarator confiurations) are best equipped with internally cooled superconducting cables. These cables, which are cooled with helium at 4 Kcooled with minimum mass flow. The present paper deals with the thermodynamic behaviour of flowing helium in conduits and with the thermal load which may occur in a cable. It describes a mehtod of optimising the operating paramters and gives a numerical calculation using typical cable data. (orig.) [Deutsch] Bei grossen supraleitenden Spulen z.B. fuer Fusionsexperimente (Tokamak- oder Stellarator Anordnungen) werden mit Vorteil intern gekuehlte Supraleiterkabel eingesetzt. Seit einigen Jahren werden solche Kabel, gekuehlt mit Helium bei 4

  6. Multi-layered Chalcogenides with potential for magnetism and superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: lil2@ornl.gov [Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Parker, David S. [Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Cruz, Clarina R. dela [Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Sefat, Athena S., E-mail: sefata@ornl.gov [Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2016-12-15

    Highlights: • A comprehensive study on multi-layered thallium copper chalcogenides TlCu{sub 2n}Ch{sub n+1}. • All the TlCu{sub 2n}Ch{sub n+1} exhibit metallic behaviors with no long-range magnetism. • Calculations suggest a lack of Fermi-level spectral weight for magnetic instability. • Our results suggest a likelihood of magnetism for multiple structural layers with Fe. - Abstract: Layered thallium copper chalcogenides can form single, double, or triple layers of Cu–Ch separated by Tl sheets. Here we report on the preparation and properties of Tl-based materials of TlCu{sub 2}Se{sub 2}, TlCu{sub 4}S{sub 3}, TlCu{sub 4}Se{sub 3} and TlCu{sub 6}S{sub 4}. Having no long-range magnetism for these materials is quite surprising considering the possibilities of inter- and intra-layer exchange interactions through Cu 3d, and we measure by magnetic susceptibility and confirm by neutron diffraction. First principles density-functional theory calculations for both the single-layer TlCu{sub 2}Se{sub 2} (isostructural to the ‘122’ iron-based superconductors) and the double-layer TlCu{sub 4}Se{sub 3} suggest a lack of Fermi-level spectral weight that is needed to drive a magnetic or superconducting instability. However, for multiple structural layers with Fe, there is much greater likelihood for magnetism and superconductivity.

  7. A superconducting solenoid and press for permanent magnet fabrication

    International Nuclear Information System (INIS)

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

    2002-01-01

    For the first time, a superconducting solenoid (SCM) was used to increase the remnant magnetization of sintered NdFeB permanent magnets (PMs). In particular, improved magnetic alignment of commercial-grade PM powder was achieved, as it was axial die pressed into 12.7-mm diameter cylindrical compacts in the 76.2-mm warm bore of a 9-T SCM. The press used to compact the powder is unique and was specifically designed for use with the SCM. Although the press was operated in the batch mode for this proof of concept study, its design is intended to enable automated production. In operation, a simple die and punch set made of nonmagnetic materials was filled with powder and loaded into a nonmagnetic press tube. The cantilevered press tube was inserted horizontally, on a carrier manually advanced along a track, into the SCM. The robustness of the mechanical components and the SCM, in its liquid helium dewar, were specifically designed to allow for insertion and extraction of the magnetic powder and compacts, while operating at 9 T. Compaction was achieved by pressing the punches between the closed end of the press tube and the hydraulic cylinder mounted on the opposite end. Improvements up to 10% in magnetization and 20% in energy products of the permanent magnets were obtained, as the alignment fields were increased above the 2-T maximum field of the electromagnets used in industry. Increases in magnetization of 3% are significant in the mature sintered magnet industry

  8. Superconducting polarizing 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 the JINR (Dubna) 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 in the centre with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet contains a main solenoidal winding 558 mm long and 206/144 mm in diameters, and compensating and correcting winding placed at its ends. The windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat. The diameter of the 'warm' aperture of the magnet cryostat is 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. A similar magnet constructed at DAPNIA, CEA/Saclay (France), represented a model for the present development. The MPT array 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)

  9. Quench propagation tests on the LHC superconducting magnet string

    CERN Document Server

    Coull, L; Krainz, G; Rodríguez-Mateos, F; Schmidt, R

    1996-01-01

    The installation and testing of a series connection of superconducting magnets (three 10 m long dipoles and one 3 m long quadrupole) has been a necessary step in the verification of the viability of the Large Hadron Collider at CERN. In the LHC machine, if one of the lattice dipoles or quadrupoles quenches, the current will be by-passed through cold diodes and the whole magnet chain will be de-excited by opening dump switches. In such a scenario it is very important to know whether the quench propagates from the initially quenching magnet to adjacent ones. A series of experiments have been performed with the LHC Test String powered at different current levels and at different de-excitation rates in order to understand possible mechanisms for such a propagation, and the time delays involved. Results of the tests and implications regarding the LHC machine operation are described in this paper.

  10. Engineering design of superconducting magnets for a torsatron experiment

    International Nuclear Information System (INIS)

    Van Sciver, S.W.; Eyssa, Y.M.; Hilal, M.A.; Miller, C.; Shohet, J.L.

    1979-01-01

    The design of superconducting magnets for a torsatron plasma confinement experiment are presented. A torsatron is a variation of a stellarator which requires half the helical windings and no toroidal field coil. Both the toroidal and poloidal fields are produced by a single set of helical winding. Due to the particular distribution of magnetic forces in the helical windings, the design of a torsatron configuration requires special consideration. In this paper, we present the force distribution on the helical coils. For the special case of uniformly distributed winding, magnetic forces and energy are calculated directly from formula for the inductance of toroids and dipoles. Significant reduction in the standard requirement can be achieved if the winding angle can be set at a particular value

  11. Low-frequency flux noise in YBCO dc SQUIDs cooled in static magnetic fields

    International Nuclear Information System (INIS)

    Sager, M.P.; Bindslev Hansen, J.; Petersen, P.R.E.; Holst, T.; Shen, Y.Q.

    1999-01-01

    The low-frequency flux noise in bicrystal and step-edge YBa 2 Cu 3 O x dc SQUIDs has been investigated. The width, w, of the superconducting strips forming the SQUID frame was varied from 4 to 42 μm. The SQUIDs were cooled in static magnetic fields up to 150 μT. Two types of low-frequency noise dominated, namely 1/f-like noise and random telegraph noise giving a Lorentzian frequency spectrum. The 1/f noise performance of the w = 4, 6 and 7 μm SQUIDs was almost identical, while the SQUIDs with w = 22 and 42 μm showed an order of magnitude higher noise level. Our analysis of the data suggests an exponential increase of the 1/f noise versus the cooling field, exhibiting a characteristic magnetic field around 40 μT. (author)

  12. Superconducting magnetic energy storage for electric utilities and fusion systems

    International Nuclear Information System (INIS)

    Rogers, J.D.; Boenig, H.J.; Hassenzahl, W.V.

    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 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. The Los Alamos Scientific Laboratory and the University of Wisconsin are developing 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. In the fusion area, inductive energy transfer and storage is being developed. Both 1-ms fast-discharge theta-pinch systems and 1-to-2-s slow energy transfer tokamak systems have been demonstrated. The major components and the method of operation of a SMES unit are described, and potential applications of different size SMES systems in electric power grids are presented. Results are given of a reference design for a 10-GWh unit for load leveling, of a 30-MJ coil proposed for system stabilization, and of tests with a small-scale, 100-kJ magnetic energy storage system. The results of the fusion energy storage and transfer tests are presented. The common technology base for the various storage systems is discussed

  13. Strong magnetic field induces superconductivity in a Weyl semimetal

    Science.gov (United States)

    Rosenstein, Baruch; Shapiro, B. Ya.; Li, Dingping; Shapiro, I.

    2017-12-01

    Microscopic theory of the normal-to-superconductor coexistence line of a multiband Weyl superconductor subjected to magnetic field is constructed. It is shown that the Weyl semimetal that is nonsuperconducting or having a small critical temperature Tc at zero field might become a superconductor at higher temperatures when the magnetic field is tuned to a series of quantized values Hn. The pairing occurs on Landau levels. It is argued that the phenomenon is detectable much easier in Weyl semimetals than in parabolic band metals since the quantum limit already has been approached in several Weyl materials. The effect of Zeeman coupling leading to splitting of the reentrant superconducting regions on the magnetic phase diagram is considered. An experimental signature of the superconductivity on Landau levels is the reduction of magnetoresistivity. This has been observed already in Cd3As2 and several other compounds. The novel kind of quantum oscillations of magnetoresistance detected in ZrTe5 is discussed along these lines.

  14. 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.

  15. Superconducting magnet development program progress report, July 1974--June 1975

    International Nuclear Information System (INIS)

    Cornish, D.N.; Harvey, A.R.; Nelson, R.L.; Taylor, C.E.; Zbasnik, J.P.

    1975-01-01

    During FY 1975, the superconducting magnet development program at the Lawrence Livermore Laboratory was primarily directed toward the development of multifilamentary Nb 3 Sn conductor for large CTR machines. It was secondarily concerned with preliminary work for the MX experiment and with the acquisition of additional testing facilities. Among the significant achievements was the construction and operation of a 27-cm-bore coil to its short-sample limit of 7-T at the windings. The coil was wound with a 100-m length of 67,507-filament Nb 3 Sn conductor

  16. Reactor structure and superconducting magnet system of ITER

    International Nuclear Information System (INIS)

    Tada, Eisuke; Yoshida, Kiyoshi; Shibanuma, Kiyoshi; Okuno, Kiyoshi; Tsuji, Hiroshi; Shimamoto, Susumu

    1993-01-01

    Fusion Experimental Reactors are one of the major steps toward realization of the fusion energy and the key objective are to demonstrate the scientific and technological feasibility prior to the Demo Fusion Reactor. ITER (International Thermonuclear Experimental Reactor) is one of experimental reactors and the conceptual design has been completed by the united efforts of USA, USSR, EC and Japan. In parallel with the conceptual design, key technology development in various areas has being conducted. This paper describes the overall design concepts and the latest technological achievements of the ITER reactor structure and superconducting magnet system. (author)

  17. Superconducting magnet development. Program annual report, July 1975--September 1976

    International Nuclear Information System (INIS)

    Deis, D.W.; Cornish, D.N.; Zbasnik, J.P.; Nelson, R.L.; Sackett, S.J.; Taylor, C.E.

    1977-01-01

    During FY76 Lawrence Livermore Laboratory (LLL) continued its development of niobium tin (Nb 3 Sn) conductors and its design support for the mirror fusion test facility (MFTF) superconducting magnet. Three highlights came from within the Laboratory. LLL completed its cryogenic tensile-test apparatus for NB 3 Sn strain measurements. Over at MFTF, engineers ordered 2100 m of prototype material for a 1-m test coil. People at the high-field test facility (HFTF) released some components for fabrication; delivery was scheduled for early FY77. Outside LLL several subcontractors advanced Nb 3 Sn manufacturing technology. One advance, in particular, improved conductor current densities at 12 T

  18. Magnetization and transport currents in thin superconducting films

    Science.gov (United States)

    Zeldov, E.; Clem, John R.; McElfresh, M.; Darwin, M.

    1994-04-01

    The critical-state behavior of an infinitely long type-II superconducting thin-film strip is theoretically analyzed for an arbitrary sequence of applied transport currents and perpendicular magnetic fields. Included are solutions for applied field only, transport current only, transport current applied to a sample initially in the remanent critical state, ac applied field, ac transport current, and simultaneously applied field and transport current. The results are compared side by side with corresponding solutions for the more famililar slab geometry; there are striking differences in behavior.

  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. Magnetic field measurements of the superEBIS superconducting magnet

    International Nuclear Information System (INIS)

    Herschcovitch, A.; Kponou, A.; Clipperton, R.; Hensel, W.; Usack, F.

    1994-01-01

    SuperEBIS was designed to have a solenoidal magnetic field of a 5 Tesla strength with a 120 cm long bore. The field was specified to be straight within 1 part in 10000 within the bore, and uniform to within 1 part in 1000 within the central 90 cm. Magnetic field measurements were performed with a computerized magnetic field measuring setup that was borrowed from W. Sampson's group. A preliminary test was made of a scheme to determine if the magnetic and mechanical axes of the solenoid coincided, and, if not, by how much

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

    CERN Document Server

    Hammerath, Franziska

    2012-01-01

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

  2. Flux-pinning-induced stress and magnetostriction in a superconducting strip under combination of transport current and magnetic field

    Science.gov (United States)

    Yang, Yumei; Wang, Xingzhe

    2017-09-01

    The magnetoelastic properties and behaviors arising from the flux-pinning effect are investigated for a long rectangular superconducting strip subject to a combination of applied transport current and magnetic field. Based on the Bean critical state model and linear elastic theory, the flux-pinning-induced stress in the superconducting strip is analytically obtained under the zero-field cooling condition. In particular, the magnetostriction performance for the strip with a one-sided restraint condition is then investigated. The results show that the trapped magnetic flux is distributed asymmetrically along the y-direction. A non-zero resultant force is consequently observed from the magnetization arising from the applied transport current and magnetic field. An obvious tension stress emerges around the constrained side of the strip along which the highest probability for cracking occurs and leads to a structural instability. The analytical results give insight into the flux-pinning-induced stress and magnetostriction response of the superconducting strip under both complex carrying-current and applied magnetic field conditions. These results may also provide helpful guidance in avoiding the breakdown of high-temperature superconductors.

  3. 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)

  4. 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.

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

    CERN Document Server

    Peñaranda, A; Ramírez-Piscina, L

    1999-01-01

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

  6. 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.)

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

    Science.gov (United States)

    Gencer, Ali; Grasso, Gianni

    2009-03-01

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

  8. Thermal Performance of the Supporting System for the Large Hadron Collider (LHC) Superconducting Magnets

    CERN Document Server

    Castoldi, M; Parma, Vittorio; Vandoni, Giovanna

    1999-01-01

    The LHC collider will be composed of approximately 1700 main ring superconducting magnets cooled to 1.9 K in pressurised superfluid helium and supported within their cryostats on low heat in-leak column-type supports. The precise positioning of the heavy magnets and the stringent thermal budgets imposed by the machine cryogenic system, require a sound thermo-mechanical design of the support system. Each support is composed of a main tubular thin-walled structure in glass-fibre reinforced epoxy resin, with its top part interfaced to the magnet at 1.9 K and its bottom part mounted onto the cryostat vacuum vessel at 293 K. In order to reduce the conduction heat in-leak at 1.9 K, each support mounts two heat intercepts at intermediate locations on the column, both actively cooled by cryogenic lines carrying helium gas at 4.5-10 K and 50-65 K. The need to assess the thermal performance of the supports has lead to setting up a dedicated test set-up for precision heat load measurements on prototype supports. This pa...

  9. Heat Load Measurements on a Large Superconducting Magnet An Application of a Void Fraction Meter

    CERN Document Server

    Pengo, R; Junker, S; Passardi, Giorgio; ten Kate, H H J

    2004-01-01

    ATLAS is one of the two major experiments of the LHC project at CERN using cryogenics. The superconducting magnet system of ATLAS is composed of the Barrel Toroid (BT), two End Caps Toroids and the Central Solenoid. The BT is formed of 8 race-track superconducting dipoles, each one 25 m long and 5 m wide. A reduced scale prototype (named B0) of one of the 8 dipoles, about one third of the length, has been constructed and tested in a dedicated cryogenic facility at CERN. To simulate the final thermal and hydraulic operating conditions, the B0 was cooled by a forced flow of 4.5 K saturated liquid helium provided by a centrifugal pump of 80 g/s nominal capacity. Both static and dynamic heat loads, generated by the induced currents on the B0 casing during a slow dump or a ramp up, have been measured to verify the expected thermal budget of the entire BT. The instrument used for the heat load measurements was a Void Fraction Meter (VFM) installed on the magnet return line. The instrument constructed at CERN was ca...

  10. Continuous Magnetic Refrigerators for Cooling in the 0.05 to 10 K Range

    Science.gov (United States)

    Shirron, Peter; DiPirro, Michael; Canavan, Edgar; Tuttle, James; Panek, John; Jackson, Michael; King, Todd; Numazawa, Takenori; Krebs, Carolyn (Technical Monitor)

    2001-01-01

    Low temperature refrigeration is an increasingly vital technology for NASA's Space Science program since most detectors being developed for x-ray, IR and sub-millimeter missions must be cooled to below 100 mK in order to meet the requirements for energy and spatial resolution. For space applications, magnetic refrigeration has an inherent advantage over alternative techniques because it does not depend on gravity. Adiabatic demagnetization refrigerators, or ADRs, are relatively simple, solid state devices. The basic elements are a magnetocaloric refrigerant (usually an encapsulated paramagnetic salt) located in the bore of a superconducting magnet, and a heat switch linking the salt to a heat sink. The alignment of magnetic spins with the magnetic field causes the refrigerant to warm as the magnetic field increases and cool as the field decreases. Thus the simple process of magnetizing the refrigerant to high field with the heat switch closed, then demagnetizing it with the heat switch open allows one to obtain temperatures well below 100 mK using a heat sink as warm as 4.2 K. The refrigerant can maintain a low temperature for a length of time depending on the applied and parasitic heat loads, its mass, and the initial magnetic field strength. Typically ADRs are designed for 12-24 hours of hold time, after which they must be warmed up and recycled.

  11. Superconductivity

    International Nuclear Information System (INIS)

    Andersen, N.H.; Mortensen, K.

    1988-12-01

    This report contains lecture notes of the basic lectures presented at the 1st Topsoee Summer School on Superconductivity held at Risoe National Laboratory, June 20-24, 1988. The following lecture notes are included: L.M. Falicov: 'Superconductivity: Phenomenology', A. Bohr and O. Ulfbeck: 'Quantal structure of superconductivity. Gauge angle', G. Aeppli: 'Muons, neutrons and superconductivity', N.F. Pedersen: 'The Josephson junction', C. Michel: 'Physicochemistry of high-T c superconductors', C. Laverick and J.K. Hulm: 'Manufacturing and application of superconducting wires', J. Clarke: 'SQUID concepts and systems'. (orig.) With 10 tabs., 128 figs., 219 refs

  12. Potential use of superconducting magnets for neutron therapy

    International Nuclear Information System (INIS)

    Duthil, R.; Kircher, F.; Lottin, J.C.; Palanque, S.; Aucouturier, J.; Fache, P.

    1984-01-01

    The results of a feasibility study on the use of superconducting magnets for neutron therapy devices will be reported. Two possibilities can be foreseen: - SC magnets used in the isocentric primary beam transport line. The advantage is to increase the energy of the particles which can be transported (up to 70 MeV for protons), compared to existing systems, with a lower weight. This solution could be used very quickly. - A SC isocentric cyclotron, working at on average field of 4.7 T for accelerating deuterons up to 30 MeV. The feasibility of such a machine is fairly established but technical developments are needed, mainly in view of the rotation and of the miniaturisation of the cyclotron

  13. Quench Simulation of Superconducting Magnets with Commercial Multiphysics Software

    CERN Document Server

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

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

  14. Magnetism and superconductivity of some Tl-Cu oxides

    Science.gov (United States)

    Datta, Timir

    1991-01-01

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

  15. FY 2000 research and development of fundamental technologies for AC superconducting power devices. R and D of fundamental technologies for superconducting power cables and faults current limiters, R and D of superconducting magnets for power applications, and study on the total systems and related subjects; 2000 nendo koryu chodendo denryoku kiki kiban gijutsu kenkyu kaihatsu seika hokokusho. Chodendo soden cable kiban gijutsu no kenkyu kaihatsu, chodendo genryuki kiban gijutsu no kenkyu kaihatsu, denryokuyo chodendo magnet no kenkyu kaihatsu, total system nado no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The project for research and development of fundamental technologies for AC superconducting power devices has been started, and the FY 2000 results are reported. The R and D of fundamental technologies for superconducting power cables include grasping the mechanical characteristics associated with integration necessary for fabrication of large current capacity and long cables; development of barrier cable materials by various methods; and development of short insulated tubes as cooling technology for long superconducting cables, and grasping its thermal/mechanical characteristics. The R and D of faults current limiters include introduction of the unit for superconducting film fabrication, determination of the structures and layouts for large currents, and improvement of performance of each device for high voltages. R and D of superconducting magnets for power applications include grasping the fundamental characteristics of insulation at cryogenic temperature, completion of the insulation designs for high voltage/current lead bushing, and development of prototype sub-cooled nitrogen cooling unit for cooling each AC power device. Study on the total systems and related subjects include analysis for stabilization of the group model systems, to confirm improved voltage stability when the superconducting cable is in service. (NEDO)

  16. Test Station for Magnetization Measurements on Large Quantities of Superconducting Strands

    CERN Document Server

    Le Naour, S; Billan, J; Genest, J

    2001-01-01

    In the superconducting main magnets of the Large Hadron Collider (LHC), persistent currents in the superconductor determine the field quality at injection field. For this reason it is necessary to check the magnetization of the cable strands during their production. During four years, this requires measurements of the width of the strand magnetization hysteresis loop at 0.5 T, 1.9 K, at a rate of up to eight samples per day. This paper describes the design, construction and the first results of a magnetization test station built for this purpose. The samples are cooled in a cryostat, with a 2-m long elliptic tail. This tail is inserted in a normal conducting dipole magnet with a field between ± 1.5 T. Racetrack pick-up coils, integrated in the cryostat, detect the voltage due to flux change, which is then integrated numerically. The sample holder can contain eight strand samples, each 20 cm long. The test station operates in two modes: either the sample is fixed while the external field is changed, or the sa...

  17. Study of magnetized accretion flow with cooling processes

    Science.gov (United States)

    Singh, Kuldeep; Chattopadhyay, Indranil

    2018-02-01

    We have studied shock in magnetized accretion flow/funnel flow in case of neutron star with bremsstrahlung cooling and cyclotron cooling. All accretion solutions terminate with a shock close to the neutron star surface, but at some regions of the parameter space, it also harbours a second shock away from the star surface. We have found that cyclotron cooling is necessary for correct accretion solutions which match the surface boundary conditions.

  18. Upper critical magnetic field of superconducting films with magnetic impurities

    International Nuclear Information System (INIS)

    Lemberger, T.R.

    1978-01-01

    The upper critical magnetic field, H/sub c2/(T), of In-Mn and Pb-Mn alloy films was measured. H/sub c2/ was determined from the resistance of the films. The results were compared with the theory of Fulde and Maki. This theory assumes that the electron-phonon coupling is weak, and that the interaction between the impurity spins and the conduction electron spins is weak. The theory predicts that the pair-breaking effect of the magnetic impurities is temperature-independent, and that the pair-breaking effects of the magnetic impurities and the applied magnetic field are additive. Furthermore, it predicts explicitly the temperature dependence of H/sub c2/. The temperature dependence of H/sub c2/ for the In-Mn alloy films is well described by the Fulde-Maki theory, despite the moderately strong electron-phonon coupling and the strong interaction between the impurity spins and the conduction electron spins. The temperature dependence of H/sub c2/ for the Pb-Mn alloy films is not well described by the Fulde-Maki theory, probably due to the strong electron-phonon coupling in Pb. However, even without a quantitatively correct theory, one can conclude from the Pb-Mn data that the pair-breaking effect of the magnetic impurities is temperature independent, and that the pair-breaking effects of the magnetic impurities and the applied magnetic field are additive. For some of the Pb-Mn alloy films, there was a region of positive curvature in H/sub c2/(T) near the zero-field transition temperature. This positive curvature is not understood

  19. Pressurized helium II-cooled magnet test facility

    International Nuclear Information System (INIS)

    Warren, R.P.; Lambertson, G.R.; Gilbert, W.S.; Meuser, R.B.; Caspi, S.; Schafer, R.V.

    1980-06-01

    A facility for testing superconducting magnets in a pressurized bath of helium II has been constructed and operated. The cryostat accepts magnets up to 0.32 m diameter and 1.32 m length with current to 3000 A. In initial tests, the volume of helium II surrounding the superconducting magnet was 90 liters. Minimum temperature reached was 1.7 K at which point the pumping system was throttled to maintain steady temperature. Helium II reservoir temperatures were easily controlled as long as the temperature upstream of the JT valve remained above T lambda; at lower temperatures control became difficult. Positive control of the temperature difference between the liquid and cold sink by means of an internal heat source appears necessary to avoid this problem. The epoxy-sealed vessel closures, with which we have had considerable experience with normal helium vacuum, also worked well in the helium II/vacuum environment

  20. Magnetic Ordering In Superconducting Nb-doped Bi2Se3

    Science.gov (United States)

    Corbae, Paul; Lawson, Benjamin; Li, Gang; Yu, Fan; Asaba, Tomoya; Tinsman, Colin; Qui, Yusheng; Hor, Yew San; Li, Lu

    Coexistence of superconductivity and magnetic order has been suggested by early studies of topological superconductor candidate, niobium doped Bi2Se3. In order to elucidate the interesting physics of this coexistence, we performed highly sensitive torque magnetometry to study the material's magnetization. We observed a bump feature in the magnetization around 8 Tesla in both the superconducting and non-superconducting samples. This is distinct from the paramagnetic torque response of the parent compound, Bi2Se3, suggesting some interesting magnetic order in Nb-doped Bi2Se3.

  1. Remote monitoring system for the cryogenic system of superconducting magnets in the SuperKEKB interaction region

    Science.gov (United States)

    Aoki, K.; Ohuchi, N.; Zong, Z.; Arimoto, Y.; Wang, X.; Yamaoka, H.; Kawai, M.; Kondou, Y.; Makida, Y.; Hirose, M.; Endou, T.; Iwasaki, M.; Nakamura, T.

    2017-12-01

    A remote monitoring system was developed based on the software infrastructure of the Experimental Physics and Industrial Control System (EPICS) for the cryogenic system of superconducting magnets in the interaction region of the SuperKEKB accelerator. The SuperKEKB has been constructed to conduct high-energy physics experiments at KEK. These superconducting magnets consist of three apparatuses, the Belle II detector solenoid, and QCSL and QCSR accelerator magnets. They are each contained in three cryostats cooled by dedicated helium cryogenic systems. The monitoring system was developed to read data of the EX-8000, which is an integrated instrumentation system to control all cryogenic components. The monitoring system uses the I/O control tools of EPICS software for TCP/IP, archiving techniques using a relational database, and easy human-computer interface. Using this monitoring system, it is possible to remotely monitor all real-time data of the superconducting magnets and cryogenic systems. It is also convenient to share data among multiple groups.

  2. 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.

  3. Analysis of magnetization loops of electrospun nonwoven superconducting fabrics

    Science.gov (United States)

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

    2017-09-01

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

  4. Radiation effects limits on copper in superconducting magnets

    International Nuclear Information System (INIS)

    Guinan, M.W.

    1984-01-01

    The determination of the response of copper stabilizers to neutron irradiation in fusion reactor superconducting magnets requires information in four areas. (1) Neutron flux and spectrum determination are a major factor in the accuracy with which stabilizer response can be predicted. Since magnet stability depends on the weakest link, calculations must be made in sufficient detail to fully account for steep flux gradients and local pertubations from penetrations. (2) Resistivity changes at zero field in magnet spectra are generally calculated from the damage energy cross-section or the equivalent displacement (dpa) rate. (3) Resistivity changes at field for conceptual designs are generally determined from the changes predicted at zero field by the use of a Kohler plot. The cyclic irradiation and annealing, expected to be characteristic of fusion reactor magnet operation, is presently the largest source of uncertainty in determining the limits of neutron exposure for copper stabilizers. Applications of our current understanding of the limits of copper stabilizers in fusion reactor designs are explored in two examples. Recommendations for future additions to the data base are discussed

  5. Cooling tests of the cryomodules at superconducting RF test facility (STF)

    International Nuclear Information System (INIS)

    Ohuchi, Norihito; Nakai, Hirotaka; Kojima, Yuuji

    2009-01-01

    KEK has been constructing the Superconducting RF Test Facility (STF) with aiming at a center of the ILC-R and D in Asia from 2005. In this project, KEK targets manufacturing and operational experiences of the RF cavity and cryomodule toward the ILC, and two cryomodules have been developed. These cryomodules are 6 meter long and have 4 nine-cell cavities in each cryostat. The designs of the cryomodules are based on the TESLA Type-3 (TTF-3) at DESY, however, each cryostat has the different type of cavities, TESLA-like type and Low-Loss type. The tests of the cryomodules were performed in two steps. In the first test, measurements of the cryogenic performances of these cryomodules were the main objective. One nine-cell cavity was assembled in each cryomodule and cool-down of the two cryomodules was performed, individually. In the second test, the four TESLA-like cavities were assembled in the cryomodule as complete integration. Cool-down of the cryomodule to 2 K was successfully completed, and thermal performances of the cryomodule and cooling capacity of the cryogenics system were studied in detail. In this paper, we will report the design of the cryomodules and the thermal performances at these cold tests. (author)

  6. 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.)

  7. Survey of domestic research on superconducting magnetic energy storage

    International Nuclear Information System (INIS)

    Dresner, L.

    1991-09-01

    This report documents the results of a survey of domestic research on superconducting magnetic energy storage (SMES) undertaken with the support of the Oak Ridge National Laboratory (ORNL) Superconductivity Pilot Center. Each survey entry includes the following: Name, address, and other telephone and facsimile numbers of the principal investigator and other staff members; funding for fiscal year 1991, 1992, 1993; brief descriptions of the program, the technical progress to date, and the expected technical progress; a note on any other collaboration. Included with the survey are recommendations intended to help DOE decide how best to support SMES research and development (R ampersand D). To summarize, I would say that important elements of a well-rounded SMES research program for DOE are as follows. (1) Construction of a large ETM. (2) Development of SMES as an enabling technology for solar and wind generation, especially in conjunction with the ETM program, if possible. (3) Development of small SMES units for electric networks, for rapid transit, and as noninterruptible power supplies [uses (2), (3), and (4) above]. In this connection, lightweight, fiber-reinforced polymer structures, which would be especially advantageous for space and transportation applications, should be developed. (4) Continued study of the potential impacts of high-temperature superconductors on SMES, with construction as soon as feasible of small SMES units using high-temperature superconductors (HTSs)

  8. Magnetization loop modelling for superconducting/ferromagnetic tube of an ac magnetic cloak

    International Nuclear Information System (INIS)

    Gömöry, F; Solovyov, M; Šouc, J

    2015-01-01

    From the combination of superconducting (SC) and ferromagnetic (FM) materials, one can prepare composites with unusual magnetic properties, e.g. for the cloaking of a dc or low-frequency ac magnetic field by a shell from a SC/FM composite. In the design and optimisation of such SC/FM structures, numerical modelling is essential. Non-linear magnetic permeability, as well as the hysteresis of both kinds of materials, are to be incorporated in the calculations aimed at achieving reliable estimates. We present a technique that allows the prediction of the ac magnetization loops of SC/FM composites. The critical state model-based approach is used to describe the properties of the superconducting material. The ferromagnetic part is characterized by its (non-hysteretic) nonlinear permeability. With these ingredients, the distributions of the magnetic field are calculated in subsequent instants of the ac cycle and are used to evaluate the preliminary data for the magnetization loop, which is still missing the hysteresis of the FM part. Afterward, the latter component is added to the magnetization loop by an approximation deduced from the known dependence of the hysteresis loss in the FM material on the ac magnetic field. In spite of its approximate nature, this approach demonstrated very good predictability in experimental tests. (paper)

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

    CERN Document Server

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

    2011-01-01

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

  10. Microtesla magnetic resonance imaging with a superconducting quantum interference device

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, Robert; Lee, SeungKyun; ten Haken, Bennie; Trabesinger, Andreas H.; Pines, Alexander; Clarke, John

    2004-03-15

    We have constructed a magnetic resonance imaging (MRI) scanner based on a dc Superconducting QUantum Interference Device (SQUID) configured as a second-derivative gradiometer. The magnetic field sensitivity of the detector is independent of frequency; it is therefore possible to obtain high-resolution images by prepolarizing the nuclear spins in a field of 300 mT and detecting the signal at 132 fYT, corresponding to a proton Larmor frequency of 5.6 kHz. The reduction in the measurement field by a factor of 10,000 compared with conventional scanners eliminates inhomogeneous broadening of the nuclear magnetic resonance lines, even in fields with relatively poor homogeneity. The narrow linewidths result in enhanced signal-to-noise ratio and spatial resolution for a fixed strength of the magnetic field gradients used to encode the image. We present two-dimensional images of phantoms and pepper slices, obtained in typical magnetic field gradients of 100 fYT/m, with a spatial resolution of about 1mm. We further demonstrate a slice-selected image of an intact pepper. By varying the time delay between removal of the polarizing field and initiation of the spin echo sequence we acquire T1-weighted contrast images of water phantoms, some of which are doped with a paramagnetic salt; here, T1 is the nuclear spin-lattice relaxation time. The techniques presented here could readily be adapted to existing multichannel SQUID systems used for magnetic source imaging of brain signals. Further potential applications include low-cost systems for tumor screening and imaging peripheral regions of the body.

  11. SSC string test facility for superconducting magnets: Testing capabilities and program for collider magnets

    International Nuclear Information System (INIS)

    Kraushaar, P.; Burgett, W.; Dombeck, T.; McInturff, A.; Robinson, W.; Saladin, V.

    1993-05-01

    The Accelerator Systems String Test (ASST) R ampersand D Testing Facility has been established at the SSC Laboratory to test Collider and High Energy Booster (HEB) superconducting magnet strings. The facility is operational and has had two testing periods utilizing a half cell of collider prototypical magnets with the associated spool pieces and support systems. This paper presents a description of the testing capabilities of the facility with respect to components and supporting subsystems (cryogenic, power, quench protection, controls and instrumentation), the planned testing program for the collider magnets

  12. Superconducting magnet development. Program annual report, July 1975--September 1976

    Energy Technology Data Exchange (ETDEWEB)

    Deis, D.W.; Cornish, D.N.; Zbasnik, J.P.; Nelson, R.L.; Sackett, S.J.; Taylor, C.E.

    1977-07-22

    During FY76 Lawrence Livermore Laboratory (LLL) continued its development of niobium tin (Nb/sub 3/Sn) conductors and its design support for the mirror fusion test facility (MFTF) superconducting magnet. Three highlights came from within the Laboratory. LLL completed its cryogenic tensile-test apparatus for NB/sub 3/Sn strain measurements. Over at MFTF, engineers ordered 2100 m of prototype material for a 1-m test coil. People at the high-field test facility (HFTF) released some components for fabrication; delivery was scheduled for early FY77. Outside LLL several subcontractors advanced Nb/sub 3/Sn manufacturing technology. One advance, in particular, improved conductor current densities at 12 T.

  13. Checking the Polarity of Superconducting Multipole LHC Magnets

    CERN Document Server

    Buzio, M; Brun, G; Fievez, G; Galbraith, P; García-Pérez, J; López, R; Masi, A; Russenschuck, Stephan; Smirnov, N; Tikhov, A

    2006-01-01

    This paper describes the design and operation of the â€ワPolarity Checker”, a scanning probe designed to check multipole field order, type and polarity of superconducting LHC magnets. First we introduce the measurement method, based on the harmonic analysis of the radial field component picked up by a rotating Hall sensor at different current levels. Then we describe the hardware and the software of the system, which features automatic powering, data acquisition and treatment, discussing the achieved sensitivity and performance. Finally we provide a summary of the test results on the first 505 cryoassemblies, showing how the system was usefully employed to detect some potentially harmful connection errors.

  14. The fabrication and characterization of high temperature superconducting magnetic shields

    Energy Technology Data Exchange (ETDEWEB)

    Purpura, J.W.; Clem, T.R.

    1989-03-01

    Tubes fabricated of polycrystalline YBa/sub 2/Cu/sub 3/O/sub 7-x/ are characterized and details of the fabrication procedure are discussed. The microstructure of the tubes determined by scanning electron microscopy and x-ray diffractometry is described. Resistive measurements of T/sub c/ and /Delta/T/sub c/ have been made. The tubes have also been characterized by means of SQUID magnetometry. The temperature dependence of magnetic fields trapped axially in the tubes has been measured and estimates of penetration depth are given. Moreover, measurements of transverse shielding effectiveness of the tubes have been made and are compared with theoretical predictions. Studies on flux penetration into the tubes are described. Findings from the microstructure studies are correlated with the observed superconductivity properties. The results on the high temperature materials are compared to results obtained previously on tubes made from conventional superconductors.

  15. Stabilization of the field of a superconducting magnetic system

    International Nuclear Information System (INIS)

    Sukhoj, V.V.; Kurochkin, V.I.; Laptienko, A.Ya.; Timoshenko, A.O.

    1981-01-01

    A way of magnetic field stabilization of short circuited superconducting system is considered theoretically. Removable field instability is caused by resistance of circuits windings in places of conductor joints or by the presence of wive defects. An equation is obtained describing the stabilization condition which connects electrical and geometrical parameters of circuits. The cases of this equation solutions by means of geometry choice or choice of resistance value of one of the circuits are considered. Field stability dependence on the accuracy of stabilization condition satisfaction is studied. Three time scales are introduced, which characterize the system operation without the deterioration of field homogeneity and stability as well as without the critical current excess in the circuit state mostly close to a critical one. Numerical calculations for concrete two- and three-circuit systems are presented [ru

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

    CERN Document Server

    Pfeffer, H.; Wolff, D.

    2016-01-01

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

  17. Incommensurate magnetism in non-superconducting PrBa2Cu3O6.92

    DEFF Research Database (Denmark)

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

    1999-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

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

  19. 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

  20. Local imaging of magnetic flux in superconducting thin films

    International Nuclear Information System (INIS)

    Shapoval, Tetyana

    2010-01-01

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

  1. Local imaging of magnetic flux in superconducting thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shapoval, Tetyana

    2010-01-26

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

  2. Adiabatic cooling processes in frustrated magnetic systems with pyrochlore structure

    Science.gov (United States)

    Jurčišinová, E.; Jurčišin, M.

    2017-11-01

    We investigate in detail the process of adiabatic cooling in the framework of the exactly solvable antiferromagnetic spin-1/2 Ising model in the presence of the external magnetic field on an approximate lattice with pyrochlore structure. The behavior of the entropy of the model is studied and exact values of the residual entropies of all ground states are found. The temperature variation of the system under adiabatic (de)magnetization is investigated and the central role of the macroscopically degenerated ground states in cooling processes is explicitly demonstrated. It is shown that the model parameter space of the studied geometrically frustrated system is divided into five disjunct regions with qualitatively different processes of the adiabatic cooling. The effectiveness of the adiabatic (de)magnetization cooling in the studied model is compared to the corresponding processes in paramagnetic salts. It is shown that the processes of the adiabatic cooling in the antiferromagnetic frustrated systems are much more effective especially in nonzero external magnetic fields. It means that the frustrated magnetic materials with pyrochlore structure can be considered as very promising refrigerants mainly in the situations with nonzero final values of the magnetic field.

  3. Cryogenic properties of austenitic stainless steels for superconducting magnet

    International Nuclear Information System (INIS)

    Nohara, K.; Kato, T.; Ono, Y.; Sasaki, T.; Suzuki, S.

    1983-01-01

    The present study examines the magnetic and mechanical properties of a variety of austenitic stainless steels and high maganese steel which are candidate materials for the superconducting magnet attached to high energy particle accelerators. The effect of a specified heat treatment for the precipitation of intermetallic compound Nb3Sn to be used as superconductor on ductility and toughness are especially examined. It is found that nitrogen-strengthened austenitic stainless steels have high strength and good ductility and toughness, but that these are destroyed by precipitation treatment. The poor ductility and toughness after precipitation are caused by a weakening of the grain boundaries due to the agglomerated chromium carbide percipitates. The addition of vanadium suppresses this effect by refining the grain. Austenitic steels are found to have low magnetic permeabilities and Neel temperatures, and show serrated flow in traction test due to strained martensitic transformation. High manganese steel has extremely low permeability, a Neel temperature about room temperature, and has a serrated flow in traction test due to adiabatic deformation at liquid helium temperature

  4. Magnetic field measurements of model SSC [Superconducting Super Collider] dipoles

    International Nuclear Information System (INIS)

    Hassenzahl, W.V.; Gilbert, W.S.; Green, M.I.; Barale, P.J.

    1986-10-01

    To qualify for use in the Superconducting Super Collider, the 8000 or so 16 m long dipole magnets must pass a series of tests. One of these will be a set of warm measurements of field quality, which must be precise to about 0.001% of the 100 G field produced by 10 A, the maximum current the coils are allowed to carry for an extended period at room temperature. Field measurements of better than this accuracy have already been carried out on 1 m long model dipoles. These measurements have included determinations of the dipole fields and the higher harmonics in the central or two dimensional region and in the total magnet. In addition, axial scans of the dipole and higher harmonic magnetic fields have been made to determine the local variations, which might reflect fabrication and assembly tolerances. This paper describes the equipment developed for these measurements, the results of a representative set of measurements of the central and integral fields and axial scans, and a comparison between warm and cold measurements. Reproducibility, accuracy and precision will be described for some of the measurements. The significance of the warm measurements as a part of the certification process for the SSC dipoles will be discussed

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

    Science.gov (United States)

    2016-06-09

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

  6. 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

  7. 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.

  8. Investigation of transient, mechanical disturbances in superconducting cables with internal cooling; Untersuchungen von transienten mechanischen Stoerungen in intern gekuehlten Supraleiterkabeln

    Energy Technology Data Exchange (ETDEWEB)

    Hertle, R.

    1994-01-01

    One of the major causes of early loss of superconductivity of cables in superconducting magnets are mechanical disturbances induced by Lorentz forces, the causes observed being frictional mechanisms, cracks, dislocations, and deformations. Although it is possible to estimate the threshold value of interfering energy up to which a superconductor will remain, stable, but it is not yet feasible to assess the defects dimensions prior to a coil test with the internally cooled, CIC wires. The report explains the development of a method which allows to determine, by way of a simple test with a piece of cable, the friction and deformation energy released in the CIC cable of a magnet during the phase of coil start up. For the test, short cable pireces of the castle to form the wiring of the magnet are used. Their stress-strain hysteresis curves are recorded at room temperature and LN{sub 2} temperature, under transverse compression. Also, the number or rate and intensity of the various frictional or deformation processes are recorded by means of acoustic emission analysis. By correlating measured data and events, conclusions can be drawn as to the mechanical energy released in every process. (MM) [Deutsch] Eine der Hauptursachen eines vorzeitigen Verlusts der Supraleitfaehigkeit von Kabeln in Supraleiter-Magneten sind durch Lorenzkraefte verusachte mechanische Stoerungen wie Reibungsvorgaenge, Risse, Spruenge und Verformungen. Es ist zwar moeglich, die Grenze abzuschaetzen, bis zu welcher Stoerenergie ein Supraleiter stabil ist, aber es ist bisher fuer intern gekuehlte CIC-Leiter (cable in conduit) nicht moeglich, die Groesse solcher Stoerungen vor einem Spulentest zu bestimmen. In dieser Arbeit wird eine Methode entwickelt mit Hilfe derer man in der Lage ist, die beim Hochfahren eines aus einem CIC-Leiter aufgebauten Magneten die im Kabel freiwerdende Reibungs- und Verformungsenergie durch einen einfachen Versuch an einem Kabelstueck schon vorher zu bestimmen. Dazu werden

  9. Automated installations for reeling up of superconducting magnet windings of the accelerating-storage complex

    International Nuclear Information System (INIS)

    Dolzhenkov, V.I.; Elistratov, V.V.; Kuznetsov, Yu.V.; Petrov, V.B.; Popov, V.V.; Savel'ev, A.V.; Sokolov, B.V.; Sytnik, V.V.; Tarakanov, N.M.; Ustinov, E.A.

    1992-01-01

    An automated facility for reeling up the windings of model and full-scale superconducting magnets of the accelerating-storage complex is described. The control system monitors superconducting cable tension, transport carriage linear velocity and some other parameters. Maximum length of the winded coils is 6 m. Cable tension stability - 5%

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

    NARCIS (Netherlands)

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

    1994-01-01

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

  11. Fusion magnet safety studies program: superconducting magnet protection system and failure. Interim report

    International Nuclear Information System (INIS)

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

    1975-11-01

    This report includes the first two quarters study of available information on schemes for protecting superconducting magnets. These schemes can be divided into two different categories. The first category deals with the detection of faulty regions (or normal regions) in the magnet. The second category relates to the protection of the magnet when a fault is detected, and the derived signal which can be used to activate a safety system (or energy removal system). The general detection and protection methods are first described briefly and then followed by a survey of the protection systems used by different laboratories for various magnets. A survey of the cause of the magnet difficulties or failures is also included. A preliminary discussion of these protection schemes and the experimental development of this program is given

  12. Fusion magnet safety studies program: superconducting magnet protection system and failure. Interim report

    Energy Technology Data Exchange (ETDEWEB)

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

    1975-11-01

    This report includes the first two quarters study of available information on schemes for protecting superconducting magnets. These schemes can be divided into two different categories. The first category deals with the detection of faulty regions (or normal regions) in the magnet. The second category relates to the protection of the magnet when a fault is detected, and the derived signal which can be used to activate a safety system (or energy removal system). The general detection and protection methods are first described briefly and then followed by a survey of the protection systems used by different laboratories for various magnets. A survey of the cause of the magnet difficulties or failures is also included. A preliminary discussion of these protection schemes and the experimental development of this program is given.

  13. 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...

  14. 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

  15. Magnetic system of a superconducting separated-sector cyclotron for hadron therapy

    Science.gov (United States)

    Smirnov, V. L.; Vorozhtsov, S. B.

    2017-07-01

    The development of a cyclotron magnetic system based on superconducting sector magnets is discussed. The cyclotron is conceived as a booster accelerator of a source of 12C6+ ions with energy of 400MeV/nucleon for the purposes of hadron therapy. The results of preliminary investigations aimed at developing such a facility have been reported in our previous papers. In this paper, we consider various configurations of the booster's magnetic system for various field levels. We also analyze the effects of the positions and shapes of superconducting coils on the magnetic field and select the optimum configuration for the cyclotron's magnetic system.

  16. Superconducting magnets. A. Some fundamentals and their state of the art

    International Nuclear Information System (INIS)

    Heinz, W.; Karlsruhe Univ.

    1978-01-01

    An introduction to the basis of superconductivity is given. Materials suitable for use in superconducting magnets and their essential properties are presented followed by a discussion on the status of conductor development. A survey of stabilization methods, behavior of the superconductor under normal operating conditions and special requirements of superconductors for fusions magnets are given. Magnet technology and its status is briefly discussed. Existing magnet systems are introduced. Finally some of the most important problems encountered in developing big toroidal magnet systems are mentioned

  17. A water-cooled 13-kG magnet system

    International Nuclear Information System (INIS)

    Rossi, J.O.; Goncalves, J.A.N.; Barroso, J.J.; Patire Junior, H.; Spassovsky, I.P.; Castro, P.J.

    1993-01-01

    The construction, performance, and reliability of a high field magnet system are reported. The magnet is designed to generate a flat top 13 kG magnetic induction required for the operation of a 35 GHz, 100 k W gyrotron under development at INPE. The system comprises three solenoids, located in the gun, cavity, and collector regions, consisting of split pair magnets with the field direction vertical. The magnets are wound from insulated copper tube whose rectangular cross section has 5.0 mm-diameter hole leading the cooling water. On account of the high power (∼ 100 k W) supplied to the cavity coils, it turned out necessary to employ a cooling system which includes hydraulic pump a heat exchanger. The collector and gun magnets operate at lower DC current (∼ 150 A), and, in this case, flowing water provided by wall pipes is far enough to cool down the coils. In addition, a 250 k V A high power AC/DC Nutek converser is used to supply power to the cavity magnet. For the collector and gun magnets, 30 V/600 A DC power supplies are used. (author)

  18. Superconductivity

    CERN Document Server

    Ketterson, John B

    2008-01-01

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

  19. Low Loss Superconducting Magnets Operating at 15 - 40 K, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal responds to the technological challenge of design and manufacture of shielded superconducting magnets generating 3-4 T at temperatures > 15 K. An...

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

    Energy Technology Data Exchange (ETDEWEB)

    Nabeta, Masahiro, E-mail: nabeta@mp.okayama-u.ac.jp; Tanaka, Kenta K.; Onari, Seiichiro; Ichioka, Masanori

    2016-11-15

    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.

  1. Assessment of some of the problems in the USA of superconducting magnets for fusion research

    International Nuclear Information System (INIS)

    Cornish, D.N.

    1981-01-01

    This paper discusses some of the general difficulties and problems encountered during the development of the technology of superconductors and superconducting magnets for fusion and expresses some personal concerns

  2. 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.

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

    Science.gov (United States)

    Wu, M. K.

    1987-01-01

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

  4. Sub-cooled liquid helium flow supply for design D magnet cooling at MDTF

    International Nuclear Information System (INIS)

    Ohmori, T.

    1986-07-01

    The parameters of the subcooled 4ATM helium flow from MTDF refrigerator and helium subcooler proposed to cool the SSC Design 'D' magnet is discussed. The system operating parameters are pressure - 4ATM and temperature - 4.35K. The higher than normal operating pressure is obtained by shutting down the cold turbine (T2) of MTDF refrigerator, and then not J-T the high pressure dense helium gas until after the magnet and liquid return line. The resultant helium temperature at the refrigerator outlet is described and the heat transfer tube length of the subcooler required to cool the flow to the ultimate desired temperature is evaluated

  5. Thermomechanical properties of the coil of the superconducting magnets for the Large Hadron Collider

    OpenAIRE

    Couturier, K; Ferracin, P; Scandale, Walter; Todesco, Ezio; Tommasini, D

    2002-01-01

    The correct definition and measurement of the thermomechanical properties of the superconducting cable used in high-field magnets is crucial to study and model the behavior of the magnet coil from assembly to the operational conditions. In this paper, the authors analyze the superconducting coil of the main dipoles for the Large Hadron Collider. They describe an experimental setup for measuring the elastic modulus at room and at liquid nitrogen temperature and for evaluating the thermal contr...

  6. 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.)

  7. Mechanical alignment of particles for use in fabricating superconducting and permanent magnetic materials

    International Nuclear Information System (INIS)

    Nellis, W.J.; Maple, M.B.

    1992-01-01

    This patent describes a method of fabricating oriented compacts of superconducting and/or permanent magnetic material. It comprises: providing a base layer of support material, mechanically orienting aligned superconducting or permanently magnetic particles into the desired orientation on the base layer, without mixing the particles with a liquid, optionally covering the particles with a support material, fabricating the base layer and oriented particles assemblage into a desired construct and recovering the resulting fabricated material

  8. 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.

  9. Exploring Magnetic Elastocaloric Materials for Solid-State Cooling

    Science.gov (United States)

    Liu, Jian; Zhao, Dewei; Li, Yang

    2017-09-01

    In the past decade, there has been an increased surge in the research on elastocaloric materials for solid-state refrigerators. The strong coupling between structure and magnetism inspires the discovery of new multi-field driven elastocaloric alloys. This work is devoted to magnetic shape memory alloys suitable for mechanical cooling applications. Some novel characteristics in magnetostructural transition materials other than conventional shape memory alloys are overviewed. From the physical and engineering points of view, we have put forward general strategies to maximize elastocaloric temperature change to increase performance reversibility and to improve mechanical properties. The barocaloric effect as a sister-cooling alternative is also discussed.

  10. Development and application of superconducting magnet for gyrotron with 4 mm wave length

    International Nuclear Information System (INIS)

    Zhu Xuewu; Pu Men; Chen Jian; Liu Jianmin; Shi Qingju

    1989-01-01

    A superconducting magnet for gyrotron with 4 mm wave legnth is developed, its main magnetic field reaches 3 T. The gyrotron combined with the magnet producesfundamental wave long pulse, its power is more than 60 kW, pulse duration 10 ∼ 20 ms, frequency 70 GHz. It is used for plasma preionization experiment on HL-1 Tokamak

  11. Some characteristics of the superconducting magnetic system of toroidal spectrometer STORS

    International Nuclear Information System (INIS)

    Andreev, S.V.; Vorozhtsov, S.B.; Kakurin, S.I.

    1993-01-01

    A superconducting toroidal spectrometer (STORS) has been suggested to provide precision measurements of structure functions in muon beams. In this paper we present the calculation of the magnet induction and forces influencing the elements of the magnet, requirements to the reliability and rigidity of the carrying elements of the magnet construction. (author.) 14 refs.; 50 figs.; 4 tabs

  12. Superconducting magnetic energy storage (SMES). Results of a technology assessment

    International Nuclear Information System (INIS)

    Fleischer, T.; Juengst, K.P.; Brandl, V.; Maurer, W.; Nieke, E.

    1995-05-01

    The authors report on results of a Technology Assessment study commissioned by the German Federal Ministry of Education, Science, Research and Technology. The objective of this study was to evaluate the potential of superconducting magnetic energy storage (SMES) technology with respect to the economical, political and organization structures in the Federal Republic of Germany. The main focus of the study was on the technical and economic potential of large-scale SMES for diurnal load levelling applications. It was shown that there is no demand for the development of large SMES in Germany in the short and medium term. A second range of applications investigated is storage of electric energy for immediate delivery or consumption of electric power in case of need or for periodic power supply within the range of seconds. Due to its excellent dynamic properties SMES has substantial advantages over conventional storage technologies in this field. For those so-called dynamic applications SMES of small and medium energy capacity are needed. It was shown that SMES may be economically attractive for the provision of spinning reserve capacity in electrical networks, in particular cases for power quality applications (uninterruptable power supply, UPS) and for the compensation of cyclic loads, as well as in some market niches. The use of SMES for storage of recuperated energy in electrical railway traction systems has been proven to be uneconomical. Mobile SMES applications are unrealistic due to technical and size limitations. In SMES systems the energy is stored in a magnetic field. Biological objects as well as technical systems in the vicinity of a SMES plant are exposed to this field. The knowledge on impacts of magnetic fields on sensitive technical systems as well as on living organisms and especially on effects on human health is rather small and quite uncertain. (orig./MM) [de

  13. Superconducting RF cavities and magnets for a 4-TeV energy muon collider

    International Nuclear Information System (INIS)

    Shu, Q.S.; Green, M.; Neuffer, D.; Summers, D.; Simrock, S.; Willen, E.

    1997-01-01

    The accelerators must take the muon beams from ∼ 100 MeV to 2 TeV energies within the muon lifetime for a 4 TeV energy muon collider. These constraints plus the muon decay heating seriously challenge the designs of the superconducting RF (SRF) cavities and magnets in the accelerators and collider ring. The multiple superconducting recirculation linac and the very rap8id-cycling superconducting synchrotron approach are both studied. The authors briefly introduce the technical considerations and preliminary designs of the SRF systems and magnets

  14. 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

  15. A 64-channel whole-head SQUID system in a superconducting magnetic shield

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, H. [Communications Research Laboratory, Ministry of Posts and Telecommunication, Nukuikitamachi 4-2-1, Koganei, Tokyo 184 (Japan); The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako-shi, Saitama 351-01 (Japan); Matsui, T. [Communications Research Laboratory, Ministry of Posts and Telecommunication, Nukuikitamachi 4-2-1, Koganei, Tokyo 184 (Japan); Aono, M. [The Institute of Physical and Chemical Research RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-01 (Japan); Uchikawa, Y.; Kobayashi, K.; Tanabe, K.; Takeuchi, S. [Tokyo Denki University, Oaza-Ishizaka, Hatoyama-cho, Hiki-gun, Saitama 350-03 (Japan); Narasaki, K.; Tsunematsu, S.; Koyabu, Y.; Kamekawa, Y. [Sumitomo Heavy Industry, Soukai-cho 5-2, Niihama-shi, Ehime 792-8588 (Japan); Nakayama, K.; Shimizu, T. [Nihonkeiki Corporation, Goshogaoka 4-3-5, Moriyacho, Kitasoma-gun, Ibaraki 302-0119 (Japan); Koike, J.; Hoshino, K.; Kotaka, H.; Sudoh, E.; Takahara, H. [Mitsui Mining and Smelting Co, Ltd., Corporate R and D Centre, Haraichi 1333-2, Ageo, Saitama 362 (Japan); Yoshida, Y. [National Research Institute of Metals, Tsukuba, Ibaraki 305-0047 (Japan); Shinada, K.; Takahata, M.; Yamaga, Y. [Shimadzu Corporation, Keihanna Research Laboratory, Inuidani-Sunagatani, Seika-cho, Soraku-gun, Kyoto 619-02 (Japan); Kamijo, K. [NEC Fundamental Research Laboratory, Tsukuba, Ibaraki 273-2310 (Japan)

    1999-11-01

    A superconducting magnetic shield of high-T{sub c} superconductor Bi(Pb)-Sr-Ca-Cu-O{sub x} has been constructed whose diameter is 65 cm and length is 160 cm. We have successfully observed magnetic fields from somatosensory-evoked human brains in the superconducting magnetic shield by stimulating the median nerves of patients by current pulses. We made a 64-channel whole-head SQUID magnetometer of superconductor/normal metal/superconductor (SNS) junctions which do not show low-frequency telegraph noise. The sensitivities of the dc SQUID mesoscopic SNS junctions are around 5 fT Hz{sup -1/2} even in rather unfavourable surroundings. The magnetic shield can reduce a magnetic field by around -80 dB or a factor of 10{sup -4} even at as low a frequency as 0.05 Hz. Therefore SQUIDs of SNS junctions and a superconducting magnetic shield are a good combination. (author)

  16. Fundamental study on recovery of resources by magnetic separation using superconducting bulk magnet

    Science.gov (United States)

    Okada, S.; Mishima, F.; Akiyama, Y.; Nishijima, S.

    2011-11-01

    The process of polishing glass substrate is necessary for production of the liquid crystal, thus the substance which mainly consists of CeO2 (ceria) is used as a polishing agent. In this study, we aim to separate impurities selectively from waste slurry and recover ceria particles in order to reuse as a polishing agent. Waste fluid contains impurities such as ferrous particles originating from aggregating agent. We focused on the difference in magnetic property of each particle, and applied the high gradient magnetic separation with superconducting magnet which can separate not only ferromagnetic particle but also paramagnetic particle with relatively high magnetization. We controlled pH based on surface potential of ceria and ferrous particles in order to avoid the aggregation of the waste fluid. As the result of optimization of the conditions such as the geometry of filters, fluid flow rate and pH by calculation and experiment, the sufficient separation efficiency was obtained.

  17. 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).

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-07-01

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

  20. Potential Applications of Microtesla Magnetic Resonance ImagingDetected Using a Superconducting Quantum Interference Device

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Whittier Ryan [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    This dissertation describes magnetic resonance imaging (MRI) of protons performed in a precession field of 132 μT. In order to increase the signal-to-noise ratio (SNR), a pulsed 40-300 mT magnetic field prepolarizes the sample spins and an untuned second-order superconducting gradiometer coupled to a low transition temperature superconducting quantum interference device (SQUID) detects the subsequent 5.6-kHz spin precession. Imaging sequences including multiple echoes and partial Fourier reconstruction are developed. Calculating the SNR of prepolarized SQUID-detected MRI shows that three-dimensional Fourier imaging yields higher SNR than slice-selection imaging. An experimentally demonstrated field-cycling pulse sequence and post-processing algorithm mitigate image artifacts caused by concomitant gradients in low-field MRI. The magnetic field noise of SQUID untuned detection is compared to the noise of SQUID tuned detection, conventional Faraday detection, and the Nyquist noise generated by conducting biological samples. A second-generation microtesla MRI system employing a low-noise SQUID is constructed to increase SNR. A 2.4-m cubic, eddy-current shield with 6-mm thick aluminum walls encloses the experiment to attenuate external noise. The measured noise is 0.75 fT Hz-1/2 referred to the bottom gradiometer loop. Solenoids wound from 30-strand braided wire to decrease Nyquist noise and cooled by either liquid nitrogen or water polarize the spins. Copper wire coils wound on wooden supports produce the imaging magnetic fields and field gradients. Water phantom images with 0.8 x 0.8 x 10 mm3 resolution have a SNR of 6. Three-dimensional 1.6 x 1.9 x 14 mm3 images of bell peppers and 3 x 3 x 26 mm3 in vivo images of the human arm are presented. Since contrast based on the transverse spin relaxation rate (T1) is enhanced at low magnetic fields, microtesla MRI could potentially be used for tumor imaging. The

  1. Potential Applications of Microtesla Magnetic Resonance Imaging Detected Using a Superconducting Quantum Interference Device

    International Nuclear Information System (INIS)

    Myers, Whittier R.

    2006-01-01

    This dissertation describes magnetic resonance imaging (MRI) of protons performed in a precession field of 132 (micro)T. In order to increase the signal-to-noise ratio (SNR), a pulsed 40-300 mT magnetic field prepolarizes the sample spins and an untuned second-order superconducting gradiometer coupled to a low transition temperature superconducting quantum interference device (SQUID) detects the subsequent 5.6-kHz spin precession. Imaging sequences including multiple echoes and partial Fourier reconstruction are developed. Calculating the SNR of prepolarized SQUID-detected MRI shows that three-dimensional Fourier imaging yields higher SNR than slice-selection imaging. An experimentally demonstrated field-cycling pulse sequence and post-processing algorithm mitigate image artifacts caused by concomitant gradients in low-field MRI. The magnetic field noise of SQUID untuned detection is compared to the noise of SQUID tuned detection, conventional Faraday detection, and the Nyquist noise generated by conducting biological samples. A second-generation microtesla MRI system employing a low-noise SQUID is constructed to increase SNR. A 2.4-m cubic, eddy-current shield with 6-mm thick aluminum walls encloses the experiment to attenuate external noise. The measured noise is 0.75 fT Hz -1/2 referred to the bottom gradiometer loop. Solenoids wound from 30-strand braided wire to decrease Nyquist noise and cooled by either liquid nitrogen or water polarize the spins. Copper wire coils wound on wooden supports produce the imaging magnetic fields and field gradients. Water phantom images with 0.8 x 0.8 x 10 mm 3 resolution have a SNR of 6. Three-dimensional 1.6 x 1.9 x 14 mm 3 images of bell peppers and 3 x 3 x 26 mm 3 in vivo images of the human arm are presented. Since contrast based on the transverse spin relaxation rate (T 1 ) is enhanced at low magnetic fields, microtesla MRI could potentially be used for tumor imaging. The measured T 1 of ex vivo normal and cancerous

  2. Field-screening calculations for superconducting tokamak magnets

    International Nuclear Information System (INIS)

    Turner, L.R.; Wang, S.T.; Kim, S.H.

    1978-01-01

    If the polodial-field (PF) coils of a tokamak reactor are placed outside the toroidal-field (TF) coils, the TF coils will be subject to a large (several kilogauss) pulsing field from the PF coils. AC losses in the TF coils would be unacceptably large unless the TF coils were wound of an ac type conductor. Such conductors are typically complicated, expensive, and mechanically weak. Alternatively, each TF coil can be shielded against the pulsed field by surrounding it with a shield of high purity aluminum. The aluminum has a skin depth of 3.1 cm at 18 K and 2.0 cm at 4.2 K, for a fundamental frequency of one pulse per 75 sec, so that a 5 cm thick or 4 cm thick shield should be adequate at these temperatures, respectively. In calculating the eddy current heating of the shield, each Fourier component is considered separately, and the parallel and perpendicular components of field are considered separately. For each component, integration around the TF coil is approximated numerically; then the results are summed. The shield temperature of 18 K was chosen by weighing the resistivity of the aluminum against the efficiency of the refrigeration; in cooling below 18 K, the decreased resistivity of the aluminum is more than offset by the poorer efficiency of refrigeration. Over the inner leg of the TF coils, where space does not permit a separate 18 K cryostat, the shield operates at the same temperature as the TF coil, 4.2 K. Of the several development problems of the aluminum shield, the most severe is probably protecting it from radiation, which would raise its resistivity and impair its screening. Passive superconducting coils are considered as an alternative to the aluminum shield, but they would require even more development work than the aluminum. They might prove especially convenient on the inner legs of the TF coils, where space and radiation effects are most difficult for the aluminum shield. (author)

  3. Characteristics of a superconducting magnet using a persistent current for a 110 GHz gyrotron

    International Nuclear Information System (INIS)

    Maebara, Sunao; Kasugai, Atsushi; Sakamoto, Keishi; Tsuneoka, Masaki; Imai, Tsuyoshi

    1996-03-01

    A superconducting magnet (SCM) using a persistent current for a 110 GHz gyrotron was developed to reduce liquid-helium loss, the boiled-off rate of 0.13 liter/hour was attained in a persistent current operation. It shows that the continuous operation for 50 days is capable without additional liquid-helium supply. Moreover, the 3040 liter in a year is used for a gyrotron test during five months and for the maintenance during seven months and liquid-helium savings of 65% was successfully demonstrated. The SCM is capable to excite the maximum magnetic field of 5.0 T in the persistent current mode. A mirror ratio between resonant cavity and magnetron injection gun (MIG) is 20 for operating the main coils in the persistent mode, since cavity coils and gun coils are connected in series. Auxiliary coils are equipped independently to control the mirror ratio, the mirror ratio of 13.6 - 37.0 at the 110 GHz is available. A two-stage refrigerator using helium gas was also installed and made liquid-nitrogen for cooling thermal shield of 80 K free. By developing this new type SCM, the number of routine works was drastically decreased in one time per 22-50 days, while routine works of a few times per week was needed up to now. (author)

  4. Superconductivity and magnetism in iron sulfides intercalated by metal hydroxides.

    Science.gov (United States)

    Zhou, Xiuquan; Eckberg, Christopher; Wilfong, Brandon; Liou, Sz-Chian; Vivanco, Hector K; Paglione, Johnpierre; Rodriguez, Efrain E

    2017-05-01

    Inspired by naturally occurring sulfide minerals, we present a new family of iron-based superconductors. A metastable form of FeS known as the mineral mackinawite forms two-dimensional sheets that can be readily intercalated by various cationic guest species. Under hydrothermal conditions using alkali metal hydroxides, we prepare three different cation and metal hydroxide-intercalated FeS phases including (Li 1- x Fe x OH)FeS, [(Na 1- x Fe x )(OH) 2 ]FeS, and K x Fe 2- y S 2 . Upon successful intercalation of the FeS layer, the superconducting critical temperature T c of mackinawite is enhanced from 5 K to 8 K for the (Li 1- x Fe x OH) δ + intercalate. Layered heterostructures of [(Na 1- x Fe x )(OH) 2 ]FeS resemble the natural mineral tochilinite, which contains an iron square lattice interleaved with a hexagonal hydroxide lattice. Whilst heterostructured [(Na 1- x Fe x )(OH) 2 ]FeS displays long-range magnetic ordering near 15 K, K x Fe 2- y S 2 displays short range antiferromagnetism.

  5. Superconductivity

    CERN Document Server

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

    2014-01-01

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

  6. Higher magnetic field multipoles generated by superconductor magnetization within a set of nested superconducting correction coils

    International Nuclear Information System (INIS)

    Green, M.A.

    1990-01-01

    Correction elements in colliding beam accelerators such as the Superconducting Super Collider (SSC) can be the source of undesirable higher magnetic field multipoles due to magnetization of the superconductor within the corrector. Quadrupole and sextupole correctors located within the main dipole will produce sextupole and decapole due to magnetization of the superconductor within the correction coils. Lumped nested correction coils can produce a large number of skew and normal magnetization multipoles which may have an adverse effect on a stored beam at injection into a high energy colliding beam machine such as the SSC. Multipole magnetization field components have been measured within the HERA storage ring dipole magnets. Calculations of these components using the SCMAG04 code, which agree substantially with the measured multipoles, are presented in the report. As a result, in the proposed continuous correction winding for the SSC, dipoles have been replaced with lumped correction elements every six dipole magnets (about 120 meters apart). Nested lumped correction elements will also produce undesirable higher magnetization multipoles. This report shows a method by which the higher multipole generated by nested correction elements can be identified. (author)

  7. Superconducting magnet systems for the ANL EPR design

    International Nuclear Information System (INIS)

    Turner, L.R.; Wang, S.T.; Kim, S.H.; Huang, Y.C.; Smith, R.P.

    1978-01-01

    The magnet systems for the current Argonne experimental power reactor (EPR) design build on the earlier designs but incorporate a number of improvements. The toroidal field (TF) coil system consists of 16 coils of the constant tension shape, with NbTi, copper, and stainless steel as superconductor, stabilizer, and support material respectively. They are designed for 10 T operation at 3.7 K or 9 T operation at 4.2 K. Two changes from earlier designs permit a saving in material requirements. The coils are wound with the conductor in precompression and the support material in pretension so that when the coils are energized, the stainless steel experiences a stress of 60,000 psi while the copper stress does not exceed 15,000 psi. Both the copper and NbTi are graded, with higher current densities where magnetic and radiation effects are smaller. The ohmic heating (OH) coil system consists of a central solenoid plus ten other coils, all located outside the TF coils for ease of maintenance. The NbTi-copper coils are cryostable and operate at 4.2 K. The solenoid is segmented, with rings of insulation between segments to transfer the centering force from the TF coils to an insulating cylinder inside the OH solenoid. Locating the OH solenoid inside the support cylinder plus raising the central field to 8 T, enables the OH system to develop more volt-seconds than the earlier designs, even though the plasma major radius is smaller. The superconducting equilibrium field coils, also outside the TF coils, provide the field pattern required for a D-shaped plasma

  8. Improving Superconducting Resonators in Magnetic Fields by Reduced Field Focussing and Engineered Flux Screening

    Science.gov (United States)

    Bothner, D.; Wiedmaier, D.; Ferdinand, B.; Kleiner, R.; Koelle, D.

    2017-09-01

    We experimentally investigate superconducting coplanar waveguide resonators in external magnetic fields and present two strategies to reduce field-induced dissipation channels and resonance frequency shifts. One of our approaches is to significantly reduce the superconducting ground-plane areas, which leads to reduced magnetic-field focussing and thus to lower effective magnetic fields inside the waveguide cavity. By this measure, the field-induced losses can be reduced by more than one order of magnitude in mT out-of-plane magnetic fields. When these resonators are additionally coupled inductively instead of capacitively to the microwave feed lines, an intrinsic closed superconducting loop is effectively shielding the heart of the resonator from magnetic fields by means of flux conservation. In total, we achieve a reduction of the field-induced resonance frequency shift by up to 2 orders of magnitude. We combine systematic parameter variations on the experimental side with numerical magnetic-field calculations to explain the effects of our approaches and to support our conclusions. The presented results are relevant for all areas, where high-performance superconducting resonators need to be operated in magnetic fields, e.g., for quantum hybrid devices with superconducting circuits or electron spin resonance detectors based on coplanar waveguide cavities.

  9. Design of force-cooled conductors for large fusion magnets

    Energy Technology Data Exchange (ETDEWEB)

    Dresner, L.; Lue, J.W.

    1977-01-01

    Conductors cooled by supercritical helium in forced convection are under active consideration for large toroidal fusion magnets. One of the central problems in designing such force cooled conductors is to maintain an adequate stability margin while keeping the pumping power tolerably low. A method has been developed for minimizing the pumping power for fixed stability by optimally choosing the matrix-to-superconductor and the metal-to-helium ratios. Such optimized conductors reduce pumping power requirements for fusion size magnets to acceptable limits. Furthermore, the mass flow and hence pumping losses can be varied through a magnet according to the local magnetic field and magnitude of desired stability margin. Force cooled conductors give flexibility in operation, permitting, for example, higher fields to be obtained than originally intended by lowering the bath temperature or increasing the pumping power or both. This flexibility is only available if the pumping power is low to begin with. Scaling laws for the pumping requirement and stability margin as functions of operating current density, number of strands and such physical parameters as stabilizer resistivity and critical current density, have been proved. Numerical examples will be given for design of conductors intended for use in large toroidal fusion magnet systems.

  10. Design of force-cooled conductors for large fusion magnets

    International Nuclear Information System (INIS)

    Dresner, L.; Lue, J.W.

    1977-01-01

    Conductors cooled by supercritical helium in forced convection are under active consideration for large toroidal fusion magnets. One of the central problems in designing such force cooled conductors is to maintain an adequate stability margin while keeping the pumping power tolerably low. A method has been developed for minimizing the pumping power for fixed stability by optimally choosing the matrix-to-superconductor and the metal-to-helium ratios. Such optimized conductors reduce pumping power requirements for fusion size magnets to acceptable limits. Furthermore, the mass flow and hence pumping losses can be varied through a magnet according to the local magnetic field and magnitude of desired stability margin. Force cooled conductors give flexibility in operation, permitting, for example, higher fields to be obtained than originally intended by lowering the bath temperature or increasing the pumping power or both. This flexibility is only available if the pumping power is low to begin with. Scaling laws for the pumping requirement and stability margin as functions of operating current density, number of strands and such physical parameters as stabilizer resistivity and critical current density, have been proved. Numerical examples will be given for design of conductors intended for use in large toroidal fusion magnet systems

  11. Experience gained during Manufacture and Testing of the W7-X Superconducting Magnets

    International Nuclear Information System (INIS)

    Wanner, M.; Sborchia, C.; Risse, K.; Viebke, H.; Baldzuhn, J.

    2006-01-01

    The W7-X basic device is presently being assembled at the Greifswald branch of IPP. The specific field configurations of this helical advanced stellarator are realised by a symmetric arrangement of 50 non-planar and 20 planar superconducting coils. In order to sustain the large electromagnetic forces and moments, all coils are bolted to a massive coil support structure and supported against each other by inter-coil support elements. Cooling of superconductor and the casing is provided by supercritical helium. For all coils the same cable-in-conduit conductor is used. This conductor is formed by a NbTi cable which is co-extruded in an aluminium jacket. Low-resistive electrical joints connect the conductor layers within a winding package and potential break provide electrical insulation of the helium pipes. After insulation and vacuum pressure impregnation, the winding packages are embedded in stainless steel casings, which are then finish-machined and equipped with cooling pipes. During a rapid shut-down of the magnet system the windings may experience voltages up to several kilovolts. High voltage tests under degraded vacuum conditions (Paschen tests) provide a sensitive method to detect weak points in the electrical insulation. Manufacture of the magnets is in a well advanced stage. All winding packages are completed, many of them are integrated in the casings and several coils have already been delivered for cold testing. These tests are performed in a cryogenic test facility at CEA Saclay. Tests at nominal operating conditions and quench tests confirmed the electric layout and the specified margin. Design changes have been implemented during fabrication due to more detailed structural analyses. Some manufacturing processes had to be modified and re-qualified to allow repair of weaknesses defects found during tests. The presentation will give an overview of the production status of the superconducting coils, the experiences gained during fabrication of the

  12. submitter Development of a Superconducting Magnet for a Compact Cyclotron for Radioisotope Production

    CERN Document Server

    Garcia-Tabares, Luis; Calero, Jesus; Gutierrez, Jose L; Munilla, Javier; Obradors, Diego; Perez, Jose M; Toral, Fernando; Iturbe, Rafael; Minguez, Leire; Gomez, Jose; Rodilla, Elena; Bajko, Marta; Michels, Matthias; Berkowitz, Daniel; Haug, Friedrich

    2016-01-01

    The present paper describes the development process of a low critical temperature superconducting magnet to be installed in a compact cyclotron producing single-dose radioisotopes for clinical and preclinical applications. After a brief description of the accelerator, the magnet development process is described, starting from the magnetic, mechanical, quench, and thermal calculations, continuing with the designing process, particularly the support structure of the magnet and the cryogenic supply system, to finish with the fabrication and the first tests than have been performed.

  13. Laser cooling of a magnetically guided ultra cold atom beam

    International Nuclear Information System (INIS)

    Aghajani-Talesh, Anoush

    2014-01-01

    This thesis examines two complimentary methods for the laser cooling of a magnetically guided ultra-cold atom beam. If combined, these methods could serve as a starting point for high-through put and possibly even continuous production of Bose-Einstein condensates. First, a mechanism is outlined to harvest ultra cold atoms from a magnetically guided atom beam into an optical dipole trap. A continuous loading scheme is described that dissipates the directed kinetic energy of a captured atom via deceleration by a magnetic potential barrier followed by optical pumping to the energetically lowest Zeeman sublevel. The application of this scheme to the transfer of ultra cold chromium atoms from a magnetically guided atom beam into a deep optical dipole trap is investigated via numerical simulations of the loading process. Based on the results of the theoretical studies the feasibility and the efficiency of our loading scheme, including the realisation of a suitable magnetic field configuration, are analysed. Second, experiments were conducted on the transverse laser cooling of a magnetically guided beam of ultra cold chromium atoms. Radial compression by a tapering of the guide is employed to adiabatically heat the beam. Inside the tapered section heat is extracted from the atom beam by a two-dimensional optical molasses perpendicular to it, resulting in a significant increase of atomic phase space density. A magnetic offset field is applied to prevent optical pumping to untrapped states. Our results demonstrate that by a suitable choice of the magnetic offset field, the cooling beam intensity and detuning, atom losses and longitudinal heating can be avoided. Final temperatures below 65 μK have been achieved, corresponding to an increase of phase space density in the guided beam by more than a factor of 30.

  14. ELECTRON COOLING OF RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI, I.; LITVINENKO, V.; BARTON, D.; ET AL.

    2005-05-16

    We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV.

  15. Application and Prospect of Superconducting High Gradient Magnetic Separation in Disposal of Micro-fine Tailings

    Science.gov (United States)

    Yang, Changqiao; Li, Suqin; Guo, Zijie; Kong, Jiawei

    2017-12-01

    Magnetic separation technology is playing an increasingly important role in the field of environmental protection such as waste gas, waste water and solid waste treatment. As a new type of solid waste treatment technology, superconducting high gradient magnetic separation (HGMS) is mainly applied in the separation of micro-fine weakly magnetic particles because of the advantages of high separation efficiency, energy saving, simple equipment and easy automation. In this paper, the basic principle of superconducting HGMS was firstly introduced, then the research status of scholars at home and aboard on the disposal of micro-fine tailings were summarized. Finally, the direction of development for HGMS was put forward.

  16. 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

  17. 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.

  18. 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

  19. 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 Sr2VO3FeAs shows that a spin-polarized tunneling current can switch the Fe-layer magnetism into a nontrivial C4 (2 ×2 ) order, which cannot be achieved by thermal excitation with an unpolarized current. Our tunneling spectroscopy study shows that the induced C4 (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 C4 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.

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-01

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

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

    NARCIS (Netherlands)

    Ravaioli, Emanuele; Datskov, V.I.; Kirby, G.; ten Kate, Herman 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

  3. Superconductivity and magnetic order in the noncentrosymmetric half-Heusler compound ErPdBi

    NARCIS (Netherlands)

    Pan, Y.; Nikitin, A.M.; Bay, T.V.; Huang, Y.K.; Paulsen, C.; Yan, B.H.; de Visser, A.

    2013-01-01

    We report superconductivity at Tc = 1.22 K and magnetic order at TN = 1.06\\ K in the semimetallic noncentrosymmetric half-Heusler compound ErPdBi. The upper critical field, Bc2, has an unusual quasi-linear temperature variation and reaches a value of 1.6 T for T - 0 . Magnetic order is found below

  4. Novel Ways of Heat Removal from Highly Irradiated Superconducting Windings in Accelerator Magnets

    NARCIS (Netherlands)

    Bielert, Erwin; Verweij, Arjan P.; ten Kate, Herman H.J.

    2012-01-01

    Novel ideas of heat removal from superconducting windings in accelerator type magnets are investigated with the help of a recently developed and validated thermal model of a magnet cold mass implemented in COMSOL Multiphysics. Here the focus is on how to improve heat removal from the midplane of a

  5. Magnetization, critical current, and injection field harmonics in superconducting accelerator magnets

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Sampson, W.B.; Wanderer, P.

    1985-01-01

    The very large energy ratio of machines such as the SSC dictates rather low injection field (for 6T, 20 TeV it is approximately 0.3T). Since the harmonic content at such low fields is largely determined by magnetization currents in the superconductor, the random errors depend on the uniformity of the superconducting wire. In principle the magnitude of the residual fields can be reduced indefinitely by using finer filaments, but in practice there is a lower limit of a few microns. We have compared the injection field harmonics for a number of accelerator dipoles with magnetization measurements made on samples of the conductor used to wind the coils. In addition both the magnetization and harmonics have been compared with short sample critical current measurements made at 5T. The results indicated that an accurate estimate of the variation in injection field harmonics can only be obtained from direct measurements of the magnetization of the cable. It appears feasible to use such measurements to ''shuffle'' magnets for a large accelerator by predicting the low field properties of a magnet before actually winding the coils. 10 refs., 4 figs., 2 tabs

  6. Minimum Contradictions Physics and Propulsion via Superconducting Magnetic Field Trapping

    Science.gov (United States)

    Nassikas, A. A.

    2010-01-01

    All theories are based on Axioms which obviously are arbitrary; e.g. SRT, GRT, QM Axioms. Instead of manipulating the experience through a new set of Arbitrary Axioms it would be useful to search, through a basic tool that we have at our disposal i.e. Logic Analysis, for a set of privileged axioms. Physics theories, beyond their particular axioms, can be restated through the basic communication system as consisting of the Classical Logic, the Sufficient Reason Principle and the Anterior-Posterior Axiom. By means of a theorem this system can be proven as contradictory. The persistence in logic is the way for a set of privileged axioms to be found. This can be achieved on the basis of the Claim for Minimum Contradictions. Further axioms beyond the ones of the basic communications imply further contradictions. Thus, minimum contradictions can be achieved when things are described through anterior-posterior terms; due to existing contradictions through stochastic space-time, which is matter itself, described through a Ψ wave function and distributed, in a Hypothetical Measuring Field (HMF), through the density probability function P(r, t). On this basis, a space-time QM is obtained and this QM is a unified theory satisfying the requirements of quantum gravity. There are both mass-gravitational space-time (g) regarded as real and charge-electromagnetic (em) space-time that could be regarded as imaginary. In a closed system energy conversion-conservation and momentum action take place through photons, which can be regarded either as (g) or (em) space-time formation whose rest mass is equal to zero. Universe Evolution is described through the interaction of the gravitational (g) with the electromagnetic (em) space-time-matter field and not through any other entities. This methodology implies that there is no need for dark matter. An experiment is proposed relative to the (g)+(em) interaction based on Superconducting Magnetic Field Trapping to validate this approach.

  7. Radiation hardness of superconducting magnet insulation materials for FAIR

    International Nuclear Information System (INIS)

    Seidl, Tim

    2013-03-01

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

  8. Superconductive material and magnetic field for damping and levitation support and damping of cryogenic instruments

    Science.gov (United States)

    Dolgin, Benjamin P. (Inventor)

    1994-01-01

    A superconductive load bearing support without a mechanical contact and vibration damping for cryogenic instruments in space is presented. The levitation support and vibration damping is accomplished by the use of superconducting magnets and the 'Meissner' effect. The assembly allows for transfer of vibration energy away from the cryogenic instrument which then can be damped by the use of either an electronic circuit or conventional vibration damping mean.

  9. Magnetization relaxation of single molecule magnets after field cooling

    Science.gov (United States)

    Fernandez, Julio F.; Alonso, Juan J.

    2004-03-01

    Magnetic clusters, such as Fe8 and Mn_12, behave at low temperatures as large single spins S. In crystals, anisotropy energies U allow magnetic relaxation only through tunneling at k_BTstackrelspins with dipolar interactions. To mimic tunneling effects, a spin on a lattice site where h is within some tunnel window -h_wmagnetic dipole field drift.

  10. 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.

    2015-01-01

    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 nm2 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. PMID:26139568

  11. 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.

  12. 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...

  13. Magnetic force acting on a magnetic dipole over a superconducting thin film

    International Nuclear Information System (INIS)

    Wei, J.C.; Chen, J.L.; Horng, L.; Yang, T.J.

    1996-01-01

    The magnetostatic interaction energy and corresponding magnetic force acting on a magnetic point dipole placed above a type-II thin superconducting film in the mixed state with a single vortex are calculated using electromagnetics coupled with the London theory of superconductivity. If a vortex is trapped by a circular defect of radius b 1, where a is the separation between the dipole and the thin film, the only difference between two results is in the cutoff length, i.e., in the case of a circular defect the only difference in the critical position calculation is the cutoff at radius b rather than at coherence length ξ. The pinning force of a single vortex by a circular defect is also calculated. Further, we investigate the conditions of the vortex creation for various cases (including the first, second, and third vortices) for a free of pinning center in the examining region. It is found that the creation of a new single vortex in the thin film causes an abrupt change in vertical levitation force: the force changed discontinuously. copyright 1996 The American Physical Society

  14. Roles of superconducting magnetic bearings and active magnetic bearings in attitude control and energy storage flywheel

    International Nuclear Information System (INIS)

    Tang Jiqiang; Fang Jiancheng; Ge, Shuzhi Sam

    2012-01-01

    Compared with conventional energy storage flywheel, the rotor of attitude control and energy storage flywheel (ACESF) used in space not only has high speed, but also is required to have precise and stable direction. For the presented superconducting magnetic bearing (SMB) and active magnetic bearing (AMB) suspended ACESF, the rotor model including gyroscopic couples is established originally by taking the properties of SMB and AMB into account, the forces of SMB and AMB are simplified by linearization within their own neighbors of equilibrium points. For the high-speed rigid discal rotor with large inertia, the negative effect of gyroscopic effect of rotor is prominent, the radial translation and tilting movement of rotor suspended by only SMB, SMB with equivalent PMB, or SMB together with PD controlled AMB are researched individually. These analysis results proved originally that SMB together with AMB can make the rotor be stable and make the radial amplitude of the vibration of rotor be small while the translation of rotor suspended by only SMB or SMB and PM is not stable and the amplitude of this vibration is large. For the stability of the high-speed rotor in superconducting ACESF, the AMB can suppress the nutation and precession of rotor effectively by cross-feedback control based on the separated PD type control or by other modern control methods.

  15. Roles of superconducting magnetic bearings and active magnetic bearings in attitude control and energy storage flywheel

    Energy Technology Data Exchange (ETDEWEB)

    Tang Jiqiang, E-mail: tjq_72@163.com [School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China) and Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Fang Jiancheng [School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China); Ge, Shuzhi Sam [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

    2012-12-14

    Compared with conventional energy storage flywheel, the rotor of attitude control and energy storage flywheel (ACESF) used in space not only has high speed, but also is required to have precise and stable direction. For the presented superconducting magnetic bearing (SMB) and active magnetic bearing (AMB) suspended ACESF, the rotor model including gyroscopic couples is established originally by taking the properties of SMB and AMB into account, the forces of SMB and AMB are simplified by linearization within their own neighbors of equilibrium points. For the high-speed rigid discal rotor with large inertia, the negative effect of gyroscopic effect of rotor is prominent, the radial translation and tilting movement of rotor suspended by only SMB, SMB with equivalent PMB, or SMB together with PD controlled AMB are researched individually. These analysis results proved originally that SMB together with AMB can make the rotor be stable and make the radial amplitude of the vibration of rotor be small while the translation of rotor suspended by only SMB or SMB and PM is not stable and the amplitude of this vibration is large. For the stability of the high-speed rotor in superconducting ACESF, the AMB can suppress the nutation and precession of rotor effectively by cross-feedback control based on the separated PD type control or by other modern control methods.

  16. The Effect of Extending the Length of the Coupling Coils in a Muon Ionization Cooling Channel

    International Nuclear Information System (INIS)

    Green, Michael A.

    2007-01-01

    RF cavities are used to re-accelerate muons that have been cooled by absorbers that are in low beta regions of a muon ionization cooling channel. A superconducting coupling magnet (or magnets) are around or among the RF cavities of a muon ionization-cooling channel. The field from the magnet guides the muons so that they are kept within the iris of the RF cavities that are used to accelerate the muons. This report compares the use of a single short coupling magnet with an extended coupling magnet that has one or more superconducting coils as part of a muon-cooling channel of the same design as the muon ionization cooling experiment (MICE). Whether the superconducting magnet is short and thick or long and this affects the magnet stored energy and the peak field in the winding. The magnetic field distribution also affects is the muon beam optics in the cooling cell of a muon cooling channel

  17. Development of a vacuum leak test method for large-scale superconducting magnet test facilities

    International Nuclear Information System (INIS)

    Kawano, Katsumi; Hamada, Kazuya; Okuno, Kiyoshi; Kato, Takashi

    2006-01-01

    Japan Atomic Energy Agency (JAEA) has developed leak detection technology for liquid helium temperature experiments in large-scale superconducting magnet test facilities. In JAEA, a cryosorption pump that uses an absorbent cooled by liquid nitrogen with a conventional helium leak detector, is used to detect helium gas that is leaking from pressurized welded joints of pipes and valves in a vacuum chamber. The cryosorption pump plays the role of decreasing aerial components, such as water, nitrogen and oxygen, to increase the sensitivity of helium leak detection. The established detection sensitivity for helium leak testing is 10 -10 to 10 -9 Pam 3 /s. A total of 850 welded and mechanical joints inside the cryogenic test facility for the ITER Central Solenoid Model Coil (CSMC) experiments have been tested. In the test facility, 73 units of glass fiber-reinforced plastic (GFRP) insulation break are used. The amount of helium permeation through the GFRP was recorded during helium leak testing. To distinguish helium leaks from insulation-break permeation, the helium permeation characteristic of the GFRP part was measured as a function of the time of helium charging. Helium permeation was absorbed at 6 h after helium charging, and the detected permeation is around 10 -7 Pam 3 /s. Using the helium leak test method developed, CSMC experiments have been successfully completed. (author)

  18. Pulsed field magnetization strategies and the field poles composition in a bulk-type superconducting motor

    Science.gov (United States)

    Huang, Zhen; Ruiz, H. S.; Coombs, T. A.

    2017-03-01

    High temperature superconducting (HTS) bulks offer the potential of trapping and maintaining much higher magnetic loading level compared with the conventional permanent magnets used in rotary machines, although the effective magnetization of multiple HTS bulks with different relative orientations over the surface of cylindrical rotors creates new challenges. In this paper, we present the design and numerical validation of the Pulse Field Magnetization (PFM) strategy considered for the magnetization of the four-pole synchronous fully superconducting motor developed at the University of Cambridge. In a first instance, singular columns of up to five HTS bulks aligned over the height of the rotor were subjected to up to three magnetic pulses of 1.5 T peak, and the experimental results have been simulated by considering the electrical and thermal properties of the system in a 2D approach. The entire active surface of the rotor is covered by HTS bulks of approximately the same dimensions, resulting in an uneven distribution of pole areas with at least one of the poles formed by up to 3 columns of magnetized bulks, with relatively the same peaks of trapped magnetic field. Thus, in order to effectively use the entire area of the superconducting rotor, multiple pulsed fields per column have been applied under the same experimental conditions, what results in about three times larger magnetic pole areas but with an average drop on the peaks of trapped magnetic field of about 50%.

  19. Design study of superconducting sextupole magnet using HTS coated conductor for neutron-focusing device

    International Nuclear Information System (INIS)

    Tosaka, T.; Koyanagi, K.; Ono, M.; Kuriyama, T.; Watanabe, I.; Tsuchiya, K.; Suzuki, J.; Adachi, T.; Shimizu, H.M.

    2006-01-01

    We performed a design study of sextupole magnet using high temperature superconducting (HTS) wires. The sextupole magnet is used as a focusing lens for neutron-focusing devices. A neutron-focusing device is desired to have a large aperture and a high magnetic field gradient of G, where G = 2B/r 2 , B is the magnetic field and r is a distance from the sextupole magnet axis. Superconducting magnets offer promising prospects to meet the demands of a neutron-focusing device. Recently NbTi coils of low temperature superconducting (LTS) have been developed for a sextupole magnet with a 46.8 mm aperture. The maximum magnetic field gradient G of this magnet is 9480 T/m 2 at 4.2 K and 12,800 T/m 2 at 1.8 K. On the other hand, rapid progress on second generation HTS wire has been made in increasing the performance of critical current and in demonstrating a long length. The second generation HTS wire is referred to as coated conductor. It consists of tape-shaped base upon which a thin coating of superconductor, usually YBCO, is deposited or grown. This paper describes a design study of sextupole magnet using coated conductors

  20. Energy transport in cooling device by magnetic fluid

    Science.gov (United States)

    Yamaguchi, Hiroshi; Iwamoto, Yuhiro

    2017-06-01

    Temperature sensitive magnetic fluid has a great potential with high performance heat transport ability as well as long distance energy (heat) transporting. In the present study experimental set-up was newly designed and constructed in order to measure basic heat transport characteristics under various magnetic field conditions. Angular dependence for the device (heat transfer section) was also taken into consideration for a sake of practical applications. The energy transfer characteristic (heat transport capability) in the magnetically-driven heat transport (cooling) device using the binary TSMF was fully investigated with the set-up. The obtained results indicate that boiling of the organic mixture (before the magnetic fluid itself reaching boiling point) effectively enhances the heat transfer as well as boosting the flow to circulate in the closed loop by itself. A long-distance heat transport of 5 m is experimentally confirmed, transferring the thermal energy of 35.8 W, even when the device (circulation loop) is horizontally placed. The highlighted results reveal that the proposed cooling device is innovative in a sense of transporting substantial amount of thermal energy (heat) as well as a long distance heat transport. The development of the magnetically-driven heat transport device has a great potential to be replaced for the conventional heat pipe in application of thermal engineering.

  1. 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.

  2. Superconductivity and magnetism in heavy-fermion UPd2(Al,Ga)3

    Science.gov (United States)

    Süllow, S.; Ludoph, B.; Becker, B.; Nieuwenhuys, G. J.; Menovsky, A. A.; Mydosh, J. A.

    1997-07-01

    We present bulk properties (resistivity, specific heat, and susceptibility) of the quasiternary system UPd2(Al1-xGax)3 and derive the superconducting and magnetic phase diagrams. For low Ga substitution (xx the magnetic transition temperature TN gradually decreases, and the mass enhancement of the electrons increases, until at x=0.8-0.9 a crystallographic transition takes place from the PrNi2Al3 to the BaB2Pt3 lattice. At the structural transition TN discontinuously increases, while the electronic specific heat γ grows smoothly through the transition. We discuss the relationship between the alloying parameter x and the magnetic ordering and electronic hybridization, respectively. The strong suppression of the superconductivity in UPd2Al3 with Ga suggests an unconventional mechanism of superconductivity, most probably related to spin fluctuations mediating the pairing.

  3. Calorimetric Measurements of Magnetic-Field-Induced Inhomogeneous Superconductivity Above the Paramagnetic Limit

    Energy Technology Data Exchange (ETDEWEB)

    Agosta, Charles C.; Fortune, Nathanael A.; Hannahs, Scott T.; Gu, Shuyao; Liang, Lucy; Park, Ju-Hyun; Schleuter, John A.

    2017-06-01

    We report the first magnetocaloric and calorimetric observations of a magnetic-field-induced phase transition within a superconducting state to the long-sought exotic Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconducting state, first predicted over 50 years ago. Through the combination of bulk thermodynamic calorimetric and magnetocaloric measurements in the organic superconductor. kappa-(BEDT-TTF)(2) Cu(NCS)(2) as a function of temperature, magnetic field strength, and magnetic field orientation, we establish for the first time that this field-induced first-order phase transition at the paramagnetic limit Hp is a transition to a higher-entropy superconducting phase, uniquely characteristic of the FFLO state. We also establish that this high-field superconducting state displays the bulk paramagnetic ordering of spin domains required of the FFLO state. These results rule out the alternate possibility of spin-density wave ordering in the high-field superconducting phase. The phase diagram determined from our measurements-including the observation of a phase transition into the FFLO phase at Hp-is in good agreement with recent NMR results and our own earlier tunnel-diode magnetic penetration depth experiments but is in disagreement with the only previous calorimetric report.

  4. Technology transfer for industrial production of superconducting magnets for the RHIC project at BNL

    International Nuclear Information System (INIS)

    Wanderer, P.; Anerella, M.D.; Greene, A.F.; Kelly, E.; Willen, E.

    1994-01-01

    Industrial production of superconducting magnets for the Relativistic Heavy Ion Collider (RHIC) has begun. The R ampersand D for the magnets was carried out at BNL. Following the award of built-to-print contracts, staff from the laboratory and the vendors worked toward transferring both design principles and practical details to an industrial framework for cost effective production. All magnets made thus far have been acceptable for use in RHIC

  5. Magnetic resonance imaging: project planning and management of a superconductive M.R.I. installation

    International Nuclear Information System (INIS)

    Condon, P.M.; Robertson, A.R.

    1989-01-01

    The planning and installation of a Superconductive Magnetic Resonance Imaging installation at the Royal Adelaide Hospital, Adelaide, South Australia is described. Tender specification, assessment of offers via criteria weighted analysis of technical and economic factors and the final recommendation for a 1.0 Tesla unit are discussed. Building and installation considerations are noted including fringe field effects, magnetic shielding, radiofrequency shielding, cryogens, metallic screening and specific considerations in the Magnet room. 9 refs., 7 figs

  6. Cryogenic system of the prototype of the superconducting magnet for a deuteron cyclotron-1

    International Nuclear Information System (INIS)

    Alenitskij, Yu.G.; Buzdavin, A.P.; Vasilenko, A.T.

    1987-01-01

    The results achieved in developing a cryogenic system for the superconducting magnet of the deuteron cyclotron are described. The cryogenic system consists of a liquefier-refrigerator with the output 40 l.h, or 150 W of power taken off at 4.5 K, a satellite refrigerator, a cryostat of the superconductiong magnet coil and vessels for liquid nitrogen and helium. Now auxiliary equipment is being mounted and the main parts of the magnet are being manufatured

  7. Magnetic field measurements of the harmonic generation FEL superconducting undulator at BNL-NSLS

    International Nuclear Information System (INIS)

    Solomon, L.; Graves, W.S.; Lehrman, I.

    1994-01-01

    A three stage superconducting undulator (modulator, dispersive section, and radiator) is under construction at Brookhaven National Laboratory. Sections of the radiator, consisting of 25cm long steel yokes, each with 18mm period, 0.54 Tesla field, and 8.6mm gap are under test. The magnetic measurements and operational characteristics of the magnet are discussed. Measurement results and analysis are presented, with emphasis on the integrated field quality. The magnet winding and the effects of the various trims are discussed

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-01

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

  10. Superconducting magnets. Volume 2. September 1976 -- September 1977 (a bibliography with abstracts). Report for Sep 76 -- Sep 77

    International Nuclear Information System (INIS)

    Reimherr, G.W.

    1977-10-01

    The cited reports discuss research on materials studies, theory, design, and applications of superconducting magnets. Examples of applications include particle accelerators, MHD power generation, superconducting generators, nuclear fusion research devices, energy storage systems, and magnetic levitation. The updated bibliography contains 122 abstracts, all of which are new entries to the previous edition

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

    Science.gov (United States)

    Schoenhuber, P.; Moon, F. C.

    1995-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

    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.

  13. Magnetic response and critical current properties of mesoscopic-size YBCO superconducting samples

    Energy Technology Data Exchange (ETDEWEB)

    Lisboa-Filho, P N [UNESP - Universidade Estadual Paulista, Grupo de Materiais Avancados, Departamento de Fisica, Bauru (Brazil); Deimling, C V; Ortiz, W A, E-mail: plisboa@fc.unesp.b [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, Sao Carlos (Brazil)

    2010-01-15

    In this contribution superconducting specimens of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} were synthesized by a modified polymeric precursor method, yielding a ceramic powder with particles of mesoscopic-size. Samples of this powder were then pressed into pellets and sintered under different conditions. The critical current density was analyzed by isothermal AC-susceptibility measurements as a function of the excitation field, as well as with isothermal DC-magnetization runs at different values of the applied field. Relevant features of the magnetic response could be associated to the microstructure of the specimens and, in particular, to the superconducting intra- and intergranular critical current properties.

  14. Structure design of the Westinghouse superconducting magnet for the Large Coil Program

    International Nuclear Information System (INIS)

    Domeisen, F.N.; Hackworth, D.T.; Stuebinger, L.R.

    1978-01-01

    In the on-going development of superconducting toroidal field coils for tokamak reactors, the Large Coil Program (LCP) managed by Union Carbide Corporation will include the design, fabrication, and testing of large superconducting coils to determine their feasibility for use in the magnetic fusion energy effort. Structural analysis of the large coil is essential to ensure adequate safety in the test coil design and confidence in the scalability of the design. This paper will discuss the action of tensile and shear loads on the various materials used in the coil. These loads are of magnetic and thermal origin

  15. Energy transport in cooling device by magnetic fluid

    International Nuclear Information System (INIS)

    Yamaguchi, Hiroshi; Iwamoto, Yuhiro

    2017-01-01

    Temperature sensitive magnetic fluid has a great potential with high performance heat transport ability as well as long distance energy (heat) transporting. In the present study experimental set-up was newly designed and constructed in order to measure basic heat transport characteristics under various magnetic field conditions. Angular dependence for the device (heat transfer section) was also taken into consideration for a sake of practical applications. The energy transfer characteristic (heat transport capability) in the magnetically-driven heat transport (cooling) device using the binary TSMF was fully investigated with the set-up. The obtained results indicate that boiling of the organic mixture (before the magnetic fluid itself reaching boiling point) effectively enhances the heat transfer as well as boosting the flow to circulate in the closed loop by itself. A long-distance heat transport of 5 m is experimentally confirmed, transferring the thermal energy of 35.8 W, even when the device (circulation loop) is horizontally placed. The highlighted results reveal that the proposed cooling device is innovative in a sense of transporting substantial amount of thermal energy (heat) as well as a long distance heat transport. The development of the magnetically-driven heat transport device has a great potential to be replaced for the conventional heat pipe in application of thermal engineering. - Highlights: • Temperature-sensitive magnetic fluid (TSMF) has a great heat transport ability. • Magnetically-driven heat transport device using binary TSMF is proposed. • The basic heat transport characteristics are investigated. • Boiling of the organic mixture effectively enhances the heat transfer. • A long-distance heat transport of 5 m is experimentally confirmed.

  16. Continuous Magnetic Refrigerators for Cooling in the 0.05 to 10 K Range: Progress and Future Development

    Science.gov (United States)

    Shirron, Peter; DiPirro, Michael; Canavan, Edgar; Tuttle, James; King, Todd; Numazawa, Takenori

    2003-01-01

    Low temperature refrigeration is an increasingly vital technology for NASA s Space Science program since most detectors being developed for x-ray, IR and sub-millimeter missions must be cooled to below 100 mK in order to meet the requirements for energy and spatial resolution. For space applications, magnetic refrigeration has an inherent advantage over alternative techniques because it does not depend on gravity. Adiabatic demagnetization refrigerators, or ADRs, are relatively simple, solid state devices. The basic elements are a magnetocaloric refrigerant (usually an encapsulated paramagnetic salt) located in the bore of a superconducting magne$, and a heat switch linking the salt to a heat sink. The alignment of magnetic spins with the magnetic field causes the refrigerant to warm as the magnetic field increases and cool as the field decreases. Thus the simple process of magnetizing the refrigerant to high field with the heat switch closed, then demagnetizing it with the heat switch open allows one to obtain temperatures well below 100 mK using a heat sink as warm as 4.2 K. The refrigerant can maintain a low temperature for a length of time depending on the applied and parasitic heat loads, its mass, and the initial magnetic field strength. Typically ADRs are designed for 12-24 hours of hold time, after which they must be warmed up and recycled. The drawback to single-shot ADRs is that the cooling power per unit mass is relatively low. Refrigerants that are suitable for low temperature operation necessarily have low magnetic ion density, and therefore low entropy density. Since ADRs store entropy, systems with even modest cooling powers (a few microwatts) at temperatures below 100 mK tend to be massive, averaging 10-15 kg.

  17. Design and analysis of the tooling upgrade for the production of the superconductive main dipole magnet prototypes of LHC

    CERN Document Server

    AUTHOR|(CDS)2093638

    Design and analysis of the tooling upgrade for the production of the superconductive main dipole magnet prototypes of LHC Master of Science Thesis, 110 pages, 12 Appendix pages September 2013 Major: Design of machines and systems Examiner: Professor Reijo Kouhia Keywords: CERN, LHC, High Luminosity LHC project, superconductive dipole magnet, welding press, Nb3Sn, pre-stress, Ar-inert gas furnace This thesis work has been carried out as a contribution to the development program of superconductive magnets within the LHC High Luminosity study. The thesis provides an insight to the steps that need to be taken in order to produce a superconductive magnet mainly focusing on mechanical assembly. Tooling upgrade is necessary for the production of the superconductive dipole magnet prototypes in near future. Major attention is given by the introduction of the welding assembly in chapter three. The structural compression is given by the so called shell stress defined by the thermal shrinkage of the weld. The associated ...

  18. Numerical analysis of the superconducting magnet outer vessel of a Maglev train by a structural and electromagnetic coupling method

    Science.gov (United States)

    Matsue, H.; Demachi, K.; Miya, K.

    2001-09-01

    The harmonic magnetic field generated by the ground coils can cause vibration of the superconducting magnet, which must be reduced as it generates heat in the liquid helium temperature range. Therefore, it is important for the design of lighter magnets to exactly estimate the electromagnetic force on the superconducting magnet. Some causes of the vibration were analyzed by the structural and electromagnetic coupling FEM-BEM method.

  19. 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....

  20. Development of an experimental system for characterization of high-temperature superconductors cooled by liquid hydrogen under the external magnetic field

    International Nuclear Information System (INIS)

    Tatsumoto, H; Shirai, Y; Shiotsu, M; Naruo, Y; Kobayashi, H; Inatani, Y

    2014-01-01

    An experimental system has been developed to investigate electro-magnetic properties of high-Tc superconductors cooled by liquid hydrogen under the external magnetic field of up to 7 T. A LH 2 cryostat is concentrically mounted on the inside of a LHe cryostat to cool a NbTi superconducting magnet. The experimental system is installed in an explosion-proof room. Explosion proof electrical devices are used and current leads are covered with an enclosure filled with nitrogen gas. A remote control system has been developed. Furthermore, the effects of stray magnetic field on the existing and the new devices are investigated and electro-magnetic shielding panels and enclosure made of iron were designed. It is confirmed through the cryogenic test that the experimental system meets the design requirements.