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Compact Superconducting Lookup Table Composed of Two-Dimensional Memory Cell Array Reconfigured by External DC Control Currents IEEE Trans. Appl. Supercond. Pub Date : 2021-01-08 Takuya Hosoya; Yuki Yamanashi; Nobuyuki Yoshikawa
We investigated the hardware implementation of an area-efficient superconducting lookup table (LUT) based on a single flux quantum (SFQ) logic by using a newly proposed small memory cell. The memory cell is composed of a nondestructive read-out (NDRO) flip-flop with input circuits that convert the input dc current to an SFQ pulse signal. The datum can be written to the selected memory cell in the 2-D
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Ginzburg–Landau Calculations for Inhomogeneous Superconducting Films IEEE Trans. Appl. Supercond. Pub Date : 2020-12-28 Pavel I. Bezotosnyi; Kristina A. Dmitrieva; Sergey Yu. Gavrilkin; Alexander N. Lykov; Alexey Yu. Tsvetkov
A method for modeling the superconducting state of an inhomogeneous film is proposed. The superconducting properties are changed by varying Ginzburg–Landau (GL) parameters over the film thickness. A system of 1-D equations was found using the standard minimization of the modified GL-free energy functional to describe the superconducting state of the inhomogeneous plate. Using the proposed method, the
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FCC-hh Conceptual Designs and Windability of the Main Quadrupoles IEEE Trans. Appl. Supercond. Pub Date : 2020-12-18 Clement Genot; Clement Lorin; Gilles Minier; Edouard Pepinter; Yosri Rabti; Etienne Rochepault; Tiina Salmi; Daniel Schoerling; Davide Tommasini
In the framework of a design study for a post-LHC 100 TeV circular hadron collider, namely FCC-hh, high-gradient Nb 3 Sn lattice quadrupoles were investigated, following closely the specifications from the optic layout of that machine. After several iterations, a baseline design of the main quadrupole was selected and, then, included in the FCC-hh Conceptual Design Report. The article deals with the
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Thermal Stability Analysis of YBCO Tapes Under DC Overcurrent IEEE Trans. Appl. Supercond. Pub Date : 2020-12-17 Ying Xu; Shaotao Dai; Tao Ma; Bangzhu Wang
High-temperature superconducting (HTS) cable has the merits of high capacity and small volume in the normal operation condition. However, the fault current, which could be 10–30 times of the nominal current, gives a great challenge to its thermal stability. Due to the overcurrent, the HTS tapes will quench to resistive state and result in generating large amount of heat, which may degrade or even damage
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Design Optimization of a Mechanically Improved 499.8-MHz Single-Cell Superconducting Cavity for HEPS IEEE Trans. Appl. Supercond. Pub Date : 2020-12-18 Hongjuan Zheng; Pei Zhang; Zhongquan Li; Qiang Ma; Zhenghui Mi; Xinying Zhang; Tongming Huang; Ruixiong Han; Changcheng Ma; Rui Ge; Weimin Pan
Superconducting 499.8-MHz radio frequency (rf) cavities have been proposed for the High Energy Photon Source (HEPS), a 6-GeV diffraction-limited synchrotron light source currently under construction in Beijing. Being an active third-harmonic system, two cavities shall provide 3.5-MV rf voltage and 400 kW of beam power to enable a complex rf gymnastics required by a novel injection scheme. Adopting
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Study on Energy Storage Magnet State Assessment Method Considering Temperature Rise IEEE Trans. Appl. Supercond. Pub Date : 2020-12-03 Shuqiang Guo; Li Ren; Ying Xu; Yuanyuan Li; Jing Shi; Guilun Chen; Zheng Li; Yuejin Tang; Jingdong Li
In the process of power compensation of the superconducting magnetic energy storage system (SMES) in the power grid, the existence of ac loss and eddy current loss will cause the magnet to heat up, and temperature rise is the main factor limiting the power output capability of SMES. This article proposes a state assessment method (SAM) that considers the temperature rise of the magnet. This method
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Binary Counters Using Adiabatic Quantum-Flux-Parametron Logic IEEE Trans. Appl. Supercond. Pub Date : 2020-12-14 Taiki Yamae; Naoki Takeuchi; Nobuyuki Yoshikawa
Adiabatic quantum-flux-parametron (AQFP) logic is an energy-efficient superconductor logic family. In this article, we design binary counters, namely an up counter, a down counter, and an up/down counter, based on AQFP logic. These binary counters are T-flip-flop-based and count logic 1s in the input signal that is synchronized with excitation currents, which clock the counters. The internal state
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Stator Optimization of Wind Power Generators With High-Temperature Superconducting Armature Windings and Permanent Magnet Rotor IEEE Trans. Appl. Supercond. Pub Date : 2020-11-10 Shaoshen Xue; Arwyn S. Thomas; Zi-Qiang Zhu; Liren Huang; Alexander Duke; Richard E. Clark; Ziad Azar
Electrical machines with high-temperature superconducting (HTS) armature windings can benefit from high power density and efficiency. Furthermore, by using permanent magnets (PM) on the rotor, the cryogenic system can be significantly simplified compared with the fully superconducting (SC) machines or the machines with SC field windings. Compared with the conventional electrical machines, the performance
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Characterization of HTS Coils for Superconducting Rotating Electric Machine Applications: Challenges, Material Selection, Winding Process, and Testing IEEE Trans. Appl. Supercond. Pub Date : 2020-12-07 Giuseppe Messina; Mohammad Yazdani-Asrami; Fabrizio Marignetti; Antonio della Corte
The second-generation high-temperature superconducting tapes (2G-HTS) such as the REBCO coated conductors are known for their strong mechanical properties and high current carrying capacity with low ac losses compared with first-generation HTS tapes as well as low-temperature superconductors. Therefore, they seem to be good candidates to assemble coils for superconducting rotating electric machines
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Corrections to “A Novel Single-Phase Tubular Permanent Magnet Linear Generator” IEEE Trans. Appl. Supercond. Pub Date : 2020-12-31 Hao Chen; Shuyan Zhao; Haiying Wang; Rui Nie
Corrections were made to finanical support information for the above named paper.
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Corrections to “Three-Dimensional Magnetic Equivalent Circuit Research of Double-Sided Switched Reluctance Linear Machine” IEEE Trans. Appl. Supercond. Pub Date : 2020-12-25 Hao Chen; Xuekun Liu; Wenju Yan
Presents corrections to financial data posted for this article.
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Analytical Approach for Optimal HTS Solenoid Design IEEE Trans. Appl. Supercond. Pub Date : 2020-11-17 Pranoti R. Raut; Himanshu J. Bahirat; M. D. Atrey
High temperature superconducting (HTS) coils have been designed for various applications such as magnetic resonance imaging (MRI), nuclear magnetic resonance (NMR), and superconducting magnetic energy storage (SMES). Typically, the coils are in kilojoule range and have solenoid structure. These are mostly optimized with MATLAB and electromagnetic analysis using finite element method (FEM) software
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Analysis of Superconducting Synchronous Motors With Halbach Array Field Excitation IEEE Trans. Appl. Supercond. Pub Date : 2020-11-30 Tobias Tymosch; Manuel Fischer; Vasken Ketchedjian; Yutaka Terao; Hiroyuki Ohsaki
This article evaluates the novel design approach of a 3 MW partially superconducting synchronous machine for electric aircraft propulsion. Its special feature is the application of an electromagnetic Halbach array for the field excitation to reduce the back yoke weight and thereby increase the overall output power density. The electromagnetic Halbach array is obtained by reproducing a permanent magnet
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Reversible Fluxon Logic With Optimized CNOT Gate Components IEEE Trans. Appl. Supercond. Pub Date : 2020-12-02 Kevin D. Osborn; Waltraut Wustmann
Reversible logic gates were previously implemented in superconducting circuits as adiabatic-reversible gates, which are powered with a sufficiently slow clock. In contrast, we are studying ballistic-reversible gates, where fluxons serve to both encode the information and power the gates. No power is applied to the gate apart from the energy of the input fluxons, and the two possible flux polarities
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The Cascade Switching of the Photon Number Resolving Superconducting Single-Photon Detectors IEEE Trans. Appl. Supercond. Pub Date : 2020-11-20 Konstantin Smirnov; Maria Moshkova; Andrey Antipov; Pavel Morozov; Yury Vakhtomin
In this article, present the first detailed study of cascade switching in superconducting photon number resolving detectors. The detectors were made in the form of four parallel nanowires, coupled with the single-mode optical fiber and mounted into a closed-cycle refrigerator with a temperature of 2.1 K. We found out the value of additional false pulses ( N cas.sw. ) appearing due to cascade switching
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An Exponential Law of Hot Spot Temperature Versus Normal Zone Propagation Velocity During the Quench of an YBa2Cu3O7-δ Pancake Magnet IEEE Trans. Appl. Supercond. Pub Date : 2020-11-24 Jùn Zhou; Justin Schwartz
Using a 2-D/3-D mixed electrothermal model, the quench behavior of an YBa 2 Cu 3 O 7-δ (YBCO) pancake magnet is investigated for operating temperature 30–65 K. From many simulations, it is found when the hot spot temperature T peak rises to the range [120 K, 300 K], both T peak and the normal zone length L NZ behave like exponential functions of the longitudinal normal zone propagation velocity (NZPV)
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Magnetization Current Simulation of High-Temperature Bulk Superconductors Using the ANSYS Iterative Algorithm Method IEEE Trans. Appl. Supercond. Pub Date : 2020-11-16 Kai Zhang; Sebastian Hellmann; Marco Calvi; Thomas Schmidt; Lucas Brouwer
The A-V formulation based iterative algorithm method (IAM), developed at Paul Scherrer Institute, shows excellent performance in modeling the critical state magnetization-current in the ReBCO tape stacks after field-cooling magnetization. This article upgrades the function of the IAM, making it realistic to take into account the widely used E – J power law, as well as to model the magnetization-current
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Application of Epoxy-Bonded FBG Temperature Sensors for High-Temperature Superconductor-Coated Conductor Quench Detection IEEE Trans. Appl. Supercond. Pub Date : 2020-11-06 Yanchao Liu; Ratu Mataira; Rod Badcock; Zhenan Jiang; Jin Fang
Fast detection of quench in high-temperature superconductors (HTS) is essential for the application of HTS magnets due to the low normal zone propagation velocity (NZPV). In this work, quench measurement of single-HTS wires has been carried out at 80 K through gas cooling. We use both electrical and thermoelectric methods to verify the ability of fiber Bragg grating (FBG) sensors to be applied to quench
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Analysis of AC Loss Contributions From Different Layers of HTS Tapes Using the A−V Formulation Model IEEE Trans. Appl. Supercond. Pub Date : 2020-10-26 Andrea Musso; Marco Breschi; Pier Luigi Ribani; Francesco Grilli
This article presents a numerical model based on the definition of the scalar and vector potentials to calculate the ac losses generated in a high-temperature superconductor coated conductor tape by an ac transport current and by an ac external magnetic field applied with a generic orientation. The material characteristics of the different layers of a reference tape are included in the model equations
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To the Optimization of Quench Performance for a Large REBCO Cable-in-Conduit Conductor IEEE Trans. Appl. Supercond. Pub Date : 2020-10-26 Rui Kang; Davide Uglietti; Yuntao Song
REBCO cable-in-conduit conductors at the level of tens of kiloamperes are being developed for application in fusion magnets. One important aspect to study is their performance in the case of a quench event. A conductor should survive from such an event without over design; therefore, they should be properly optimized. Using a simulation model developed based on THEA code, we studied the parameters
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Compact MR Magnet Design Methodology for Superconducting Animal MRI Scanner IEEE Trans. Appl. Supercond. Pub Date : 2020-10-12 Geli Hu; Zhipeng Ni; Baogui Zhang; Tianzi Jiang
A 4.7 T compact superconducting magnet system for active shielding animal magnetic resonance imaging scanner was designed in this work. The resulting magnet consists of nine coaxial coils symmetrical about the z -axis. The innermost main coils and outermost shielding coils were made up of six inner coils with the positive current direction and three outer coils with the negative current direction,
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Implementation of the H-$\phi$ Formulation in COMSOL Multiphysics for Simulating the Magnetization of Bulk Superconductors and Comparison With the H-Formulation IEEE Trans. Appl. Supercond. Pub Date : 2020-10-26 Alexandre Arsenault; Frédéric Sirois; Francesco Grilli
The H-formulation, used abundantly for the simulation of high-temperature superconductors, has shown to be a very versatile and easily implementable way of modeling electromagnetic phenomena involving superconducting materials. However, the simulation of a full vector field in current-free domains unnecessarily adds degrees of freedom to the model, thereby increasing computation times. In this contribution
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Semianalytical Modeling of AC Losses in HTS Stacks Near Ferromagnetic Parts IEEE Trans. Appl. Supercond. Pub Date : 2020-10-26 Yazid Statra; Hocine Menana; Bruno Douine
This article presents a semianalytical modeling approach for ac losses computation in high-temperature superconducting (HTS) stacks and coils near ferromagnetic parts. The Brandt's model is combined with the equivalent current model to take into account of the proximity of ferromagnetic materials with finite relative permeability. Large stacks of HTS tapes are considered. A homogenization is applied
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Millimeter-Wave Response of All Metal-Organic Deposited YBCO Transition Edge Bolometer IEEE Trans. Appl. Supercond. Pub Date : 2020-10-23 Rana Nazifi; Roya Mohajeri; Zeynab Alipour; S. Iman Mirzaei; Mehdi Ahmadi-Boroujeni; M. A. Vesaghi; J.-C. Grivel; Mehdi Fardmanesh
We report on the response of a monolithic high $\mathrm{T_{c}}$ transition-edge bolometer to about 3 mmWave for the first time. The detector structure consisting of 400-nm $\mathrm{YBa_{2}Cu_{3}O_{7-x}}$ (YBCO) film on buffered yttria stabilized zirconia substrate without any coupled antenna, shows bolometric type responsivity to the 3-mmWave radiation at its transition temperature. The YBCO thin film
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A New Approach to Measure Magnetic Field of High-Temperature Superconducting Coil Based on Magneto-Optical Faraday Effect IEEE Trans. Appl. Supercond. Pub Date : 2020-10-19 Junjie Jiang; Zeming Wu; Jie Sheng; Jianwen Zhang; Meng Song; Kyungwoo Ryu; Zhuyong Li; Zhiyong Hong; Zhijian Jin
Magnetic field monitoring devices are essential for studying and operating high-temperature superconducting (HTS) magnets. Apart from conventional Hall sensor, passive optical fiber sensor is also an option for magnetic field monitoring. In this article, we proposed a novel access based on yttrium iron garnet magneto-optic (YM) sensor, which is one kind of optical fiber sensors, to measure magnetic
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Conduction-Cooled Superconducting Magnet for Active-Target TPC Experiments at RAON IEEE Trans. Appl. Supercond. Pub Date : 2020-10-13 Shin Hyung Kim; Jung Keun Ahn
A compact superconducting magnet was constructed for low-energy nuclear physics experiments at the RAON heavy-ion accelerator facility. Conduction-cooled Helmholtz coils with a radius of 40 cm generate a uniform magnetic field of up to 1.51 T at a current of 71 A. The magnet has two crossing beam windows that allows the beam to pass either parallel (solenoid mode) or perpendicular (dipole mode) to
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A Resistance Model of Fault Current Limiting Coils Under DC Impact IEEE Trans. Appl. Supercond. Pub Date : 2020-09-01 Haonan Wang; Guomin Zhang; Zhifeng Zhang; Guanjie Liu; Wenhan Zha; Huijuan Gao
The short-circuit fault current on the dc side affects the operation safety of the multiterminal flexible HVdc (MTDC) transmission system seriously. The resistance-type superconducting fault current limiter (RSFCL) has received extensive attention in limiting the dc impact current because it has a fast response speed and zero impedance at a steady state. At present, there are so many works on the simulations
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AC Transport Loss in Superconductors Carrying Harmonic Current With Different Phase Angles for Large-Scale Power Components IEEE Trans. Appl. Supercond. Pub Date : 2020-08-27 Mohammad Yazdani-Asrami; Wenjuan Song; Min Zhang; Weijia Yuan; Xiaoze Pei
It is of great industrial interest and academic importance to investigate current harmonics impacts on AC losses of superconductors, especially in large-scale power devices. However, only effect of amplitude of in-phase current harmonics on AC loss has been studied in the works of literature. We numerically characterized nonsinusoidal AC loss of superconducting tape carrying harmonic currents with
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Deployment of a Resistive Superconducting Fault Current Limiter for Improvement of Voltage Quality and Transient Recovery Voltage IEEE Trans. Appl. Supercond. Pub Date : 2020-08-13 Wescley Tiago Batista de Sousa; Dustin Kottonau; Shahab Karrari; Jörn Geisbüsch; Mathias Noe
This article presents a theoretical investigation of a resistive superconducting fault current limiter (R-SFCL) operating in a medium-voltage network. The considered power system presents a high level of fault current as well as a high transient recovery voltage. The simulation result shows that the R-SFCL not only limits the fault current to a desirable value, but also improves transient recovery
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Thermal-Hydraulic Analysis on Quench Behavior of Indium-Tin Soldered REBCO Composite Conductor IEEE Trans. Appl. Supercond. Pub Date : 2020-07-24 Zhengshuo Zhang; Jinxing Zheng; Yuntao Song; Shuyue Zheng; Timing Qu; Min Zhang; Weijia Yuan
The second-generation high-temperature superconductor REBCO is one of the most valuable candidates that meet the requirements of future magnetic confinement fusion device. Quench behavior of an improved high-current REBCO composite conductor is simulated by a 1-D finite element method. Indium-tin alloy foil placed in the gap between stabilizer, jacket, and superconducting tape stacks can significantly
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Characterization of Freeze-Dried Boron Nanopowders and Parameter Optimization in Ex Situ MgB2 Wire Production IEEE Trans. Appl. Supercond. Pub Date : 2020-08-05 Marco Capra; Gianmarco Bovone; Federico Loria; Cristina Bernini; Matteo Tropeano; Andrea Tumino; Gianni Grasso; Simon C. Hopkins; Amalia Ballarino; Carlo Ferdeghini; Marina Putti; Maurizio Vignolo
This article reports a study to identify optimal synthesis parameters for a pure boron precursor prepared following a patented process developed at CNR-SPIN laboratories, performed in the framework of a collaboration between CNR-SPIN and CERN. Boron is a precursor that plays a crucial role in the MgB 2 wire manufacturing, as a consequence, the synthesis parameters of the superconducting phase have
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The Importance of Geometrical Parameters on the Mechanical Stability of Roebel Cables IEEE Trans. Appl. Supercond. Pub Date : 2020-08-28 Gijoy S; K. E. Reby Roy
AC loss from Roebel cables with high-temperature superconducting strands are comparatively less, and they possess large current carrying capacity since they have a transposed structure. However, the strands should be strong enough to withstand various types of external loads during their operation. The present work simulates the performance of the Roebel strand against an external tensile load using
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Electrical Insulation Characteristics of LN2/CF4 Mixture at Cryogenic Temperatures IEEE Trans. Appl. Supercond. Pub Date : 2020-08-18 Jianhui Chen; Guomin Zhang; Wenju Sang; Yuhuai Wang; Chuansheng Zhang; Yanxing Zhao; Qingquan Qiu; Yuping Teng; Liwei Jing
High-temperature superconducting (HTS) power equipment and tests at present require operating temperatures higher than the liquid nitrogen (LN 2 ). LN 2 is an important cryogenic refrigerant and liquid insulation material, which is widely used in HTS equipment. Although pressurized LN 2 can achieve temperatures higher than 77 K, it requires the use of sealed pressure vessels. Thus, a liquid cryogen
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An on-Chip Planar Broadband 3-Way Power Divider for Josephson Voltage Circuits IEEE Trans. Appl. Supercond. Pub Date : 2020-08-05 Lanruo Wang; Jinjin Li; Xueshen Wang; Yuan Zhong; Jie Tong; Wenhui Cao; Qing Zhong
This article presents a superconducting material based planar broadband 3-way Wilkinson power divider which can be used in the Josephson quantum voltage device for the voltage standards. The 3-way Wilkinson power divider aims to improve the integration of Josephson voltage device compared to the commonly used 2-way power divider. A two-stage λ /4 section on each branch is used to increase the bandwidth
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Verification of Superconducting Feeder Cable in Pulse Current and Notch Operation on Railway Vehicles IEEE Trans. Appl. Supercond. Pub Date : 2020-08-04 Masaru Tomita; Kenji Suzuki; Yusuke Fukumoto; Atsushi Ishihara; Takenori Torii; Tomoyuki Akasaka; Yusuke Kobayashi
Railway transportation is of safety, convenience, economy, and environmental friendliness. However, with energy issues becoming increasingly important in this century, it is important to assess the situation in the transportation sector. When the superconducting cable is used as a feeder of the railway electrification system, the voltage drop can be significantly reduced. Therefore, the superconducting
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Test of a Prototype Nb3Sn Sextupole Coil for 45-GHz ECR Ion Source Using Mirror Structure IEEE Trans. Appl. Supercond. Pub Date : 2020-09-01 Yuquan Chen; Li Zhu; Enming Mei; Xianjin Ou; Xudong Wang; Peng Ma; Chao Li; Beimin Wu; Canjie Xin; Wei Wu; Liangting Sun
Institute of Modern Physics is developing a Nb 3 Sn superconducting magnet system for a 45-GHz electron cyclotron resonance ion source. To achieve this complicated and challenging Nb 3 Sn magnet, a prototype with identical cross section but half the length of the magnet is proposed. A single sextupole coil prototype with 457 mm length has been fabricated and tested. This sextupole coil is 38 mm thick
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Electromagnetic and Mechanical Analysis of DC Magnet for Super X Test Facility IEEE Trans. Appl. Supercond. Pub Date : 2020-07-30 Aihua Xu; Kaihong Wu; Yi Shi; Yu Wu; Xiaopeng Yu; Chao Dai; Qiangwang Hao; HouXiang Han; Huan Jin; Yongliang Zhang; Junrong Wu; Libiao Hu
The conceptual design of China fusion engineering test reactor (CFETR) is now ongoing. Its toroidal field magnets with a peak field of ∼15 T require a new conductor testing facility with higher background magnetic field to test and evaluate the performance of these conductors. As part of the study of CFETR, the facility named Super X (SUPERconducting eXperiment) is planning to be constructed at Institute
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Critical Current Characteristics of HTS Round Strand Using REBCO Tapes Under Transverse and Cyclic Load IEEE Trans. Appl. Supercond. Pub Date : 2020-07-30 Yi Shi; Fang Liu; Xingtao Zhang; Huan Jin; Huijuan Chen; Yunfei Tan; Huajun Liu
Various strand concept for high-temperature superconductor (HTS) flat tapes have been developed in the past few years for fusion magnet applications. We developed a round HTS strand with soldered multilayer copper tapes as filler and support called SaMiT following the technic path of twisted stacked-tape cable. DC tests performed under bending and twisting condition demonstrated that the proposed design
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Electromagnetic Modeling of Superconductors With Commercial Software: Possibilities With Two Vector Potential-Based Formulations IEEE Trans. Appl. Supercond. Pub Date : 2020-08-07 Francesco Grilli; Enric Pardo; Antonio Morandi; Fedor Gömöry; Mykola Solovyov; Víctor M. R. Zermeño; Roberto Brambilla; Tara Benkel; Nicolò Riva
In recent years, the $H$ formulation of Maxwell's equations has become the de facto standard for simulating the time-dependent electromagnetic behavior of superconducting applications with commercial software. However, there are cases where other formulations are desirable, for example for modeling superconducting turns in electrical machines or situations where the superconductor is better described
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Vertical–Lateral Coupling Force Relation of the High-Temperature Superconducting Magnetic Levitation System IEEE Trans. Appl. Supercond. Pub Date : 2020-08-07 Li Wang; Zigang Deng; Yanxing Li; Haitao Li
A high-temperature superconducting (HTS) magnetic levitation (maglev), based on YBaCuO bulk superconductors and permanent magnet guideways, shows the potential to be applied in the future rail transportation. The maglev forces (levitation and guidance force) of the HTS maglev system, which bond the vehicle and the guideway, are the key factors of its dynamics studies. In practical operation, the HTS
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SFQ Parallel Encoders Promising for Video Imaging With Superconductor Stripline Detectors IEEE Trans. Appl. Supercond. Pub Date : 2020-07-31 Masamitsu Tanaka; Misaki Kozaka; Kyohei Kamiya; Kübra Üşenmez; Eren Can Aydoğan; Sasan Razmkhah; Ali Bozbey; Akira Fujimaki
We report demonstration of a readout circuit with high-throughput single flux quantum (SFQ) based encoders for a large-scale video imaging system with a conventional frame rate. The encoders are fully parallel and integrated on the same chip as linear arrays of serially connected superconductor stripline detectors (SSLDs), superconducting quantum interference device (SQUID) based comparators, and SFQ
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Design and Electromechanical Properties of Round HTS Strand With Soldered Multilayer Copper Tapes as Filler and Tube IEEE Trans. Appl. Supercond. Pub Date : 2020-07-30 Yi Shi; Fang Liu; Huajun Liu; Yunfei Tan; Xingtao Zhang; Huan Jin; Huijuan Chen
Design and feasible verification of the round high-temperature superconducting (HTS) strand with REBCO tapes is the key technology for future fusion magnet application such as China Fusion Engineering Test Reactor (CFETR). Flat tape configuration of REBCO tapes and incompatibility with cable design based on round low-temperature superconducting (LTS) strand lead to the development of new cable technology
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Research on Delamination Damage of YBCO Tape Under DC Impact Based on Hilbert–Huang Transform IEEE Trans. Appl. Supercond. Pub Date : 2020-07-21 Haonan Wang; Guomin Zhang; Zhifeng Zhang; Guanjie Liu; Wenhan Zha; Huijuan Gao
The short-circuit fault current on the dc side affects the operation safety of the multiterminal flexible HVdc transmission system seriously. The resistance-type superconducting fault current limiter (RSFCL) has received extensive attention in limiting the dc impact current because it has fast response speed and zero impedance at steady state. YBCO tapes are susceptible to delamination damage under
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Shielding Effect of (RE)Ba2Cu3O7-d-Coated Conductors on Eddy Current Loss of Adjacent Metal Layers Under AC Magnetic Fields With Various Orientations IEEE Trans. Appl. Supercond. Pub Date : 2020-07-27 Yueming Sun; Nicholas J. Long; Gennady Sidorov; Jin Fang; Rodney A. Badcock; Zhenan Jiang
(RE)Ba 2 Cu 3 O 7-d (REBCO) coated conductors are becoming a preferred wire choice for many potential high temperature superconducting (HTS) applications, where additional metal layers are usually attached to the REBCO conductors to improve reliability and stability. In such cases, the eddy current loss in the metal layers is affected by the magnetic field shielding by adjacent REBCO coated conductors
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Influence of Coil Location and Current Angle in Permanent Magnet Wind Power Generators With High-Temperature Superconducting Armature Windings IEEE Trans. Appl. Supercond. Pub Date : 2020-07-10 Shaoshen Xue; Arwyn S. Thomas; Zi-Qiang Zhu; Liren Huang; Alexander Duke; Richard E. Clark; Ziad Azar
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
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Flexible Coaxial Ribbon Cable for High-Density Superconducting Microwave Device Arrays IEEE Trans. Appl. Supercond. Pub Date : 2020-07-10 Jennifer Pearl Smith; Benjamin A. Mazin; Alex B. Walter; Miguel Daal; J. I. Bailey III; Clinton Bockstiegel; Nicholas Zobrist; Noah Swimmer; Sarah Steiger; Neelay Fruitwala
Superconducting electronics often require high-density microwave interconnects capable of transporting signals between temperature stages with minimal loss, cross talk, and heat conduction. We report the design and fabrication of superconducting 53 wt% Nb-47 wt% Ti (Nb47Ti) FLexible coAXial ribbon cables (FLAX). The ten traces each consist of a ${\oslash}$ 0.076 mm NbTi inner conductor insulated with
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Effect of Defects on the Quench Properties of Stacked REBCO Tapes IEEE Trans. Appl. Supercond. Pub Date : 2020-07-14 Jiangtao Shi; Xinsheng Yang; Min Xu; Yue Zhao; Yong Zhao
The local thermal disturbance will produce a joule heat. When the joule heat is larger than the minimum quench energy (MQE), it will lead to the phenomenon of a quench. The same problem exists in stacked superconducting tapes. In this article, the defects in REBCO tapes were created using the bending method. The voltage and temperature traces were measured during the quench process. The quench characteristics
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High-Frequency Impulse Modeling and Longitudinal Insulation Analysis of Bifilar Superconducting Coil IEEE Trans. Appl. Supercond. Pub Date : 2020-07-21 Jing Zhang; Shaotao Dai; Tao Ma; Ying Xu; Xufeng Yan
Bifilar coil is one of the most applicable structures used for resistive-type superconducting fault current limiter. However, the turn-to-turn (longitudinal) insulation of the bifilar coil under lightning and switching impulse is rather different from the conventional pancake coil. The longitudinal insulation is characterized as the distributed circuit of the coil under high-frequency excitation, and
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AC Loss of Bi-2212 Round Wire at Wide Frequency Ranges up to 500 kHz IEEE Trans. Appl. Supercond. Pub Date : 2020-07-15 Wei Chen; Xinsheng Yang; Boyang Shen; Qingbin Hao; Shengnan Zhang; Chengshan Li; Yong Zhao
The Bi-2212 round wire has a multifilamentary structure, and the use of numerical method to study ac loss of such multifilamentary superconducting wire requires a long calculation time and large memory. Adopting a homogenization method at low frequency to study the ac loss of multifilamentary structural wire/tape has been proven to have high enough accuracy and can save a lot of calculation time. With
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Numerical Simulation of Superconducting Generator Based on the T–A Formulation IEEE Trans. Appl. Supercond. Pub Date : 2020-06-29 Yu Yang; Huadong Yong; Xingyi Zhang; Youhe Zhou
Due to the excellent electromagnetic properties of superconductor materials, superconducting generators have higher efficiency, lower weight and volume than traditional rotating machines. However, it is difficult to simulate the electromagnetic behavior in the superconducting generator due to the nonlinear $E - J$ relationship. A numerical model based on the $T - A$ formulation and moving mesh method
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DC Breakdown and Surface Potential Behavior of Epoxy/Al2O3 Nanocomposites at Cryogenic Temperature IEEE Trans. Appl. Supercond. Pub Date : 2020-07-07 Tie Jiang; Xiangrong Chen; Chao Dai; Honglu Guan; Ashish Paramane
For high temperature superconducting (HTS) dc cables, one key issue is the necessity of using polymer dielectrics with higher dielectric strength at cryogenic temperature in liquid nitrogen. Nanocomposites have played an important role in improving the dielectric properties of epoxy resin (EP). This article investigates on the dc breakdown strength and the surface potential behavior of the epoxy/Al
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A Compact 2-D Stochastic FDTD Method for Uncertainty Analysis in Superconducting Transmission Lines IEEE Trans. Appl. Supercond. Pub Date : 2020-07-02 Yifan Yang; Xiao-Chun Li; Yan Li; Junfa Mao
In this article, a stochastic finite-difference time-domain (S-FDTD) method is proposed for analyzing the influence of physical size uncertainty on the time-domain response of superconducting transmission lines. The formulations of the proposed method are, in detail, derived with the two-fluid model and London equation. A typical superconducting microstrip line is simulated to verify the effectiveness
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Mechanical Tests, Analysis, and Validation of the Support Structure of the eRMC and RMM Magnets of the FCC R&D at CERN IEEE Trans. Appl. Supercond. Pub Date : 2020-06-26 Manuel García Pérez; Susana Izquierdo Bermudez; Juan Carlos Perez; Nicolas Bourcey; Philippe Grosclaude; Michael Guinchard; Davide Tommasini; Sohrab Emami Naini; Salvador Ferradas Troitiño
The enhanced racetrack model coil and racetrack model magnet constitute the current R&D Nb $_3$ Sn magnets under development at CERN aiming to achieve dipole fields of 16–18 T, the design baseline of the Future Circular Collider. This article reports the mechanical behavior of their common support structure, which underwent three different levels of room-temperature preload (with the bladders and key
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Harmonic Suppression Study on Twin Aperture CCT Type Superconducting Quadrupole for CEPC Interaction Region IEEE Trans. Appl. Supercond. Pub Date : 2020-06-29 Quanng Peng; Qingjin XU
Iron-free twin-aperture superconducting quadrupole in the interaction region is a key technology to increase the luminosity of high-energy future colliders, such as the circular electron-positron collider that China will build in the next ten years with a center-of-mass energy of 240 GeV and a small crossing angle of 33 mrad in the interaction region. The final focusing quadrupole QD0, which is 2.2
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Modeling Quench Propagation in the ENEA HTS Cable-In-Conduit Conductor IEEE Trans. Appl. Supercond. Pub Date : 2020-06-17 Andrea Zappatore; Andrea Augieri; Roberto Bonifetto; Giuseppe Celentano; Laura Savoldi; Angelo Vannozzi; Roberto Zanino
The quench protection in high-temperature superconducting (HTS) magnets is a well-known issue. Therefore, it is fundamental to have reliable models available for the analysis of the quench propagation in such magnets. The quench propagation in an ENEA HTS cable-in-conduit conductor, developed for fusion applications with the particular reference to an insert for the central solenoid of the Italian
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Repeater Insertion in SFQ Interconnect IEEE Trans. Appl. Supercond. Pub Date : 2020-06-09 Tahereh Jabbari; Gleb Krylov; Stephen Whiteley; Jamil Kawa; Eby G. Friedman
Superconductive passive transmission lines (PTL) are widely used for signal routing in large-scale rapid single flux quantum (RSFQ) circuits. Due to the imperfect matching of the transmission lines between the driver and receiver, single flux quantum (SFQ) pulses are partially reflected. The round trip propagation time of these reflections can coincide with the following SFQ pulse, resulting in a decrease
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Electric-Field- and Temperature-Dependent Nonlinear Conductivity of SiC/Epoxy Resin Composites at Cryogenic Temperature IEEE Trans. Appl. Supercond. Pub Date : 2020-07-03 Zhonglei Li; Renjie Huang; Boxue Du; Tao Han
Nonlinear conductive composite insulation has been widely used to reduce nonuniformities in the local high electric field of high-voltage direct-current equipment. The silicon carbide (SiC)/epoxy resin composites with nonlinear conductivities have great potential applications in high temperature superconducting equipment. In this article, SiC/epoxy resin composites with different filler loading are
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Terahertz Reflectivity of YBa2Cu3O7-δ at Cryogenic Temperatures IEEE Trans. Appl. Supercond. Pub Date : 2020-05-15 Vladimir V. Parshin; Evgeny A. Serov; Grigoriy M. Bubnov; Vyacheslav F. Vdovin; Andrey S. Nikolenko; Ilya V. Lesnov; Aleksandra A. Gunbina; Andrey V. Smirnov; Vladimir A. Malginov; Dmitry E. Dolzhenko; Dmitry R. Khokhlov
Modern space-based telescopes operating in the terahertz (THz) spectral range require highly reflecting and cryogenically cooled optics ensuring extremely low noise. The idea of using high-temperature superconductor YBa 2 Cu 3 O 7-δ as a telescope's mirror coating for providing low dissipation and high reflectivity of the surface for the subTHz frequency band has been explored. We are presenting here
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Experimental Research of a 10 kA HTS Current Lead Using YBCO Tapes IEEE Trans. Appl. Supercond. Pub Date : 2020-06-24 Shuo Zhang; Hansheng Feng; Ming Zhuang; Kaizhong Ding; Chenglian Liu; Yaqi Zhou
A 10 kA high-temperature superconductor current lead (HTS-CL) using a double-tube stainless steel (SS) shunt has been designed, fabricated, and tested at Institute of plasma physics, Chinese Academy of Sciences (ASIPP). The current lead consists of 80 parallel the second generation HTS coated conductor with critical current of 220 A at 77 K in self-field, a double-tube SS shunt, and Cu connectors.
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The Mechanical Analyses of CFETR CSMC Local Components Under the Steady-Operating Condition IEEE Trans. Appl. Supercond. Pub Date : 2020-06-03 Xianwei Wang; Aihua Xu; Zhaoliang Wang
The R&D of the central solenoid model coil (CSMC) is preparatory toward the final fabrication of the Chinese fusion engineering test reactor central solenoid coil. CSMC is being designed and partly fabricated in the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). During the process, new manufacturing technologies are developed and some design optimization is proposed. Based on the