Search

A superconducting joint for multi-filamentary Bi2Sr2Ca2Cu3O10+ δ (Bi2223) tape, which has applications in nuclear magnetic resonance and magnetic resonance imaging, has been developed based on incongruent melting and multi-junction methods. In this study, the critical current limit, optimal oxygen annealing conditions, and reproducibility of this joint are experimentally evaluated. The results indicate that the critical current limit of the joint at 77 K is determined by that of the tape. The critical current limit was estimated to be about 40 A. Additional oxygen annealing after heat treatment below 1143 K. appears to have no effect on the critical current, and that above 1153 K slightly increases the critical current. It is found that the multi-junction method effectively increases the reproducibility of obtaining a high critical current. To obtain a high critical current at 77 K, the highest temperature in the joint creation process should be lowered to near the incongruent melting temperature of Bi2223 (about 1133 K in air). Two Bi2223 coils, each with one joint (four junctions), were prepared and their persistent current at 77 K was tested. A persistent current of above 20 A was measured with a resistance of about 10 pΩ. [ABSTRACT FROM AUTHOR]

Predicting analytically the coupling losses generated in a cable for fusion magnets is still a significant challenge. Difficulties are related to the complex geometry of the system: several multi-strand stages embedded in one another with different twist pitches length, difficulty to model multiplets of strands, including compaction to the final shape. A two-stage analytical geometry based model (COLISEUM) has previously been developed at CEA. We try to extend it to any n-stage cables We detail here an iterative enhancement method to an n-stage model. We validated it against experimental data and shown that it is robust enough to fit our measured coupling losses. Finally, this upgraded model can be used to assess coupling losses in fusion n-stage cables in a particularly precise way from only geometrical information and analytical tools. [ABSTRACT FROM AUTHOR]

The paper proposed double-sided superconducting linear generator with YBCO tape windings. An analytical model of linear generator was developed based on electromagnetic field theory. A parameter-scanning method is used to search for optimal dimension parameters with the purpose of minimizing the non-sinusoidal components of the induced voltage curve. The results obtained show a significant improvement in the quality of air-gap magnetic field, and reduction of the higher harmonic in voltage wave obviously. The induction voltage in the generator coils at the speed of 130 m/s are studied. Finally, the feasibility of the superconducting linear generator was analyzed and confirmed. [ABSTRACT FROM AUTHOR]

In this article, the operating current and torque of surface-mounted permanent magnet (SPM) wind power generators with high-temperature superconducting (HTS) armature windings are analyzed. The influence of coil location and current angle on the electromagnetic performance is investigated systematically. The results show that the location of the HTS coils significantly affects the operating current and torque. Furthermore, the maximum torque current angle of SPM wind power generators with HTS armature windings can be different from 180° due to the interaction between the armature and magnet fields. A design optimization method for wind power generators with HTS armature windings is developed in this article. The optimal design is then identified with consideration of the coupling influence of coil location and current angle. [ABSTRACT FROM AUTHOR]

The aim of this article is to develop a risk management procedure, which could be applied to the magnet design process, for both superconducting and normal magnets at the Jefferson Laboratory (JLab). This procedure allowed us to identify the key risks at each of the critical phases of design and propose procedures, tests, and checks to mitigate each risk. In this article, we present a qualitative and quantitative risk management procedure commonly referred to a “failure modes and effects analysis.” As part of this procedure, we calculated a risk priority number (RPN) for each activity of the process, identified the most critical activities and proposed mitigation activities, which in turn resulted in a revised RPN. Another benefit of this procedure was the identification of appropriate “control and hold” points within the design process, which allowed one to review and approve a particular outcome before proceeding to the next sequential activity. [ABSTRACT FROM AUTHOR]

When a quench occurs, a fast discharge resistor (FDR) system is required to dissipate the huge energy stored inside a superconducting magnet during the quench protection (QP) process. The FDR system design is a challenging element in the overall QP scheme, due to the necessity of protecting the superconducting magnet, especially under the condition of large current and high energy. In this article, a novel conceptual design of the FDR system with parameter variance is put forward. The design can meet the stable operating requirement under extremely large currents up to 100 kA. The system structure can also be altered to provide specific power characteristics to meet the QP energy transfer demand. In this article, the working condition of the QP process is introduced first and the structure design is illustrated. Then, the layout, structure, material, and stability of a single resistor module are described. Finally, the simulation process with FEA is presented to verify the feasibility of the FDR system design. By analyzing the conceptual design of the FDR system, it is shown that the conceptual design can be acceptable and economical for the energy transfer and consumption for superconducting magnets in fusion devices. [ABSTRACT FROM AUTHOR]

In this article, a new method of spacecraft travelling in outer space is considered. It consists in using the magnetic field and the gravitational field of the celestial bodies of the Solar System, with the help of a new engine (consisting of a superconducting magnet and an electric jet propulsor). The superconducting magnet is made as sealed toroidal hollow balloon whose surface is covered with a thin layer of superconductor. When the spacecraft moves near a celestial body, the flux of the magnetic field changes and it leads to the appearance of an electromotive force. As a result, a superconducting magnet produces an electric current, which is used to operate an electric jet propulsor. It is shown that the thrust force of the electric jet propulsor can exceed the braking force (which acts on a superconducting magnet), and the spacecraft increases the flight velocity. The proposed engine is appropriate to be used when exercising Oberth maneuver when a spacecraft falls into a gravitational well and its velocity fall reaches a maximum value. The obtained results show that the creation of new engines can be a promising direction in the development of space technology. [ABSTRACT FROM AUTHOR]

This paper presents an electromagnetic design of a permanent magnet superconducting wind power generator with different stator teeth structures and armature winding arrangements. The main contribution of this paper is that a novel stator configuration is proposed, which is beneficial for superconducting machines. The topology of tapering poles makes it possible for the machine to carry larger current without severe magnetic saturation in the stator teeth. Meantime, the distributed arrangement of wires in the stator slot can reduce the ac loss in the same output power condition. Finite element analysis with commercial software is used to support these results. [ABSTRACT FROM AUTHOR]

The SC200 proton therapy facility is consisting of a superconducting cyclotron, a gantry treatment room and a fixed beam room. The proton beams are transported mainly with beam transport devices, such as dipole magnets, quadrupole magnets, and corrector magnets which lie on the beam transport line layout of which is based on the beam optics design. A series of dipole, quadrupole, and corrector magnets ultimately make high-quality transmission of proton beams possible. Dipole magnets are mainly for beams deflection, quadrupole magnets are for beam focusing, and corrector magnets for orbit correction of beams. This paper shows the design of such magnets for the beam transport line. Besides, main parameters of magnets are presented and magnetic analysis work is also illustrated in this paper. The magnetic fields of dipole and quadrupole magnets are measured by hall mapping system and rotary coil measuring system. The results show that the measuring results are a little worse than the simulation results. However, both methods can meet the design requirement and the basic trend is similar to each other. [ABSTRACT FROM AUTHOR]

Highlights • A novel method to cool superconducting magnet by using Stirling cooler is proposed. • The Stirling cryocooler is capable of providing 1048 W cooling power at 77 K. • Cooling processes of superconducting magnet by different cryocoolers are compared. • STL2 needs 23 days to cool a 30-ton superconducting magnet from 300 K to 40 K. Abstract Superconducting magnets have been widely applied in medical, transportation, scientific research, power storage and transmission systems, etc. The mass of superconducting magnets is often large in applications, so the cooling process is frequently quite slow. A novel method to speed up the cooling process by applying a large cooling capacity Stirling cryocooler is studied. The present cooling system consists of a Stirling cryocooler, a cryofan, and accessories, using helium gas as the circulating cryogen. A single-stage Stirling cryocooler is developed and it can provide 1048 W cooling power at 77 K with a relative Carnot efficiency of 26.1%. Under ideal conditions, the cryocooler is able to cool a 30-ton superconducting magnet from 77 K to 40 K in 59.7 h, which is faster than GM cryocooler. Considering the heat transfer temperature difference and heat leakage, the Stirling cryocooler needs 23 days to cool a 30-ton superconducting magnet from 300 K to 40 K. Furthermore, compared with the cooling process with liquid nitrogen and helium, this method makes the operation cleaner, simpler and more controllable. [ABSTRACT FROM AUTHOR]

Smart grids are a concept which is evolving quickly with the implementation of renewable energies and concepts such as Distributed Generation (DG) and micro-grids. Energy storage systems play a very important role in smart grids. The characteristics of smart cities enhance the use of high power density storage systems, such as SMES systems. Because of this, we studied the possibility of adapting these systems in this kind of electrical topology by simulating the effects of an energy storage system with high power density (as SMES). An electrical and control adaptation circuit for storing energy was designed. The circuit consisted of three blocks. The first one was a passive filter LCL. The second was a converter system that allows rectifying of the signal when the system runs in charge mode but acts as an inverter when it changes to discharge mode. Finally, there is a chopper that allows the current levels to be modified. Throughout simulations, we have seen the possibility of controlling the energy supply so as the storage. This permits to adapt to different contingencies which may induce the wiring of the charge in the net, as well as different types of charges. Despite the technical contribution of this kind of systems in the Spanish electrical network, there are big obstacles that would prevent its inclusion in the network, such as the high cost of manufacturing and maintenance compared with other cheaper systems such as superconductors or the low energy density, which limits their use. [ABSTRACT FROM AUTHOR]

Superconducting devices have emerged in many applications during the last few decades. They offer many advantages, including high efficiency, compact size, and superior performance. However, the main drawback of these devices is the high cost. An option to reduce the high cost and improve the cost-benefit ratio is to integrate two functions into one device. This paper presents the superconducting fault current limiting transformer (SFCLT) as a superior alternative to normal power transformers. The transformer has superconducting windings and also provides fault current limiting capability to reduce high fault currents. The SFCLT is tested in two power system models: a 7 bus wind farm-based model simulated in PSCAD and on the 80 bus simplified Australian power system model simulated in real-time digital simulator. Various conditions were studied to investigate the effectiveness of the fault current limiting transformer. [ABSTRACT FROM AUTHOR]

Coupling losses induced in cable-in-conduit conductors (CICC) when subject to a time-varying magnetic field are a major issue commonly encountered in large fusion tokamaks (e.g., JT-60SA, ITER, DEMO). The knowledge of these losses is crucial to determine the stability of CICC but is yet difficult to achieve analytically (thus in a short computation time) given the specific and complex architecture of these conductors although numerical solutions such as THELMA and JACKPOT already exist. In an attempt to ease the resolution of this problem, we have previously presented a theoretical generic study of a group of elements twisted together (representing a cabling stage of a CICC) and derived the analytical expression of its coupling losses. We have now extended this study to a two cabling stage conductor by establishing an analytical model to calculate its coupling losses as function of its effective features. In a second part, we compare our results to these of THELMA and JACKPOT on geometries representing ITER CS and JT-60SA TF conductors. Finally, we have set up a specific algorithm to reconstruct strand trajectories from X-ray images and have extracted the effective geometrical parameters of a JT-60SA TF conductor. Our next objective is then to extract its effective electrical parameters from interstrand resistivity measurements to be able to compare the coupling losses predicted by our analytical model with those measured within the SULTAN facility. [ABSTRACT FROM AUTHOR]

A strong field and short period undulator can be a desirable light source device in a storage ring or a free-electron laser. Bulk YBCO can be used to construct a high-temperaturesuperconducting undulator in a staggered array structure. The YBCO material in form of 32 mm diameter and 2.5 mm thick was used to assemble a staggered magnet array. The period length is 5 mm and the magnet gap is 4 mm. To estimate the strength of a sinusoidal field and to optimize the end-pole design to minimize the first (i.e., electron angle) and second field integral (electron position), an energy-minimization method (EM-method) based on Bean's model to simulate the field trapped in the HTS-Block is introduced. In this paper, we focus on promoting the practical value of the EM-method simulation. Combining the experimental experience of a YBCO staggered undulator and the simulation experience based on the EM-method, we address some issues to enhance the efficacy of this undulator design. [ABSTRACT FROM AUTHOR]

The Muon Ionization Cooling Experiment located at Rutherford Appleton Laboratory in England utilizes a superconducting solenoid system for the muon cooling channel that also holds particle-tracking detectors and muon absorbers inside their bores. The solenoid system installation was completed in summer of 2015 and after commissioning the system it has been running successfully. This paper summarizes the commissioning results and operational experience with the magnets focusing on the performance of the two spectrometer solenoids built by the U.S. [ABSTRACT FROM AUTHOR]

The Mu2e experiment at Fermilab plans to search for charged-lepton flavor violations by looking for neutrino-less muon to electron conversions in the field of the nucleus. A complex solenoid system and precise knowledge of its magnetic field play a major role in the experimental approach Mu2e has chosen. It is essential to map the solenoid field up to 10-4accuracy. This article describes the design of the Field Mapping System Mu2e will use to measure the magnetic field. Two different mechanical mapper systems, a survey-based position determination of the inhouse calibrated three-dimensional Hall probes, a motion control system, and a data acquisition and readout system are presented. [ABSTRACT FROM AUTHOR]

A next step of energy increase of hadron colliders beyond the LHC requires high-field superconducting magnets capable of providing a dipolar field in the range of 16 T in a 50-mm aperture with accelerator quality. These characteristics could meet the requirements for an upgrade of the LHC to twice the present beam energy or for a 100-TeV center of mass energy future circular collider. This paper summarizes the activities and plans for the development of these magnets, in particular within the 16 T Magnet Technology Program, the WP5 of the EuroCirCol, and the U.S. Magnet Development Program. [ABSTRACT FROM AUTHOR]

Superconducting magnetic bearings may be utilized for various applications. In recent decades, efforts have been made to design new structures for specific applications. One of the most important issues in superconducting magnetic bearings design is the superconducting part. In this paper, a novel design is presented for rotational bearing systems, in which the superconducting discs are used instead of superconducting cylinders of classic rotational structures. The proposed structure provides the advantages of easy fabrication, lower superconductor volume and therefore lower cost, easy extension for large scale applications and higher mechanical strength. The levitation force of the proposed design is investigated via finite element method and compared to bearing systems with superconductor cylinders in the stator part. Prototypes have been fabricated and experimental tests have shown good consistency with the simulation results. [ABSTRACT FROM AUTHOR]

On the wheel-rail supported hybrid railway system, the linear synchronous motor (LSM) for very high-speed transit must be a system that can maintain a large air gap, and the maximum vertical displacement must be taken into consideration in designing the LSM. As such, this paper designs two small-scale LSM models that produce equal output power—one with the normal-conducting magnet and the other with the superconducting magnet. In addition, this paper conducts a comparative analysis of the various characteristics by applying the electromagnetic numerical analysis method. Furthermore, this paper manufactures two small-scale LSM prototypes which have the normal-conducting magnet and the superconducting magnet, while also conducting a no-load and load test. Through such comparisons, this paper attempts to verify the characteristic values of the two models. [ABSTRACT FROM AUTHOR]

The magnet system is one of the critical core components of the ITER magnets, defining the machine capabilities to form and drive 15 MA 500 MW nuclear plasmas for hundreds of seconds. The magnets, the largest superconducting magnet system ever built with 50 GJ of stored energy, are technologically highly advanced components using large composite Nb3Sn 4–6 K force flow cooled conductors that, in order to maximise plasma performance and minimise cost, stretch current manufacturing technology to its limits. They work at the highest possible electrical (20–30 kV), mechanical (primary stresses up to 600 MPa) and superconducting performance consistent with very safe and very reliable operation over the life of the machine. The magnets, and the associated feeder system, are now entering the final manufacturing stages. Almost all prototyping and qualification work is completed, the sub-components such as the conductors are nearly fully manufactured (over 80% complete), some of the coil production lines are nearly fully ‘loaded’ and in several cases the ‘first of a kind’ final winding packs are nearing completion. In this article we review the main manufacturing difficulties that have been overcome, summarise the present production status of the magnets and describe the coming challenges of testing and assembly. [ABSTRACT FROM AUTHOR]

In order to enhance the beam efficiency of the J-PARC main ring, installation of a new ring is being considered. The new ring, which can accommodate up to 30-GeV proton beam, enables to operate the fast and slow extractions simultaneously with the maximum throughput. Use of superconducting transmission line magnets is proposed as bending magnets for the new ring. Design study of the magnets has started. This paper reports on the brief concept of the new ring, requirements to the magnets, and the status of the design study [ABSTRACT FROM PUBLISHER]

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

A four-layer canted-cosine-theta 16-T dipole has been designed as a possible candidate for future hadron colliders. The design maintains part of the future-circular-collider magnet requirements, i.e., a 50 mm clear bore and 16 T operating at 1.9 K. The magnet intercepts Lorentz forces with an internal structure of ribs and spars, minimizes conductor, and reduces the number of layers and magnet size by using wide cables. The role of iron and its impact on field and magnet size is discussed. A three-dimensional magnetic analysis was carried out for 1-in-1 and 2-in-1 designs including a structural analysis for the 1-in-1 case. Thoughts on future improvements during winding are also discussed. [ABSTRACT FROM PUBLISHER]

A key challenge for a future circular collider (FCC) with centre-of-mass energy of 100 TeV and a circumference in the range of 100 km is the development of high-field superconducting accelerator magnets, capable of providing a 16 T dipolar field of accelerator quality in a 50 mm aperture. This paper summarizes the strategy and actions being undertaken in the framework of the FCC 16 T Magnet Technology Program and the Work Package 5 of the EuroCirCol. [ABSTRACT FROM PUBLISHER]

The current capacity of superconducting materials is far larger than that of copper. This paper utilizes MgB2 wires as stator armature windings to obtain a higher output power capacity and presents the electromagnetic design of a direct drive dual-stator superconducting permanent magnet (PM) wind power generator of several megawatts. Considering the irreversible demagnetization in PM materials caused by the huge stator current, several new rotor pole configurations are presented. The features of each configuration are discussed, and the finite element method results show that the output power capacity of the proposed generator can be raised by 8% because the stator current can be larger for the generator with new rotor configurations under the restriction of demagnetization. [ABSTRACT FROM AUTHOR]

A critical component of the 1.3-GHz nuclear magnetic resonance magnet (1.3 G) program, currently ongoing at the Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology, and now approaching its final stage, is the all high-temperature superconductor 800-MHz insert (H800). The insert consists of three nested double-pancake (DP) coils fabricated with 6-mm-wide REBCO conductor. Coil 1, the innermost coil of H800, has already been fabricated and tested at 77 and 4.2 K. In addition, one third of the DPs for Coil 2 have been wound and each DP individually fully tested. Work described here includes details of Coil 1 fabrication: DP winding, DP testing, assembling, joint performance, overbanding, and coil testing; winding details of DPs for Coil 2 and their testing are also included. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM PUBLISHER]

A multilayer high field dipole magnet has been designed for future particle accelerators. The magnet has eight layers of a \Nb3\Sn outsert coil and four layers of a Bi-2212 insert coil (see Figs. 1 and 2). The layers are graded, delivering a short-sample field of 17.7 T in a 40-mm bore. The coil layers are of a canted cosine–theta design—with ribs and spars that guide and support the coil windings, shape the field, intercept Lorentz forces, and minimize conductor prestress. We present a general overview of the concept and report on the magnetic and mechanical design including an initial cost estimate and construction plan. [ABSTRACT FROM PUBLISHER]

In Free Electron Lasers (FEL), the electron trajectory through the undulator must meet stringent requirements in terms of trajectory wander and phase variation. This paper analyzes the feasibility of using line current pairs as correctors for superconducting undulators given a set of expected fabrication errors. A tolerance study has first been performed to investigate the impact of geometrical errors on the field quality. These errors are corrected with line currents that increase or decrease the magnetic field locally. Once the uncorrected trajectory is known, an algorithm finds the minimum number of correctors required to fulfill the trajectory specifications, and gives the corrector locations. All the correctors can be powered with the same current, greatly simplifying the implementation. The current then offers a degree of freedom to correct the trajectory and can be tuned dynamically as a function of the magnetic deflection. [ABSTRACT FROM PUBLISHER]

The Mu2e experiment at Fermilab has been approved by the Department of Energy to proceed with the development of the preliminary design. Integral to the success of Mu2e is the superconducting solenoid system. One of the three major solenoids is the detector solenoid that houses the stopping target and the detectors. The goal of the detector solenoid team is to produce detailed design specifications that are sufficient for vendors to produce the final design drawings, tooling and fabrication procedures and proceed to production. In this paper we summarize the reference design of the detector solenoid. [ABSTRACT FROM PUBLISHER]

JT-60SA is foreseen in the Broader Approach Agreement as the satellite tokamak for ITER. It uses 18 toroidal field coils, a central solenoid with four modules, and six equilibrium field coils. The coils are all superconducting with forced-flow cooled conductors. Series production of conductors and coils is progressing in Japan and Europe. This paper shows the latest manufacturing activities of the magnet system and its utilities. [ABSTRACT FROM PUBLISHER]

A solid understanding and accurate analysis of the voltage transients in the quench process of superconducting magnets is the basis for verifying quench protection system design. This paper presents an analysis of the voltage spike that triggered a quench in a serially connected set of superconducting solenoid magnets, which are protected by a stack of cold diodes and dump resistors. The voltage development associated with the normal zone growth is analyzed. The magnets were trained close to the full design current and all the terminal voltages of the coils were captured by a specialized quench detection system. In the analyses described in this paper, the different stages of the voltage transient development will be detailed. Comparisons of simulations and the training results are provided to substantiate the mechanism of the quench voltage behavior in this passive protection scheme. [ABSTRACT FROM PUBLISHER]

Red mud (RM) accumulated over the years and caused a serious environmental problem. Iron-rich fraction separation is a cost-effective way to reduce the amount of disposal RM. A circulating high-gradient superconducting magnetic separator was produced in this work. Steel wool was filled in the circulating boxes. The boxes were connected by two chains, which moved in and out the magnetic field by a drive motor. The efficiency of iron-rich RM separation by the superconducting magnetic separator was investigated. An amount of 25% (w/w) iron-rich RM fractions with a grade of 65% were separated from the 56% iron content raw RM. The parameters of the steel wool matrix were important in controlling the iron-rich RM magnetic separation. Finer steel wool increased the iron recovery ratio, but decreased the grade of the iron-rich RM concentrates. Microscopic photographs of the RM particles showed that opaque mineral particles were enriched in the collected RM. The particle size distributions of raw, concentrate and residue RM were measured. The increased particle size of concentrate RM implied that large particles were entrapped in the steel wool matrix. [ABSTRACT FROM PUBLISHER]

Abstract: General expressions of Ampere-Turns for superconducting dipole and quadrupole magnets based on sector coils are proposed. According to the magnetic field generated by simplified coil layouts using the line current theory, the required excitation current to achieve the desired field strength in the aperture is calculated. The contribution of magnetic field by an iron yoke is taken into account by using the image current method. The validity of derived equations is confirmed by applications to main superconducting magnets which have been built in several high energy accelerators. The proposed analytical expressions provide a simple relationship among the bore field, main dimensions of the magnet, and the total excitation current. These expressions are complementary to the existing method in the electromagnetic design, and are shown to be quite similar to those of conventional magnets. Finally, the comparison of Ampere-Turns between superconducting magnets and conventional magnets is presented. [Copyright &y& Elsevier]

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

Abstract: A novel neutron spin-echo spectrometer with superconducting main coils enabling enclosure by a double walled -metal magnetic shielding chamber has been built and set into operation at the spallation neutron source in Oak Ridge. The layout of the spectrometer is described. Performance with emphasis on the superconducting main solenoids and the time-of-flight operation is described. Data on resolution, stability and first experiments are shown. [Copyright &y& Elsevier]

Numerical simulation of the superconducting magnetically levitated bogie (JR Maglev) has been studied. The electrodynamic suspension is used for levitation and guidance. Although this suspension needs no gap control, the damping factor of the system is shown to be small. In Japan, the ground condition is not good. When the bogie passes the vertical displacement of the guideway, oscillation of the bogie occurs. And this oscillation does not converge immediately. The damper coil system is introduced to increase damping of the levitation system. Running simulation of the bogie when the bogie passes the guideway displacement is undertaken. The damper coil decreases the oscillation of the bogie. To increase the damping factor, the semi-active system is considered. This system shows large effect against oscillation of the bogie. [ABSTRACT FROM PUBLISHER]

Superconducting magnet is a key component of Superconducting Magnetic Energy Storage (SMES), so it is necessary to investigate into the characteristics of superconducting magnet before the SMES run in power system. In the paper, a superconducting hybrid magnet based on YBCO wires and BSCCO wires, which were from Superpower and American Superconductor Company respectively, was designed and produced, and then through the cooling test, critical current test, energy storage test, ground insulation test and exchanging power experiments with power system, the electrical specifications and low temperatures insulating performance of the superconducting magnet were investigated. The results proved that the performance of the hybrid magnet satisfied the design requirements. [ABSTRACT FROM PUBLISHER]

The planned upgrade of the LHC collimation system includes additional collimators to be installed in the dispersion suppressor areas of points 2, 3 and 7. To provide the necessary longitudinal space for the collimators, a replacement of 8.33 T Nb-Ti LHC main dipoles with 11 T dipoles based on Nb3Sn superconductor compatible with the LHC lattice and main systems is being considered. To demonstrate this possibility FNAL and CERN have started a joint program to develop a 2 m long single-aperture dipole magnet with the nominal field of 11 T at \sim11.85 kA current and 60 mm bore. This paper describes the demonstrator magnet magnetic and mechanical designs and analysis, coil fabrication procedure. The Nb3Sn strand and cable parameters and test results are also reported. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM PUBLISHER]

The Korea Superconducting Tokamak Advanced Research (KSTAR) device is aimed at advanced tokamak (AT) research. Three years have passed since it achieved its first plasma in 2008. Because it is a superconducting machine and is working toward AT research, it has unique features in terms of the machine engineering and operation. The toroidal field (TF) magnet coils are made of \Nb3\Sn, which provide high TFs up to 3.5 T, and have been fully tested. The poloidal field (PF) magnet coils, consisting of both \Nb3\Sn and NbTi, which have a maximum current of 25 kA in their design, were tested up to 15 kA. A thermal hydraulic analysis is being conducted for PF magnet coil operation. All plasma-facing components (PFCs) are equipped with water cooled graphite tiles and have the capability of being baked up to 350 ^\circ\C. A startup scenario, which considered both the effect of the ferromagnetic material in the cable in conduit conductor jacket of the magnet coils as well as a nonferromagnetic up-down asymmetry in the cryostat structure, was developed and demonstrated its effectiveness by the last two year's reliable operations. Passive stabilizers and in-vessel control coils (IVCCs) are key components to realize AT operation in KSTAR. The segmented IVCC coils were connected to form circular coils for internal vertical control in 2010, and diverted plasmas with high elongation (\kappa \sim 1.8,\ \delta > 0.6) were achieved. A neutral beam injection (NBI) system was developed aiming at 2 MW, 300 s per ion source which meets the long-pulse requirement of KSTAR. An NBI ion source with a power of 1.7 MW at 100 kV has been commissioned for 10 s. Finally, ELMy H-modes were successfully produced with 1.3-MW NBI power at a plasma current of 0.6 MA in the 2010 campaign. The first H-mode discharge (#4200) in KSTAR was achieved one year earlier than officially planned and was done at BT = 2\ \T with Ip = 0.6\ \MA in a well-balanced double null configuration after boronization on the PFC. Successful operations in the early days of KSTAR including H-mode experiments revealed the capability of advanced and steady-state operation which is essential for the international thermonuclear experimental reactor (ITER) and future fusion reactors. [ABSTRACT FROM PUBLISHER]

This paper presents a new structure of an induction heater for aluminum billets. The device consists in using a strong direct-current magnetic field created by a superconducting inductor in which the conducting billet is actuated by a linear motion at a constant velocity. The analysis, which is based on the analytical model for the magnetic field in the billet, has been developed, and then, the eddy currents and the induced heating power have been evaluated. The analytical results are compared with those issued from the finite-element software (COMSOL). The magnetothermal analysis shows that the temperature profile in the billet is homogenous. [ABSTRACT FROM AUTHOR]

The prospect of medium/high field superconducting magnets using 2G HTS tapes is approaching to reality with continued enhancement in the performance of these conductors. Direct measurements of 1D adiabatic quench initiation and propagation of a Cu-stabilized 2G conductor have been carried out with spatial–temporal recording of temperature and voltage following the deposition of various local heat pulses to the conductor at different temperatures between 40K and 64K carrying different transport currents. It was found that the stabilizer-free 2G tape maintains the unique characteristics previously measured in non-stabilized tape of increasing minimum propagation zone, (MPZ), with transport current and higher quench energy at lower temperatures. The minimum propagation zone length is investigated at low temperatures and in a background field of \sim0.1T. The change in MPZ size is discussed in the context of the temperature dependent physical properties including the E–J characteristics. The results add more detail to help understand the unique characteristics of increasing MPZ with transport current and lower temperatures. [ABSTRACT FROM AUTHOR]

Hall B at Jefferson Laboratory (JLAB) will need a 6-coil Torus producing a required integral of B-dl for an upgrade 12 GeV beam. In Sept. 2009, Wang NMR was awarded a contract to design, fabricate, assemble, deliver, and test at JLAB this exciting magnet. [ABSTRACT FROM AUTHOR]

Magnesium diboride (MgB2) shows a wide application prospect in the field of low field DC application for its relatively simple structure and rather higher critical temperature than LTS. With the development of MgB2 composite superconductor manufacturing technology and cryogenic technology, developing conduction cooled superconducting MRI system with MgB2 composite superconductor is becoming increasingly feasible. An MgB2 superconducting magnet for MRI was developed. The MgB2 superconducting magnet is used to investigate the fundamental scientific problem of the MRI main magnet, including field uniformity and stability, influencing factors of MgB2 composite superconductor on field uniformity and stability. The superconducting magnet consists of 2 solenoids wound with MgB2 wire with the length of 60 m. The magnet has an outer diameter of 169 mm, an iron core diameter of 135 mm, and air gap of 32 mm. The superconducting magnet is fabricated and tested. The central magnetic field reaches 1.0 T when the current of the MgB2 magnet is 290 A. The central magnetic field is 0.39 T when the current of the MgB2 magnet is 100 A. In this paper, the minimum quench energy, the quench propagation velocity and the minimum propagation zone of the MgB2 composite conductor are measured. Main magnet for MRI with MgB2 composite superconductor is analysed and proposed, including magnet design and test results. By theoretical modeling and simulation, the detailed quench propagation of the magnet is further analysed. Finally, the stability criteria of conduction-cooled MRI magnet are established. [ABSTRACT FROM AUTHOR]

The first production focusing lens for the HINS beam line at Fermilab has been assembled into a cryostat and tested. A total of 5 devices will be tested before they are installed in the low energy section of the HINS beam line, which uses copper Crossbar-H (CH) style RF cavities. One of the tested CH-section lens assemblies includes a pair of weak orthogonal steering dipoles nested within a strong focusing solenoid, and has six vapor cooled power leads. The other device has only the strong focusing solenoid, and utilizes a single pair of HTS power leads. The production test program is designed to measure the thermal performance of the cryostat, minimum cooling requirements for the HTS leads, quench performance of all superconducting components, and precise determination of the magnetic axis and field angles. Results and future plans for the first production device tests are presented. [ABSTRACT FROM AUTHOR]

The high energy sections of the Fermilab HINS R&D proton linac will utilize superconducting spoke resonator (SSR) RF cavities. These will be assembled into cryomodules with strong solenoid focusing lenses closely interleaved with the cavities. A design for lenses has been made for the lower (SSR1) and higher (SSR2) energy ranges of the SSR-section. Prototype lenses for both SSR1 and SSR2 sections have been built and the SSR1 has been tested. Shielding is needed to reduce the solenoid fringe field on the cavity wall below the 10 \muT level, and a preliminary design was built and tested with the SSR1 prototype lens. We discuss the design requirements and challenges, and the results from quench testing and magnetic measurements of the SSR1 prototype lens. [ABSTRACT FROM AUTHOR]

For upgrading the electron-positron collider KEKB, the final focusing magnet system in the beam interaction region has been studied. The designed magnet system consists of five superconducting and three permanent quadrupole magnets. A superconducting quadrupole magnet has been constructed as the R&D of this system. In this paper, design and construction of this R&D magnet are reported. [ABSTRACT FROM AUTHOR]

The development of large multi-pixel detector applications with lumped element kinetic inductance detectors (LEKID) requires a detailed knowledge about the mode of operation in respect of the microwave regime. In this paper the basic properties of LEKID structures for applications at liquid helium temperatures were investigated. In consideration of the operation temperature, the different microwave behavior of LEKID structures coupled to microstrip and coplanar strip readout transmission lines, e.g. loaded and unloaded quality factors, have been examined. For this purpose several test structures, which are suitable for large arrays, in multi-pixel applications, were designed and characterized with frequency around 6 GHz. Loaded quality factors QL up to 10,000 at 4.2 K were achieved. The devices were fabricated in niobium thin film technology on silicon substrates. LEKID arrays with 3 resonators were designed, fabricated and measured with our self-developed FDM readout system. The results of the measurements will be presented and discussed. [ABSTRACT FROM AUTHOR]

Transition-edge sensor microcalorimeter arrays in compact geometries and large formats experience local heating from bias power and x-ray hits that must be dissipated in the frame. For devices on solid, non-perforated silicon substrates, we have introduced an underlying embedded copper heatsinking layer to enhance the ability of the frame to remove this heat. In particular, such a layer can mitigate thermal crosstalk between nearby pixels within the array. Further improvements in array performance, such as decreased magnetic field sensitivity and stray inductance, are possible by turning the heatsinking layer into a superconducting ground plane. In this presentation, we report on the development of heatsinking layers consisting of a 1–2 \mum thick high-quality copper layer which is sandwiched between two thin refractory metal-based diffusion barriers. These diffusion barriers are designed to avoid copper migration into the surrounding material over time, especially during our high temperature TES fabrication process which takes place in excess of 400^\circC. A 0.3–0.5 \mum thick PECVD SiO2 cover layer isolates the heatsinking layer from the detector circuit. We present first results on our attempt to tailor the materials forming the diffusion barrier to fabricate both well defined superconducting ground planes and non-superconducting layers with the desired barrier characteristics. [ABSTRACT FROM AUTHOR]