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Sample records for quenching superconducting magnets

  1. Quenches in large superconducting magnets

    International Nuclear Information System (INIS)

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

    1977-08-01

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

  2. 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

  3. Quenches in the superconducting magnet CELLO

    International Nuclear Information System (INIS)

    Hassenzahl, W.V.

    1979-01-01

    The superconducting magnet CELLO was tested with currents up to 3200 A at Saclay and has been installed at DESY in Hamburg where it will be used for particle physics experiments requiring colliding beams of electrons and positrons. The testing of this unique, large, one-layer solenoid provides an excellent opportunity to evaluate the theory of quench propagation under adiabatic conditions, that is, in a coil in which the conductors are not in direct contact with helium. In an early test of this coil, quenches that occurred, gives the details of the damaged conductor, and includes an analysis of the quenches. Observed axial quench velocities are compared to the calculated values based on both measurements and calculations of the thermal conductivity of the fabricated coil

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

    International Nuclear Information System (INIS)

    Wang Xingzhe; Guan Mingzhi; Ma Lizhen

    2012-01-01

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

  5. Quench antenna for superconducting particle accelerator magnets

    International Nuclear Information System (INIS)

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

    1993-10-01

    We report on the design, fabrication, and test of an assembly of stationary pickup coils which can be used to localize quench origins. After describing the pickup coils configuration, we develop a simple model of current redistribution which allows interpretation of the measured voltages and determination of the turn of the magnet coil in which the quench started. The technique is illustrated by analyzing the data from a quench of a 5-cm-aperture, 15-m-long SSC dipole magnet prototype

  6. Studies of quench propagation in a superconducting window frame magnet

    International Nuclear Information System (INIS)

    Allinger, J.; Carroll, A.; Danby, G.; DeVito, B.; Jackson, J.; Leonhardt, M.; Prodell, A.; Stoehr, R.

    1981-01-01

    During the testing of a meter long, superconducting window frame magnet, information from many spontaneously generated quenches have been recorded by an on-line computer system. Nearly every layer in an eleven layer dipole had a voltage tap and for some layers this subdivided into two halves. This allowed us to study development of the quenches in some detail. Knowledge of the resistances throughout the magnet also allowed the temperature distributions in the superconducting windings to be determined. A qualitative picture of the quench was developed and quantitative values of quench propagation velocities were compared to heat transfer calculations

  7. Optimization of a quench detection system for superconducting magnets

    International Nuclear Information System (INIS)

    Borlein, M.

    2004-12-01

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

  8. 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

  9. Quench detection of superconducting magnets using ultrasonic wave

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  10. 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...

  11. Temperature Profiles During Quenches in LHC Superconducting Dipole Magnets Protected by Quench Heaters

    OpenAIRE

    Maroussov, V; Sanfilippo, S; Siemko, A

    1999-01-01

    The efficiency of the magnet protection by quench heaters was studied using a novel method which derives the temperature profile in a superconducting magnet during a quench from measured voltage signals. In several Large Hadron Collider single aperture dipole models, temperature profiles and temperature gradients in the magnet coil have been evaluated in the case of protection by different sets of quench heaters and different powering and protection parameters. The influence of the insulation...

  12. A magnetically coupled quench detector for superconducting magnets

    International Nuclear Information System (INIS)

    Jaskierny, W.; Kristalinski, A.; Visser, A.T.

    1993-12-01

    This note describes a low voltage signal detector that is useful for detecting quenches or excessive lead voltages at superconducting magnets. It can also be used for other applications where it is needed to detect low level signals present on high voltage installations. The application of isolated operational amplifiers is often not practical for high voltage applications because of their limited input voltage rating, common mode rejection and sensitivity. The described detector can withstand 7.5 kV input to ground voltage. It has a typical common mode rejection of -150 dB at 60 Hz and an input sensitivity better than 1 mV. The magnetically coupled quench detector assembly is very sensitive to extremely small (order of 1 μAmp) current changes in the sense windings. The detector assembly can therefore also be referred to as a micro current detector

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

    NARCIS (Netherlands)

    Ravaioli, Emanuele

    2015-01-01

    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

  14. 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...

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

    International Nuclear Information System (INIS)

    Schwerg, Juljan Nikolai

    2010-01-01

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

  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. Testing beam-induced quench levels of LHC superconducting magnets

    Directory of Open Access Journals (Sweden)

    B. Auchmann

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-06-01

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

  19. 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.

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

    CERN Document Server

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

    2015-06-25

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

  1. Superconductive magnet having shim coils and quench protection circuits

    International Nuclear Information System (INIS)

    Schwall, R.E.

    1987-01-01

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

  2. 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)

  3. Modelling of the quenching process in complex superconducting magnet systems

    International Nuclear Information System (INIS)

    Hagedorn, D.; Rodriguez-Mateos, F.

    1992-01-01

    This paper reports that the superconducting twin bore dipole magnet for the proposed Large Hadron Collider (LHC) at CERN shows a complex winding structure consisting of eight compact layers each of them electromagnetically and thermally coupled with the others. This magnet is only one part of an electrical circuit; test and operation conditions are characterized by different circuits. In order to study the quenching process in this complex system, design adequate protection schemes, and provide a basis for the dimensioning of protection devices such as heaters, current breakers and dump resistors, a general simulation tool called QUABER has been developed using the analog system analysis program SABER. A complete set of electro-thermal models has been crated for the propagation of normal regions. Any network extension or modification is easy to implement without rewriting the whole set of differential equations

  4. 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...

  5. Magnet Quench 101

    OpenAIRE

    Bottura, L.

    2014-01-01

    This paper gives a broad summary of the physical phenomena associated with the quench of a superconducting magnet. This paper gives a broad summary of the physical phenomena associated with the quench of a superconducting magnet.

  6. Quench propagation and training in simulated superconducting magnet windings

    International Nuclear Information System (INIS)

    Sampson, W.B.; Garber, M.; Ghosh, A.

    1981-01-01

    Training behavior similar to that which occurs in full scale superconducting accelerator magnets has been observed in small test windings. The test coils are formed from approximately 20 meters of conductor wound non-inductively, in Bifilar fashion. The resulting racetrack shaped coil is molded at elevated temperature to simulate the construction techniques used for the ISABELLE dipoles. The quench current of such windings has been measured as a function of applied field and the effect of parameters such as mechanical loading and porosity have been investigated. The velocity of propagation of the normal front has been measured both along and transverse to the direction of current flow for several test windings. The minimum energy required to produce a self propagating normal zone has also been determined in an attempt to quantify the relative stability of the coils

  7. Quench Heater Experiments on the LHC Main Superconducting Magnets

    OpenAIRE

    Rodríguez-Mateos, F; Pugnat, P; Sanfilippo, S; Schmidt, R; Siemko, A; Sonnemann, F

    2000-01-01

    In case of a quench in one of the main dipoles and quadrupoles of CERN's Large Hadron Collider (LHC), the magnet has to be protected against excessive temperatures and high voltages. In order to uniformly distribute the stored magnetic energy in the coils, heater strips installed in the magnet are fired after quench detection. Tests of different quench heater configurations were performed on various 1 m long model and 15 m long prototype dipole magnets, as well as on a 3 m long prototype quad...

  8. Thermo-hydraulic Quench Propagation at the LHC Superconducting Magnet String

    CERN Document Server

    Rodríguez-Mateos, F; Serio, L

    1998-01-01

    The superconducting magnets of the LHC are protected by heaters and cold by-pass diodes. If a magnet quenches, the heaters on this magnet are fired and the magnet chain is de-excited in about two minu tes by opening dump switches in parallel to a resistor. During the time required for the discharge, adjacent magnets might quench due to thermo-hydraulic propagation in the helium bath and/or heat con duction via the bus bar. The number of quenching magnets depends on the mechanisms for the propagation. In this paper we report on quench propagation experiments from a dipole magnet to an adjacent ma gnet. The mechanism for the propagation is hot helium gas expelled from the first quenching magnet. The propagation changes with the pressure opening settings of the quench relief valves.

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

    International Nuclear Information System (INIS)

    Kishimoto, Takeshi; Mori, Shigeki; Noguchi, Masaharu

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Green, M.A.

    1981-03-01

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

  11. CLIQ – Coupling-Loss Induced Quench System for Protecting Superconducting Magnets

    CERN Multimedia

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

    2014-01-01

    The recently developed Coupling-Loss-Induced Quench (CLIQ) protection system is a new method for initiating a fast and voluminous transition to the normal state for protecting high energy density superconducting magnets. Upon quench detection, CLIQ is triggered to generate an oscillating current in the magnet coil by means of a capacitive discharge. This in turn introduces a high coupling loss in the superconductor which provokes a quick transition to the normal state of the coil windings. The system is now implemented for the protection of a two meter long superconducting quadrupole magnet and characterized in the CERN magnet test facility. Various CLIQ configurations with different current injection points are tested and the results compared to similar transients lately measured with a not optimized configuration. Test results convincingly show that the newly tested design allows for a more global quench initiation and thus a faster discharge of the magnet energy. Moreover, the performance of CLIQ for reduc...

  12. Quench protection system for 1 MJ superconducting magnet coil for SMES Project at VECC, Kolkata

    International Nuclear Information System (INIS)

    Thakur, S.K.; Bera, A.; Kumar, Y.; Bhunia, U.; Pradhan, J.; Saha, S.

    2012-01-01

    This paper describes the indigenous development of a system which is used for quench detection, protection and monitoring the parameters of superconducting coil of superconducting magnetic energy storage (SMES) system. Resistive voltage measurement method is used for detecting the quench. The voltage across each current lead is also monitored and over voltage across the current lead is detected by comparing it with a set voltage limit. By using isolation amplifier and timer circuit, false quench trigging due to noise and spikes are minimized. If quench is detected a relay operated to turn-off the SMES power supply followed by the release of stored energy of the magnet to the external dump resistance by closing a switch. (author)

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

    CERN Document Server

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

    2012-01-01

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

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

    CERN Document Server

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

    2003-01-01

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

  15. The location of the quench origin in a superconducting accelerator magnet

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Robins, K.E.; Sampson, W.B.

    1987-01-01

    A method of calculating the initial rate of rise of the resistive voltage in a quenching superconducting magnet is described. Comparison of such calculations with data from spontaneously occurring quenches gives the location of the quench origin since the normal state resistance of the conductor is determined by its position in the windings due to the magnetoresistance of the copper matrix. The characteristics of the voltage buildup is used to separate quenches occurring in low field regions, such as the magnet ends, from those starting in the two-dimensional straight section of the coil. The magnitude of V dot is a measure of performance and can be used to determine if the magnet is reaching the maximum current permitted by the conductor parameters

  16. Statistical Diagnosis Method of Conductor Motions in Superconducting Magnets to Predict their Quench Performance

    CERN Document Server

    Khomenko, B A; Rijllart, A; Sanfilippo, S; Siemko, A

    2001-01-01

    Premature training quenches are usually caused by the transient energy released within the magnet coil as it is energised. Two distinct varieties of disturbances exist. They are thought to be electrical and mechanical in origin. The first type of disturbance comes from non-uniform current distribution in superconducting cables whereas the second one usually originates from conductor motions or micro-fractures of insulating materials under the action of Lorentz forces. All of these mechanical events produce in general a rapid variation of the voltages in the so-called quench antennas and across the magnet coil, called spikes. A statistical method to treat the spatial localisation and the time occurrence of spikes will be presented. It allows identification of the mechanical weak points in the magnet without need to increase the current to provoke a quench. The prediction of the quench level from detailed analysis of the spike statistics can be expected.

  17. Quench calculations for the superconducting dipole magnet of CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Kurilkin, P.; Akishin, P.; Bychkov, A.; Gusakov, Yu.; Ladygin, V.; Malakhov, A.; Shabunov, A.; Toral, F.; Floch, E.; Moritz, G.; Ramakers, H.; Senger, P.; Szwangruber, P.

    2016-01-01

    The scientific mission of the Compressed Baryonic Matter (CBM) experiment is the study of the nuclear matter properties at the high baryon densities in heavy ion collisions at the Facility of Antiproton and Ion Research (FAIR) in Darmstadt. The 5.15 MJ superconducting dipole magnet will be used in the silicon tracking system of the CBM detector. It will provide a magnetic field integral of 1 Tm which is required to obtain a momentum resolution of 1% for the track reconstruction. This paper presents quench modeling and evaluation of candidate protection schemes for the CBM dipole magnet. Two quench programs based on finite-difference method were used in simulation. One of them is currently used at GSI, and the other based on CIEMAT (Madrid, Spain) was modified to perform quench calculation for the CBM magnet. (paper)

  18. New, Coupling Loss Induced, Quench Protection System for Superconducting Accelerator Magnets

    CERN Document Server

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

    2014-01-01

    Email Print Request Permissions Save to Project A new and promising method for the protection of superconducting high-field magnets is developed and tested on the so-called MQXC quadrupole magnet at the CERN magnet test facility. The method relies on a capacitive discharge system inducing, during a few periods, an oscillation of the transport current in the superconducting cable of the coil. The corresponding fast change of the local magnetic field introduces a high coupling-current loss, which, in turn, causes a fast quench of a large fraction of the coil due to enhanced temperature. Results of measured discharges at various levels of transport current are presented and compared to discharges by quenching the coils using conventional quench heaters and an energy extraction system. The hot-spot temperature in the quenching coil is deduced from the coil voltage and current. The results are compared to simulations carried out using a lumped-element dynamic electro-thermal model of the so-called MQX...

  19. Theory and modelling of quench in cable-in-conduit superconducting magnets

    International Nuclear Information System (INIS)

    Shajii, A.

    1994-04-01

    A new simple, self consistent theoretical model is presented that describes the phenomena of quench propagation in Cable-In-Conduit superconducting magnets. The model (Quencher) circumvents many of the difficulties associated with obtaining numerical solutions in more general existing models. Specifically, a factor of 30-50 is gained in CPU time over the general, explicit time dependent codes used to study typical quench events. The corresponding numerical implementation of the new model is described and the numerical results are shown to agree very well with those of the more general models, as well as with experimental data. Further, well justified approximations lead to the MacQuench model that is shown to be very accurate and considerably more efficient than the Quencher model. The MacQuench code is suitable for performing quench studies on a personal computer, requiring only several minutes of CPU time. In order to perform parametric studies on new conductor designs it is required to utilize a model such as MacQuench because of the high computational efficiency of this model. Finally, a set of analytic solutions for the problem of quench propagation in Cable-In-Conduit Conductors is presented. These analytic solutions represent the first such results that remain valid for the long time scales of interest during a quench process. The assumptions and the resulting simplifications that lead to the analytic solutions are discussed, and the regimes of validity of the various approximations are specified. The predictions of the analytic results are shown to be in very good agreement with numerical as well as experimental results. Important analytic scaling relations are verified by such comparisons, and the consequences of some of these scalings on currently designed superconducting magnets are discussed

  20. Development of Industrially Produced Composite Quench Heaters for the LHC Superconducting Lattice Magnets

    CERN Document Server

    Szeless, Balázs; Calvone, F

    1996-01-01

    The quench heaters are vital elements for the protection of the LHC superconducting lattice magnets in the case of resistive transitions of the conductor. The basic concept of magnet protection and technical solutions are briefly presented. The quench heater consists of partially copper clad stainless steel strips sandwiched in between electric insulating carrier foils with electrical and mechanical properties such as to withstand high voltages, low temperatures, pressures and ionizing radiation. Testing of some commercial available electric insulation foils, polyimide (PI), polyetheretherketon (PEEK) and polyarylate (PA) and combinations of adhesive systems which are suitable for industrial processing are described. Possible industrial methods for series production for some 80 km of these composite quench heaters are indicated.

  1. Quench Protection and Powering in a String of Superconducting Magnets for the Large Hadron Collider

    CERN Document Server

    Krainz, G

    1997-01-01

    Practical experience has been attained on the LHC Test String (String~1), composed of one 3~m long superconducting twin-aperture prototype quadrupole and three 10~m long superconducting twin-aperture prototype dipoles. The protection diodes are housed in the cold mass of the short straight section. The quench protection system acts on the half-cell level. During the operation of the LHC Test String, magnet quenches have been provoked manually by firing the quench heaters or occured manually by exceeding the critical temperature or critical current density of the superconductor. Most of the data could be measured while some parameters (magnet current, diode current, average temperature, etc.) cannot be directly measured. A simulation progam has been developed to calculate the missing data. The validation of the model has been performed by comparing measured and simulated data. The modelling of the quench behaviour of the final version of the LHC magnets show that hot-spot temperatures and voltages to ground ca...

  2. An FPGA-based quench detection and protection system for superconducting accelerator magnets

    International Nuclear Information System (INIS)

    Carcagno, R.H.; Feher, S.; Lamm, M.; Makulski, A.; Nehring, R.; Orris, D.F.; Pischalnikov, Y.; Tartaglia, M.; Fermilab

    2005-01-01

    A new quench detection and protection system for superconducting accelerator magnets was developed for the Fermilab's Magnet Test Facility (MTF). This system is based on a Field-Programmable Gate Array (FPGA) module, and it is made of mostly commercially available, integrated hardware and software components. It provides all the functions of our existing VME-based quench detection and protection system, but in addition the new system is easily scalable to protect multiple magnets powered independently and a more powerful user interface and analysis tools. The new system has been used successfully for testing LHC Interaction Region Quadrupoles correctors and High Field Magnet HFDM04. In this paper we describe the system and present results

  3. An FPGA-based quench detection and protection system for superconducting accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Carcagno, R.H.; Feher, S.; Lamm, M.; Makulski, A.; Nehring, R.; Orris, D.F.; Pischalnikov, Y.; Tartaglia, M.; /Fermilab

    2005-05-01

    A new quench detection and protection system for superconducting accelerator magnets was developed for the Fermilab's Magnet Test Facility (MTF). This system is based on a Field-Programmable Gate Array (FPGA) module, and it is made of mostly commercially available, integrated hardware and software components. It provides all the functions of our existing VME-based quench detection and protection system, but in addition the new system is easily scalable to protect multiple magnets powered independently and a more powerful user interface and analysis tools. The new system has been used successfully for testing LHC Interaction Region Quadrupoles correctors and High Field Magnet HFDM04. In this paper we describe the system and present results.

  4. An FPGA-Based Quench Detection and Protection System for Superconducting Accelerator Magnets

    CERN Document Server

    Carcagno, Ruben H; Lamm, Michael J; Makulski, Andrzej; Nehring, Roger; Orris, Darryl; Pishchalnikov, Yu M; Tartaglia, M

    2005-01-01

    A new quench detection and protection system for superconducting accelerator magnets was developed at the Fermilab's Magnet Test Facility (MTF). This system is based on a Field-Programmable Gate Array (FPGA) module, and it is made of mostly commerically available, integrated hardware and software components. It provides most of the functionality of our existing VME-based quench detection and protection system, but in addition the new system is easily scalable to protect multiple magnets powered independently and has a more powerful user interface and analysis tools. First applications of the new system will be for testing corrector coil packages. In this paper we describe the new system and present results of testing LHC Interaction Region Quadrupole (IRQ) correctors.

  5. A fiber optic strain measurement and quench localization for use in superconducting accelerator dipole magnets

    International Nuclear Information System (INIS)

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

    1994-01-01

    A novel fiber-optic measurement system for superconducting accelerator magnets is described. The principal component is an extrinsic Fabry-Perot Interferometer to determine localized strain and stress in coil windings. The system can be used either as a sensitive relative strain measurement system or as an absolute strain detector. Combined, one can monitor the mechanical behaviour of the magnet system over time during construction, long time storage and operation. The sensing mechanism is described, together with various tests in laboratory environments. The test results of a multichannel test matrix to be incorporated first in the dummy coils and then in the final version of a 13T Nb 3 Sn accelerator dipole magnet are presented. Finally, the possible use of this system as a quench localization system is proposed

  6. Superconducting Magnet Power Supply and Hard-Wired Quench Protection at Jefferson Lab for 12 GeV Upgrade

    International Nuclear Information System (INIS)

    Ghoshal, Probir K.; Bachimanchi, Ramakrishna; Fair, Ruben J.; Gelhaar, David; Kumar, Onish

    2017-01-01

    The superconducting magnet system in Hall B being designed and built as part of the Jefferson Lab 12 GeV upgrade requires powering two conduction cooled superconducting magnets - a torus and a solenoid. The torus magnet is designed to operate at 3770 A and solenoid at 2416 A. Failure Modes and Effects Analysis (FMEA) determined that voltage level thresholds and dump switch operation for magnet protection should be tested and analyzed before incorporation into the system. The designs of the quench protection and voltage tap sub-systems were driven by the requirement to use a primary hard-wired quench detection sub-system together with a secondary PLC-based protection. Parallel path voltage taps feed both the primary and secondary quench protection sub-systems. The PLC based secondary protection is deployed as a backup for the hard-wired quench detection sub-system and also acts directly on the dump switch. Here, we describe a series of tests and modifications carried out on the magnet power supply and quench protection system to ensure that the superconducting magnet is protected for all fault scenarios.

  7. Methods for the evaluation of quench temperature profiles and their application for LHC superconducting short dipole magnets

    Science.gov (United States)

    Sanfilippo, S.; Siemko, A.

    2000-08-01

    This paper presents a study of the thermal effects on quench performance for several large Hadron collider (LHC) single aperture short dipole models. The analysis is based on the temperature profile in a superconducting magnet evaluated after a quench. Peak temperatures and temperature gradients in the magnet coil are estimated for different thicknesses of insulation layer between the quench heaters and the coil and different powering and protection parameters. The results show clear correlation between the thermo-mechanical response of the magnet and quench performance. They also display that the optimisation of the position of quench heaters can reduce the decrease of training performance caused by the coexistence of a mechanical weak region and of a local temperature rise.

  8. Development of quench detection/protection system based on active power method for superconducting magnet by using capacitor circuit

    International Nuclear Information System (INIS)

    Nanato, N.; Otsuka, T.; Hesaka, S.; Murase, S.

    2013-01-01

    Highlights: ► The authors have presented an active power method for quench detection. ► A method for improving its characteristics using a capacitor circuit was proposed. ► Quench detection/protection test for a Bi2223 superconducting coil was carried out. ► The proposed method was more useful than the conventional one. -- Abstract: When a quench occurs in a superconducting magnet, excessive joule heating in normal region may damage the magnet. It is necessary to detect the quench as soon as possible and discharge magnetic energy stored in the magnet. The authors have presented a quench detection/protection system based on an active power method which detects the quench regardless of a self-inductive and mutual-inductive voltages and electromagnetic noise. In the conventional active power method, the inductive voltages are removed by cancel coils. In this paper, the authors propose a method to cancel an inductive voltage using a capacitor circuit. The quench detection/protection system becomes more precise and smaller than the conventional system through the capacitor circuit

  9. Infrared Quenched Photoinduced Superconductivity

    Science.gov (United States)

    Federici, J. F.; Chew, D.; Guttierez-Solana, J.; Molina, G.; Savin, W.; Wilber, W.

    1996-03-01

    Persistant photoconductivity (PPC) and photoinduced superconductivity (PISC) in oxygen deficient YBa_2Cu_3O_6+x have received recent attention. It has been suggested that oxygen vacancy defects play an important role in the PISC/PPC mechanism.(J. F. Federici, D. Chew, B. Welker, W. Savin, J. Gutierrez-Solana, and T. Fink, Phys. Rev. B), December 1995 Supported by National Science Foundation In this model, defects trap photogenerated electrons so that electron-hole recombination can not occur thereby allowing photogenerated holes to contribute to the carrier density. Nominally, the photoinduced state is long-lived, persisting for days at low temperature. Experiment results will be presented demonstrating that the photoinduced superconductivity state can be quenched using infrared radiation. Implications for the validity of the PISC/PCC defect model will be discussed.

  10. Quench detection of superconducting magnet by dual-core optical fiber

    International Nuclear Information System (INIS)

    Tsukamoto, O.; Kawai, K.; Kokubun, Y.; Takao, T.

    1988-01-01

    A quench-detecting technique using two single-mode optical cores in one fiber has been developed. The technique can detect quench from a temperature rise of 1.0 K at 4.2 K. An electromagnetic force-stress to the fiber did not deteriorate quench detection sensitivity. A quench detector using this method was immune from electromagnetic noise and free from troubles caused by high voltage tension. Problems arising when applying this method to a large scale magnet and possible improvements in the instrumentation are discussed

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  12. Observation of magnetic flux generated spontaneously during a rapid quench of superconducting films

    International Nuclear Information System (INIS)

    Maniv, A.; Polturak, E.; Koren, G.

    2003-01-01

    We report observations of spontaneous formation of magnetic flux lines during a rapid quench of YBa 2 Cu 3 O 7-δ films through T c . This effect is predicted according to the Kibble-Zurek mechanism of creation of topological defects of the order parameter during a symmetry-breaking phase transition. Our previous experiment, at a quench rate of 20 K/s, gave null results. In the present experiment, the quench rate was increased to >10 8 K/s. The amount of spontaneous flux increases weakly with the cooling rate

  13. High field superconducting magnets

    Science.gov (United States)

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

    2011-01-01

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

  14. On the Use of Wavelet Transform for Quench Precursors Characterisation in the LHC Superconducting Dipole Magnets

    CERN Document Server

    Calvi, M; Bottura, L; Masi, A; Siemko, A

    2006-01-01

    Premature training quenches are caused by transient energy released within the magnet coil while it is energized. Signals recorded across the so-called quench antenna carry information about these disturbances. A new method for identifying and characterizing those events is proposed, which applies the wavelet transform approach to the recorded signals. Such an approach takes into account the time of occurrence as well as frequency content of the events. The choice of the optimal mother wavelet is discussed, and the results obtained from the application of the method to actual signals are given. The criteria to recognize the interesting events are presented as well as the methodology to classify their global behavior.

  15. Novel quench detection methods for the superconducting magnets in ITER and TPX

    International Nuclear Information System (INIS)

    Schultz, J.H.; Pourrahimi, S.; Diatchenko, N.; Guss, W.; Chaniotakis, E.; Pillsbury, R.D. Jr.; Smith, S.; Wang, P.W.; Citrolo, J.; Chaplin, M.; Zbasnik, J.

    1995-01-01

    The US is providing novel sensors to Japan to be used in the conductor for QUELL, the ITER Quench Experiment on Long-Lengths to be performed in the SULTAN magnet in 1995. These include cowound voltage sensors, fiber optic thermometers, cowound and conventional pressure sensors, and flow meters. TPX has a redundant quench detection system using cowound voltage sensors, fiber-optic temperaure sensors, conventional voltage taps, and flow meters. Sensors are extracted only at joint regions, but are terminated every two pancakes, providing high signal-noise ratios through differencing techniques. (orig.)

  16. Vent rate of superconducting magnets during quench in the Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    Slack, D.S.

    1979-01-01

    When a superconducting magnet goes normal, resistive heating in the conductor evaporates surrounding LHe, which must be vented. The nature and speed at which the magnet goes normal and He is vented are not subject to rigorous analysis. This paper presents vent data from an existing magnet. An approximate mathematical model is derived and fitted to the data to permit scaling of vent requirements to larger size magnets. The worst case models of the vent employed in Mirror Fusion Test Facility (MFTF) cryogenic system design are also presented

  17. LHC magnet quench protection system

    Science.gov (United States)

    Coull, L.; Hagedorn, D.; Remondino, V.; Rodriguez-Mateos, F.

    1994-07-01

    The quench protection system for the superconducting magnets of the CERN Large Hadron Collider (LHC) is described. The system is based on the so called 'cold diode' concept. In a group of series connected magnets if one magnet quenches then the magnetic energy of all the magnets will be dissipated in the quenched magnet so destroying it. This is avoided by by-passing the quenched magnet and then rapidly de-exciting the unquenched magnets. For the LHC machine it is foreseen to use silicon diodes situated inside the cryostat as by-pass elements - so called 'cold diodes'. The diodes are exposed to some 50 kGray of radiation during a 10 year operation life-time. The high energy density of the LHC magnets (500 kJ/m) coupled with the relatively slow propagation speed of a 'natural' quench (10 to 20 m/s) can lead to excessive heating of the zone where the quench started and to high internal voltages. It is therefore necessary to detect quickly the incipient quench and fire strip heaters which spread the quench out more quickly over a large volume of the magnet. After a quench the magnet chain must be de-excited rapidly to avoid spreading the quench to other magnets and over-heating the by-pass diode. This is done by switching high-power energy-dump resistors in series with the magnets. The LHC main ring magnet will be divided into 16 electrically separated units which has important advantages.

  18. LHC magnet quench protection system

    International Nuclear Information System (INIS)

    Coull, L.; Hagedorn, D.; Remondino, V.; Rodriguez-Mateos, F.

    1994-01-01

    The quench protection system for the superconducting magnets of the CERN Large Hadron Collider (LHC) is described. The system is based on the so called ''cold diode'' concept. In a group of series connected magnets if one magnet quenches then the magnetic energy of all the magnets will be dissipated in the quenched magnet so destroying it. This is avoided by by-passing the quenched magnet and then rapidly de-exciting the unquenched magnets. For the LHC machine it is foreseen to use silicon diodes situated inside the cryostat as by-pass elements--so called ''cold diodes''. The diodes are exposed to some 50 kGray of radiation during a 10 year operation life-time. The high energy density of the LHC magnets (500 kJ/m) coupled with the relatively slow propagation speed of a ''natural'' quench (10 to 20 m/s) can lead to excessive heating of the zone where the quench started and to high internal voltages. It is therefore necessary to detect quickly the incipient quench and fire strip heaters which spread the quench out more quickly over a large volume of the magnet. After a quench the magnet chain must be de-excited rapidly to avoid spreading the quench to other magnets and over-heating the by-pass diode. This is done by switching high-power energy-dump resistors in series with the magnets. The LHC main ring magnet will be divided into 16 electrically separated units which has important advantages

  19. Quench performance of superconducting quadrupole magnets for the new Fermilab low beta insertion

    International Nuclear Information System (INIS)

    Gourlay, S.A.; Carson, J.A.; Hanft, R.; Jaffery, T.S.; Koepke, K.; Lamm, M.J.; Mantsch, P.M.; McInturff, A.D.; Mokhtarani, A.; Orris, D.; Peterson, T.

    1991-05-01

    Construction and testing of the components for the new Tevatron D0/B0 low beta insertion has been nearly completed. The devices include superconducting cold iron quadrupoles utilizing a 2-shell, cos2θ coil geometry with a 7.6 cm aperture. The maximum design gradient is 1.41 T/cm at an operating current of 4832 A. They have the highest current density with the highest peak field on the winding of any quadrupole yet built. This paper summarizes the quench performance and ramp rate sensitivity of the 2-shell design and relates the performance characteristics to the relevant aspects of design and fabrication. 8 refs., 6 figs., 3 tabs

  20. Superconducting synchrotron power supply and quench protection scheme

    International Nuclear Information System (INIS)

    Stiening, R.; Flora, R.; Lauckner, R.; Tool, G.

    1978-01-01

    The power supply and quench protection scheme for the proposed Fermilab 6 km circumference superconducting synchrotron is described. Specifically, the following points are discussed: (1) the 46 MW thyristor power supply; (2) the 3 x 10 8 J emergency energy dump; (3) the distributed microprocessing system for the detection of quenches; (4) the thyristor network for shunting current around quenched magnets; and (5) the heaters internal to the magnets which cause rapid propagation of quenches. Test results on prototype systems are given

  1. Quench simulation of SMES consisting of some superconducting coils

    International Nuclear Information System (INIS)

    Noguchi, S.; Oga, Y.; Igarashi, H.

    2011-01-01

    A chain of quenches may be caused by a quench of one element coil when SMES is consists of many element coils. To avoid the chain of quenches, the energy stored in element coil has to be quickly discharged. The cause of the chain of the quenches is the short time constant of the decreasing current of the quenched coil. In recent years, many HTS superconducting magnetic energy storage (HTS-SMES) systems are investigated and designed. They usually consist of some superconducting element coils due to storing excessively high energy. If one of them was quenched, the storage energy of the superconducting element coil quenched has to be immediately dispersed to protect the HTS-SMES system. As the result, the current of the other element coils, which do not reach to quench, increases since the magnetic coupling between the quenched element coil and the others are excessively strong. The increase of the current may cause the quench of the other element coils. If the energy dispersion of the element coil quenched was failed, the other superconducting element coil would be quenched in series. Therefore, it is necessary to investigate the behavior of the HTS-SMES after quenching one or more element coils. To protect a chain of quenches, it is also important to investigate the time constant of the coils. We have developed a simulation code to investigate the behavior of the HTS-SMES. By the quench simulation, it is indicated that a chain of quenches is caused by a quench of one element coil.

  2. 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

  3. Superconducting magnets

    International Nuclear Information System (INIS)

    Willen, E.

    1996-01-01

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

  4. Quench simulations for superconducting elements in the LHC accelerator

    Science.gov (United States)

    Sonnemann, F.; Schmidt, R.

    2000-08-01

    The design of the protection system for the superconducting elements in an accelerator such as the large Hadron collider (LHC), now under construction at CERN, requires a detailed understanding of the thermo-hydraulic and electrodynamic processes during a quench. A numerical program (SPQR - simulation program for quench research) has been developed to evaluate temperature and voltage distributions during a quench as a function of space and time. The quench process is simulated by approximating the heat balance equation with the finite difference method in presence of variable cooling and powering conditions. The simulation predicts quench propagation along a superconducting cable, forced quenching with heaters, impact of eddy currents induced by a magnetic field change, and heat transfer through an insulation layer into helium, an adjacent conductor or other material. The simulation studies allowed a better understanding of experimental quench data and were used for determining the adequate dimensioning and protection of the highly stabilised superconducting cables for connecting magnets (busbars), optimising the quench heater strip layout for the main magnets, and studying quench back by induced eddy currents in the superconductor. After the introduction of the theoretical approach, some applications of the simulation model for the LHC dipole and corrector magnets are presented and the outcome of the studies is compared with experimental data.

  5. Superconducting accelerator magnet design

    International Nuclear Information System (INIS)

    Wolff, S.

    1994-01-01

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

  6. Superconducting magnet

    Science.gov (United States)

    1985-01-01

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

  7. Quench Protection of SC Quadrupole Magnets

    Science.gov (United States)

    Feher, S.; Bossert, R.; Dimarco, J.; Mitchell, D.; Lamm, M. J.; Limon, P. J.; Mazur, P.; Nobrega, F.; Orris, D.; Ozelis, J. P.; Strait, J. B.; Tompkins, J. C.; Zlobin, A. V.; McInturff, A. D.

    1997-05-01

    The energy stored in a superconducting accelerator magnet is dissipated after a quench in the coil normal zones, heating the coil and generating a turn to turn and coil to ground voltage drop. Quench heaters are used to protect the superconducting magnet by greatly increasing the coil normal zone thus allowing the energy to be dissipated over a larger conductor volume. Such heaters will be required for the Fermilab/LBNL design of the high gradient quads (HGQ) designed for the LHC interaction regions. As a first step, heaters were installed and tested in several Tevatron low-β superconducting quadrupoles. Experimental studies in normal and superfluid helium are presented which show the heater-induced quench response as a function of magnet excitation current, magnet temperature and peak heater energy density.

  8. Minimum Quench Energy and Early Quench Development in NbTi Superconducting Strands

    CERN Document Server

    Breschi, M; Boselli, M; Bottura, Luca; Devred, Arnaud; Ribani, P L; Trillaud, F

    2007-01-01

    The stability of superconducting wires is a crucial task in the design of safe and reliable superconducting magnets. These magnets are prone to premature quenches due to local releases of energy. In order to simulate these energy disturbances, various heater technologies have been developed, such as coated tips, graphite pastes, and inductive coils. The experiments studied in the present work have been performed using a single-mode diode laser with an optical fiber to illuminate the superconducting strand surface. Minimum quench energies and voltage traces at different magnetic flux densities and transport currents have been measured on an LHC-type, Cu/NbTi wire bathed in pool boiling helium I. This paper deals with the numerical analysis of the experimental data. In particular, a coupled electromagnetic and thermal model has been developed to study quench development and propagation, focusing on the influence of heat exchange with liquid helium.

  9. Quench simulation in the thin superconducting solenoid

    International Nuclear Information System (INIS)

    Tominaka, T.; Takasaki, M.; Wake, M.; Yamada, R.

    1983-07-01

    The propagation velocities of a normal zone were calculated for a 1 mdiameter x 1 m superconducting solenoid and for a 3 mdiameter x 5 m thin solenoid based on a simple model using the one-dimensional thermal equation. The quench back effect can be observed in certain conditions. The quench of the large thin solenoid was also simulated by using the computer program 'QUENCH'. (author)

  10. 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 ...

  11. Superconducting magnets for HERA

    International Nuclear Information System (INIS)

    Wolff, S.

    1987-01-01

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

  12. 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

  13. Quench Protection and Magnet Powe Supply Requirements for the MICE Focusing and Coupling Magnets

    International Nuclear Information System (INIS)

    Green, Michael A.; Witte, Holger

    2005-01-01

    This report discusses the quench protection and power supply requirements of the MICE superconducting magnets. A section of the report discusses the quench process and how to calculate the peak voltages and hotspot temperature that result from a magnet quench. A section of the report discusses conventional quench protection methods. Thermal quench back from the magnet mandrel is also discussed. Selected quench protection methods that result in safe quenching of the MICE focusing and coupling magnets are discussed. The coupling of the MICE magnets with the other magnets in the MICE is described. The consequences of this coupling on magnet charging and quenching are discussed. Calculations of the quenching of a magnet due quench back from circulating currents induced in the magnet mandrel due to quenching of an adjacent magnet are discussed. The conclusion of this report describes how the MICE magnet channel will react when one or magnets in that channel are quenched

  14. A fiber-optic strain measurement and quench localization system for use in superconducting accelerator dipole magnets

    NARCIS (Netherlands)

    van Oort, J.M.; Scanlan, Ronald M.; ten Kate, Herman H.J.

    1995-01-01

    A novel fiber-optic measurement system for superconducting accelerator magnets is described. The principal component is an extrinsic Fabry-Perot interferometer to determine localized strain and stress in coil windings. The system can be used either as a sensitive relative strain measurement system

  15. Mechanical design and protection of superconducting magnets

    CERN Document Server

    Asner, Alfred M

    1978-01-01

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

  16. Quench simulations for superconducting elements in the LHC accelerator

    CERN Document Server

    Sonnemann, F

    2000-01-01

    The design of he protection system for he superconducting elements in an accel- erator such as the Large Hadron Collider (LHC),now under construction at CERN, requires a detailed understanding of the hermo-hydraulic and electrodynamic pro- cesses during a quench.A numerical program (SPQR -Simulation Program for Quench Research)has been developed o evaluate temperature and voltage dis ri- butions during a quench as a func ion of space and ime.The quench process is simulated by approximating the heat balance equation with the finite di fference method in presence of variable cooling and powering conditions.The simulation predicts quench propagation along a superconducting cable,forced quenching with heaters,impact of eddy curren s induced by a magnetic field change,and heat trans- fer hrough an insulation layer in o helium,an adjacen conductor or other material. The simulation studies allowed a better understanding of experimental quench data and were used for determining the adequ...

  17. Superconductivity, magnetic susceptibility, and electronic properties of amorphous (Mo/sub 1-x/Ru/sub x/)80P20 alloys obtained by liquid quenching

    International Nuclear Information System (INIS)

    Johnson, W.L.; Poon, S.J.; Duwez, P.

    1977-11-01

    Results of x-ray diffraction, transmission electron diffraction, and crystallization studies on amorphous (Mo/sub 1-x/Ru/sub x/) 80 P 20 alloys obtained by liquid quenching are presented and discussed. The alloys are all found to be superconducting with transition temperatures ranging from approximately 3 0 K to approximately 9 0 K. The variation of T/sub c/ with alloy composition is compared to that obtained by Collver and Hammond for vapor quenched transition metal films. Results of magnetic susceptibility measurements are used to estimate the variation of the electronic density of states at the Fermi level, N(0), from the Pauli paramagnetic contribution. The relationship between the variation of T/sub c/ and N(0) is discussed in terms of the microscope theory of superconductivity. Finally, results of measurements of the upper critical field H/sub c2/, and the normal state electronic transport properties are presented and compared with recent theoretical models for amorphous superconductors

  18. Detection of temperature rise at 4.2K by using a dual-core optical fiber-an optical method to detect a quench of a superconducting magnet

    International Nuclear Information System (INIS)

    Tsukamoto, O.; Kokubun, Y.; Toyama, T.

    1986-01-01

    We performed an experiment to detect a temperature rise at cryogenic temperature using a dual-core optical fiber. This fiber has two single-mode optical cores in one fiber. We demonstrated that a temperature rise of 4 K was detectable at 4.2 K. The sensitivity of this method can be improved using a longer fiber. This method may be applicable as a quench detector for superconducting magnets. A quench detector using this optical method is immune from electromagnetic noise, free from troubles caused by break-down of electrical insulator, and has many advantages over a conventional quench detector measuring voltages of a magnet

  19. Superconducting Magnets for Accelerators

    Science.gov (United States)

    Brianti, G.; Tortschanoff, T.

    1993-03-01

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

  20. Quench detection, protection and simulation studies on SST-1 magnets

    International Nuclear Information System (INIS)

    Sharma, Aashoo N.; Khristi, Yohan; Pradhan, Subrata; Doshi, Kalpesh; Prasad, Upendra; Banaudha, Moni; Varmora, Pankaj; Praghi, Bhadresh R.

    2015-01-01

    Steady-state Superconducting Tokamak-1 (SST-1) is India's first tokamak with superconducting toroidal field (TF) and Poloidal Field (PF) magnets. These magnets are made with NbTi based Cable-In-Conduit-Conductors. The quench characteristic of SST-1 CICC has been extensively studied both analytically and using simulation codes. Dedicated experiments like model coil test program, TF coil test program and laboratory experiments were conducted to fully characterize the performance of the CICC and the magnets made using this CICC. Results of quench experiments performed during these tests have been used to design the SST-1 quench detection and protection system. Simulation results of TF coil quenches and slow propagation quench of TF busbars have been used to further optimize these systems during the SST-1 tokamak operation. Redundant hydraulic based quench detection is also proposed for the TF coil quench detection. This paper will give the overview of these development and simulation activities. (author)

  1. Quenching of superconductivity in disordered thin films by phase fluctuations

    International Nuclear Information System (INIS)

    Hebard, A.F.; Palaanen, M.A.

    1992-01-01

    The amplitude Ψ 0 and phase Φ of the superconducting order parameter in thin-film systems are affected differently by disorder and dimensionality. With increasing disorder superconducting long range order is quenched in sufficiently thin films by physical processes driven by phase fluctuations. This occurs at both the zero-field vortex-antivortex unbinding transition and at the zero-temperature magnetic-field-tuned superconducting-insulating transition. At both of these transitions Ψ 0 is finite and constant, vanishing only when temperature, disorder, and/or magnetic field are increased further. Experimental results on amorphous-composite InO x films are presented to illustrate these points and appropriate comparisons are made to other experimental systems. (orig.)

  2. Electrical protection of superconducting magnet systems

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  3. Quench detection on a superconducting radio-frequency cavity

    OpenAIRE

    Lai, Ru-Yu; Spirn, Daniel

    2017-01-01

    We study quench detection in superconducting accelerator cavities cooled with He-II. A rigorous mathematical formula is derived to localize the quench position from dynamical data over a finite time interval at a second sound detector.

  4. Quench detector and analyser for a UNK superconducting string

    International Nuclear Information System (INIS)

    Augueres, J.L.; Kircher, F.; Molinie, F.; Sellier, J.C.; Andriichine, A.; Prima, M.; Vassiliev, L.; Yerachin, A.

    1992-01-01

    In a close collaboration between physicists and engineers from IHEP and CEN Saclay, a system for quench detection on a UNK superconducting string (from 4 to 100 magnets) has been designed and is now under construction at Saclay; this system also enables the data analysis in normal conditions or in case of a quench. The paper describes the architectural design of the system, the hardware (microprocessors are used for the whole system) and the software. Emphasis will be put on the main problems of construction friability, quench detection at a low level and in a very short time, high voltages, data transmission on long distances and integration in the general system of the accelerator

  5. Application of AE technique for on-line monitoring of quenching in racetrack superconducting coil at cryogenic environment

    International Nuclear Information System (INIS)

    Lee, Jun Hyun; Lee, Min Rae; Shon, Myung Hwan; Kwon, Young Kil

    1998-01-01

    An acoustic emission(AE) technique has been used to monitor and diagnose quenching phenomenon in racetrack shaped superconducting magnets at cryogenic environment of 4.2 K. The ultimate goal is to ensure the safety and reliability of large superconducting magnet systems by being able to identity and locate the sources of quench in superconducting magnets. The characteristics of AE parameters have been analyzed by correlating with quench number, winding tension of superconducting coil and charge rate by transport current. It was found in this study that there was good correlation between quench current and AE parameters. The source location of quenching in superconducting magnet was also discussed on the hashing of correlation between magnet voltage and AE energy.

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

    OpenAIRE

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

    2014-01-01

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

  7. 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).

  8. Quench Propagation in the Superconducting 6 kA Flexible Busbars of the LHC

    OpenAIRE

    Calvi, M; Herzog, R; Pelegrin-Carcelen, J M; Sonnemann, F

    2001-01-01

    Flexible superconducting cables with currents up to 6 kA will be used to power magnets individually in the insertion regions of the LHC. In case of a quench, the currents in these circuits will decay very fast (with time constants of about 200 ms) such that relatively small copper cross sections are sufficient for these busbars. Quench propagation experiments on a prototype cable and corresponding simulations led to a detailed understanding of the quench behavior of these busbars and to recom...

  9. Hybrid superconducting magnetic suspensions

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  10. Stacked magnet superconducting bearing

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  11. 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)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

  14. Shunt protection for superconducting Maglev magnets

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-09-01

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

  15. Shunt protection for superconducting Maglev magnets

    International Nuclear Information System (INIS)

    Atherton, D.L.

    1979-01-01

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

  16. New Fast Response Thin Film-Based Superconducting Quench Detectors

    CERN Document Server

    Dudarev, A; van de Camp, W; Ravaioli, E; Teixeira, A; ten Kate, H H J

    2014-01-01

    Quench detection on superconducting bus bars and other devices with a low normal zone propagation velocity and low voltage build-up is quite difficult with conventional quench detection techniques. Currently, on ATLAS superconducting bus bar sections, superconducting quench detectors (SQD) are mounted to detect quench events. A first version of the SQD essentially consists of an insulated superconducting wire glued to a superconducting bus line or windings, which in the case of a quench rapidly builds up a relatively high resistance that can be easily and quietly detected. We now introduce a new generation of drastically improved SQDs. The new version makes the detection of quenches simpler, more reliable, and much faster. Instead of a superconducting wire, now a superconducting thin film is used. The layout of the sensor shows a meander like pattern that is etched out of a copper coated 25 mu m thick film of Nb-Ti glued in between layers of Kapton. Since the sensor is now much smaller and thinner, it is easi...

  17. Simulation of quenches in SSC magnets with passive quench protection

    International Nuclear Information System (INIS)

    Koepke, K.

    1985-06-01

    The relative ease of protecting an SSC magnet following a quench and the implications of quench protection on magnet reliability and operation are necessary inputs in a rational magnet selection process. As it appears likely that the magnet selection will be made prior to full scale prototype testing, an alternative means is required to ascertain the surviveability of contending magnet types. This paper attempts to provide a basis for magnet selection by calculating the peak expected quench temperatures in the 3 T Design C magnet and the 6 T Design D magnet as a function of magnet length. A passive, ''cold diode'' protection system has been assumed. The relative merits of passive versus active protection systems have been discussed in a previous report. It is therefore assumed that - given the experience gained from the Tevatron system - that an active quench protection system can be employed to protect the magnets in the eventuality of unreliable cold diode function

  18. Heater induced quenches in SSC [Superconducting Super Collider] model dipoles

    International Nuclear Information System (INIS)

    Hassenzahl, W.V.

    1986-10-01

    A 1-m long SSC dipole constructed at the Lawrence Berkeley laboratory was subjected to a series of heater induced quenches to determine: axial quench propagation velocities, transverse quench propagation, and conductor temperature rise. Quenches were produced by 3 heaters at different locations in the magnet and at several currents. The results of these studies are described and are compared to previously published theoretical studies of quenches on the SSC dipoles. These results are shown to be in agreement with the calculations of the program ''QUENCH'', which includes an increase of the quench velocity during the first few milliseconds of the quench

  19. 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

  20. Two phase cooling for superconducting magnets

    International Nuclear Information System (INIS)

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

    1985-08-01

    A closed circuit tubular cooling system for superconducting magnets offers advantages of limiting boiloff and containing high pressures during quenches. Proper location of automatic valves to lower pressures and protect the refrigerator in the event of quenches is described. Theoretical arguments and exprimental evidence are given against a previously suggested method to determine He two phase flow regimes. If loss of flow occurs due to some types of refrigeration failure and transfer lines have enough heat leak to warm up, quenches are induced when the flow is restored. Examples are taken from experience with the TPC magnet

  1. Quench observation using quench antennas on RHIC IR quadrupole magnets

    International Nuclear Information System (INIS)

    Ogitsu, T.; Terashima, A.; Tsuchiya, K.; Ganetis, G.; Muratore, J.; Wanderer, P.

    1995-01-01

    Quench observation using quench antennas is now being performed routinely on RHIC dipole and quadrupole magnets. Recently, a quench antenna was used on a RHIC IR magnet which is heavily instrumented with voltage taps. It was confirmed that the signals detected in the antenna coils do not contradict the voltage tap signals. The antenna also detects a sign of mechanical disturbance which could be related to a training quench. This paper summarizes signals detected in the antenna and discusses possible causes of these signals

  2. Quench observation using quench antennas on RHIC IR quadrupole magnets

    International Nuclear Information System (INIS)

    Ogitsu, T.; Terashima, A.; Tsuchiya, K.; Ganetis, G.; Muratore, J.; Wanderer, P.

    1996-01-01

    Quench observation using quench antennas is now being performed routinely on RHIC dipole and quadrupole magnets. Recently, a quench antenna was used on a RHIC IR magnet which is heavily instrumented with voltage taps. It was confirmed that the signals detected in the antenna coils do not contradict the voltage tap signals. The antenna also detects a sign of mechanical disturbance which could be related to a training quench. This paper summarizes signals detected in the antenna and discusses possible causes of these signals

  3. 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...

  4. Quench detection and behaviour in case of quench in the ITER magnet systems

    International Nuclear Information System (INIS)

    Coatanea-Gouachet, M.

    2012-02-01

    The quench of one of the ITER magnet system is an irreversible transition from superconducting to normal resistive state, of a conductor. This normal zone propagates along the cable in conduit conductor dissipating a large power. The detection has to be fast enough to dump out the magnetic energy and avoid irreversible damage of the systems. The primary quench detection in ITER is based on voltage detection, which is the most rapid detection. The very magnetically disturbed environment during the plasma scenario makes the voltage detection particularly difficult, inducing large inductive components in the coils and voltage compensations have to be designed to discriminate the resistive voltage associated with the quench. A conceptual design of the quench detection based on voltage measurements is proposed for the three majors magnet systems of ITER. For this, a clear methodology was developed. It includes the classical hot spot criterion, the quench propagation study using the commercial code Gandalf and the careful estimation of the inductive disturbances by developing the TrapsAV code. Specific solutions have been proposed for the compensation in the three ITER magnet systems and for the quench detection parameters, which are the voltage threshold (in the range of 0.1 V - 0.55 V) and the holding time (in the range of 1-1.4 s). The selected values, in particular the holding time, are sufficiently high to ensure the reliability of the system and avoid fast safety discharges not induced by a quench, which is a classical problem. (author)

  5. Superconducting magnets for accelerators

    International Nuclear Information System (INIS)

    Denisov, Yu.N.

    1979-01-01

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

  6. Superconducting solenoid model magnet test results

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-01

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

  7. Superconducting solenoid model magnet test results

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  8. Superconducting 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

  9. ESCAR superconducting magnet system

    International Nuclear Information System (INIS)

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

    1975-01-01

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

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

    CERN Document Server

    Priebe, A; Sapinski, M

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

  11. 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

  12. Review of quench simulations for the protection of LHC main dipole magnets

    OpenAIRE

    Sonnemann, F; Danner, A

    1999-01-01

    The simulation program QUABER [1] allows studying the quench process of superconducting magnets for the LHC. The performance of the protection system of the LHC main dipole magnets was simulated under various parameter dependencies at different magnet excitation currents. This simulation study was motivated to complement measurement results in order to help preparing and understanding experiments of the quench propagation and magnet protection. The influence of the quench propagation velocity...

  13. The quench detector on magnetic modulator for the UNK quench protection system

    International Nuclear Information System (INIS)

    Bolotin, I.M.; Enbaev, A.V.; Erokhin, A.N.; Gridasov, V.I.; Priyma, M.V.; Sychev, V.A.; Vasiliev, L.M.

    1992-01-01

    When designing and constructing superconducting high energy accelerators, the development of the Quench Detection System (QDS) for superconducting (SC) magnets becomes an important and critical problem. At present there is experience in developing such systems for the Tevatron (FNAL, USA) and HERA (Hamburg, Germany). The machines for more than 3 TeV-the UNK (Russia) and SSC (USA), which are presently under construction, have very large circumferences, 21 and 87 km, respectively. The QDS's, similar to those of the Tevatron, require a larger part of the active components of the electronic equipment be placed in the machine tunnel close to the magnets, and protected from irradiation or additional surface buildings will have to be constructed. In either case the cost of such a QDS increases. In addition the former ones reliability decreases and maintenance becomes more difficult. For such machines, a QDS in which the quench signal, in each superconducting magnet (SCM) or groups of SCM'S, is extracted with the help of a bridge circuit (BC) appears to be more suitable. The half coils of SCM's are connected as two arms of the bridge and the resistors placed in the vacuum vessels of the magnet cryostats are connected to the other two. The off-balance signal of each BC is enhanced with the help of magnetic amplifiers. This note describes the experimental prototype of a bridge-type Quench Detector (QD) based on a magnetic amplifier Magnetic Modulator (MM) type, allowing one not only to detect a quench in a SCM, but also making feasible a wider system capability, namely: to record the signals from all SC elements during a quench for further analysis of its causes; to check the presence of short circuits of the ring electromagnet bus relative to the cryostats and to localize their position

  14. Large Superconducting Magnet Systems

    CERN Document Server

    Védrine, P.

    2014-07-17

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb$_{3}$Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  15. Large Superconducting Magnet Systems

    Energy Technology Data Exchange (ETDEWEB)

    Védrine, P [Saclay (France)

    2014-07-01

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

  16. 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

  17. 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.

  18. Mechanical disturbances in superconducting magnets

    International Nuclear Information System (INIS)

    Sugimoto, Makoto

    1990-03-01

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

  19. AGS superconducting bending magnets

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  20. Magnetically leviated superconducting bearing

    Science.gov (United States)

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

    1993-01-01

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

  1. Numerical Study of Quench Protection for Fast-Ramping Accelerator Magnets

    CERN Document Server

    Schwerg, N; Mess, K-N; Russenschuck, S

    2009-01-01

    The quench module of the ROXIE field computation program has been presented at previous conferences. In this paper we discuss recently implemented features that allow quench simulation of fast-ramping superconducting magnets. As the reliability of quench detection during the ramps depends on the signal to noise ratio, we simulate the influence of detection thresholds and the propagation of undetected quenches during the ramps. We also study the effect of an increased copper content and the feasibility of a self-protected magnet surviving a powering cycle with an undetected quench and without quench heater firing or energy-extraction system.

  2. 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.

  3. Reliability of the quench protection system for the LHC superconducting elements

    International Nuclear Information System (INIS)

    Vergara Fernandez, A.; Rodriguez-Mateos, F.

    2004-01-01

    The Quench Protection System (QPS) is the sole system in the Large Hadron Collider machine monitoring the signals from the superconducting elements (bus bars, current leads, magnets) which form the cold part of the electrical circuits. The basic functions to be accomplished by the QPS during the machine operation will be briefly presented. With more than 4000 internal trigger channels (quench detectors and others), the final QPS design is the result of an optimised balance between on-demand availability and false quench reliability. The built-in redundancy for the different equipment will be presented, focusing on the calculated, expected number of missed quenches and false quenches. Maintenance strategies in order to improve the performance over the years of operation will be addressed

  4. Reliability of the quench protection system for the LHC superconducting elements

    Science.gov (United States)

    Vergara Fernández, A.; Rodríguez-Mateos, F.

    2004-06-01

    The Quench Protection System (QPS) is the sole system in the Large Hadron Collider machine monitoring the signals from the superconducting elements (bus bars, current leads, magnets) which form the cold part of the electrical circuits. The basic functions to be accomplished by the QPS during the machine operation will be briefly presented. With more than 4000 internal trigger channels (quench detectors and others), the final QPS design is the result of an optimised balance between on-demand availability and false quench reliability. The built-in redundancy for the different equipment will be presented, focusing on the calculated, expected number of missed quenches and false quenches. Maintenance strategies in order to improve the performance over the years of operation will be addressed.

  5. Modelling of the Quench Process for the Optimisation of the Design and Protection of Superconducting Busbars for the LHC

    OpenAIRE

    Schmidt, R; Sonnemann, F

    2000-01-01

    The superconducting busbars powering the LHC magnets are highly stabilised with copper to reduce the probability of a quench starting in a busbar and to avoid excessive temperatures after a quench during current discharge. In order to determine the required copper stabilisation and the parameters of the protection system a finite difference program has been developed. The program numerically approximates the heat balance equation and evaluates the temperature profile after a quench as a funct...

  6. Numerical Study of Quench Protection for Fast-Ramping Accelerator Magnets

    OpenAIRE

    Schwerg, N; Auchman, B; Mess, K-N; Russenschuck, S

    2009-01-01

    The quench module of the ROXIE field computation program has been presented at previous conferences. In this paper we discuss recently implemented features that allow quench simulation of fast-ramping superconducting magnets. As the reliability of quench detection during the ramps depends on the signal to noise ratio, we simulate the influence of detection thresholds and the propagation of undetected quenches during the ramps. We also study the effect of an increased copper content and the fe...

  7. 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

  8. Magnetic levitation and superconductivity

    International Nuclear Information System (INIS)

    Albrecht, C.

    1989-01-01

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

  9. 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.

  10. Quench propagation in the superconducting 6 kA flexible busbars of the LHC

    International Nuclear Information System (INIS)

    Herzog, R.; Calvi, M.; Sonnemann, F.; Pelegrin-Carcelen, J.M.

    2002-01-01

    Flexible superconducting cables with currents up to 6 kA will be used to power magnets individually in the insertion regions of the LHC. In case of a quench, the currents in these circuits will decay very fast (with time constants of about 200 ms) such that relatively small copper cross sections are sufficient for these busbars. Quench propagation experiments on a prototype cable and corresponding simulations led to a detailed understanding of the quench behavior of these busbars and to recommendations for the design and application of the cable. Simulations of the quench process in a multi-strand conductor led to a detailed understanding of the way current crosses from superconducting to pure copper strands and how this affects the quench propagation velocity. At nominal current (6 kA), the quench propagation velocities are high (10 m/s) and the hot spot temperature increases rapidly. In this situation, timely quench detection and energy extraction (current reduction) are vital to prevent damage of circuit components

  11. Quench Propagation in the Superconducting 6 kA Flexible Busbars of the LHC

    CERN Document Server

    Calvi, M; Pelegrin-Carcelen, J M; Sonnemann, F

    2002-01-01

    Flexible superconducting cables with currents up to 6 kA will be used to power magnets individually in the insertion regions of the LHC. In case of a quench, the currents in these circuits will decay very fast (with time constants of about 200 ms) such that relatively small copper cross sections are sufficient for these busbars. Quench propagation experiments on a prototype cable and corresponding simulations led to a detailed understanding of the quench behavior of these busbars and to recommendations for the design and application of the cable. Simulations of the quench process in a multi-strand conductor led to a detailed understanding of the way current crosses from superconducting to pure copper strands and how this affects the quench propagation velocity. At nominal current (6 kA), the quench propagation velocities are high (10 m/s) and the hot spot temperature increases rapidly. In this situation, timely quench detection and energy extraction (current reduction) are vital to prevent damage of circuit c...

  12. Quench propagation in the superconducting 6 kA flexible busbars of the LHC

    Science.gov (United States)

    Herzog, R.; Calvi, M.; Sonnemann, F.; Pelegrin-Carcelen, J. M.

    2002-05-01

    Flexible superconducting cables with currents up to 6 kA will be used to power magnets individually in the insertion regions of the LHC. In case of a quench, the currents in these circuits will decay very fast (with time constants of about 200 ms) such that relatively small copper cross sections are sufficient for these busbars. Quench propagation experiments on a prototype cable and corresponding simulations led to a detailed understanding of the quench behavior of these busbars and to recommendations for the design and application of the cable. Simulations of the quench process in a multi-strand conductor led to a detailed understanding of the way current crosses from superconducting to pure copper strands and how this affects the quench propagation velocity. At nominal current (6 kA), the quench propagation velocities are high (10 m/s) and the hot spot temperature increases rapidly. In this situation, timely quench detection and energy extraction (current reduction) are vital to prevent damage of circuit components.

  13. Superconductivity and magnet technology

    International Nuclear Information System (INIS)

    Lubell, M.S.

    1975-01-01

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

  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. A superconducting magnetic gear

    International Nuclear Information System (INIS)

    Campbell, A M

    2016-01-01

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

  16. Magnetic Design of Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  17. Superconducting magnets for ISABELLE

    International Nuclear Information System (INIS)

    Sampson, W.B.

    1976-01-01

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

  18. Superconducting magnet for 'ML-100'

    Energy Technology Data Exchange (ETDEWEB)

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

    1974-07-01

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

  19. Energy extraction system using dual-capacitor switching for quench protection of HTS magnet

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Yo Jong; Song, Seung Hyun; Jeon, Hae Ryong; Ko, Tae Kuk [Yonsei University, Seoul (Korea, Republic of); Lee, Woo Seung [JH ENGINEERING CO., LTD., Anyang (Korea, Republic of); Kang, Hyoung Ku [Korea National University of Transportation, Chungju (Korea, Republic of)

    2017-09-15

    The superconducting magnets have a large inductance as well as high operating current. Therefore, mega-joule scale energy can be stored in the magnet. The energy stored in the magnet is sufficient to damage the magnet when a quench occurs. Quench heater and dump resistor can be used to protect the magnet. However, using quench heater to create quench resistors through heat transfer can be slower than instantly switching resistors. Also, electrical short, overheating and breakdown can occur due to quench heater. Moreover, the number of dump resistor should be limited to avoid large terminal voltage. Therefore, in this paper, we propose a quench protection method for extracting the energy stored in a magnet by charging and discharging energy through a capacitor switching without increasing resistance. The simulation results show that the proposed system has a faster current decay within the allowable voltage level.

  20. Energy extraction system using dual-capacitor switching for quench protection of HTS magnet

    International Nuclear Information System (INIS)

    Chi, Yo Jong; Song, Seung Hyun; Jeon, Hae Ryong; Ko, Tae Kuk; Lee, Woo Seung; Kang, Hyoung Ku

    2017-01-01

    The superconducting magnets have a large inductance as well as high operating current. Therefore, mega-joule scale energy can be stored in the magnet. The energy stored in the magnet is sufficient to damage the magnet when a quench occurs. Quench heater and dump resistor can be used to protect the magnet. However, using quench heater to create quench resistors through heat transfer can be slower than instantly switching resistors. Also, electrical short, overheating and breakdown can occur due to quench heater. Moreover, the number of dump resistor should be limited to avoid large terminal voltage. Therefore, in this paper, we propose a quench protection method for extracting the energy stored in a magnet by charging and discharging energy through a capacitor switching without increasing resistance. The simulation results show that the proposed system has a faster current decay within the allowable voltage level

  1. Review of quench simulations for the protection of LHC main dipole magnets

    CERN Document Server

    Sonnemann, F

    1999-01-01

    The simulation program QUABER [1] allows studying the quench process of superconducting magnets for the LHC. The performance of the protection system of the LHC main dipole magnets was simulated under various parameter dependencies at different magnet excitation currents. This simulation study was motivated to complement measurement results in order to help preparing and understanding experiments of the quench propagation and magnet protection. The influence of the quench propagation velocity and the time for a quench propagation between adjacent turns was studied. The different copper plating cycles of the quench heater strips were simulated. Experimental measurement results [2] were used to calibrate the input parameters. The performance of the protection system for various quench detection thresholds was investigated and different failure modes of the system were considered. The maximum voltages and values of the quench load are discussed. The values given are obtained using conservatively chosen parameter...

  2. Superconducting magnets of SST-1 tokamak

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  3. Superconducting energy storage magnet

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  4. Two phase cooling for superconducting magnets

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  5. 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

  6. Analysis of Voltage Signals from Superconducting Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-30

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

  7. 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

  8. Superconducting magnetic coil

    Science.gov (United States)

    Aized, Dawood; Schwall, Robert E.

    1996-06-11

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

  9. A summary of the quench behavior of B ampersand W 1 m collider quadrupole model magnets

    International Nuclear Information System (INIS)

    Rey, C.M.; Xu, M.F.; Hlasnicek, P.; Kelley, J.P.; Dixon, K.; Savignano, J.; Letterman, S.; Craig, P.; Maloney, J.; Boyes, D.

    1994-01-01

    In order to evaluate the quench performance of a B ampersand W-Siemens designed quadrupole magnet at the earliest possible stage, a model magnet program was developed at B ampersand W for the support of the Superconducting Super Collider. The authors report the quench performance, training behavior, and the ramp rate dependence for the QSH-801 through QSH-804 series of short (1.2 meter) quadrupole model magnets

  10. 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

  11. Superconducting magnet for MAGLEV

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-07-25

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

  12. Study of the thermo-electronic stability of LTS conductors and contribution to the study of the thermo-electric stability of HTS conductors. Novel techniques to simulate quench precursors in superconducting electro-magnets

    International Nuclear Information System (INIS)

    Trillaud, F.

    2005-09-01

    Most of this work deals with the development of new heater technology to simulate quench precursors in super-conducting electro-magnets. The carbon paste point heater and 2 alternative technologies have been used: induction coils and the diode laser. 2 main experimental setups with 2 different heaters have been used to study the stability of Cu/NbTi composite wires. The order of magnitude of the results obtained with the charged point heater and the diode laser is consistent. Our work covered both low critical temperature (LTS) conductors and high critical temperature (HTS) conductors. A large body of data has been gathered on quench energies and normal zone propagation velocities (NZPV). Concerning quench energy: LTS conductors appear largely more sensitive to heat disturbances than HTS conductors. NZPV enables one to define the criteria for which a magnet can be considered as self-protected. It is commonly assumed that, below 1 m/s, active protection is necessary to ensure safe quenches. This is the case for HTS conductors whose NZPV is of the order of a few centimeters per seconds, at most. However, the NZPVs of LTS conductors are above a few meters per seconds. While HTS conductors can suffer from local hot spots which diffuse slowly resulting in damaging overheating, LTS conductors spread the normal zone quickly enough owing to their good thermal conductivity to minimize local overheating. In addition, this gives enough time to dump the energy of the magnet. This work clears a new path to carry out accurate and reproducible experiment on superconductors. It demonstrates the powerfulness of diode laser technology for stability studies. Numerical simulations of the thermal behaviour of a Cu/NbTi multi-filament composite wire have been performed, they are based on a simplified transient liquid helium heat exchange model. This model appears to be not accurate enough to simulate the early time evolution of the voltage between the current sharing temperature and the

  13. Quench propagation in the SSC dipole magnets

    International Nuclear Information System (INIS)

    Lopez, G.; Snitchler, G.

    1990-09-01

    The effects of quench propagation are modeled in 40mm and 50mm diameter collider dipole magnet designs. A comparative study of the cold diode (passive) and quench heater (active) protection schemes will be presented. The SSCQ modeling program accurately simulates the axial quench velocity and uses phenomenological time delays for turn-to-turn transverse propagation. The axial quench velocity is field dependent and consequently, each conductor's quench profile is tracked separately. No symmetry constraints are employed and the distribution of the temperatures along the conductor differs from the adiabatic approximation. A single magnet has a wide margin of self protection which suggests that passive protection schemes must be considered. 6 refs., 3 figs., 1 tab

  14. Protecting a full-scale Nb3Sn magnet with CLIQ, the new coupling-loss-induced quench system

    NARCIS (Netherlands)

    Ravaioli, Emanuele; Bajas, H.; Datskov, V.I.; Desbiolles, V.; Feuvrier, J.; Kirby, G.; Maciejewski, M.; Sabbi, G.; ten Kate, Herman H.J.; Verweij, A.P.

    2015-01-01

    A new protection system for superconducting magnets called coupling-loss induced quench system (CLIQ) has been recently developed at CERN. Recent tests on Nb-Ti coils have shown that CLIQ is a valid, efficient, and promising method for the protection of high-magnetic-field superconducting magnets.

  15. Cooldown of superconducting magnet strings

    International Nuclear Information System (INIS)

    Yuecel, A.; Carcagno, R.H.

    1995-01-01

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

  16. Dynamical quenching of tunneling in molecular magnets

    Energy Technology Data Exchange (ETDEWEB)

    José Santander, María, E-mail: maria.jose.noemi@gmail.com [Recursos Educativos Quántica, Santiago (Chile); Departamento de Física, Universidad de Santiago de Chile and CEDENNA, Avda. Ecuador 3493, Santiago (Chile); Nunez, Alvaro S., E-mail: alnunez@dfi.uchile.cl [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago (Chile); Roldán-Molina, A. [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso (Chile); Troncoso, Roberto E., E-mail: r.troncoso.c@gmail.com [Centro para el Desarrollo de la Nanociencia y la Nanotecnología, CEDENNA, Avda. Ecuador 3493, Santiago 9170124 (Chile); Departamento de Física, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso (Chile)

    2015-12-15

    It is shown that a single molecular magnet placed in a rapidly oscillating magnetic field displays the phenomenon of quenching of tunneling processes. The results open a way to manipulate the quantum states of molecular magnets by means of radiation in the terahertz range. Our analysis separates the time evolution into slow and fast components thereby obtaining an effective theory for the slow dynamics. This effective theory presents quenching of the tunnel effect, in particular, stands out its difference with the so-called coherent destruction of tunneling. We support our prediction with numerical evidence based on an exact solution of Schrödinger's equation. - Highlights: • Single molecular magnets under rapidly oscillating magnetic fields is studied. • It is shown that this system displays the quenching of tunneling processes. • Our findings provide a control of quantum molecular magnets via terahertz radiation.

  17. Dynamical quenching of tunneling in molecular magnets

    International Nuclear Information System (INIS)

    José Santander, María; Nunez, Alvaro S.; Roldán-Molina, A.; Troncoso, Roberto E.

    2015-01-01

    It is shown that a single molecular magnet placed in a rapidly oscillating magnetic field displays the phenomenon of quenching of tunneling processes. The results open a way to manipulate the quantum states of molecular magnets by means of radiation in the terahertz range. Our analysis separates the time evolution into slow and fast components thereby obtaining an effective theory for the slow dynamics. This effective theory presents quenching of the tunnel effect, in particular, stands out its difference with the so-called coherent destruction of tunneling. We support our prediction with numerical evidence based on an exact solution of Schrödinger's equation. - Highlights: • Single molecular magnets under rapidly oscillating magnetic fields is studied. • It is shown that this system displays the quenching of tunneling processes. • Our findings provide a control of quantum molecular magnets via terahertz radiation

  18. Superconducting magnet development in Japan

    International Nuclear Information System (INIS)

    Yasukochi, K.

    1983-01-01

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

  19. Design of CR superconducting dipole magnet in German FAIR project

    International Nuclear Information System (INIS)

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

    2008-01-01

    The engineering design of CR (collector ring) superconducting magnet of German FAIR (facility for antiproton and ion research) project is introduced. 3-D model is formed by CATIA, and the magnetic filed of 1/4 magnet is analyzed with ANSYS. Then the displacement and stress of the coil case, liquid helium (LHe) case, especially, the maximal displacement and stress when quenching happens are calculated based on the analysis of magnetic field. These results are necessary for manufacturing the formal magnet. (authors)

  20. 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

  1. Quench-Induced Degradation of the Quality Factor in Superconducting Resonators

    Science.gov (United States)

    Checchin, M.; Martinello, M.; Romanenko, A.; Grassellino, A.; Sergatskov, D. A.; Posen, S.; Melnychuk, O.; Zasadzinski, J. F.

    2016-04-01

    Quench of superconducting radio-frequency cavities frequently leads to the lowered quality factor Q0 , which had been attributed to the additional trapped magnetic flux. Here we demonstrate that the origin of this magnetic flux is purely extrinsic to the cavity by showing no extra dissipation (unchanged Q0) after quenching in zero magnetic field, which allows us to rule out intrinsic mechanisms of flux trapping such as generation of thermal currents or trapping of the rf field. We also show the clear relation of dissipation introduced by quenching to the orientation of the applied magnetic field and the possibility to fully recover the quality factor by requenching in the compensated field. We discover that for larger values of the ambient field, the Q -factor degradation may become irreversible by this technique, likely due to the outward flux migration beyond the normal zone opening during quench. Our findings are of special practical importance for accelerators based on low- and medium-β accelerating structures residing close to focusing magnets, as well as for all high-Q cavity-based accelerators.

  2. Superconducting pipes and levitating magnets.

    Science.gov (United States)

    Levin, Yan; Rizzato, Felipe B

    2006-12-01

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

  3. Quench Detection and Instrumentation for the Tokamak Physics Experiment magnets

    International Nuclear Information System (INIS)

    Chaplin, M.R.; Hassenzahl, W.V.; Schultz, J.H.

    1993-01-01

    The design of the Local Instrumentation ampersand Control (I ampersand C) System for the Tokamak Physics Experiment (TPX) superconducting PF ampersand TF magnets is presented. The local I ampersand C system monitors the status of the magnet systems and initiates the proper control sequences to protect the magnets from any foreseeable fault. Local I ampersand C also stores magnet-system data for analysis and archiving. Quench Detection for the TPX magnets must use a minimum of two independent sensing methods and is allowed a detection time of one second. Proposed detection methods include the measurement of; (1) normal-zone resistive voltage, (2) cooling-path helium flow, (3) local temperature in the winding pack, (4) local pressure in the winding pack. Fiber-optic based isolation systems are used to remove high common-mode magnet voltages and eliminate ground loops. The data acquisition and fault-detection systems are computer based. The design of the local I ampersand C system incorporates redundant, fault-tolerant, and/or fail-safe features at all component levels. As part of a quench detection R ampersand D plan, a Quench Detection Model Coil has been proposed to test all detection methods. Initial cost estimates and schedule for the local I ampersand C system are presented

  4. 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.

  5. Superconducting energy storage magnet

    Science.gov (United States)

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

    1993-01-01

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

  6. 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

  7. 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

  8. Superconducting composite for magnetic bearings

    International Nuclear Information System (INIS)

    Rigney, T.K. II.

    1995-01-01

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

  9. Superconducting Magnetic Energy Storage

    International Nuclear Information System (INIS)

    Hassenzahl, W.

    1989-01-01

    Recent programmatic developments in Superconducting Magnetic Energy Storage (SMES) have prompted renewed and widespread interest in this field. In mid 1987 the Defense Nuclear Agency, acting for the Strategic Defense Initiative Office issued a request for proposals for the design and construction of SMES Engineering Test Model (ETM). Two teams, one led by Bechtel and the other by Ebasco, are now engaged in the first phase of the development of a 10 to 20 MWhr ETM. This report presents the rationale for energy storage on utility systems, describes the general technology of SMES, and explains the chronological development of the technology. The present ETM program is outlined; details of the two projects for ETM development are described in other papers in these proceedings. The impact of high Tc materials on SMES is discussed

  10. Quench Detection and Magnet Protection Study for MFTF. LLL final review

    International Nuclear Information System (INIS)

    1979-06-01

    The results of a Quench Detection and Magnet Protection Study for MFTF are summarized. The study was directed toward establishing requirements and guidelines for the electronic package used to protect the MFTF superconducting magnets. Two quench detection schemes were analyzed in detail, both of which require a programmable quench detector. Hardware and software recommendations for the quench detector were presented as well as criteria for dumping the magnet energy in the event of a quench. Overall magnet protection requirements were outlined in a detailed Failure Mode Effects and Criticality analysis, (FMECA). Hardware and software packages compatible with the FMECA were recommended, with the hardware consisting of flexible, dedicated intelligent modules specifically designed for magnet protection

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  12. Fast superconducting magnetic field switch

    Science.gov (United States)

    Goren, Yehuda; Mahale, Narayan K.

    1996-01-01

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

  13. Fast superconducting magnetic field switch

    International Nuclear Information System (INIS)

    Goren, Y.; Mahale, N.K.

    1996-01-01

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

  14. Design of a large superconducting spectrometer magnet

    International Nuclear Information System (INIS)

    Shintomi, T.; Makida, Y.; Mito, T.; Yamanoi, Y.; Hashimito, O.; Nagae, T.

    1989-04-01

    The superconducting spectrometer magnet for nuclear physics experiments has been under construction by Institute for Nuclear Study, University of Tokyo with collaboration from KEK. The magnet has a sector type coil. The magnetic field is 3 T with the magnet gap of 50 cm and the stored energy is 11.8 MJ. The easy operation and maintenance are taken into consideration in addition to usual design concept. Three dimensional magnetic field calculation and the stress analysis have been performed. The code 'QUENCH' was applied to decide the operation current and to check the safety of the coil. As a result, the current of 500 A was selected. The heat leaks were checked and estimated less than 2 W at 4 K. A small refrigerator is to be used for thermal insulations at 80 and 20 K. (author)

  15. Superconducting permanent magnets

    International Nuclear Information System (INIS)

    Wipf, S.L.; Laquer, H.L.

    1989-01-01

    The concept of superconducting permanent magnets with fields trapped in shells or cylinders of Type II superconductors is an old one. Unfortunately, the low values of 0.5 to 1T for the first flux jump field, which is independent of the actual current density, have frustrated its implementation with classical Type II superconductors. The fact that the flux jump fields for high temperature superconductors should be an order of magnitude larger at liquid nitrogen temperatures allows us to reconsider these options. Analysis of the hysteresis patterns, based on the critical state model, shows that, if the dimensions are chosen so that the sample is penetrated at a field B/sub p/, which is equal to or just less than the first flux jump field, B/sub fj/, a temporarily applied field of 2B/sub fj/ will trap 0.5 B/sub fj/. Thus for a 90 K superconductor with a B/sub fj/ of 6T, a permanent field of 3 T should be trapped, with an energy product of 1.8 MJ/m/sup 3/ (225 MG . Oe). This is five times as large as for the best permanent magnet materials. The authors discuss means to verify the analysis and the limitations imposed by the low critical current densities in presently available high temperature superconductors

  16. Safety concerns for superconducting magnets of upcoming fusion experiments

    International Nuclear Information System (INIS)

    Turner, L.R.

    1983-01-01

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

  17. Internal trim coils for CBA superconducting magnets

    International Nuclear Information System (INIS)

    Thompson, P.A.; Aronson, S.; Cottingham, J.G.; Garber, M.; Hahn, H.; Sampson, W.B.

    1983-01-01

    In order to correct iron saturation effects and shape the beam working line, superconducting trim coils have been constructed, which operate inside the main coils. Detailed studies of mechanical properties, quench behavior, fields produced, and hysteresis have lead to the production of accelerator-quality coils generating the required-strength harmonics up to cos (7theta). These are routinely installed in CBA main magnets and operate at 80% of short sample with negligible training in an ambient field of more than 5.3T

  18. Superconducting magnet applications in Finland

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-01-01

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

  19. Interplay of magnetism and superconductivity

    International Nuclear Information System (INIS)

    Akhavan, M.

    2006-01-01

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

  20. Safety of superconducting fusion magnets: twelve problem areas

    International Nuclear Information System (INIS)

    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

  1. Safety of superconducting fusion magnets: twelve problem areas

    International Nuclear Information System (INIS)

    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

  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. Analysis of voltage spikes in superconducting Nb3Sn magnets

    International Nuclear Information System (INIS)

    Rahimzadeh-Kalaleh, S.; Ambrosio, G.; Chlachidze, G.; Donnelly, C.

    2008-01-01

    Fermi National Accelerator Laboratory has been developing a new generation of superconducting accelerator magnets based on Niobium Tin (Nb 3 Sn). The performance of these magnets is influenced by thermo-magnetic instabilities, known as flux jumps, which can lead to premature trips of the quench detection system due to large voltage transients or quenches at low current. In an effort to better characterize and understand these instabilities, a system for capturing fast voltage transients was developed and used in recent tests of R and D model magnets. A new automated voltage spike analysis program was developed for the analysis of large amount of voltage-spike data. We report results from the analysis of large statistics data samples for short model magnets that were constructed using MJR and RRP strands having different sub-element size and structure. We then assess the implications for quench protection of Nb 3 Sn magnets

  4. Process of producing superconducting bar magnets

    International Nuclear Information System (INIS)

    Wilson, M.A.

    1988-01-01

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

  5. 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

  6. Superconductive energy storage magnet study

    International Nuclear Information System (INIS)

    Rhee, S.W.

    1982-01-01

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

  7. Hermetically sealed superconducting magnet motor

    Science.gov (United States)

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

    1996-01-01

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

  8. 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).

  9. Modeling of Interfilament Coupling Currents and Their Effect on Magnet Quench Protection

    CERN Document Server

    Ravaioli, E; Chlachidze, G; Maciejewski, M; Sabbi, G; Stoynev, S E; Verweij, A

    2017-01-01

    Variations in the transport current of a superconducting magnet cause several types of transitory losses. Due to its relatively short time constant, usually of the order of a few tens of milliseconds, interfilament coupling loss can have a significant effect on the coil protection against overheating after a quench. This loss is deposited in the strands and can facilitate a more homogeneous transition to the normal state of the coil turns. Furthermore, the presence of local interfilament coupling currents reduces the magnet's differential inductance, which in turn provokes a faster discharge of the transport current. The lumped-element dynamic electrothermal model of a superconducting magnet has been developed to reproduce these effects. Simulations are compared to experimental electrical transients and found in good agreement. After its validation, the model can be used for predicting the performance of quench protection systems based on energy extraction, quench heaters, the newly developed coupling-loss-in...

  10. Accelerator Magnet Quench Heater Technology and Quality Control Tests for the LHC High Luminosity Upgrade

    CERN Document Server

    AUTHOR|(CDS)2132435; Seifert, Thomas

    The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) foresees the installation of new superconducting Nb$_{3}$Sn magnets. For the protection of these magnets, quench heaters are placed on the magnet coils. The quench heater circuits are chemically etched from a stainless steel foil that is glued onto a flexible Polyimide film, using flexible printed circuit production technology. Approximately 500 quench heaters with a total length of about 3000 m are needed for the HL-LHC magnets. In order to keep the heater circuit electrical resistance in acceptable limits, an approximately 10 µm-thick Cu coating is applied onto the steel foil. The quality of this Cu coating has been found critical in the quench heater production. The work described in this thesis focuses on the characterisation of Cu coatings produced by electrolytic deposition, sputtering and electron beam evaporation. The quality of the Cu coatings from different manufacturers has been assessed for instance by ambient temperature electrica...

  11. Superconducting Magnets for Particle Accelerators

    CERN Document Server

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

    2016-01-01

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

  12. Current leads for superconducting magnets

    International Nuclear Information System (INIS)

    Ishibashi, Kenji

    1989-01-01

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

  13. 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.

  14. Successful magnet quench test for CAST.

    CERN Multimedia

    Brice Maximilien

    2002-01-01

    The CERN Axion Solar Telescope (CAST) consists of a prototype LHC dipole magnet with photon detectors at each end. It searches for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. The telescope, located at Point 8, can move vertically within its wheeled platform, which travels horizontally along tracks in the floor. In this way, the telescope can view the Sun at sunrise through one end and at sunset through the other end. It has been cooled down to below 1.8 K and reached ~95% of its final magnetic field of 9 tesla before a quench was induced to test the whole cryogenic system under such conditions. The cryogenic system responded as expected to the magnet quench and CAST is now ready to start its three-year search for solar axions. Photos 01 & 02 : Members of the LHC cryogenics team pose in front of the axion telescope on the day of the first quench test, together with some of the CAST collaboration.

  15. Can magnetism and superconductivity coexist

    International Nuclear Information System (INIS)

    Ishikawa, M.

    1982-01-01

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

  16. Superconducting magnets and leads thereto

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  17. Superconducting magnets technologies for large accelerator

    International Nuclear Information System (INIS)

    Ogitsu, Toru

    2017-01-01

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

  18. Superconducting magnets for the CBA project

    International Nuclear Information System (INIS)

    Bleser, E.J.; Cottingham, J.G.; Dahl, P.F.; Engelmann, R.J.; Fernow, R.C.; Garber, M.; Ghosh, A.K.; Goodzeit, C.L.; Greene, A.F.; Herrera, J.C.; Kahn, S.A.; Kaugerts, J.; Kelly, E.R.; Kirk, H.G.; Leroy, R.J.; Morgan, G.H.; Palmer, R.B.; Prodell, A.G.; Rahm, D.C.; Sampson, W.B.; Shutt, R.P.; Stevens, A.J.; Tannenbaum, M.J.; Thompson, P.A.; Wanderer, P.J.; Willen, E.H.

    1985-01-01

    The superconducting magnets that were designed and tested for the BNL colliding beam accelerator are described, including dipoles, quadrupoles and trim coils. The dipoles had an effective length of 436 cm, a good field aperture of 8.8 cm diameter, and were designed for an operating field of 5.28 T in a temperature range between 2.6 K and 3.8 K (provided by supercritical helium). The quadrupoles had the same aperture, an effective length of 138.5 cm, and were designed to operate in series with the dipoles, with a gradient of 70.8 T/m. The dipoles incorporated internal sextupole, octupole, and decapole trim coil windings; the quadrupole trim coils consisted of dipole, quadrupole, and dodecapole windings. The design, construction, and performence (training, field quality, quench protection characteristics) of prototype magnets are discussed in considerable detail. (orig.)

  19. Controllable manipulation of superconductivity using magnetic vortices

    International Nuclear Information System (INIS)

    Villegas, J E; Schuller, Ivan K

    2011-01-01

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

  20. 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.

  1. Optimum copper to superconductor ratio in cables for superconducting magnets at 1.9 K

    International Nuclear Information System (INIS)

    Wolf, R.

    1994-01-01

    In this paper the optimum copper to superconducting ratio is calculated to prevent quenching for superconducting cables used in accelerator magnets like the LHC dipoles, operating in superfluid helium at 1.9K. The duration of the perturbations leading to a quench are estimated from flux measurements made with pickup coils in the LHC dipole models. The optimum copper to superconducting ratio is then found by studying the minimum quench energy and the influence of the length and the duration or the perturbation and heat transfer to the surroundings. A comparison is made of the behavior at temperatures of 1.9 and 4.3 K

  2. 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.

  3. Cryotribological applications in superconducting magnets

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  4. Superconducting magnet systems for MRI

    International Nuclear Information System (INIS)

    Hawksworth, D.G.

    1988-01-01

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

  5. Reliability of the Quench Protection System for the LHC Superconducting Elements

    OpenAIRE

    Vergara-Fernández, A; Rodríguez-Mateos, F

    2003-01-01

    The huge energy stored in the Large Hadron Collider (LHC) could potentially cause severe damage when the superconducting state disappears (quench) if precautions are not taken. Most of the superconducting elements in this accelerator require protection in case of resistive transition. The reliability of the Quench Protection System will have a very important impact on the overall LHC performance. Existing high energy accelerators were conceived as prototypes whose main objective was not the e...

  6. Superconducting magnet wire

    Science.gov (United States)

    Schuller, Ivan K.; Ketterson, John B.; Banerjee, Indrajit

    1986-01-01

    A superconducting tape or wire with an improved critical field is formed of alternating layers of a niobium-containing superconductor such as Nb, NbTi, Nb.sub.3 Sn or Nb.sub.3 Ge with a thickness in the range of about 0.5-1.5 times its coherence length, supported and separated by layers of copper with each copper layer having a thickness in the range of about 170-600 .ANG..

  7. 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.

  8. Mechanical stress analysis during a quench in CLIQ protected 16 T dipole magnets designed for the future circular collider

    Science.gov (United States)

    Zhao, Junjie; Prioli, Marco; Stenvall, Antti; Salmi, Tiina; Gao, Yuanwen; Caiffi, Barbara; Lorin, Clement; Marinozzi, Vittorio; Farinon, Stefania; Sorbi, Massimo

    2018-07-01

    Protecting the magnets in case of a quench is a challenge for the 16 T superconducting dipole magnets presently designed for the 100 TeV: Future Circular Collider (FCC). These magnets are driven to the foreseen technological limits in terms of critical current, mechanical strength and quench protection. The magnets are protected with CLIQ (Coupling-Loss Induced Quench) system, which is a recently developed quench protection method based on discharging a capacitor bank across part of the winding. The oscillation of the magnet currents and the dissipation of the high stored energy into the windings cause electrodynamic forces and thermal stresses, which may need to be considered in the magnet mechanical design. This paper focuses on mechanical stress analysis during a quench of the 16 T cos-θ and block type dipole magnets. A finite element model allowed studying the stress due to the non-uniform temperature and current distribution in the superconducting coils. Two different CLIQ configurations were considered for the cos-θ design and one for the block type magnet. The analyses of the mechanical behavior of two magnets during a quench without or with hot spot turn were separately carried out. The simulation results show that the stress related to a quench should be considered when designing a high field magnet.

  9. Physics of Limiting Phenomena in Superconducting Microwave Resonators: Vortex Dissipation, Ultimate Quench and Quality Factor Degradation Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Checchin, Mattia [Illinois Inst. of Technology, Chicago, IL (United States)

    2016-12-01

    Superconducting niobium accelerating cavities are devices operating in radio-frequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described in detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associate d to the

  10. Physics of limiting phenomena in superconducting microwave resonators: Vortex dissipation, ultimate quench and quality factor degradation mechanisms

    Science.gov (United States)

    Checchin, Mattia

    Superconducting niobium accelerating cavities are devices operating in radiofrequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described in detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associated to the superheating

  11. Quenching effect on properties of Bi-Sr-Ca-Cu-O superconducting ceramics of various composition

    International Nuclear Information System (INIS)

    Amitin, E.B.; Gromilov, S.A.; Naumov, V.N.; Royak, A.Ya.; Starikov, M.A.

    1989-01-01

    Bismuth ceramics quenching effect on superconducting properties of samples of various composition is investigated. Two types of quenching effect on sample properties are detected: an increase of superconducting transition temperature T c by 15-20 K; broadening of temperature interval of the phase transition without anynatable T c displacement. X ray diffraction investigations have not detected sufficient differences in diffraction patterns of quenched and non-quenched samples. Within the limits of composition analysis by oxygen (±3%) no change of its content prior to and after quenching is detected. A correlation between the presence of an amorphous phase in a sample and the type of quenching effect is observed: T c increases in ceramics where an amorphous component is detected

  12. Superconducting magnets for a muon collider

    International Nuclear Information System (INIS)

    Green, M.A.

    1996-01-01

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

  13. 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

  14. Quench propagation and heating in the superconducting 600 A auxiliary busbars of the LHC

    International Nuclear Information System (INIS)

    Herzog, R.; Calvi, M.; Sonnemann, F.

    2002-01-01

    In the Large Hadron Collider (LHC) at CERN 22 km of flexible superconducting cable, the auxiliary busbar cable, will conduct currents of up to 600 A to a large number of corrector magnets distributed throughout the accelerator. A prototype cable with 42 active conductors underwent several experiments to measure the hot spot temperature and the quench propagation velocity as a function of the current. The former was evaluated for various energy extraction scenarios as they are foreseen for the LHC corrector circuits. The experimental results and the heat flow simulations show that the quench behavior in this busbar prototype is strongly influenced by the heat flow through the insulation material (polyimide) into the helium bath, leading to stable configurations above the critical temperature T c for currents between 250 A and 500 A. Special attention was paid to the study of discontinuities in the wires, like feed-throughs, where the wire is not immersed in liquid helium, and joints, where the wire cross-section is increased. The experiments and simulations led to a thorough understanding of the quench process in the wires of the prototype cable, which resulted in guidelines for the design, the use and the installation of the cable in the LHC

  15. Superconducting magnet cooling system

    Science.gov (United States)

    Vander Arend, Peter C.; Fowler, William B.

    1977-01-01

    A device is provided for cooling a conductor to the superconducting state. The conductor is positioned within an inner conduit through which is flowing a supercooled liquid coolant in physical contact with the conductor. The inner conduit is positioned within an outer conduit so that an annular open space is formed therebetween. Through the annular space is flowing coolant in the boiling liquid state. Heat generated by the conductor is transferred by convection within the supercooled liquid coolant to the inner wall of the inner conduit and then is removed by the boiling liquid coolant, making the heat removal from the conductor relatively independent of conductor length.

  16. The Inductive Coupling of the Magnets in MICE and its Effect on Quench Protection

    International Nuclear Information System (INIS)

    Green, Michael A.; Witte, Holger

    2005-01-01

    The inductive coupling between various MICE magnet circuits is described. The consequences of this coupling on magnet charging and quenching are discussed. Magnet quench protection is achieved through the use of quench-back. Calculations of the quenching of a magnet due to quench-back resulting from circulating currents induced in the magnet mandrel due to quenching of an adjacent magnet are discussed. This report describes how the MICE magnet channel will react when magnets in that channel are quenched

  17. Method of constructing a superconducting magnet

    Science.gov (United States)

    Satti, John A.

    1981-01-01

    A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.

  18. Magnetic design of a FFAG superconducting magnet

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  19. Quark contributions to baryon magnetic moments in full, quenched, and partially quenched QCD

    International Nuclear Information System (INIS)

    Leinweber, Derek B.

    2004-01-01

    The chiral nonanalytic behavior of quark-flavor contributions to the magnetic moments of octet baryons is determined in full, quenched and partially quenched QCD, using an intuitive and efficient diagrammatic formulation of quenched and partially quenched chiral perturbation theory. The technique provides a separation of quark-sector magnetic-moment contributions into direct sea-quark loop, valence-quark, indirect sea-quark loop and quenched valence contributions, the latter being the conventional view of the quenched approximation. Both meson and baryon mass violations of SU(3)-flavor symmetry are accounted for. Following a comprehensive examination of the individual quark-sector contributions to octet baryon magnetic moments, numerous opportunities to observe and test the underlying structure of baryons and the nature of chiral nonanalytic behavior in QCD and its quenched variants are discussed. In particular, the valence u-quark contribution to the proton magnetic moment provides the optimal opportunity to directly view nonanalytic behavior associated with the meson cloud of full QCD and the quenched meson cloud of quenched QCD. The u quark in Σ + provides the best opportunity to display the artifacts of the quenched approximation

  20. 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

  1. Tests of high gradient superconducting quadrupole magnets for the Tevatron

    International Nuclear Information System (INIS)

    Lamm, M.J.; Carson, J.; Gourlay, S.; Hanft, R.; Koepke, K.; Mantsch, P.; McInturff, A.D.; Riddiford, A.; Strait, J.

    1989-09-01

    Tests have been completed on three prototype magnets and two production magnets to be used for the Tevatron Dφ/Bφ low- β insertion. These cold iron, two shell quadrupoles are made of 36 strand Rutherford type NbTi superconducting cable. Magnet field gradients well in excess of the design 1.41 T/cm have been achieved at a transfer function of 0.291 T/cm/kA. Quench performance at 4.2 K and 3.7 K and magnetic multipole measurement data are presented and discussed. 9 refs., 4 figs., 4 tabs

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

    International Nuclear Information System (INIS)

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

    1988-07-01

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

  3. Superconducting magnet and fabrication method

    Science.gov (United States)

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

    1994-01-01

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

  4. A quench detection/logging system for the SSCL Magnet Test Laboratory

    International Nuclear Information System (INIS)

    Kim, K.; Coles, M.; Dryer, J.; Lambert, D.

    1993-05-01

    The quench in a magnet describes a process which occurs while the superconductivity state goes to the normal resistive state. The consequence of a quench is the conversion of the stored electromagnetic energy into heat. During this process the initiating point will reach a high temperature, which will char the insulation or melt the conductor and thereby destroy the magnet. To prevent the magnet from being lost, it is standard practice to observe several resistance and/or inductance voltages across the magnet as quench signatures -- detection. When a quench symptom is detected, protection operations are initiated: proper shutdown of the magnet excitation systems and treatment to dilute the heat energy at a spot -- protection. The temperature rise is diluted by firing heaters along the length of the magnet to insure that the dissipated energy is spread. To develop a reliable quench detection system, two distinct approaches have been tried in the past: (i) Understanding of the Noise Mechanism and Sub-system Optimization, and (ii) Escaping from the Known Electromagnetic Noises by Observing Optical Waves or Acoustic Waves. The MTL of SSCL confronts a mass-measurement of about 10,000 production magnets. To meet the testing schedule, the false quench detection rate needs to be further optimized while the true quench detection rate remains secure for the magnet measurement safety. To meet these requirements, we followed an iterative top-down approach. First we defined the signal and noise characteristics of the quench phenomena by using existing software tools to build a rapid prototype system incorporating all proven functionality of the existing system. Then we further optimize the system through iterative upgrading based on our signal and noise character findings

  5. A quench detection/logging system for the SSCL Magnet Test Laboratory

    International Nuclear Information System (INIS)

    Kim, K.; Coles, M.; Dryer, J.; Lambert, D.

    1994-01-01

    The quench in a magnet describes a process which occurs while the superconductivity state goes to the normal resistive state. The consequence of a quench is the conversion of the stored electromagnetic energy into heat. During this process the initiating point will reach a high temperature, which will char the insulation or melt the conductor and thereby destroy the magnet. To prevent the magnet from being lost, it is standard practice to observe several resistance and/or inductance voltages across the magnet as quench signatures - Detection. When a quench symptom is detected, protection operations are initiated: proper shutdown of the magnet excitation systems and treatment to dilute the heat energy at a spot - Protection. The temperature rise is diluted by firing heaters along the length of the magnet to ensure that the dissipated energy is spread. It is interesting that there is not a significant amount of published research on detection. To afford a more reliable quench detection system, two distinct approaches have been tried in the past: (i) Understanding of the Noise Mechanism and Sub-system Optimization, and (ii) Escaping from the Known Electromagnetic Noises by Observing Optical Waves or Acoustic Waves. The MTL of SSCL confronts a mass-measurement of about 10,000 production magnets. To meet the testing schedule, the false quench detection rate needs to be further optimized while the true quench detection rate remains secure for the magnet measurement safety. To meet these requirements, the authors followed an iterative top-down approach. First they defend the signal and noise characteristics of the quench phenomena by using existing software tools to build a rapid prototype system incorporating all proven functionality of the existing system. Then they further optimize the system through iterative upgrading based on their signal and noise character findings

  6. Towards Computing Ratcheting and Training in Superconducting Magnets

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  7. Superconducting magnet for EHS

    International Nuclear Information System (INIS)

    Desportes, H.; Duthil, R.; Celebart, J.C.; Leschevin, C.; Lesmond, C.

    1980-10-01

    A 55 Mjoules Magnet has been installed and commissioned at CERN for the Rapid Cycling Bubble Chamber of the EHS experiment (European Hybrid Spectrometer). The magnet consists of two separate circular coils, assembled with their axis horizontal into a massive iron structure, and provides a central field of 3 T in a useful volume of 1.4 m in diameter and 0.82 m gap with a completely azimuthally free acceptance of +-18 deg from the central plane. Special features of the magnet, which is otherwise of a classical pancake-type, bath-cooled design, are a relatively high average current density (2500 Amp/cm 2 ) and an elaborate support structure required by the particular force configuration within the iron structure

  8. Field quality evaluation of the superconducting magnets of the relativistic heavy ion collider

    International Nuclear Information System (INIS)

    Wei, J.; Gupta, R.C.; Jain, A.; Peggs, S.G.; Trahern, C.G.; Trbojevic, D.; Wanderer, P.

    1995-01-01

    In this paper, the authors first present the procedure established to evaluate the field quality, quench performance, and alignment of the superconducting magnets manufactured for the Relativistic Heavy Ion Collider (RHIC), and then discuss the strategies used to improve the field quality and to minimize undesirable effects by sorting the magnets. The field quality of the various RHIC magnets is briefly summarized

  9. Superconductivity for Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Flükiger, R [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

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

  10. Quench characterization and thermo hydraulic analysis of SST-1 TF magnet busbar

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, A.N., E-mail: ansharma@ipr.res.in [Institute for Plasma Research, Gandhinagar (India); Pradhan, S. [Institute for Plasma Research, Gandhinagar (India); Duchateau, J.L. [CEA Cadarache, 13108 St Paul lez Durance Cedex (France); Khristi, Y.; Prasad, U.; Doshi, K.; Varmora, P.; Tanna, V.L.; Patel, D.; Panchal, A. [Institute for Plasma Research, Gandhinagar (India)

    2015-01-15

    Highlights: • Details of SST-1 TF busbar quench detection. • Simulation of slow propagating normal zone. • Thermo hydraulic analyses of TF busbar in current feeder system. - Abstract: Toroidal field (TF) magnet system of steady-state superconducting tokamak-1 (SST-1) has 16 superconducting coils. TF coils are cooled with forced flow supercritical helium at 0.4 MPa, at 4.5 K and operate at nominal current of 10,000 A. Prior to TF magnet system assembly in SST-1 tokamak, each TF coil was tested individually in a test cryostat. During these tests, TF coil was connected to a pair of conventional helium vapor cooled current leads. The connecting busbar was made from the same base cable-in-conduit-conductor (CICC) of SST-1 superconducting magnet system. Quenches experimentally observed in the busbar sections of the single coil test setups have been analyzed in this paper. A steady state thermo hydraulic analysis of TF magnet busbar in actual SST-1 tokamak assembly has been done. The experimental observations of quench and results of relevant thermo hydraulic analyses have been used to predict the safe operation regime of TF magnet system busbar during actual SST-1 tokamak operational scenarios.

  11. Selection of a quench detection system for the ITER CS magnet

    International Nuclear Information System (INIS)

    Coatanea, Marc; Duchateau, Jean-Luc; Lacroix, Benoit; Nicollet, Sylvie; Rodriguez-Mateos, Felix; Topin, Frederic

    2011-01-01

    At variance with most of the existing superconducting systems operating in the world, the ITER central solenoid (CS) magnet is a fast pulsed system. This peculiarity creates a specific situation regarding the quench detection system, as a small resistive signal associated with a quench has to be discriminated from the high inductive signals imposed by the plasma scenario. The quench detection is based on an inductive compensation built from three adjacent double pancakes. The ITER protection rules for a superconducting magnet impose to respect the so-called maximum hot spot temperature criterion of 250 K in the quenched cable at the end of the fast discharge. A careful analysis of the residual inductive signals in the detection voltage shows that a blanking of the quench detection cannot be avoided during the early times of the plasma discharge (i.e. during 3.5 s). It is demonstrated that this blanking is, however, acceptable while fulfilling the hot spot criterion because the plasma initiation phase (PIP) is very similar to a fast safety discharge and corresponds to a fast decrease of the modules currents, which is favourable for the magnet protection.

  12. Decay and snapback in superconducting accelerator magnets

    OpenAIRE

    Haverkamp, M.

    2003-01-01

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

  13. 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)

  14. 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)

  15. Fiber optic quench detection via optimized Rayleigh Scattering in high-field YBCO accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, Gene [North Carolina State Univ., Raleigh, NC (United States)

    2016-02-17

    Yttrium barium copper oxide (YBCO) coated conductors are known for their ability to operate in the superconducting state at relatively high temperatures, even above the boiling point of liquid nitrogen (77 K). When these same conductors are operated at lower temperatures, they are able to operate in much higher magnetic fields than traditional superconductors like NiTi or Nb3Sn. Thus, YBCO superconducting magnets are one of the primary options for generating the high magnetic fields needed for future high energy physics devices. Due to slow quench propagation, quench detection remains one of the primary limitations to YBCO magnets. Fiber optic sensing, based upon Rayleigh scattering, has the potential for spatial resolution approaching the wavelength of light, or very fast temporal resolution at low spatial resolution, and a continuum of combinations in between. This project has studied, theoretically and experimentally, YBCO magnets and Rayleigh scattering quench detection systems to demonstrate feasibility of the systems for YBCO quench protection systems. Under this grant an experimentally validated 3D quench propagation model was used to accurately define the acceptable range of spatial and temporal resolutions for effective quench detection in YBCO magnets and to evaluate present-day and potentially improved YBCO conductors. The data volume and speed requirements for quench detection via Rayleigh scattering required the development of a high performance fiber optic based quench detection/data acquisition system and its integration with an existing voltage tap/thermo-couple based system. In this project, optical fibers are tightly co-wound into YBCO magnet coils, with the fiber on top of the conductor as turn-to-turn insulation. Local changes in the temperature or strain of the conductor are sensed by the optical fiber, which is in close thermal and mechanical contact with the conductor. Intrinsic imperfections in the fiber reflect Rayleigh

  16. BNL Direct Wind Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-12

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

  17. 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....

  18. Magnetic shielding for MRI superconducting magnets

    International Nuclear Information System (INIS)

    Ishiyama, A.; Hirooka, H.

    1991-01-01

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

  19. The g-2 storage ring superconducting magnet system

    International Nuclear Information System (INIS)

    Green, M.A.

    1993-09-01

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

  20. 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

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-04-20

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

  3. Reliability of large superconducting magnets through design

    International Nuclear Information System (INIS)

    Henning, C.D.

    1980-01-01

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

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

    CERN Document Server

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

    2014-01-01

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

  5. Magnetization Controlled Superconductivity in a Film with Magnetic Dots

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  6. Quench Property of Twisted-Pair MgB$_2$ Superconducting Cables in Helium Gas

    CERN Document Server

    Spurrell, J; Falorio, I; Pelegrin, J; Ballarino, A; Yang, Y

    2015-01-01

    CERN's twisted-pair superconducting cable is a novel design which offers filament transposition, low cable inductance and is particularly suited for tape conductors such as 2G YBCO coated conductors, Ag-sheathed Bi2223 tapes and Ni/Monel-sheathed MgB2 tapes. A typical design of such twistedpair cables consists of multiple superconducting tapes intercalated with thin copper tapes as additional stabilizers. The copper tapes are typically not soldered to the superconducting tapes so that sufficient flexibility is retained for the twisting of the tape assembly. The electrical and thermal contacts between the copper and superconducting tapes are an important parameter for current sharing, cryogenic stability and quench propagation. Using an MgB2 twisted-pair cable assembly manufactured at CERN, we have carried out minimum quench energy (MQE) and propagation velocity (vp) measurements with point-like heat deposition localized within a tape. Furthermore, different contacts between the copper and superconductor aroun...

  7. Design and implementation of quench detection instrumentation for TF magnet system of SST-1

    International Nuclear Information System (INIS)

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

    2014-01-01

    Steady State Superconducting Tokamak-1 (SST-1) at Institute for Plasma Research (IPR), India is now in engineering validation phase. The assembled Toroidal Field (TF) magnet system of SST-1 will be operated at 10 kA of nominal current at helium cooled condition of 4.5 K. A reliable and fail proof quench detection (QD) system is essential for the safety and the investment protection requirements of the magnets. This QD system needs to continuously monitor all the superconducting coils, which include 16 TF magnets, return-loop, bus bars and current leads. In case of any event initiating the normal resistive zone and reaching thermal run-away, the QD system needs to trigger the magnet protection circuits. Precision instrumentation and control system with 204 signal channels had been developed for detection of quench anywhere in the entire TF magnet system. In the present configuration of quench detection scheme, the voltage drop across each double pancake (DP) of each TF coil are compared with its two adjacent DPs for the detection of normal zone and cancelation of inductive couples. Two identical redundant systems with one out of two configurations are successfully commissioned and tested at IPR. This paper describes the design and implementation of the QD system, Installation experience, validation test and initial results from the recent SST-1 magnet system charging

  8. 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.)

  9. High-field superconducting nested coil magnet

    Science.gov (United States)

    Laverick, C.; Lobell, G. M.

    1970-01-01

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

  10. Superconducting magnetic systems and electrical machines

    International Nuclear Information System (INIS)

    Glebov, I.A.

    1975-01-01

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

  11. Electrical insulation for large multiaxis superconducting magnets

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  12. 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

  13. 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

  14. 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

  15. Considerations of coil protection and electrical connection schemes in large superconducting toroidal magnet system

    International Nuclear Information System (INIS)

    Yeh, H.T.

    1976-03-01

    A preliminary comparison of several different coil protection and electrical connection schemes for large superconducting toroidal magnet systems (STMS) is carried out. The tentative recommendation is to rely on external dump resistors for coil protection and to connect the coils in the toroidal magnet in several parallel loops (e.g., every fourth coil is connected into a single series loop). For the fault condition when a single coil quenches, the quenched coil should be isolated from its loop by switching devices. The magnet, as a whole, should probably be discharged if more than a few coils have quenched

  16. Superconducting magnet activities at CEN Saclay

    International Nuclear Information System (INIS)

    Lesmond, C.

    1981-07-01

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

  17. Field errors in superconducting magnets

    International Nuclear Information System (INIS)

    Barton, M.Q.

    1982-01-01

    The mission of this workshop is a discussion of the techniques for tracking particles through arbitrary accelerator field configurations to look for dynamical effects that are suggested by various theoretical models but are not amenable to detailed analysis. A major motivation for this type of study is that many of our accelerator projects are based on the use of superconducting magnets which have field imperfections that are larger and of a more complex nature than those of conventional magnets. Questions such as resonances, uncorrectable closed orbit effects, coupling between planes, and diffusion mechanisms all assume new importance. Since, simultaneously, we are trying to do sophisticated beam manipulations such as stacking, high current accelerator, long life storage, and low loss extraction, we clearly need efficient and accurate tracking programs to proceed with confidence

  18. Operation of multiple superconducting energy doubler magnets in series

    International Nuclear Information System (INIS)

    Kalbfleisch, G.; Limon, P.J.; Rode, C.

    1977-01-01

    In order to understand the operational characteristics of the Energy Doubler, a series of experiments were begun which were designed to be a practical test of running superconducting accelerator magnets in series. Two separate tests in which two Energy Doubler dipoles were powered in series are described. Of particular interest are the static losses of the cryostats and the behavior of the coils and cryostats during quenches. The results of the tests show that Energy Doubler magnets can be safely operated near their short sample limit, and that the various safety devices used are adequate to protect the coils and the cryostats from damage

  19. Safety of superconducting fusion magnets: twelve problem areas

    International Nuclear Information System (INIS)

    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

  20. 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)

  1. SAFE AND FAST QUENCH RECOVERY OF LARGE SUPERCONDUCTING SOLENOIDS COOLED BY FORCED TWO-PHASE HELIUM FLOW

    International Nuclear Information System (INIS)

    Jia, L.X.

    1999-01-01

    The cryogenic characteristics in energy extraction of the four fifteen-meter-diameter superconducting solenoids of the g-2 magnet are reported in this paper. The energy extraction tests at full-current and half-current of its operating value were deliberately carried out for the quench analyses and evaluation of the cryogenic system. The temperature profiles of each coil mandrel and pressure profiles in its helium cooling tube during the energy extraction are discussed. The low peak temperature and pressure as well as the short recovery time indicated the desirable characteristics of the cryogenic system

  2. A novel approach to quench detection for high temperature superconducting coils

    International Nuclear Information System (INIS)

    Song, W.J.; Fang, X.Y.; Fang, J.; Wei, B.; Hou, J.Z.; Liu, L.F.; Lu, K.K.; Li, Shuo

    2015-01-01

    Highlights: • We proposed a novel quench detection method mainly based on phase for HTS coil. • We showed theory model and numerical simulation system by LabVIEW. • Experiment results are showed and analyzed. • Little quench voltage will cause obvious change on phase. • The approach can accurately detect quench resistance voltage in real-time. - Abstract: A novel approach to quench detection for high temperature superconducting (HTS) coils is proposed, which is mainly based on phase angle between voltage and current of two coils to detect the quench resistance voltage. The approach is analyzed theoretically, verified experimentally and analytically by MATLAB Simulink and LabVIEW. An analog quench circuit is built on Simulink and a quench alarm system program is written in LabVIEW. Experiment of quench detection is further conducted. The sinusoidal AC currents ranging from 19.9 A to 96 A are transported to the HTS coils, whose critical current is 90 A at 77 K. The results of analog simulation and experiment are analyzed and they show good consistency. It is shown that with the increase of current, the phase undergoes apparent growth, and it is up to 60° and 15° when the current reaches critical value experimentally and analytically, respectively. It is concluded that the approach proposed in this paper can meet the need of precision and quench resistance voltage can be detected in time.

  3. A novel approach to quench detection for high temperature superconducting coils

    Energy Technology Data Exchange (ETDEWEB)

    Song, W.J., E-mail: songwenjuan@bjtu.edu.cn [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); China Electric Power Research Institute, Beijing (China); Fang, X.Y. [Department of Electrical and Computer Engineering, University of Victoria, PO Box 1700, STN CSC, Victoria, BC V8W 2Y2 (Canada); Fang, J., E-mail: fangseer@sina.com [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Wei, B.; Hou, J.Z. [China Electric Power Research Institute, Beijing (China); Liu, L.F. [Guangzhou Metro Design & Research Institute Co., Ltd, Guangdong (China); Lu, K.K. [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Li, Shuo [College of Information Science and Engineering, Northeastern University, Shenyang (China)

    2015-11-15

    Highlights: • We proposed a novel quench detection method mainly based on phase for HTS coil. • We showed theory model and numerical simulation system by LabVIEW. • Experiment results are showed and analyzed. • Little quench voltage will cause obvious change on phase. • The approach can accurately detect quench resistance voltage in real-time. - Abstract: A novel approach to quench detection for high temperature superconducting (HTS) coils is proposed, which is mainly based on phase angle between voltage and current of two coils to detect the quench resistance voltage. The approach is analyzed theoretically, verified experimentally and analytically by MATLAB Simulink and LabVIEW. An analog quench circuit is built on Simulink and a quench alarm system program is written in LabVIEW. Experiment of quench detection is further conducted. The sinusoidal AC currents ranging from 19.9 A to 96 A are transported to the HTS coils, whose critical current is 90 A at 77 K. The results of analog simulation and experiment are analyzed and they show good consistency. It is shown that with the increase of current, the phase undergoes apparent growth, and it is up to 60° and 15° when the current reaches critical value experimentally and analytically, respectively. It is concluded that the approach proposed in this paper can meet the need of precision and quench resistance voltage can be detected in time.

  4. Mechanical Design of Superconducting Accelerator Magnets

    International Nuclear Information System (INIS)

    Toral, F

    2014-01-01

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

  5. 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.

  6. Mechanical Design of Superconducting Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Toral, F [Madrid, CIEMAT (Spain)

    2014-07-01

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

  7. Modelling of Quench Limit for Steady State Heat Deposits in LHC Magnets

    CERN Document Server

    Bocian, D; Siemko, A

    2008-01-01

    A quench, the transition of a conductor from the superconducting to the normal conducting state, occurs irreversibly in the accelerator magnets if one of the three parameters: temperature, magnetic field or current density exceeds a critical value. Energy deposited in the superconductor by the particle beams provokes quenches detrimental for the accelerator operation. In particular if particles impacting on the vacuum chamber and their secondary showers depose energy in the magnet coils. The Large Hadron Collider (LHC) nominal beam intensity is 3.2 ldr 10^14 protons. A quench occurs if a fraction of the order of 10^7 protons per second is lost locally. A network model is used to simulate the thermodynamic behaviour of the magnets. The heat flow in the network model was validated with measurements performed in the CERN magnet test facility. A steady state heat flow was introduced in the coil by using the quench heaters implemented in the LHC magnets. The value of the heat source current is determined by the ne...

  8. 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

  9. 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...

  10. 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

  11. A study on metastable superconducting magnets

    International Nuclear Information System (INIS)

    Koyama, Kenichi

    1976-01-01

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

  12. 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.

  13. 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.

  14. Superconducting magnets advanced in particle physics

    International Nuclear Information System (INIS)

    Yamamoto, Akira

    2000-01-01

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

  15. Durability Evaluation of Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-01

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

  16. 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

  17. Field quality of LHC superconducting dipole magnets

    International Nuclear Information System (INIS)

    Mishra, R.K.

    2003-01-01

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

  18. Decay and Snapback in Superconducting Accelerator Magnets

    CERN Document Server

    Haverkamp, M

    2003-01-01

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

  19. Superconducting property measuring system by magnetization method

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  20. 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.

  1. Maximum field capability of energy saver superconducting magnets

    International Nuclear Information System (INIS)

    Turkot, F.; Cooper, W.E.; Hanft, R.; McInturff, A.

    1983-01-01

    At an energy of 1 TeV the superconducting cable in the Energy Saver dipole magnets will be operating at ca. 96% of its nominal short sample limit; the corresponding number in the quadrupole magnets will be 81%. All magnets for the Saver are individually tested for maximum current capability under two modes of operation; some 900 dipoles and 275 quadrupoles have now been measured. The dipole winding is composed of four individually wound coils which in general come from four different reels of cable. As part of the magnet fabrication quality control a short piece of cable from both ends of each reel has its critical current measured at 5T and 4.3K. In this paper the authors describe and present the statistical results of the maximum field tests (including quench and cycle) on Saver dipole and quadrupole magnets and explore the correlation of these tests with cable critical current

  2. Improved thermal isolation for superconducting magnet systems

    Science.gov (United States)

    Wiebe, E. R.

    1974-01-01

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

  3. Superconducting permanent magnets and their application in magnetic levitation

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  4. Superconductivity

    International Nuclear Information System (INIS)

    Taylor, A.W.B.; Noakes, G.R.

    1981-01-01

    This book is an elementray introduction into superconductivity. The topics are the superconducting state, the magnetic properties of superconductors, type I superconductors, type II superconductors and a chapter on the superconductivity theory. (WL)

  5. Superconducting magnetic shielding apparatus and method

    Science.gov (United States)

    Clem, John R.; Clem, John R.

    1983-01-01

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

  6. Superconducting magnetic shielding apparatus and method

    Science.gov (United States)

    Clem, J.R.

    1982-07-09

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

  7. 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

  8. 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

  9. 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

  10. Pulsed field losses and intentional quenches of superconducting coils

    International Nuclear Information System (INIS)

    Kim, S.H.

    1983-01-01

    Pulsed field losses of several 5-20 kJ coils have been measured under triangular field variations. The conductors, developed as potential subcables of 25-50 kA cables, consist of Cu wires and NbTi strands with or without CuNi barriers. Losses of soft-soldered subcables are compared with those of well-compacted cables. The coils were quenched intentionally by pulsing the coils above the critical current to observe loss variations due to possible conductor damage. The method of measurements, and effects of soldering and compactness of the conductors on the pulsed field losses will be presented

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

    International Nuclear Information System (INIS)

    Nicol, T.H.

    1989-09-01

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

  12. 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.

  13. A Cryogenic Test Stand for Large Superconducting Solenoid Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Rabehl, R. [Fermilab; Carcagno, R. [Fermilab; Nogiec, J. [Fermilab; Orris, D. [Fermilab; Soyars, W. [Fermilab; Sylvester, C. [Fermilab

    2013-01-01

    A new test stand for testing large superconducting solenoid magnets at the Fermilab Central Helium Liquifier (CHL) has been designed, and operated. This test stand has been used to test a coupling coil for the Muon Ionization Cooling Experiment (MICE), and future uses include solenoids for the Fermilab mu2e experiment. This paper describes the test stand design and operation including controlled cool-down and warm-up. Overviews of the process controls system and the quench management system are also included.

  14. Development of high field superconducting magnet

    International Nuclear Information System (INIS)

    Irie, Fujio; Takeo, Masakatsu.

    1986-01-01

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

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

    International Nuclear Information System (INIS)

    Lecrevisse, Thibault

    2012-01-01

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

  16. 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

  17. 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

  18. 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

  19. Quench Simulation Studies: Program documentation of SPQR

    CERN Document Server

    Sonnemann, F

    2001-01-01

    Quench experiments are being performed on prototypes of the superconducting magnets and busbars to determine the adequate design and protection. Many tests can only be understood correctly with the help of quench simulations that model the thermo-hydraulic and electrodynamic processes during a quench. In some cases simulations are the only method to scale the experimental results of prototype measurements to match the situation of quenching superconducting elements in the LHC. This note introduces the theoretical quench model and the use of the simulation program SPQR (Simulation Program for Quench Research), which has been developed to compute the quench process in superconducting magnets and busbars. The model approximates the heat balance equation with the finite difference method including the temperature dependence of the material parameters. SPQR allows the simulation of longitudinal quench propagation along a superconducting cable, the transverse propagation between adjacent conductors, heat transfer i...

  20. Quench detection electronics testing protocol for SST-1 magnets

    International Nuclear Information System (INIS)

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

    2017-01-01

    Quench Detection (QD) system consisting 204 signal channels has been successfully installed and working well during plasma experiment of SST-1 Tokamak. QD system requires testing, validation and maintenance in every SST-1 campaign for better reliability and maintainability of the system. Standalone test of each channel of the system is essential for hard-ware validation. The standard Testing Protocol follow in every campaign which validate each section of QD electronics as well as voltage tap signal cables which are routed inside the cryostat and then extended outside of the SST-1 machine up-to the magnet control room. Fiber link for Quench signal transmission to the SST-1 magnet power supply is also test and validate before every plasma campaign. Precise instrument used as a dummy source of quench signal and for manual quench generation to test the each channel and Master Quench Logic. Each signal Integrated with the magnet DAQ system, signal observed at 1Hz and 50Hz configuration to validate the logging data, compare with actual and previous test data. This paper describes the testing protocol follow in every campaign to validate functionality of QD electronics, limitation of testing, test results and overall integration of the quench detection system for SST-1 magnet. (author)

  1. Control of the superconducting magnet power supply for SECRAL

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  2. A superconductive electromagnet for nuclear magnetic resonance

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  3. Civilian applications for superconducting magnet technology developed for defense

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  4. Reluctance motor employing superconducting magnetic flux switches

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  5. Analysis of quench in the NHMFL REBCO prototype coils for the 32 T Magnet Project

    International Nuclear Information System (INIS)

    Breschi, M; Cavallucci, L; Ribani, P L; Gavrilin, A V; Weijers, H W

    2016-01-01

    A 32 T all-superconductive magnet with high field REBCO inner coils is under development at the National High Magnetic Field Laboratory, Tallahassee, Florida, USA. As part of the development activity, two prototype coils with full scale radial dimensions and final design features, but with reduced axial length were constructed. The prototype coils consist of six dry-wound double pancakes modules with uninsulated conductor and insulated stainless steel cowind. Quench studies on one of the prototype coils at 4.2 K in self-field and in a background magnetic field of 15 T were performed by activating a set of quench protection heaters. In this paper, we present a numerical analysis of the experimental results of the quench tests of one of the prototype coils. The numerical analysis was carried out through a coupled electro-thermal FEM model developed at the University of Bologna. The model is based on the coupling with distributed contact resistances of the coil pancakes described as 2D elements. A homogenization procedure of the REBCO tape and other coil materials is presented, which allows reducing the number of degrees of freedom and the computational effort. The model is applied to the analysis of the current and voltage evolutions during the experimental quench tests on the prototype coil. (paper)

  6. 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

  7. Designing of superconducting magnet for clinical MRI

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  8. Study of the thermo-electronic stability of LTS conductors and contribution to the study of the thermo-electric stability of HTS conductors. Novel techniques to simulate quench precursors in superconducting electro-magnets; Etude de la stabilite thermoelectronique des conducteurs supraconducteurs a basse temperature critique et contribution a l'etude de la stabilite thermoelectrique des supraconducteurs a haute temperature critique

    Energy Technology Data Exchange (ETDEWEB)

    Trillaud, F

    2005-09-01

    Most of this work deals with the development of new heater technology to simulate quench precursors in super-conducting electro-magnets. The carbon paste point heater and 2 alternative technologies have been used: induction coils and the diode laser. 2 main experimental setups with 2 different heaters have been used to study the stability of Cu/NbTi composite wires. The order of magnitude of the results obtained with the charged point heater and the diode laser is consistent. Our work covered both low critical temperature (LTS) conductors and high critical temperature (HTS) conductors. A large body of data has been gathered on quench energies and normal zone propagation velocities (NZPV). Concerning quench energy: LTS conductors appear largely more sensitive to heat disturbances than HTS conductors. NZPV enables one to define the criteria for which a magnet can be considered as self-protected. It is commonly assumed that, below 1 m/s, active protection is necessary to ensure safe quenches. This is the case for HTS conductors whose NZPV is of the order of a few centimeters per seconds, at most. However, the NZPVs of LTS conductors are above a few meters per seconds. While HTS conductors can suffer from local hot spots which diffuse slowly resulting in damaging overheating, LTS conductors spread the normal zone quickly enough owing to their good thermal conductivity to minimize local overheating. In addition, this gives enough time to dump the energy of the magnet. This work clears a new path to carry out accurate and reproducible experiment on superconductors. It demonstrates the powerfulness of diode laser technology for stability studies. Numerical simulations of the thermal behaviour of a Cu/NbTi multi-filament composite wire have been performed, they are based on a simplified transient liquid helium heat exchange model. This model appears to be not accurate enough to simulate the early time evolution of the voltage between the current sharing temperature and the

  9. Study of the thermo-electronic stability of LTS conductors and contribution to the study of the thermo-electric stability of HTS conductors. Novel techniques to simulate quench precursors in superconducting electro-magnets; Etude de la stabilite thermoelectronique des conducteurs supraconducteurs a basse temperature critique et contribution a l'etude de la stabilite thermoelectrique des supraconducteurs a haute temperature critique

    Energy Technology Data Exchange (ETDEWEB)

    Trillaud, F

    2005-09-01

    Most of this work deals with the development of new heater technology to simulate quench precursors in super-conducting electro-magnets. The carbon paste point heater and 2 alternative technologies have been used: induction coils and the diode laser. 2 main experimental setups with 2 different heaters have been used to study the stability of Cu/NbTi composite wires. The order of magnitude of the results obtained with the charged point heater and the diode laser is consistent. Our work covered both low critical temperature (LTS) conductors and high critical temperature (HTS) conductors. A large body of data has been gathered on quench energies and normal zone propagation velocities (NZPV). Concerning quench energy: LTS conductors appear largely more sensitive to heat disturbances than HTS conductors. NZPV enables one to define the criteria for which a magnet can be considered as self-protected. It is commonly assumed that, below 1 m/s, active protection is necessary to ensure safe quenches. This is the case for HTS conductors whose NZPV is of the order of a few centimeters per seconds, at most. However, the NZPVs of LTS conductors are above a few meters per seconds. While HTS conductors can suffer from local hot spots which diffuse slowly resulting in damaging overheating, LTS conductors spread the normal zone quickly enough owing to their good thermal conductivity to minimize local overheating. In addition, this gives enough time to dump the energy of the magnet. This work clears a new path to carry out accurate and reproducible experiment on superconductors. It demonstrates the powerfulness of diode laser technology for stability studies. Numerical simulations of the thermal behaviour of a Cu/NbTi multi-filament composite wire have been performed, they are based on a simplified transient liquid helium heat exchange model. This model appears to be not accurate enough to simulate the early time evolution of the voltage between the current sharing temperature and the

  10. Detection of Second Sound in He-II for Thermal Quench Mapping of Superconducting Radio Frequency Accelerating Cavities

    OpenAIRE

    Stegmaier, Tobias; Grohmann, Steffen; Kind, Matthias; Furci, Hernán; Koettig, Torsten; Peters, Benedikt

    2018-01-01

    The development of future particle accelerators requires intensive testing of superconducting radio frequency cavities with different sizes and geometries. Non-contact thermometry quench localisation techniques proved to be beneficial for the localisation of surface defects that can originate a quench (sudden loss of superconducting state). These techniques are based on the detection of second sound in helium II. Transition Edge Sensors (TES) are highly sensitive thin film thermometers with f...

  11. Specific heat measurement set-up for quench condensed thin superconducting films.

    Science.gov (United States)

    Poran, Shachaf; Molina-Ruiz, Manel; Gérardin, Anne; Frydman, Aviad; Bourgeois, Olivier

    2014-05-01

    We present a set-up designed for the measurement of specific heat of very thin or ultra-thin quench condensed superconducting films. In an ultra-high vacuum chamber, materials of interest can be thermally evaporated directly on a silicon membrane regulated in temperature from 1.4 K to 10 K. On this membrane, a heater and a thermometer are lithographically fabricated, allowing the measurement of heat capacity of the quench condensed layers. This apparatus permits the simultaneous thermal and electrical characterization of successively deposited layers in situ without exposing the deposited materials to room temperature or atmospheric conditions, both being irreversibly harmful to the samples. This system can be used to study specific heat signatures of phase transitions through the superconductor to insulator transition of quench condensed films.

  12. Warm measurements of CBA superconducting magnets

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  13. Magnetization, Low Field Instability and Quench of RHQT Nb(3)Al Strands

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, R.; Wake, M.; Kikuchi, A.; Velev, V.; /Fermilab

    2009-01-01

    Since 2005, we made and tested three RHQT Nb{sub 3}Al strands, one with Nb matrix and two with Ta matrix, which are fully stabilized with Cu electroplating. We observed anomalously large magnetization curves extending beyond 1 to 1.5 Tesla with the F1 Nb matrix strand at 4.2 K, when we measured its magnetization with a balanced coil magnetometer. This problem was eliminated with the Ta matrix strands operating at 4.2 K. But with these strands a similar but smaller anomalous magnetization was observed at 1.9 K. We studied these phenomena with FEM. With the F1 Nb matrix strand, it is explained that at low external field, inter-filamentary coupling currents in the outer layers of sub-elements create a shielding effect. It reduces the inside field, keeps the inside Nb matrix superconductive, and stands against a higher outside field beyond the Hc of Nb. At an even higher external field, the superconductivity of the whole Nb matrix collapses and releases a large amount of energy, which may cause a big quench. Depending on the size of the energy in the strand or the cable, a magnet could quench, causing the low field instability. Some attempt to analyze the anomaly with FEM is presented.

  14. A parasitic magnetic refrigerator for cooling superconducting magnet

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  15. Quench tests of Nb3Al small racetrack magnets

    International Nuclear Information System (INIS)

    Yamada, R.; Kikuchi, A.; Tartaglia, Michael Albert; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Feher, S.; Kashikhin, V.V.; Kotelnikov, S.; Lamm, Michael J.; Fermilab; NIMC, Tsukuba; KEK, Tsukuba

    2007-01-01

    Two Cu stabilized Nb3Al strands, F1 (Nb matrixed) and F3 (Ta matrixed), have been made at NIMS and their Rutherford cables were made at Fermilab in collaboration with NIMS. A Small Race-track magnet using F1 Rutherford cable, the first Nb3Al dipole magnet in the world, was constructed and tested to full current at Fermilab. This magnet was tested extensively to full short sample data and its quench characteristics were studied and reported. The 3-D magnetic field calculation was done with ANSYS to find the peak field. The quench characteristics of the magnet are explained with the characteristics of the Nb3Al strand and Rutherford cable. The other Small Race-track magnet using Ta matrixed F3 strand was constructed and will be tested in the near future. The advantages and disadvantages of these Nb3Al cables are discussed

  16. Quench tests of Nb3Al small racetrack magnets

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, R.; Kikuchi, A.; Tartaglia, Michael Albert; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Feher, S.; Kashikhin, V.V.; Kotelnikov, S.; Lamm, Michael J.; /Fermilab /NIMC, Tsukuba /KEK, Tsukuba

    2007-08-01

    Two Cu stabilized Nb3Al strands, F1 (Nb matrixed) and F3 (Ta matrixed), have been made at NIMS and their Rutherford cables were made at Fermilab in collaboration with NIMS. A Small Race-track magnet using F1 Rutherford cable, the first Nb3Al dipole magnet in the world, was constructed and tested to full current at Fermilab. This magnet was tested extensively to full short sample data and its quench characteristics were studied and reported. The 3-D magnetic field calculation was done with ANSYS to find the peak field. The quench characteristics of the magnet are explained with the characteristics of the Nb3Al strand and Rutherford cable. The other Small Race-track magnet using Ta matrixed F3 strand was constructed and will be tested in the near future. The advantages and disadvantages of these Nb3Al cables are discussed.

  17. Quench Detection and Protection of the MQT Type Magnet

    CERN Document Server

    Teng, M

    1998-01-01

    The LHC design as from version 5 is equipped with tuning, trim and skew quadrupoles with similar cross-section designs (MQT). To qualify the quench detection and magnet protection needs, several compu tational methods have been applied. They range from global calculation of a uniform adiabatic temperature rise to more refined simulations, including the Quaber simulation package which is also applie d for quench calculations on the main magnets. A very important parameter is the quench propagation velocity, on which the Quaber simulations rely. An attempt was made to simulate the physics of the p ropagation itself, taking into account the temperature dependence of the wire parameters with the Quenchprop algorithm described in this report. The calculated results were compared with those from ex periments on a single wire. Further results of measurements on prototype magnets will allow fine-tuning of the program parameters.

  18. Superconducting magnets for particle large accelerators

    International Nuclear Information System (INIS)

    Kircher, F.

    1994-01-01

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

  19. Thermally and magnetically controlled superconducting rectifiers

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  20. Decay and snapback in superconducting accelerator magnets

    NARCIS (Netherlands)

    Haverkamp, M.

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Peng, Quanling; Xu, Fengyu; Wang, Ting; Yang, Xiangchen; Chen, Anbin; Wei, Xiaotao; Gao, Yao; Hou, Zhenhua; Wang, Bing; Chen, Yuan; Chen, Haoshu

    2014-01-01

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

  2. Eddy current and quench loads and stress of SSC collider 4-K liner and the bore tube during magnet quench

    International Nuclear Information System (INIS)

    Leung, K.K.; Shu, Q.S.

    1993-07-01

    This paper describes the response of the eddy current and quench loads on a proposed Superconducting SuperCollider 4-K liner system. The liner within a bore tube is designed to remove the radiated power and the photodesorbed gas that impair the beam tube vacuum. The bimetallic liner tube is subjected to cooldown and eddy current loads. The square liner tube is a two-shell laminated Nitronic-40 steel is used for strength and a copper inner layer for low impedance to the image currents. Perforated holes are used to remove the photodesorbed gases for vacuum maintenance. The holes are located in a low-stress area of the liner. Rectangular holes in a four-pole symmetry pattern are required for beam dynamic stability. The liner is conductivity cooled by the round steel bore tube with a 2-mm wall. The copper layer must not be stressed over the yield strength limit because copper properties such as conductivity are known to change when the copper is stressed over yield strength. This analysis will address liner system response under thermal, eddy current, and vaporized liquid helium loads in a quenching dipole magnet

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    The LHC is a complex machine requiring more than 7400 superconducting corrector magnets distributed along a circumference of 26.7 km. These magnets are powered in 1446 different electrical circuits at currents ranging from 60 A up to 600 A. Among the corrector circuits the 600 A corrector magnets form the most diverse and differentiated group. All together, about 60000 high current connections had to be made. A fault in a circuit or one of the superconducting connections would have severe consequences for the accelerator operation. All magnets are wound from various types of Nb-Ti superconducting strands, and many contain parallel protection resistors to by-pass the current still flowing in the other magnets of the same circuit when they quench. In this paper the performance of these magnet circuits is presented, focusing on the quench behavior of the magnets. Quench detection and the performance of the electrical interconnects will be dealt with. The results as measured on the entire circuits are compared to the test results obtained at the reception of the individual magnets

  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. Quench Detection and Protection for High Temperature Superconducting Transformers by Using the Active Power Method

    Science.gov (United States)

    Nanato, N.; Kobayashi, Y.

    AC high temperature superconducting (HTS) coils have been developed for transformers, motors and so on. Quench detection and protection system are essential for safety operations of the AC HTS facilities. The balance voltage method is universally used for the quench detection and protection, however especially for AC operations, the method has risks in terms of high voltage sparks. Because the method needs a voltage tap soldered to a midpoint of the coil winding and the AC HTS facilities generally operate at high voltages and therefore high voltage sparks may occur at the midpoint with no insulation. We have proposed the active power method for the quench detection and protection. The method requires no voltage tap on the midpoint of the coil winding and therefore it has in-built effectiveness for the AC HTS facilities. In this paper, we show that the method can detect the quench in an HTS transformer and moreover our proposed quench protection circuits which consist of thyristors are simple and useful for the AC HTS facilities.

  7. Status of superconducting magnets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Schermer, R.I.

    1993-09-01

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

  8. Status of superconducting magnets for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Schermer, R.I.

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  10. 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

  11. Thermal, Electrical and Mechanical Response to a Quench in Nb3Sn Superconducting Coils

    International Nuclear Information System (INIS)

    Ferracin, F.; Caspi, S.; Chiesa, L.; Gourlay, S.A.; Hafalia, R.R.; Imbasciati, L.; Lietzke, A.F.; Sabbi, G.; Scanlan, R.M.

    2003-01-01

    During a quench, significant temperatures can arise as a magnet's stored energy is dissipated in the normal zone. Temperature gradients during this process give rise to localized strains within the coil. Reactive forces in the magnet structure balance the electromagnetic and thermal forces and maintain on equilibrium. In this paper we present a complete 3D finite element analysis of a racetrack coil. Specifically, the analysis focuses on thermal, electrical and mechanical conditions in a 10 T Nb 3 Sn coil built and tested as part of LBNL's Subscale Magnet Program. The study attempts to simulate time history of the temperature and voltage rise during quench propagation. The transient thermal stress after the quench is then evaluated and discussed

  12. Detection of Second Sound in He-II for Thermal Quench Mapping of Superconducting Radio Frequency Accelerating Cavities

    CERN Document Server

    Stegmaier, Tobias; Kind, Matthias; Furci, Hernán; Koettig, Torsten; Peters, Benedikt

    The development of future particle accelerators requires intensive testing of superconducting radio frequency cavities with different sizes and geometries. Non-contact thermometry quench localisation techniques proved to be beneficial for the localisation of surface defects that can originate a quench (sudden loss of superconducting state). These techniques are based on the detection of second sound in helium II. Transition Edge Sensors (TES) are highly sensitive thin film thermometers with fast time response. In the present work, their capability as a thermal quench mapping device for superconducting radio frequency cavities is proven experimentally by detecting second sound waves emitted by SMD heaters in a He-II bath at saturated vapour pressure. A characterisation of the sensors at steady bath temperatures was conducted to calculate the thermal sensitivity. An intense metallurgical study of gold-tin TES with different compositions revealed important relations between the superconducting behaviour and the ...

  13. Quench Performance of the LHC Insertion Magnets

    CERN Document Server

    Lasheras, N C; Siemko, A; Ostojic, R; Kirby, G

    2009-01-01

    After final installation in the LHC tunnel, the MQM and MQY quadrupole magnets of the LHC insertions are now being commissioned to their nominal currents. These two types of magnets operate at 1.9 K and 4.5 K and with nominal currents ranging from 3600 A to 5390 A. From the very first acceptance tests of the bare magnets coming from the manufacturers, they have been powered using different cycles, in different configurations, at different temperatures and in different tests facilities. In this paper we present the global results of these powering tests. We aim at separating common from individual features of these groups of magnets. Temperature dependence of the training, temperature margin, and ultimate current can be extracted from these tests. As these magnets are used to match the optics and the dispersion in the machine, the projected ultimate current at which they can be operated is critical in view of operation of LHC.

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

    CERN Document Server

    Venturini-Delsolaro, W; Ballarino, A; Bellesia, B; Bordry, Frederick; Cantone, A; Casas Lino, M; Castaneda Serra, A; Castillo Trello, C; Catalan-Lasheras, N; Charifoulline, Z; Charrondiere, C; Dahlerup-Petersen, K; D'Angelo, G; Denz, R; Fehér, S; Flora, R; Gruwé, M; Kain, V; Karppinen, M; Khomenko, B; Kirby, G; MacPherson, A; Marqueta Barbero, A; Mess, K H; Modena, M; Mompo, R; Montabonnet, V; le Naour, S; Nisbet, D; Parma, V; Pojer, M; Ponce, L; Raimondo, A; Redaelli, S; Remondino, V; Reymond, H; de Rijk, G; Rijllart, A; Romera Ramirez, I; Saban, R; Sanfilippo, S; Schirm, K; Schmidt, R; Siemko, A; Solfaroli Camillocci, M; Thurel, Y; Thiesen, H; Vergara Fernandez, A; Verweij, A; Wolf, R; Zerlauth, M

    2008-01-01

    The LHC is a complex machine requiring more than 7400 superconducting corrector magnets distributed along a circumference of 26.7 km. These magnets are powered in 1446 different electrical circuits at currents ranging from 60 A up to 600 A. Among the corrector circuits the 600 A corrector magnets form the most diverse and differentiated group. All together, about 60000 high current connections had to be made. A fault in a circuit or one of the superconducting connections would have severe consequences for the accelerator operation. All magnets are wound from various types of Nb-Ti superconducting strands, and many contain parallel protection resistors to by-pass the current still flowing in the other magnets of the same circuit when they quench. In this paper the performance of these magnet circuits is presented, focussing on the quench behaviour of the magnets. Quench detection and the performance of the electrical interconnects will be dealt with. The results as measured on the entire circuits are compar...

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  16. Stress analysis of superconducting magnets for magnetic fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-01-01

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

  17. 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

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

    Science.gov (United States)

    Boom, R. W. (Inventor)

    1967-01-01

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

  19. Superconductivity and magnetism: Materials properties and developments

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, N H; Bay, N; Grivel, J C [and others

    2003-07-01

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

  20. 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.)

  1. 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)

  2. Quench detection for high temperature superconductor magnets: a novel technique based on Rayleigh-backscattering interrogated optical fibers

    International Nuclear Information System (INIS)

    Scurti, F; Ishmael, S; Schwartz, J; Flanagan, G

    2016-01-01

    High temperature superconducting materials are the only option for the generation of magnetic fields exceeding 25 T and for magnets operating over a broad range of temperature and magnetic field for power applications. One remaining obstacle for the implementation of high temperature superconductors magnets into systems, however, is the inability to rapidly detect a quench. In this letter we present a novel quench detection technique that has been investigated experimentally. Optical fibers are co-wound into two small Bi 2 Sr 2 Ca 2 Cu 3 O 10+x superconducting coils and interrogated by Rayleigh-backscattering. Two different configurations are used, one with the fiber atop the conductor and the other with the fiber located as turn-to-turn insulation. Each coil is also instrumented with voltage taps (VTs) and thermocouples for comparison during heater-induced quenches. The results show that Rayleigh-backscattering interrogated optical fibers (RIOF) have significant advantages over traditional techniques, including very high spatial resolution and the ability to detect a hot-spot well before the peak local temperature exceeds the current sharing temperature. Thus, RIOF quench detection is intrinsically faster than VTs, and this intrinsic advantage is greater as the coil size and/or current margin increases. (letter)

  3. 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

  4. 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

  5. Manufacturing and Testing of Accelerator Superconducting Magnets

    CERN Document Server

    Rossi, L

    2014-01-01

    Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of the accelerator magnets having an impact on the construction technology. We put in evidence how the design and component quality impact on construction and why the final product calls for a total-quality approach. LHC experience is widely discussed and main lessons are spelled out. Then the new Nb$_{3}$Sn technology, under development for the next generation magnet construction, is outlined. Finally, we briefly review the testing procedure of accelerator superconducting magnets, underlining the close connection with the design validation and with the manufacturing process.

  6. Manufacturing and Testing of Accelerator Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  7. Stationary quenching wave in magnetized plasma

    International Nuclear Information System (INIS)

    Alikhanov, S.G.; Glushkov, I.S.

    1976-01-01

    The interaction of a magnetized hot plasma (ωsub(e)tau sub(e)>>1) with cold plasma or a gas leads to the appearanci of a cooling wave. The transition layer between hot and cold plasma is the main source of radiation losses which should be compensated by a heat flow from the hot region. A stationary state is considered, equations are written in the system in which temperature and magnetic field profiles are steady, and the plasma flux with magnetic field passes through the cooling wave. Calculations, have been carried out on a computer. The dependence of the magnetized plasma flux velocity Vsub(r) on the ratio p/Hsub(r) is shown, where p is the pressure, Hsub(r) is the magnetic field in the hot reqion. The dependence of the characteristic dimension of the cooling wave on the magnetic field is determined for the hot plasma region. A considerable fraction of the rediation losses is shown to fall to the region of (ωsub(e)tausub(e)< or approximately)1

  8. Design considerations for superconducting magnets as a maglev pad

    International Nuclear Information System (INIS)

    Ichikawa, H.; Ogiwara, H.

    1974-01-01

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

  9. 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

  10. Influence of an inner short-circuit on the behaviour of the superconducting magnet

    International Nuclear Information System (INIS)

    Zizek, F.

    1984-01-01

    On exciting one of the superconducting quadrupole magnets, voltage pulses were observed on the winding outlets. Over a certain current level the pulses disappeared and a quench of the magnet was registered. A subsequent analysis proved that phenomenon was caused by short-circuiting of the turns inside one of the quadrupole coils. The voltage pulses were caused by repeated quenches of the short-circuited part of the winding. The above effect did not appear until a certain rate of rise of the current was attained

  11. Influence of an inner short-circuit on the behaviour of the superconducting magnet

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F. (Skoda k.p., Plzen (Czechoslovakia))

    1984-01-01

    On exciting one of the superconducting quadrupole magnets, voltage pulses were observed on the winding outlets. Over a certain current level the pulses disappeared and a quench of the magnet was registered. A subsequent analysis proved that phenomenon was caused by short-circuiting of the turns inside one of the quadrupole coils. The voltage pulses were caused by repeated quenches of the short-circuited part of the winding. The above effect did not appear until a certain rate of rise of the current was attained.

  12. Observation of thermal quench induced by runaway electrons in magnetic perturbation

    Science.gov (United States)

    Cheon, MunSeong; Seo, Dongcheol; Kim, Junghee

    2018-04-01

    Experimental observations in Korea Superconducting Tokamak Advanced Research (KSTAR) plasmas show that a loss of pre-disruptive runaway electrons can induce a rapid radiative cooling of the plasma, by generating impurity clouds from the first wall. The synchrotron radiation image shows that the loss of runaway electrons occurs from the edge region when the resonant magnetic perturbation is applied on the plasma. When the impact of the runaway electrons on the wall is strong enough, a sudden drop of the electron cyclotron emission (ECE) signal occurs with the characteristic plasma behaviors such as the positive spike and following decay of the plasma current, Dα spike, big magnetic fluctuation, etc. The visible images at this runaway loss show an evidence of the generation of impurity cloud and the following radiative cooling. When the runaway beam is located on the plasma edge, thermal quenches are expected to occur without global destruction of the magnetic structure up to the core.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  14. Levitating a Magnet Using a Superconductive Material.

    Science.gov (United States)

    Juergens, Frederick H.; And Others

    1987-01-01

    Presented are the materials and a procedure for demonstrating the levitation of a magnet above a superconducting material. The demonstration can be projected with an overhead projector for a large group of students. Kits to simplify the demonstration can be purchased from the Institute for Chemical Education of the University of Wisconsin-Madison.…

  15. DESY: HERA superconducting magnets OK; Theory workshop

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The HERA electron-proton collider being built at the DESY Laboratory in Hamburg is the first accelerator using superconducting magnets manufactured by industry on a large scale. For this pioneering step several potential problems now seem to be all well under control, with important contributions coming from both the manufacturers and DESY's accelerator specialists

  16. 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)

  17. Numerical simulation of superconducting accelerator magnets

    CERN Document Server

    Kurz, Stefan

    2002-01-01

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

  18. Quench protection challenges in long nb3sn accelerator magnets

    Science.gov (United States)

    Salmi, Tiina-Mari; Ambrosio, G.; Caspi, S.; Chlachidze, Guram; Dhallé, Marc; Felice, Helene; Ferracin, Paolo; Marchevsky, M.; Sabbi, G. L.; ten Kate, H. H. J.

    2012-06-01

    The quench protection of the several meter long, large aperture high-field Nb3Sn quadrupoles that the LARP collaboration is developing for the LHC interaction region upgrade, requires efficient protection heaters to quickly generate large resistive segments across the windings. To support the protection design, experiments in the recently tested LARP R&D magnets are aimed to characterize the coil response to different protection schemes. In particular, the delay to quench and the final hotspot temperatures are evaluated after firing the heaters at different powering regimes and coverage. Also, the contribution of external energy extraction is investigated. Based on the performed studies and computer simulations, it seems that if the same protection efficiency per unit length that is measured in a 1 m long model magnet can be scaled to a 3.6 m long magnet, and the heater coverage can be improved, about 1 MJ/m of stored energy can be absorbed in the magnet after a quench. However, significant technology developments are needed to scale the protection heater efficiency to longer magnets and to increase the coverage.

  19. Development of superconducting magnets for RAON 28 GHz ECR ion source.

    Science.gov (United States)

    Heo, Jeongil; Choi, Sukjin; Kim, Yonghwan; Hong, In-Seok

    2016-02-01

    RAON, a 28 GHz electron cyclotron resonance ion source (ECR IS), was designed and tested as a Rare Isotope Science Project. It is expected that RAON would provide not only rare-isotope beams but also stable heavy ions ranging from protons to uranium. In order to obtain the steady heavy-ion beam required for ECR IS, we must use a 28 GHz microwave source as well as a high magnetic field. A superconducting magnet using a NbTi wire was designed and manufactured for producing the ECR IS and a test was conducted. In this paper, the design and fabrication of the superconducting magnet for the ECR IS are presented. Experimental results show that the quench current increases whenever quenching occurs, but it has not yet reached the designed current. The experiment is expected to reveal the ideal conditions required to reach the designed current.

  20. Superconducting magnet package for the TESLA test facility

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  1. Calculation of persistent currents in superconducting magnets

    Directory of Open Access Journals (Sweden)

    C. Völlinger

    2000-12-01

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

  2. Development of superconducting magnet systems for HIF Experiments

    International Nuclear Information System (INIS)

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

    2004-01-01

    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 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

  3. 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

  4. 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)

  5. Magnetic shielding for superconducting RF cavities

    Science.gov (United States)

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

    2017-03-01

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

  6. Development of superconducting magnets for magnetically suspended highspeed trains

    Energy Technology Data Exchange (ETDEWEB)

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

    1975-01-01

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

  7. Comparing superconducting and permanent magnets for magnetic refrigeration

    Directory of Open Access Journals (Sweden)

    R. Bjørk

    2016-05-01

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

  8. Effect of coupling currents on the dynamic inductance during fast transient in superconducting magnets

    Directory of Open Access Journals (Sweden)

    V. Marinozzi

    2015-03-01

    Full Text Available We present electromagnetic models aiming to calculate the variation of the inductance in a magnet due to dynamic effects such as the variation of magnetization or the coupling with eddy currents. The models are studied with special regard to the calculation of the inductance in superconducting magnets which are affected by interfilament coupling currents. The developed models have been compared with experimental data coming from tests of prototype Nb_{3}Sn magnets designed for the new generation of accelerators. This work is relevant for the quench protection study of superconducting magnets: quench is an unwanted event, when part of the magnet becomes resistive; in these cases, the current should be discharged as fast as possible, in order to maintain the resistive zone temperature under a safe limit. The magnet inductance is therefore a relevant term for the description of the current discharge, especially for the high-field new generation superconducting magnets for accelerators, and this work shows how to calculate the correct value during rapid current changes, providing a mean for simulations of the reached temperature.

  9. Towards an optimized coupling-loss induced quench protection system (CLIQ) for quadrupole magnets (Proc. 25th ICEC & ICMC2014 conference)

    NARCIS (Netherlands)

    Ravaioli, Emanuele; Datskov, Vladimir I.; Desbiolles, Vincent; Feuvrier, Jerome; Kirby, Glyn; Maciejewski, Michal; Sperin, Kevin A.; ten Kate, Herman H.J.; Verweij, Arjan P.; Willering, G.

    2015-01-01

    The recently developed Coupling-Loss-Induced Quench (CLIQ) protection system is a new method for initiating a fast and voluminous transition to the normal state for protecting high energy density superconducting magnets. Its simple and robust electrical design, its lower failure rate, and its more

  10. Superconducting magnets for toroidal fusion reactors

    International Nuclear Information System (INIS)

    Haubenreich, P.N.

    1980-01-01

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

  11. 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

  12. 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

    cryogenic pump and not obtain in the design phase. For the estimation in design phase, evaluation equations of the flow reduction based on the helium expansion model were developed. The flow reduction by AC losses is predictable by helium expansion model even in the design phase on which the conductor friction and pump performances are not obtained. The phenomenon of flow reduction of the forced flow coil has been applied for coil quench detection and has been developed by Japan Atomic Energy Research Institute (JAERI). It is named the 'fluid method' and essential technology for quench detection of large scale forced flow superconducting coil as fusion magnets and superconducting magnetic energy storage (SMES) coil. In the fluid method, the inlet flow reduction is caused by Joule heating on the normal zone of superconducting coil. The fluid method has no electric noise in its detection. This is an advantage for pulsed operation in comparison with other electrical quench detection systems. There are no quantitative considerations between the inlet flow reduction and Joule heating on the coil in previous studies. The flow reduction for the quench detection has been determined by the operation experience of forced flow superconducting coil. The evaluation method for the flow reduction for the quench detection was developed. The energy consumption in the coil by Joule heating was defined from the inlet flow reduction. It means the quench detection duration from the normal initiation is available. And it makes the protection of the superconducting coil more reliable. It is a new idea on the study of flow reduction and applicable not only fusion magnet but also all of forced flow superconducting coils like a SMES coil. (author)

  13. Superconductivity

    CERN Document Server

    Thomas, D B

    1974-01-01

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

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

    International Nuclear Information System (INIS)

    Wanderer, P.

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Wanderer, P.

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Kanamaru, Y.; Amemiya, Y.

    1991-01-01

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

  17. Large superconducting magnet systems for plasma and fusion applications

    International Nuclear Information System (INIS)

    Heinz, W.

    1976-05-01

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

  18. 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.

  19. 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

  20. Bubble behavior and breakdown characteristics in LHe under simulating quench condition of S.C. magnet

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z.; Yoshizuka, H.; Takano, K.; Hara, M. [Kyushu University, Fukuoka (Japan)

    1996-09-20

    In large superconducting magneto, liquid helium is usually used both as coolant and electrical insulator. An abnormal high voltage and thermal bubbles often appear simultaneously during the quenching period. Such an incident is thought serious from a point of view of electrical insulation. In this work, thermal bubble behavior affected by the electrostatic forces in liquid helium and electrical breakdown mechanism of liquid helium are studied under the simulating quench condition of S.C magnet. The results show that (1) the electrostatic forces produced by nonuniform electric field are useful for reducing the effect of thermal bubbles on electrical breakdown in almost all cases, although the bubble aggregation occurs in the region where the gradient force is counterbalancing with the buoyancy and (2) the fins on the surface of superconducting wires are helpful to prevent the bubbles from being released into strong field region if the groove between fins is formed along the field decreasing direction on the wire surface. 11 refs., 14 figs., 1 tab.

  1. Generation of high magnetic fields using superconducting magnets

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  2. Architecture of a software quench management system

    International Nuclear Information System (INIS)

    Jerzy M. Nogiec et al.

    2001-01-01

    Testing superconducting accelerator magnets is inherently coupled with the proper handling of quenches; i.e., protecting the magnet and characterizing the quench process. Therefore, software implementations must include elements of both data acquisition and real-time controls. The architecture of the quench management software developed at Fermilab's Magnet Test Facility is described. This system consists of quench detection, quench protection, and quench characterization components that execute concurrently in a distributed system. Collaboration between the elements of quench detection, quench characterization and current control are discussed, together with a schema of distributed saving of various quench-related data. Solutions to synchronization and reliability in such a distributed quench system are also presented

  3. Nested shell superconducting magnet designs

    International Nuclear Information System (INIS)

    Bromberg, L.; Williams, J.E.C.; Titus, P.

    1992-01-01

    A new concept for manufacturing the toroidal field coil is described in this paper. Instead of structural plates, the magnet is wound in interlocking shells. The magnet configuration is described and the advantages explored. Structural analysis of the concept is performed using the ARIES tokamak reactor parameters. The effectiveness of a structural cap, placed above and below the toroidal field coils and used only to balance opposing torques generated in different places of the coil, is quantified

  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. Design of superconducting corrector magnets for LHC

    International Nuclear Information System (INIS)

    Baynham, D.E.; Coombs, R.C.; Ijspeert, A.; Perin, R.

    1994-01-01

    The Large Hadron Collider (LHC) will require a range of superconducting corrector magnets. This paper presents the design of sextupole and decapole corrector coils which will be included as spool pieces adjacent to reach main ring dipole. The paper gives detailed 3D field computations of the coil configurations to meet LHC beam dynamics requirements. Coil protection within a long string environment is addressed and mechanical design outlines are presented

  7. Design of superconducting corrector magnets for LHC

    Science.gov (United States)

    Baynham, D. E.; Coombs, R. C.; Ijspeert, A.; Perin, R.

    1994-07-01

    The Large Hadron Collider (LHC) will require a range of superconducting corrector magnets. This paper presents the design of sextupole and decapole corrector coils which will be included as spool pieces adjacent to each main ring dipole. The paper gives detailed 3D field computations of the coil configurations to meet LHC beam dynamics requirements. Coil protection within a long string environment is addressed and mechanical design outlines are presented.

  8. Magnetic-Field-Tunable Superconducting Rectifier

    Science.gov (United States)

    Sadleir, John E.

    2009-01-01

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

  9. Superconductivity and magnetism in the ruthenocuprates

    International Nuclear Information System (INIS)

    Klamut, Piotr W

    2008-01-01

    The ruthenocuprates are high temperature superconductors, which have raised a substantial interest due to the simultaneous presence of the transition metal magnetism and superconductivity. The compounds represent a complex and experimentally challenging research arena, with interesting recent experimental developments. The author reviews some key properties of RuSr 2 RECu 2 O 8 , RuSr 2 RE 2-x Ce x Cu 2 O 10-y , and of a few derivative compounds of the ruthenocuprate family. (topical review)

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

    Science.gov (United States)

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

    2016-12-01

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

  11. Radiation effects on superconducting fusion magnet components

    International Nuclear Information System (INIS)

    Weber, H.W.

    2011-01-01

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

  12. SSC [Superconducting Super Collider] magnet mechanical interconnections

    International Nuclear Information System (INIS)

    Bossert, R.C.; Niemann, R.C.; Carson, J.A.; Ramstein, W.L.; Reynolds, M.P.; Engler, N.H.

    1989-03-01

    Installation of superconducting accelerator dipole and quadrupole magnets and spool pieces in the SSC tunnel requires the interconnection of the cryostats. The connections are both of an electrical and mechanical nature. The details of the mechanical connections are presented. The connections include piping, thermal shields and insulation. There are seven piping systems to be connected. These systems must carry cryogenic fluids at various pressures or maintain vacuum and must be consistently leak tight. The interconnection region must be able to expand and contract as magnets change in length while cooling and warming. The heat leak characteristics of the interconnection region must be comparable to that of the body of the magnet. Rapid assembly and disassembly is required. The magnet cryostat development program is discussed. Results of quality control testing are reported. Results of making full scale interconnections under magnet test situations are reviewed. 11 figs., 4 tabs

  13. 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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  15. DFBX boxes -- electrical and cryogenic distribution boxes for the superconducting magnets in the LHC straight sections

    International Nuclear Information System (INIS)

    Zbasnik, Jon P.; Corradi, Carol A.; Gourlay, S.A.; Green, MichaelA.; Hafalia, Aurelio Q.; Kajiyama, Yoichi Jr.; Knolls, Michael J.; LaMantia, Roberto F.; Rasson, Joseph E.; Reavill, Dulie; Turner, William C.

    2002-01-01

    DFBX distribution boxes provide cryogenic and electrical services to superconducting quadrupoles and to a superconducting dipole at either end of four of the long straight sections in the LHC. The DFBX boxes also provide instrumentation and quench protection to the magnets. Current for the quadrupole and the dipole magnet is delivered through leads that combine HTS and gas cooled leads. Current for the 600 A and 120 A correction magnets is provided by pure gas-cooled leads. The bus bars from the leads to the magnets pass through low leak-rate lambda plugs between 1.8 K and 4.4 K. The heat leak into the 1.9 K region from the liquid helium tank is determined by the design of the lambda plugs. This paper describes the DFBX boxes and their function of delivering current and instrumentation signals to the magnets

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

    International Nuclear Information System (INIS)

    Montoya, C.R.

    1981-01-01

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

  17. Superconductivity

    International Nuclear Information System (INIS)

    Onnes, H.K.

    1988-01-01

    The author traces the development of superconductivity from 1911 to 1986. Some of the areas he explores are the Meissner Effect, theoretical developments, experimental developments, engineering achievements, research in superconducting magnets, and research in superconducting electronics. The article also mentions applications shown to be technically feasible, but not yet commercialized. High-temperature superconductivity may provide enough leverage to bring these applications to the marketplace

  18. Testing of high current by-pass diodes for the LHC magnet quench protection

    International Nuclear Information System (INIS)

    Berland, V.; Hagedorn, D.; Rodriguez-Mateos, F.

    1996-01-01

    Within the framework of the Large Hadron Collider (LHC) R and D program, CERN is performing experiments to establish the current carrying capability of irradiated diodes at liquid Helium temperatures for the superconducting magnet protection. Even if the diodes are degraded by radiation dose and neutron fluence, they must be able to support the by-pass current during a magnet quench and the de-excitation of the superconducting magnet ring. During this discharge, the current in the diode reaches a maximum value up to 13 kA and decreased with an exponential time constant of 100 s. Two sets of 75 mm wafer diameter epitaxial diodes, one irradiated and one non-irradiated, were submitted to this experiment. The irradiated diodes have been exposed to radiation in the accelerator environment up to 20 kGy and then annealed at room temperature. After the radiation exposure the diodes had shown a degradation of forward voltage of 50% which reduced to about 14% after the thermal annealing. During the long duration high current tests, one of the diodes was destroyed and the other two irradiated diodes showed a different behavior compared with non-irradiated diodes

  19. Instrumentation and Quench Protection for LARP Nb3Sn Magnets

    International Nuclear Information System (INIS)

    Felice, H.; Ambrosio, G.; Chlachidize, G.; Ferracin, P.; Hafalia, R.; Hannaford, R.C.; Joseph, J.; Lietzke, A.; McInturff, A.; Muratore, J.; Prestemon, S.; Sabbi, G.L.; Schmalzle, J.; Wanderer, P.; Wang, X.

    2008-01-01

    The US LHC Accelerator Research Program (LARP) is developing Nb 3 Sn prototype quadrupoles for the LHC interaction region upgrades. Several magnets have been tested within this program and understanding of their behavior and performance is a primary goal. The instrumentation is consequently a key consideration, as is protection of the magnet during quenches. In all LARP magnets, the flexible circuits traces combine the instrumentation and the protection heaters. Their fabrication relies on printed circuit technology based on a laminate made of a 45-micron thick kapton sheet and a 25-micron thick foil of stainless steel. This paper reviews the protection heaters designs used in the TQ (Technology Quadrupole) and LR (Long Racetrack) series as well as the one used in LBNL HD2a high field dipole and presents the design of the traces for the Long Quadrupole (LQ), addressing challenges associated with the stored energy and the length of the magnet.

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

    CERN Document Server

    Ambjørndalen, Sara; Verweij, Arjan

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

  1. Magnetization effects in superconducting dipole magnets

    International Nuclear Information System (INIS)

    Ishimoto, H.; Peters, R.E.; Price, M.E.; Yamada, R.

    1977-01-01

    Magnetization effect of superconductors on the field quality was investigated for some of the typical Energy Doubler bending magnets. Calculations were made using the computor program GFUN2D and compared with some measured results. Agreement between them is good. The field quality at low excitation is mainly determined by the magnetization effect. A similar effect due to a stainless collar mechanical support was also calculated, although it is not as big as the first one

  2. Superconductive magnetic-field-trapping device

    Science.gov (United States)

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

    1965-01-01

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

  3. Artificial magnetic-field quenches in synthetic dimensions

    Science.gov (United States)

    Yılmaz, F.; Oktel, M. Ö.

    2018-02-01

    Recent cold atom experiments have realized models where each hyperfine state at an optical lattice site can be regarded as a separate site in a synthetic dimension. In such synthetic ribbon configurations, manipulation of the transitions between the hyperfine levels provide direct control of the hopping in the synthetic dimension. This effect was used to simulate a magnetic field through the ribbon. Precise control over the hopping matrix elements in the synthetic dimension makes it possible to change this artificial magnetic field much faster than the time scales associated with atomic motion in the lattice. In this paper, we consider such a magnetic-flux quench scenario in synthetic dimensions. Sudden changes have not been considered for real magnetic fields as such changes in a conducting system would result in large induced currents. Hence we first study the difference between a time varying real magnetic field and an artificial magnetic field using a minimal six-site model. This minimal model clearly shows the connection between gauge dependence and the lack of on-site induced scalar potential terms. We then investigate the dynamics of a wave packet in an infinite two- or three-leg ladder following a flux quench and find that the gauge choice has a dramatic effect on the packet dynamics. Specifically, a wave packet splits into a number of smaller packets moving with different velocities. Both the weights and the number of packets depend on the implemented gauge. If an initial packet, prepared under zero flux in an n -leg ladder, is quenched to Hamiltonian with a vector potential parallel to the ladder, it splits into at most n smaller wave packets. The same initial wave packet splits into up to n2 packets if the vector potential is implemented to be along the rungs. Even a trivial difference in the gauge choice such as the addition of a constant to the vector potential produces observable effects. We also calculate the packet weights for arbitrary initial and

  4. 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

  5. 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…

  6. 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...

  7. Superconductivity, magnetics, cryogenics, and vacuum coating

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  8. Design and test of a short mockup magnet for the superconducting undulator at the SSRF

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jieping, E-mail: jpxu@sinap.ac.cn; Ding, Yi; Cui, Jian; Zhang, Wei; Wang, Hongfei; Yin, Lixin [Department of Mechanical Engineering, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)

    2016-07-27

    A superconducting planar undulator is under development at the Shanghai Synchrotron Radiation Facility (SSRF) to provide the SSRF users with higher photon fluxes at higher photon energies. A 5-period magnet was designed and built for feasibility study. The short mockup magnet is composed of NbTi/Cu winding and low carbon steel former and was tested in a vertical cryocooler-cooled cryostat. The nominal current of 387 A was reached after 2 quenches and the maximum current of 433.2 A was achieved. The magnetic field profile was measured and a peak field of 0.93 T was obtained when stably operating at 400 A.

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

    Directory of Open Access Journals (Sweden)

    Weishi Wan

    2015-10-01

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

  10. Sweeping a persisting superconducting magnet with a transformer

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  11. 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...

  12. 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.

  13. OPERATIONAL EXPERIENCE WITH BEAM ABORT SYSTEM FOR SUPERCONDUCTING UNDULATOR QUENCH MITIGATION*

    Energy Technology Data Exchange (ETDEWEB)

    Harkay, Katherine C.; Dooling, Jeffrey C.; Sajaev, Vadim; Wang, Ju

    2017-06-25

    A beam abort system has been implemented in the Advanced Photon Source storage ring. The abort system works in tandem with the existing machine protection system (MPS), and its purpose is to control the beam loss location and, thereby, minimize beam loss-induced quenches at the two superconducting undulators (SCUs). The abort system consists of a dedicated horizontal kicker designed to kick out all the bunches in a few turns after being triggered by MPS. The abort system concept was developed on the basis of single- and multi-particle tracking simulations using elegant and bench measurements of the kicker pulse. Performance of the abort system—kick amplitudes and loss distributions of all bunches—was analyzed using beam position monitor (BPM) turn histories, and agrees reasonably well with the model. Beam loss locations indicated by the BPMs are consistent with the fast fiber-optic beam loss monitor (BLM) diagnostics described elsewhere [1,2]. Operational experience with the abort system, various issues that were encountered, limitations of the system, and quench statistics are described.

  14. 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

  15. Novel Approach to Linear Accelerator Superconducting Magnet System

    International Nuclear Information System (INIS)

    Kashikhin, Vladimir

    2011-01-01

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

  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. US superconducting magnet data base assessment for INTOR

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  18. 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)

  19. Thermal and mechanical effects of quenches on Nb3Sn high field hadron collider magnets

    International Nuclear Information System (INIS)

    Ryuji, Yamada

    2001-01-01

    Thermal and its resulting mechanical stress due to quenches inside short and long epoxy impregnated Nb 3 Sn high field magnets are studied with a quench simulation program, Kuench, and ANSYS program. For the protection of a long high field magnet, we have to use heaters to dump the stored energy uniformly inside the magnet, after detection of a spontaneous quench. The time delay of starting a forced quench with heaters, is estimated using ANSYS. Using this information, the thermal distribution in two-dimensional magnet cross section is studied. First a one meter model magnet with a dump resistor is used to estimate the effects and then a 10 meter long magnet is studied. The two-dimensional temperature distributions in the magnet cross sections are recorded every 5 ms, and visually displayed. With this visual animation displays we can understand intuitively the thermal and quench propagation in 2-dimensional field. The quenching cables get heated locally much more than the surrounding material and non-quenching conductor cables. With a one meter magnet with a dump resistor of 30 mOmega, typically only the quench starting cables and its neighbor cables get heated up to 100 K without significant effects from the heaters. With a10 meter magnet, heaters cause the quenches to most of the conductor blocks. The quench initiating cables get up to 250 to 300 K in 100 ms, but the surrounding and wedges are not heated up significantly. This causes the excessive stress in the quenching conductors and in their insulation material locally. The stress and strain in the conductor as well as in the insulation become excessive, and they are studied using the ANSYS stress analysis, using Von Mises criterion. It is concluded that for the one meter magnet with the presented cross section and configuration, the thermal effects due to the quench is tolerable. But we need much more quench study and improvements in the design for the extended ten meter long magnet [1

  20. 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...

  1. 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

  2. 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

  3. Introduction of fuzzy logic theorem for quench detection in the superconducting coil system of a Large Helical Device

    International Nuclear Information System (INIS)

    Adachi, Yamato; Ninomiya, Akira; Uriu, Yoshihisa; Ishigohka, Takeshi; Mito, Toshiyuki; Imagawa, Shinsaku; Yanagi, Nagato; Sekiguchi, Haruo; Yamada, Shuichi

    2005-01-01

    We have analyzed the state of the superconducting coil system in a LHD at NIFS (National Institute of Fusion Science) using a fuzzy logic theorem to detect quenching at an early stage. In this method, the 'warning coefficient' of the coil system is calculated. As for the fuzzy variables, 'effective stored heat' in the coil is introduced in addition to the voltage signal in order to improve quench detection and state estimation. The 'effective stored heat' is an integrated value of the heat generated in the coil on the assumption that instantaneous heat in the conductor is continuously cooled by liquid helium. Experiments conducted using the LHD coils confirmed that quench alarm signals can be issued with sufficient lead time before quenching. On the other hand, in the case of small local disturbances, the system shows only a small increase in the caution level. (author)

  4. Cooling system for superconducting magnet

    Science.gov (United States)

    Gamble, Bruce B.; Sidi-Yekhlef, Ahmed

    1998-01-01

    A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir. In a second mode, the heater heats the second reservoir to cause the refrigerant to flow from the second reservoir through the load and heat exchanger via the conduit circuit and into the first reservoir.

  5. Structural alloys for high field superconducting magnets

    International Nuclear Information System (INIS)

    Morris, J.W. Jr.

    1985-08-01

    Research toward structural alloys for use in high field superconducting magnets is international in scope, and has three principal objectives: the selection or development of suitable structural alloys for the magnet support structure, the identification of mechanical phenomena and failure modes that may influence service behavior, and the design of suitable testing procedures to provide engineering design data. This paper reviews recent progress toward the first two of these objectives. The structural alloy needs depend on the magnet design and superconductor type and differ between magnets that use monolithic and those that employ force-cooled or ICCS conductors. In the former case the central requirement is for high strength, high toughness, weldable alloys that are used in thick sections for the magnet case. In the latter case the need is for high strength, high toughness alloys that are used in thin welded sections for the conductor conduit. There is productive current research on both alloy types. The service behavior of these alloys is influenced by mechanical phenomena that are peculiar to the magnet environment, including cryogenic fatigue, magnetic effects, and cryogenic creep. The design of appropriate mechanical tests is complicated by the need for testing at 4 0 K and by rate effects associated with adiabatic heating during the tests. 46 refs

  6. On the interplay of superconductivity and magnetism

    International Nuclear Information System (INIS)

    Powell, Benjamin James

    2002-01-01

    We explore the exchange field dependence of the Hubbard model with a attractive, effective, pairwise, nearest neighbour interaction via the Hartree-Fock-Gorkov approximation. We derive a Ginzburg-Landau theory of spin triplet superconductivity in an exchange field. For microscopic parameters which lead to ABM phase superconductivity in zero field, the Ginzburg-Landau theory allows both an axial (A, A 1 or A 2 ) solution with the vector order parameter, d(k), perpendicular to the field, H, and an A phase solution with d(k) parallel to H. We study the spin-generalised Bogoliubov-de Gennes (BdG) equations for this model with parameters suitable for strontium ruthenate (Sr 2 RuO 4 ). The A 2 phase is found to be stable in a magnetic field. However, in the real material, spin-orbit coupling could pin the order parameter to the crystallographic c-axis which would favour the A phase for fields parallel to the c-axis. We show that the low temperature thermodynamic behaviour in a magnetic field could experimentally differentiate between these two possible behaviours. Further we show that this pinning could cause a Freedericksz (Frederiks) transition in bulk Sr 2 RuO 4 (Freedericksz transitions have only previously been seen in confined geometries.) We calculate the superconducting critical temperature, T C , of ZrZn 2 in the presence of non-magnetic impurity scattering from the Abrikosov-Gorkov formula. Residual resistivity experiments indicate that the transition temperature in the absence of impurity scattering, T CO = 1.15 ± 0.15 K, while de Haas-van Alphen experiments give T CO ∼ 3 K. We discuss this disagreement and conclude that the former estimate is the more reliable. We derive the equal spin pairing (ESP) gap equations for a ferromagnetic superconductor, which we solve for parameters chosen for ZrZn 2 . We show that for ESP states in a ferromagnetic superconductor, in the absence of spin flip processes, the two spin states are separate subsystems due to exchange

  7. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-15

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

  9. Cold test facility for 1.8 m superconducting model magnets at the SSC

    International Nuclear Information System (INIS)

    LaBarge, A.

    1993-07-01

    A new facility has been constructed to measure the characteristic features of superconducting model magnets and cable at cryogenic temperatures -- a function which supports the design and development process for building full-scale accelerator magnets. There are multiple systems operating in concert to test the model magnets, namely: cryogenic, magnet power, data acquisition and system control. A typical model magnet test includes the following items: (1) warm measurements of magnet coils, strain gauges and voltage taps; (2) hipot testing of insulation integrity; (3) cooling with liquid nitrogen and then liquid helium; (4) measuring quench current and magnetic field; (5) magnet warm-up. While the magnet is being cooled to 4.22 K, the mechanical stress is monitored through strain gauges. Current is then ramped into the magnet until it reaches some maximum value and the magnet transitions from the superconducting state to the normal state. Normal-zone propagation is monitored using voltage taps on the magnet coils during this process, thus indicating where the transition began. The current ramp is usually repeated until a plateau current is reached, where the magnet has mechanically settled

  10. 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...

  11. 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 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 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

  12. 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

  13. 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...

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

    1985-04-01

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

  17. Processing of the quench detection signals in W7-X

    International Nuclear Information System (INIS)

    Birus, Dietrich; Schneider, Matthias; Rummel, Thomas; Fricke, Marko; Petry, Klaus; Ebersoldt, Andreas

    2009-01-01

    The Wendelstein 7-X (W7-X) project uses superconductive coils for generation of the magnetic field to keep the plasma. One of the important safety systems is the protection against quench events. The quench detection system of W7-X protects the superconducting coils, the superconducting bus bar sections and the high temperature superconductor of the current leads against the damage because of a quench and against the high stress by a fast discharge of the magnet system. Therefore, the present design of the quench detection system (QDS) uses a two-stage safety concept for discharging the magnetic system. This paper describes the present design of the system assembly from the quench detection unit (QDU) for the detection of the quench to the quench detection interface (QDI) to implement the two-stage safety concept.

  18. 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

  19. 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.

  20. 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.

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

    Science.gov (United States)

    Hull, John R.

    1996-01-01

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

  2. FPGA-based quench detection system for super-FRS super-ferric dipole prototype

    International Nuclear Information System (INIS)

    Yang Tongjun; Wu Wei; Yao Qinggao; Yuan Ping; He Yuan; Han Shaofei; Ma Lizhen

    2011-01-01

    The quench detection system for Super-FRS super-ferric dipole prototype magnet of FAIR has been designed and built. The balance bridge was used to detect quench signal. In order to avoid blind zone of quench detection, two independent bridges were used. NI PXI-7830R FPGA was used to implement filter to quench signal and algorithm of quench decision and to produce quench trigger signal. Pre-sample technique was used in quench data acquisition. The data before and after quench could be recorded for analysis later. The test result indicated that the quench of the dipole's superconducting coil could be reliably detected by the quench detection module. (authors)

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

    CERN Document Server

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

    2014-01-01

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

  4. Superconductivity and the magnetic electron bond

    International Nuclear Information System (INIS)

    Szurek, P.

    1989-01-01

    The concept of the magnetic electron bond as the fundamental characteristic of superconductivity was first introduced during a presentation at the 1988 Winter Annual Meeting of the American Society of Mechanical Engineers. Postulates describing the role of the electron and the magnetic bond were suggested to explain in a consistent manner known observations. What may becoming clear is that a boundary set of conditions may exist above and below the transition temperature at which a material superconducts. Prior to recent history, scientists have concentrated on postulating, experimenting, and learning about the set of conditions that exist above the transition temperature, which has set the standard for todays quantum theory. Above the transition temperature they have learned about the interrelationships that exist between the electron, a small magnetic and negatively charged body, and the nucleus, a large positively charged body. By grouping common general characteristics due to the interaction between the outer shell electrons and the nucleus of different elements, three bond types have been established, covalent, ionic, and metallic. They may now be in the process of determining those conditions that lie below the transition temperature, a realm where charge effects may no longer dominate magnetic effects. This may involve updating the quantum theory to reflect those conditions that exist above and below the transition temperature. The following discussion reviews, updates, and attempts to answer some preliminary questions regarding postulates that may define some of the conditions that lie below the transition temperature. As an introduction, figure 1 depicts what may occur to loosely held outer shell electrons below the transition temperature due to increased inner electron shielding. 7 refs., 9 figs

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  6. Electrical joints in the CMS superconducting magnet

    CERN Document Server

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

    2002-01-01

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

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

    Science.gov (United States)

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

    2014-02-01

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

  8. First experience with the new coupling loss induced quench system

    NARCIS (Netherlands)

    Ravaioli, Emanuele; Datskov, V.I.; Dudarev, A.V.; Kirby, G.; Sperin, K.A.; ten Kate, Herman H.J.; Verweij, A.P.

    2014-01-01

    New-generation high-field superconducting magnets pose a challenge relating to the protection of the coil winding pack in the case of a quench. The high stored energy per unit volume calls for a very efficient quench detection and fast quench propagation in order to avoid damage due to overheating. A

  9. Superconductivity

    International Nuclear Information System (INIS)

    Palmieri, V.

    1990-01-01

    This paper reports on superconductivity the absence of electrical resistance has always fascinated the mind of researchers with a promise of applications unachievable by conventional technologies. Since its discovery superconductivity has been posing many questions and challenges to solid state physics, quantum mechanics, chemistry and material science. Simulations arrived to superconductivity from particle physics, astrophysic, electronics, electrical engineering and so on. In seventy-five years the original promises of superconductivity were going to become reality: a microscopical theory gave to superconductivity the cloth of the science and the level of technological advances was getting higher and higher. High field superconducting magnets became commercially available, superconducting electronic devices were invented, high field accelerating gradients were obtained in superconductive cavities and superconducting particle detectors were under study. Other improvements came in a quiet progression when a tornado brought a revolution in the field: new materials had been discovered and superconductivity, from being a phenomenon relegated to the liquid Helium temperatures, became achievable over the liquid Nitrogen temperature. All the physics and the technological implications under superconductivity have to be considered ab initio

  10. Magnetism and superconductivity in Eu-based iron pnictides

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  11. New method to improve the accuracy of quench position measurement on a superconducting cavity by a second sound method

    Directory of Open Access Journals (Sweden)

    ZhenChao Liu

    2012-09-01

    Full Text Available Quench is a common phenomenon in a superconducting cavity and often limits the accelerating gradient of the cavity. Accurate location of the quench site, typically located at a material or geometrical defect, is the key to improve the cavity accelerating gradient. Here, the second sound propagation in liquid helium II is used to detect the quench location on the cavity. The technique is relatively convenient and complements the traditional temperature mapping which measures the “prequench” temperature rise on the cavity using an array of sensors. The speed of the second sound in liquid helium II is roughly 1.7  cm/ms at 2 K which is sufficiently fast to provide a millimeter-size position resolution. However, the dynamics of the quench at the cavity surface are also found to significantly affect the achievable resolution with real cavities. Here we use a dynamic quench model, based on ANSYS, to calculate the quench area and the temperature distribution on the cavity. The detection error caused by the thermal conduction in the niobium was calculated.

  12. Superconducting materials for particle accelerator magnets

    International Nuclear Information System (INIS)

    Larbalestier, D.C.

    1983-01-01

    Present accelerator designs are clustered around a field of 5 Tesla with several future studies looking at the 8-to-10 Tesla range. There has also been some recent interest in low-field iron-dominated dipoles in which the superconductor will see a field of about 2 Tesla. The demands of this present range of interest can still be met, with the upper limit at about 10 Tesla, by the use of Nb-Ti (or Nb-Ti-Ta) or Nb 3 Sn. Both of these conductors are available in multifilamentary form from industrial sources and are suitable for accelerator magnets. The upper critical field and transition temperature of both types of composite cover the foreseeable range of demand for such magnets. There is no magical new composite on the horizon that is likely to replace Nb-Ti or Nb 3 Sn. One class of materials which has a potentially exciting prospect is that of the ternary molybdenum sulfides. These can have an upper critical field of greater than 50 T, which extends their superconductivity into field ranges unattainable with A15 compounds; the two drawbacks to such materials, however, are the amount of development needed to produce superconductors from them with useful current densities and the fact that it does not appear that they would offer any features not already possessed by Nb-Ti or Nb 3 Sn in the field range presently of interest to accelerator designers. Using this pragmatic approach, this paper addresses these and other superconducting composites in terms of their fabrication, their testing, the measurement aspects of their critical current densities, and other properties which are pertinent to their selection for particle accelerator magnet use

  13. Magnetism, Superconductivity, and Spontaneous Orbital Order in Iron-Based Superconductors: Which Comes First and Why?

    Directory of Open Access Journals (Sweden)

    Andrey V. Chubukov

    2016-12-01

    Full Text Available Magnetism and nematic order are the two nonsuperconducting orders observed in iron-based superconductors. To elucidate the interplay between them and ultimately unveil the pairing mechanism, several models have been investigated. In models with quenched orbital degrees of freedom, magnetic fluctuations promote stripe magnetism, which induces orbital order. In models with quenched spin degrees of freedom, charge fluctuations promote spontaneous orbital order, which induces stripe magnetism. Here, we develop an unbiased approach, in which we treat magnetic and orbital fluctuations on equal footing. Key to our approach is the inclusion of the orbital character of the low-energy electronic states into renormalization group (RG analysis. We analyze the RG flow of the couplings and argue that the same magnetic fluctuations, which are known to promote s^{+-} superconductivity, also promote an attraction in the orbital channel, even if the bare orbital interaction is repulsive. We next analyze the RG flow of the susceptibilities and show that, if all Fermi pockets are small, the system first develops a spontaneous orbital order, then s^{+-} superconductivity, and magnetic order does not develop down to T=0. We argue that this scenario applies to FeSe. In systems with larger pockets, such as BaFe_{2}As_{2} and LaFeAsO, we find that the leading instability is either towards a spin-density wave or superconductivity. We argue that in this situation nematic order is caused by composite spin fluctuations and is vestigial to stripe magnetism. Our results provide a unifying description of different iron-based materials.

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

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  15. The status of superconducting magnet safety research

    International Nuclear Information System (INIS)

    Herring, J.S.; Juengst, Klaus-Peter; Thome, R.J.

    1989-01-01

    The superconducting magnet set for a fusion reactor may store in excess of 100 GJ which must be controlled and, if necessary, safely dissipated under electrical fault conditions. While the radioactive inventory of the magnet set and its support equipment is small, the stored energy and potential off-normal forces between the coils have the capability for damaging systems which do contain large radioactive inventories. During the past eight years a coordinated series of codes, analyses, experiments and accident investigations have been carried out in the US and Europe with the goals of understanding the accident processes in magnets and developing criteria for safe magnet design. Several codes have been developed and are discussed. Each of these codes deals with a different environment and can be applied to different transient scenarios. In addition, preliminary analyses have been carried out on some large scale magnet systems to determine likely fault locations and scenarios for the purpose of developing a methodology for risk assessment. Safety specific experiments have been carried out at MIT, on the Large Coil Project at ORNL and on the TESPE facility at KfK. These experiments have served both to verify code predictions and to supply basic input data to further analyses, such as hot spot temperatures and arc voltages. This paper summarizes selected results from the above tasks. Some accidents have occurred in the course of magnet development, testing and use. By carefully, analyzing the root causes of these incidents, criteria have been studied for the design of more robust and fault-tolerant systems. 6 refs., 1 fig., 2 tabs

  16. Design and construction of a resistive energy dump device for bipolar superconducting magnet systems

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, M. J.

    1977-05-01

    When superconducting magnets quench, the resistance of the conductor material rises rapidly to its normal value. This increase in resistance can result in catastrophic heating in the magnet unless stored field energy is quickly removed from the system. Phase inversion is the normal mode of energy removal. SCR's in the power supply are phased back, the output of the supply is inverted, and magnetic field energy is directed back into the utility grid. Under certain conditions, however, the power supply may fail to invert properly, and an alternate energy removal scheme must protect the superconducting magnet system. Composed of an isolation switch, a semiconductor switching module, and a dump resistor, the resistive dump device provides a viable protection scheme. Operationally, several conditions are capable of activating the isolation switch and triggering the bipolar SCR switching module. Manual dump commands, for instance, permit the operator to dump field energy in the event of observed abnormalities. A special voltage tap quench detector senses the aforementioned abnormal power supply output inversion and also fires the dump circuit. Regardless of the nature of the trigger input, however, activation of the energy dump device diverts coil current through the dump resistor. I/sup 2/R losses over time then safely dissipate stored magnetic field energy.

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  18. 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

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

    Science.gov (United States)

    Yu, Huixian

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  1. Slip-Stick Mechanism in Training the Superconducting Magnets in the Large Hadron Collider

    CERN Document Server

    Granieri, P P; Todesco, E

    2011-01-01

    Superconducting magnets can exhibit training quenches during successive powering to reaching nominal performance. The slip–stick motion of the conductors is considered to be one of the mechanisms of training. In this paper, we present a simple quantitative model where the training is described as a discrete dynamical system matching the equilibrium between the energy margin of the superconducting cable and the frictional energy released during the conductor motion. The model can be explicitly solved in the linearized case, showing that the short sample limit is reached via a power law. Training phenomena have a large random component. A large set of data of the large hadron collider magnet tests is postprocessed according to previously defined methods to extract an average training curve for dipoles and quadrupoles. These curves show the asymptotic power law predicted by the model. The curves are then fit through the model, which has two free parameters. The model shows good agreement over a large range, bu...

  2. Slip-Stick Mechanism in Training the Superconducting Magnets in the Large Hadron Collider

    CERN Document Server

    Granieri, P P; Lorin, C

    2011-01-01

    Superconducting magnets can exhibit training quenches during successive powering to reaching nominal performance. The slip-stick motion of the conductors is considered to be one of the mechanisms of training. In this paper, we present a simple quantitative model where the training is described as a discrete dynamical system matching the equilibrium between the energy margin of the superconducting cable and the frictional energy released during the conductor motion. The model can be explicitly solved in the linearized case, showing that the short sample limit is reached via a power law. Training phenomena have a large random component. A large set of data of the large hadron collider magnet tests is postprocessed according to previously defined methods to extract an average training curve for dipoles and quadrupoles. These curves show the asymptotic power law predicted by the model. The curves are then fit through the model, which has two free parameters. The model shows good agreement over a large range, but ...

  3. 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

  4. Vol. 34 - Optimization of quench protection heater performance in high-field accelerator magnets through computational and experimental analysis

    CERN Document Server

    Salmi, Tiina

    2016-01-01

    Superconducting accelerator magnets with increasingly hi gh magnetic fields are being designed to improve the performance of the Large Hadron Collider (LHC) at CERN. One of the technical challenges is the magnet quench p rotection, i.e., preventing damage in the case of an unexpected loss of superc onductivity and the heat generation related to that. Traditionally this is d one by disconnecting the magnet current supply and using so-called protection he aters. The heaters suppress the superconducting state across a large fraction of the winding thus leading to a uniform dissipation of the stored energy. Preli minary studies suggested that the high-field Nb 3 Sn magnets under development for the LHC luminosity upgrade (HiLumi) could not be reliably protected using the existing heaters. In this thesis work I analyzed in detail the present state-of-the-art protection heater technology, aiming to optimize its perfo rmance and evaluate the prospects in high-field magnet protection. The heater efficiency analyses ...

  5. 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...

  6. A finite element model of the LHC dipole cold mass with hysteretic, non-linear behavior and single turn description: towards the interpretation of magnet quenches

    CERN Document Server

    AUTHOR|(CDS)2067087

    In one of its acceptation, the word quench is synonym of destruction. And this is even more consistent with reality in the case of the Large Hadron Collider dipole magnets, whose magnetic field and stored energy are unprecedented: the uncontrolled transition from the superconducting to the resistive state can be the origin of dramatic events. This is why the protection of magnets is so important, and why so many studies and investigations have been carried out on quench origin. The production, cold testing and installation of the 1232 arc dipole magnets is completed. They have fulfilled all the requirements and the operation reliability of these magnets has already been partially confirmed. From an academic standpoint, nevertheless, the anomalous mechanical behaviour, which was sometimes observed during power tests, has not yet been given a clear explanation. The work presented in this thesis aims at providing an instrument to better understand the reasons for such anomalies, by means of finite element modell...

  7. Radiation resistant organic composites for superconducting fusion magnets

    International Nuclear Information System (INIS)

    Nishijima, S.; Okada, T.

    1993-01-01

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

  8. Magnetism in structures with ferromagnetic and superconducting layers

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-15

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

  9. Spatial and temporal resolution requirements for quench detection in (RE)Ba2Cu3Ox magnets using Rayleigh-scattering-based fiber optic distributed sensing

    International Nuclear Information System (INIS)

    Chan, W K; Schwartz, J; Flanagan, G

    2013-01-01

    One of the key remaining challenges to safe and reliable operation of large, high temperature superconductor (HTS)-based magnet systems is quench detection and protection. Due to the slow quench propagation in HTS systems, the conventional discrete voltage-tap approach developed for NbTi and Nb 3 Sn magnets may not be sufficient. In contrast, a distributed temperature profile, generated by a distributed temperature sensor and facilitating continuous monitoring of the temperature at any monitored locations within a magnet with high spatial resolution, may be required. One such distributed temperature sensing option is the use of Rayleigh-based fiber optic sensors (FOS), which are immune to electromagnetic interference. The detection of a quench via Rayleigh-based FOS relies on converting the spectral shifts in the Rayleigh scattering spectra into temperature variations. As a result, the higher the spatial sampling resolution the larger the data processing volume, and thus the lower the temporal sampling resolution. So, for effective quench detection, which requires the quick and accurate identification of a hot spot, it is important to find a balance between the spatial and temporal resolutions executable on a given data acquisition and processing (DAQ) system. This paper discusses a method for finding an appropriate DAQ technology that matches the characteristic of a superconducting coil, and determining the acceptable resolutions for efficient and safe quench detection. A quench detection algorithm based on distributed temperature sensing is proposed and its implementation challenges are discussed. (paper)

  10. Superconducting magnetic energy storage for asynchronous electrical systems

    Science.gov (United States)

    Boenig, Heinrich J.

    1986-01-01

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

  11. Superconducting magnet and cryostat for a space application

    Science.gov (United States)

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

    1975-01-01

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

  12. Study of the Tokamak-15 Superconducting Toroidal Field Coil (STFC) heating under the quench

    International Nuclear Information System (INIS)

    Anashkin, I.O.; Kabanovsky, S.V.; Chudnovsky, A.N.; Khvostenko, P.P.; Vertiporokh, A.N.; Ivanov, D.P.; Posadsky, I.A.

    1994-01-01

    Experiments in Tokamak-15 were performed to study the STFC heating under the quench. The quench was specially caused by current introduction into STFC at the unchanged input helium temperature. The experimental results and simulation data on temperature heating and amount of heat realized in the pancakes under the quench are given. In the experiments was shown that quench occurs in the internal turns of pancakes and estimations of maximal temperature heating corresponds to calculated ones

  13. 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

  14. A contribution to the study of superconducting magnets

    International Nuclear Information System (INIS)

    Ciazynski, D.

    1983-09-01

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

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-04-01

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

  17. 1999 Review of superconducting dipole and quadrupole magnets for particle accelerators

    International Nuclear Information System (INIS)

    Devred, A.

    1999-12-01

    (section 6). We also show how these concepts have evolved in time to accommodate higher and higher Lorentz forces. We follow by presenting the complex formalism used to describe magnetic measurement systems based on rotating pick-up coil arrays (section 7), and we summarize the various sources of field errors (section 8). Finally, after describing the cooling schemes that have been implemented in large superconducting particle accelerators (section 9), we discuss issues related to quench performance (section 10) and to quench protection (section 11). (authors)

  18. 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

    conductor positioning (section 6). We also show how these concepts have evolved in time to accommodate higher and higher Lorentz forces. We follow by presenting the complex formalism used to describe magnetic measurement systems based on rotating pick-up coil arrays (section 7), and we summarize the various sources of field errors (section 8). Finally, after describing the cooling schemes that have been implemented in large superconducting particle accelerators (section 9), we discuss issues related to quench performance (section 10) and to quench protection (section 11). (authors)

  19. Near-field microwave magnetic nanoscopy of superconducting radio frequency cavity materials

    Science.gov (United States)

    Tai, Tamin; Ghamsari, Behnood G.; Bieler, Thomas R.; Tan, Teng; Xi, X. X.; Anlage, Steven M.

    2014-06-01

    A localized measurement of the RF critical field on superconducting radio frequency (SRF) cavity materials is a key step to identify specific defects that produce quenches of SRF cavities. Two measurements are performed to demonstrate these capabilities with a near-field scanning probe microwave microscope. The first is a third harmonic nonlinear measurement on a high Residual-Resistance-Ratio bulk Nb sample showing strong localized nonlinear response, with surface RF magnetic field Bsurface˜102 mT. The second is a raster scanned harmonic response image on a MgB2 thin film demonstrating a uniform nonlinear response over large areas.

  20. 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

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  3. 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)

  4. Commissioning of cryogen delivery system for superconducting cyclotron magnet

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-02-01

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

  6. 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

  7. Recent development of the superconducting magnet in Japan

    International Nuclear Information System (INIS)

    Umeda, M.; Aiyama, Y.

    1980-01-01

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

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  9. A modular and extensible data acquisition and control system for testing superconducting magnets

    International Nuclear Information System (INIS)

    Darryl F. Orris and Ruben H. Carcagno

    2001-01-01

    The Magnet Test Facility at Fermilab tests a variety of full-scale and model superconducting magnets for both R and D and production. As the design characteristics and test requirements of these magnets vary widely, the magnet test stand must accommodate a wide range of Data Acquisition (DAQ) and Control requirements. Such a system must provide several functions, which includes: quench detection, quench protection, power supply control, quench characterization, and slow DAQ of temperature, mechanical strain gauge, liquid helium level, etc. The system must also provide cryogenic valve control, process instrumentation monitoring, and process interlock logic associated with the test stand. A DAQ and Control system architecture that provides the functionality described above has been designed, fabricated, and put into operation. This system utilizes a modular approach that provides both extensibility and flexibility. As a result, the complexity of the hardware is minimized while remaining optimized for future expansion. The architecture of this new system is presented along with a description of the different technologies applied to each module. Commissioning and operating experience as well as plans for future expansion are discussed

  10. 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

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

    International Nuclear Information System (INIS)

    Tateishi, Hiroshi; Schmidt, C.

    1992-01-01

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

  12. 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.

  13. Superconducting and hybrid systems for magnetic field shielding

    International Nuclear Information System (INIS)

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

    2016-01-01

    In this paper we investigate and compare the shielding properties of superconducting and hybrid superconducting/ferromagnetic systems, consisting of cylindrical cups with an aspect ratio of height/radius close to unity. First, we reproduced, by finite-element calculations, the induction magnetic field values measured along the symmetry axis in a superconducting (MgB 2 ) and in a hybrid configuration (MgB 2 /Fe) as a function of the applied magnetic field and of the position. The calculations are carried out using the vector potential formalism, taking into account simultaneously the non-linear properties of both the superconducting and the ferromagnetic material. On the basis of the good agreement between the experimental and the computed data we apply the same model to study the influence of the geometric parameters of the ferromagnetic cup as well as of the thickness of the lateral gap between the two cups on the shielding properties of the superconducting cup. The results show that in the considered non-ideal geometry, where the edge effect in the flux penetration cannot be disregarded, the superconducting shield is always the most efficient solution at low magnetic fields. However, a partial recovery of the shielding capability of the hybrid configuration occurs if a mismatch in the open edges of the two cups is considered. In contrast, at high magnetic fields the hybrid configurations are always the most effective. In particular, the highest shielding factor was found for solutions with the ferromagnetic cup protruding over the superconducting one. (paper)

  14. Magnetism and superconductivity in Eu(Ho)Mo/sub 6/S/sub 8/

    Energy Technology Data Exchange (ETDEWEB)

    Capone, D.W. II; Lai Fook, M.S.; Guertin, R.P.; Hinks, D.G.; Dunlap, B.D.; Foner, S.; Abou-Aly, A.I.; Brooks, J.S.

    1984-10-01

    A variety of ambient and high pressure experimental results reveal the interplay between magnetism and superconductivity in Ho doped samples of the pressure induced superconductor, EuMo/sub 6/S/sub 8/. Ho concentrations up to 50 atomic percent of the rare earth ions were used. High resolution magnetic measurements are consistent with the crystalline electric field ground state for the Ho/sup 3 +/ ions being a magnetic doublet consisting largely of J/sub z/ = 18. The results of high pressure magnetization experiments reveal negligible effects of reduced lattice constant on the rare earth-rare earth interactions. Resistivity in a 10 atomic percent sample for P = 10 kbar shows the suppression of a P = 0 structural transition, metallic conductivity down to low temperatures, and finally superconductivity at 8 K. The upper critical field, H/sub c2/(T), for this sample was measured for P = 7, 10 and 12 kbar and showed strong reentrant behavior (dH/sub c2/(T)/dT > 0 as T ..-->.. 0 K). A minimum with field in the resistivity above H/sub c2/ was also observed at lowest temperatures. The H/sub c2/(T) data are compared with those of EuMo/sub 6/S/sub 8/ at high pressure, which shows positive curvature, and HoMo/sub 6/S/sub 8/, in which superconductivity is quenched by ferromagnetism at low temperatures. 14 references, 4 figures.

  15. Magnetism and superconductivity in Eu(Ho)Mo6S8

    International Nuclear Information System (INIS)

    Capone, D.W. II; Lai Fook, M.S.; Guertin, R.P.; Hinks, D.G.; Dunlap, B.D.; Foner, S.; Abou-Aly, A.I.; Brooks, J.S.

    1984-10-01

    A variety of ambient and high pressure experimental results reveal the interplay between magnetism and superconductivity in Ho doped samples of the pressure induced superconductor, EuMo 6 S 8 . Ho concentrations up to 50 atomic percent of the rare earth ions were used. High resolution magnetic measurements are consistent with the crystalline electric field ground state for the Ho 3+ ions being a magnetic doublet consisting largely of J/sub z/ = 18. The results of high pressure magnetization experiments reveal negligible effects of reduced lattice constant on the rare earth-rare earth interactions. Resistivity in a 10 atomic percent sample for P = 10 kbar shows the suppression of a P = 0 structural transition, metallic conductivity down to low temperatures, and finally superconductivity at 8 K. The upper critical field, H/sub c2/(T), for this sample was measured for P = 7, 10 and 12 kbar and showed strong reentrant behavior (dH/sub c2/(T)/dT > 0 as T → 0 K). A minimum with field in the resistivity above H/sub c2/ was also observed at lowest temperatures. The H/sub c2/(T) data are compared with those of EuMo 6 S 8 at high pressure, which shows positive curvature, and HoMo 6 S 8 , in which superconductivity is quenched by ferromagnetism at low temperatures. 14 references, 4 figures

  16. Design and operation of the quench protection system for the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Martin, P.S.

    1986-05-01

    A method is required to protect the magnets of a superconducting accelerator from possible overheating or overvoltage conditions in the event that some magnets quench, that is, are elevated in temperature such that they are no longer superconducting. A brief discussion of the basic properties of superconductors and the phenomenon of quench propagation is given, followed by the configuration of a quench protection system for the Fermilab Tevatron

  17. Study on industrial wastewater treatment using superconducting magnetic separation

    Science.gov (United States)

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

    2011-06-01

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

  18. Superconducting magnet for a Ku-band maser.

    Science.gov (United States)

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

    1972-01-01

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

  19. Modeling the static fringe field of superconducting magnets.

    Science.gov (United States)

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

    2001-05-01

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

  20. 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.