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The High Energy Photo Source (HEPS) is being built in China and the magnets are in batch production. The octupole magnets with skew quadrupole component used in the storage ring have been designed and manufactured. The octupole has an aperture of 30 mm, a field gradient of 735000 T/m3 and a length of 0.26 m. In this paper, detailed magnetic design of HEPS octupole magnets is presented. Different design schemes of the skew quadrupole coils are compared, and the temperature effect on magnetic center and the integral field in the first batch of octupole magnets are also given. In addition, the influence of the combined power-on mode on the magnetic field is studied. [ABSTRACT FROM AUTHOR]

The 100 T pulsed magnetic field project is under development at the Wuhan National High Magnetic Field Center, Wuhan, China. Using the NI CompactRIO hardware and Lab-VIEW software platforms, a control and data acquisition system (CADAS) for the 100 T pulsed high magnetic field facility is designed and implemented. This paper briefly introduces the design of the control system and presents the aspects of the implementation. The CADAS developed in this paper communicates with three types of power supply systems and controls their discharge coordinately, and records discharge waveforms. It has been put into test, and 67.6 T pulsed magnetic field has been generated by a test three-coil magnet. [ABSTRACT FROM AUTHOR]

A great progress in the electrical performance of high-temperature superconductor (HTS) REBCO tapes allows for a much increased transport current capability in cables especially at high magnet fields. This is of interest to future fusion magnet applications. A variant type of twisted stacked-tape cable called quasi-round twisted stacked-tapes conductor (QisTac) is proposed and developed for the superconducting conductor of the China fusion engineering test reactor. The stack of the twisted HTS tapes is wrapped by a tight spiral made with copper wires. The stack with the copper wire is, then, soldered to form the solid round conductor, which is reliable and easy to manufacture in long lengths. A QisTac sample with four REBCO tapes was prepared and measured at 77 K and in the self-field condition. The measurement result shows the expected critical current calculated from the individual tapes considering the self-field effect. The bending characteristic of the sample was also tested under different bending radii. The critical current is reduced by roughly 5% at 0.54% bending strain. Some residual bending strain is maintained when the maximal bending force is released. This result is promising, but reproducibility testing and tests at high field and current are needed for future high field application. [ABSTRACT FROM AUTHOR]

China fusion engineering test reactor is a new tokamak device, which is one design option under the consideration of the China National Integration Design Group employs superconducting magnets. The main target of this project is to build a self-sufficient fusion engineering tokamak reactor with its fusion power 50–200 MW. Toroidal field coils, center solenoid coils, and poloidal field (PF) coils, whose rated current range from 52.9 to 90 kA, produce the magnetic field for plasma generation and confinement. The core of quench protection unit is to divert the coil current into discharge resistor by using commutation technology, which should be determined by the rated current and voltage requirement of magnets. Different kinds of technologies for quench protection unit (QPU) are considered, and an advanced commutation technology composed of a mechanical bypass switch, vacuum circuit breaker (VCB), and LC commutation circuit based on artificial current zero technology has been worked out to meet the current and voltage requirement (10 kV/100 kA). To provide a faster and more reliable removal of the energy stored in those superconducting coils, this paper analyzes in detail the feasibility of a commutation scheme based on artificial current zero technology by analyzing and simulating each stage of the commutation process at such large rated current and voltage conditions. Both analysis and simulation results verified that the operating reliability of QPU can be guaranteed by this 100 kA dc commutation scheme. [ABSTRACT FROM AUTHOR]

A quasi-continuous high magnetic field is a special kind of pulsed magnetic field with a flat-top field longer than 100 ms. This paper proposes a hybrid power supply that consists of a capacitor power supply and a generator-rectifier power supply. A dual-coil magnet is powered to generate a 65 T/100 ms quasicontinuous high magnetic field with a ripple less than 500 ppm at the Wuhan National High Magnetic Field Center, Wuhan, China. A protection circuit consists of an R-C branch and a diode array is discussed for the worst short-circuit fault, which occurs between the first turns of inner coil and outer coil. This type of faultwill produce oscillation voltage with a high peak value and high frequency on the rectifiers. A self-adaptive PI controller with the coefficients corrected by a back propagation neural network is adopted to reduce the ripple of a flat-top. [ABSTRACT FROM AUTHOR]

A higher magnetic field can provide more opportunities to reveal new phenomena in a scientific research. Aiming to achieve a higher magnetic field, Wuhan National High Magnetic Field Center (WHMFC), Wuhan, China has designed a a power supply system for 100 T magnetic field under existing power supply conditions in April 2015. The 100 T magnet consisting of three coils is energized by a multipower supply system. The outer coil is energized by a pulsed generator-rectifier connected to battery bank in series. The middle coil and the inner coil are energized by two capacitor bank, respectively. To ensure safety and reliable operation, control sequence as well as protection system for the power system is designed and developed. A test system including the prototype of three-coil magnet is established at WHMFC. A series of tests are carried out on hybrid power supply systems. 73.3 T peak field has been achieved as the highest magnetic field in the test. The test results presented in this paper show the hybrid power supply system is feasible and operable. [ABSTRACT FROM AUTHOR]

CYCIAE-100, a 100 MeV H-cyclotron under construction at China Institute of Atomic Energy, is a compact H-cyclotron. Since its upper/bottom and return yokes are each made of a casting steel of large dimension (with final dimension of 6160 mm in diameter and weight of 140 tons each piece), special attention has to be paid to the annealing procedure to insure the magnetic properties of this kind of large scale casting steel pieces with high purity. First, this paper presents an overview of annealing strategies to improve the magnetic properties of large scale casting steel. Then an estimation of heating time during annealing procedure has been made by FEM simulation based on the current status of annealing facility in China and has been indirectly verified by a rule of thumb from the results in TRIUMF design note. Based on that as well as on a close collaboration with CITIC HMC, the manufacturer of large casting steel mill, an agreement on detailed annealing procedure has been reached and issued for production of large casting steel for CYCIAE-100. The results from the practice have been obtained and the detail procedure will be presented in this paper as well. [ABSTRACT FROM AUTHOR]

Chinese Spallation Neutron Source (CSNS) is a facility planned to be built in China in the coming years. It is composed of 80 MeV Linac, 1.6 GeV Rapid Cycling Synchrotron (RCS) and target station. To accelerate the proton beam from 80 MeV to 1.6 GeV, the RCS requires the field of dipole and quadrupole magnets to change with sine waveform of 25 Hz plus a biased DC. For large amplitude AC magnets with large aperture, there are critical issues to be addressed, such as eddy current induced in the magnet yoke, coils and endplates, vibration of the yoke and coil, field tracking between dipoles and quadrupoles, and so on. To study these issues, one prototype dipole magnet and one prototype quadrupole magnet have been developed and tested. In this paper, the design, fabrication and tests of the two magnets will be described. [ABSTRACT FROM PUBLISHER]

It is expected that superconducting technologies will play an important role in the future smart grid, because the application of superconductor technologies in the power grid can decrease power losses, relieve overload, avoid higher levels of transmission voltage, increase power transmission capacity, and improve power quality and grid stability. In recent years, high temperature (high-Tc) superconducting power technologies have achieved remarkable progress. High temperature superconducting (HTS) power equipment, such as HTS power cables, HTS transformers, high-Tc superconducting fault current limiters (SFCL), and high-Tc superconducting magnetic energy storage devices (SMES) have been demonstrated in the power grids of many countries. With the development of HTS power equipment, the construction of a HTS power substation is ready. In China, a 10.5 kV HTS power substation is under construction in Baiyin city, Gansu province. The substation integrates a HTS power cable, a HTS transformer, a HTS fault current limiter, and a high-Tc SMES. All these HTS power devices, which were previously developed by the Institute of Electrical Engineering (IEE), Chinese Academy of Sciences (CAS), have been demonstrated to operate for a long time in the commercial power grid. In this paper, the design and constructing progress of the HTS substation are introduced in detail. [ABSTRACT FROM AUTHOR]

Many applications using accelerator beams require a nearly uniform beam distribution at the target. A nested structure magnet producing a step-like magnet field has been proposed to transform an originally Gaussian or even irregular distribution into a more-or-less uniform one at targets. In this paper, the prototyping of a step-like field magnet is presented, which is based on the application in the China Spallation Neutron Source where the magnets are used to obtain a uniform beam profile from an initially irregular distribution at the spallation target. It includes the magnet design, 3D magnetic field calculation, prototype fabrication and field measurement. The prototyping confirms the technical feasibility of the magnet structure and the magnetic field quality consistent with the field calculations. The design improvements are discussed from the prototyping experience. [ABSTRACT FROM AUTHOR]

The High Magnetic Field Laboratory, Chinese Academy of Sciences is developing a 40 T hybrid magnet. The hybrid magnet cryostat consists of two separate but attached cryostats. The main function of the cryostats is to provide a thermal barrier between the ambient temperature experimental hall and the supercritical helium forced cooled superconducting magnet. It also provides feed-through penetrations for all the connecting elements inside and outside the cryostat. The Outsert Magnet Cryostat is a large vacuum vessel with cylindrical shell, standard elliptical top, and flat bottom. The structural analyses, including buckling, for the cryostat vessel have been carried out using finite element code. Stress analysis results show that the maximum Von Mises stress will be below the allowable value. In this paper, we focus on the structural analyses and design of the cryostat. [ABSTRACT FROM AUTHOR]

Coils for pulsed magnets in the range of 50-75 T are developed with optimized combinations of conductors and reinforcement for the prototype laboratory of the Wuhan High Magnetic Field Center (WHMFC). The basic design tool is a Pulsed Magnet Design Software package (PMDS) for calculating the capacitor discharge, conductor heating, mechanical stresses and the residual stress, including plastic deformation and winding tension. A 1 MJ capacitor bank is equipped with a thyristor switch, a mechanical switch, polarity reversal switches, a current limiting inductor and a diode crowbar. The design and the test results of the magnets, of the protection inductance and of the capacitor bank are presented and discussed in this paper. [ABSTRACT FROM AUTHOR]

A25 kV/40 kA protection inductor with low stray field was designed and the first prototype was fabricated. The protection inductor protected the thyristor switch in the capacitor bank, limit the current at 40 kA in case of a short circuit. It was designed as a toroidal system consisting of 12 coils evenly distributed in the perimeter of a circle. The inductance could be changed easily by adjusting the number of coils. The structure of coils was optimized to withstand the great electromagnetic force produced by the 40 kA current. The coils were wound by a 4 ∗ 45 mm copper strip standing on edge. Each coil was externally reinforced by a stainless steel ring tightly enclosing the coil. The first prototype was fabricated. Its inductance and magnetic field were tested. The prototype has been mounted in the 1 MJ module and is now in operation. In this paper, the structure design, fabrication and testing of a new protection inductor are presented. The testing results are discussed. Tested inductance was 1.05 mH and direct resistance was 16 MΩ. The first prototype was proved to be successful and 13 more protection inductors will be made after some improvements. [ABSTRACT FROM AUTHOR]

A 40 T hybrid magnet system will be built at the Chinese High Magnet Field Laboratory (CHMFL), Chinese Academy of Sciences. It will include a 29 T resistive insert with a clear bore of 32 mm and a 11 T superconducting outsert with a room temperature bore of 580 mm. The superconducting outsert, which will be wound with cable-in-conduit conductors (CICC), is graded in function of the magnetic field. The high field section of the superconducting outsert will use Nb3Sn superconductors and the low field section will be made of NbTi superconductors. At present, the preliminary design of the superconducting outsert has almost been completed. This paper describes features, such as conductor design, coil winding, heat treatment, support structure design, mechanical stress analysis. [ABSTRACT FROM AUTHOR]

The Shanghai Synchrotron Radiation Facility (SSRF) is a third-generation light source with major emphasis on insertion device (ID) sources. In the storage ring there are 20 straight sections, each about six or ten meters in length, for possible insertion devices. Currently there installed three undulators and two wiggler installed in five straight sections [1]-[3]. They were originally designed and fabricated by the Shanghai Institute of Applied Physics (SINAP). A variable polarizing undulator was constructed as the light source of the soft X-rays beamline for SSRF. This local control system consists of a Siemens PLC and a six axis Masterdrive motion controller. Four servo motors control the gap--two on the upper girder and two on the lower girder, and another two servos controls the phase--one on the upper girder outer and one on the lower girder inner. The main control system at the SSRF is experimental physics and industrial control system (EPICS). This paper will discuss in detail the design philosophy and the implementation of the Six-motor insertion device control system. This control system has been in operation for about one year. [ABSTRACT FROM AUTHOR]

After the first man-loading high temperature superconducting (HTS) Maglev demonstration had been tested successfully years ago, its future application attracts more and more researchers and engineers. This paper reviews the recent development of HTS Maglev system in China. In the past seven years, quasi-static forces, dynamic characteristics and running performances have been studied by three self-developed HTS maglev measurement systems and 11-ch vibration measurement apparatus. Some practical problems are considered in details for further engineering application of HTS Maglev train, such as running along the forward direction with inhomogeneous magnetic field, construction cost estimation, propulsion optimization, and so on. On the other hand, a systematic method is introduced to analyze or optimize the force interaction between bulk high temperature superconductor and permanent magnetic guideway. Primary running parameters and data are obtained for the safety design of future HTS Maglev system. Furthermore, a low-mid speed HTS Maglev test line is blue printed with a maximum speed of 100 km/h, which will be the first step of practical HTS Maglev engineering application. [ABSTRACT FROM AUTHOR]

For the superconducting magnet system of the International Thermonuclear Experimental Reactor, ITER, 60 current leads for a total current of more than 2500 kA are needed. The use of High Temperature Superconductor current leads (HTS-CL) will reduce the resultant large refrigerator load considerably. Within the EU Fusion Technology Programme, the Forschungszentrum Karlsruhe and CRPP have developed and built a 70 kA HTS-CL demonstrator optimized for 50 K Helium operation. In 2004-2005, the CL was successfully tested with 50 K as well as 80 K Helium, and finally with LN2. In the meantime, ITER has decided to use HTS-CLs for the magnet system and China has taken the responsibility to provide the sc feeders for ITER including the current leads. In this paper, the performance of a 70 kA HTS-CL in fault conditions will be analysed using the FZK-CRPP demonstrator as a model. In particular, the quench performance and the safety behavior in case of a loss-of-flow accident (LOFA) will be described and an extrapolation of the leads performance in real ITER conditions will be given. Finally the effect of different shunt materials is discussed. [ABSTRACT FROM AUTHOR]

With strong support from Chinese government bodies such as the National High Technology Research and Development Program of China, National Natural Science Foundation of China and the National Basic Research Program of China, the field of applied superconductivity in China has been developed in different areas. Especially in the fusion application area, the first fully-superconducting tokamak, EAST (Experimental Advanced Superconducting Tokamak), has been successfully constructed and commissioned in the last two years. Based on the requirement from the ITER project, high performance Bi-2223 HTS tape, and Nb3Sn and NbTi strands have been developed as well. In the area of HTS applications for electric power systems, R&D has been focused on superconducting power cable, superconducting magnetic energy storage, superconducting transformer, superconducting fault current limiters. In this paper, the recent progress in applied superconductivity in China is reported. [ABSTRACT FROM AUTHOR]

In this paper, the design, fabrication and tests of a 1 MJ HTS magnet for SMES was presented. The magnet was fabricated by BSSCO tapes, it consisted of 44 pancakes, the inner diameter of the winding is 400 mm, the outer diameter is 568 mm and the height is 648 mm, the inductance is 6.38 H and the rated operation current is 560 A at 4.2 K. The tests show the magnet could be operated at the design parameters. The magnet will be used for the 1 MJ/500 kVA SMES unit which will be demonstrated at a 10 kV substation in Beijing. [ABSTRACT FROM AUTHOR]

A pulsed high magnetic field laboratory has been funded to be established at the Huazhong University of Science and Technology (HUST), Wuhan, China by the National Development and Reform Committee. The facility is planned to be open for external users in 2011 with the implementation of various experimental techniques in pulsed magnetic fields up to 80 T. Pulse durations are in the range from 15 to 1000 ms with the magnet bore sizes from 12 to 34 mm. The pulsed power supplies are a 12 MJ, 25 kV capacitor bank and a 100 MVA/100 MJ flywheel pulse generator. The design and analysis of the power supplies and the magnets of short and long pulse durations and the multi-stage pulsed magnets with controllable waveforms are presented in this paper. [ABSTRACT FROM AUTHOR]

A pair of dual-purpose superconducting quadrupole magnets and a superconducting detector solenoid were fabricated and installed in Beijing Electron-Positron Collider Upgrade (BEPCII). The magnets are symmetrically inserted into the BESIII detector with respect to the interaction point. They are identical, iron-free, non-collared, multi-layered and active shielded superconducting magnets for the micro-beta focusing at the interaction region of the collider rings. Each quadrupole magnet is composed of seven coils at different operating currents wound layer by layer on a common cylindrical support. The magnet has an overall effective length of 0.96 m and provides a good field aperture of 65 mm in diameter. They are cooled by supercritical helium in order to eliminate the flow instabilities in constrained cooling channels. The BESIII superconducting solenoid magnet was designed to provide an axial magnetic field of about 1.0 T over the' tracking volume and to meet the requirement of particle momentum resolution to particle detectors. A single layer of coil, in-direct cooling by forced two-phase helium, high purity aluminum based stabilizer and NbTi/Cu superconductor is adopted for the solenoid. The solenoid is 3.4 m in diameter and 3.89 m in length. This paper presents the design of the superconducting magnets in the BEPCII as well as their cryomodules. The cooling system for the magnets is also discussed. [ABSTRACT FROM AUTHOR]

The development of the Maglev train is a very important achievement in passenger transportation for the 20th century. Based on the recent information this paper describes the development of different Maglev systems, the application of Maglev for passenger transportation, and the experience of promoting the Maglev transportation in China. [ABSTRACT FROM AUTHOR]

The significant progresses in high Tc superconducting wires or tapes have excited a great deal of research interests in power application. This paper will review the recent progresses of power application of superconductor in China. An improved bridge-type fault current limiter was tested and a 10.5 kV/1.5 kA demonstrator has been operated at a substation in Hunan Province in 2005. A 75 meter, 10.5 kV/1.5 kA three phase HTS cable has been installed and operated at the Changtong Cable Headquarter in the end of 2004, and a 30 meter, 35 kV/2 kA HTS power cable was installed at substation and has been operated since July 2004. A 10.5 kV/400 V/630 kVA HTS transformer has been installed and operated at TBEA Electric Factory in 2005. A 500 k J/150 kVA SMES unit was developed and tested. 1.0 M J/0.5 MW SMES will be installed in a power grid in 2006. Besides, a new kind equipment of fault-current-limiting SMES is being developed and a 100 kJ/25 kW prototype has been made and tested. [ABSTRACT FROM AUTHOR]

EAST (HT-7U) is a large fusion experimental device being built at IPP, Hefei, China. Its superconducting magnet system consists of sixteen Toroidal Field (TF) coils and fourteen Poloidal Field (PF) coils. The TF coil includes the winding pack with a square cable-in-conduit (CIC) type superconductor in NbTi cooled by a force flow of supercritical helium, the welded case structure, the gravity support which is composed of pedestals with flexible plates, the coil joint with low resistance at high current and other components. At present, the production of all TF coils has been finished and all of the TF coils have been installed in the machine. This paper describes mainly the special fabrication processes of the TF coil. [ABSTRACT FROM AUTHOR]

The projects for large science devices and industrial applications are strongly driving the progress of superconductivity and magnet technology in China. One example is the EAST Tokamak—the biggest superconductivity project in China. The magnet system of EAST consists of twenty-eight large superconducting coils. The technology of superconducting magnet for fusion device is well developed. At same time, three accelerator projects are funded: the HIRFL—CSR, a cooler storage ring for the Heavy Ion Research Facility has been built and its commissioning is starting; the BEPCII High Luminosity Double ring Collider and its superconducting BESIII detector magnet are in progress; The Shanghai Synchrotron Radiation Facility (SSRF) project is going on. The proposed high magnetic field laboratory project would bring along the magnet technology further. The R&D for prototype of power cable, transformer, fault current limiter and SMES show good possibility of application of HTS in the future. The recent development of magnet technology in China is introduced in this paper. [ABSTRACT FROM AUTHOR]

China's first HTS power cable project was started in the second half of 2002 and on site system installation was finished at Puji Substation of China Southern Power Grid in March, 2004. This cable system consists of three 33.5 m, 35 kV/2 kArms cables, six terminations, and a dosed cycle liquid nitrogen cooling station. The conductors of the cables were made of 4 layers of BSCCO 2223 HTS tapes. Off grid field testing and live grid trial operation has been carded out since the completion of the installation. In this paper, we will report the key technical parameters of the system. Descriptions of the installation site, demonstration of the system installation, and results of testing and trial operation will also be presented and discussed. [ABSTRACT FROM AUTHOR]

December 31 2002 the Shanghai maglev demonstration and operation line celebrated its opening ceremony, the world first maglev commercial line born in China. The next maglev development step in China is under active discussion. Based on our past active work to promote the high-speed maglev development and application in China, we suggested that it is needed to make decision that the Beijing-Shanghai high-speed line should select the high-speed maglev option. The present paper describes comprehensively our consideration, including: (1) the quite good foundation for maglev option selection for Beijing-Shanghai line based on the successful construction and operation of the Shanghai demonstration line; (2) the very important significance of selection of the maglev option for Beijing-Shanghai line; (3) the suggestion for the near-future work. [ABSTRACT FROM AUTHOR]