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Behaviour prediction of closed-loop HTS coils in non-uniform AC fields Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-15 Zhuoyan Zhong, Wei Wu, Xueliang Wang, Xiao-Fen Li, Jie Sheng, Zhiyong Hong and Zhijian Jin
Field decay rate is the key characteristic of superconducting magnets based on closed-loop coils. However, in Maglev trains or rotating machines, closed-loop magnets work in external AC fields and will exhibit an evidently accelerated field decay resulting from dynamic resistances, which are usually much larger than joint resistance. Nevertheless, there has not been a numerical model capable of systematically
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The transport properties of ultrathin 2H–NbSe 2 Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-15 L B Lei, C Zhang, A B Yu, Y F Wu, W Peng, H Xiao, S Qiao and T Hu
The competing orders arising in a two-dimensional limit are the key to understanding unconventional superconductivity. The monolayer NbSe 2 possessing a charge density wave (CDW) and superconducting orders provides a playground to study unconventional superconductivity. Here we fabricate an ultrathin 2H–NbSe 2 device based on the mechanical exfoliation method and our electrode transfer technique. Detailed
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Critical current density defined at low electric field criterion and energy margin of superconducting MgB 2 wires in wide temperature and magnetic field range Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-15 Motomune Kodama, Hiroshi Kotaki, Takaaki Suzuki and Hideki Tanaka
High-temperature superconductors (HTS) and MgB 2 may potentially improve the usability of superconducting magnets dramatically owing to their large energy margin. When HTS and MgB 2 wires are used for magnets operated in the persistent current mode, such as in magnetic resonance imaging (MRI) scanners, the electric field generated in the wires must be lower than 10 −10 V m −1 . In this paper, critical
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Mechanical and critical current characteristics of high-strength (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O ##IMG## [http://ej.iop.org/images/0953-2048/34/2/025017/toc_sustabced2ieqn1.gif] {$_{10+\delta}$} tapes under uniaxial tensile strain Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-15 Tatsunori Okada, Kohei Sakai and Satoshi Awaji
We investigated the mechanical properties and superconducting characteristics of high-strength (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O ##IMG## [http://ej.iop.org/images/0953-2048/34/2/025017/sustabced2ieqn2.gif] {$_{10+\delta}$} tapes reinforced by Ni-based alloy lamination over a wide range of temperature (30 K≤ T ≤ 300 K), magnetic field ( ##IMG## [http://ej.iop.org/images/0953-2048/34/2/025017/sustabced2ieqn3
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Electromagnetic-thermal-mechanical behaviors of a no-insulation double-pancake coil induced by a quench in the self field and the high field Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-14 Donghui Liu, Dongke Li, Weiwei Zhang, Huadong Yong and Youhe Zhou
High-temperature superconducting double-pancake (DP) coils wound by the no-insulation (NI) approach have been proved to have a high thermal stability and a self-protecting ability. This paper mainly studies the effect of a quench of one pancake coil on the electromagnetic-thermal-mechanical behaviors of an NI DP coil in the self field and the high field. An electromagnetic-thermal coupling quench model
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Successful DC current limitation above 100 Vm −1 for 50 ms using HTS tapes with critical currents exceeding 750 A/cm-width Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-14 Christian Lacroix, Olivier Lavergne, Thomas Leduc, Félix Dupuis-Desloges, Lucile Moret, Frédéric Sirois, Guillaume Escamez, Christian-Éric Bruzek, Pascal Tixador, Veit Grosse and Markus Bauer
High-voltage direct current transmission systems are expected to allow the transmission of huge volumes of electricity over long distances. The use of superconducting fault current limiters (SFCLs) based on second-generation (2G) high-temperature superconductor (HTS) coated conductors (CCs) is a promising solution to mitigate fault currents in DC transmission systems. To fabricate a SFCL whose size
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Low-power high-speed half-flux-quantum circuits driven by low bias voltages Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-13 Feng Li, Yuto Takeshita, Daiki Hasegawa, Masamitsu Tanaka, Taro Yamashita and Akira Fujimaki
Half-flux-quantum (HFQ) circuits store and propagate half-flux quanta. The basic circuit element is a 0-π SQUID, which is a superconducting quantum interference device with a conventional Josephson junction (0-junction) and a π-shifted ferromagnetic junction (π-junction). A 0-π SQUID achieves a small critical current in the absence of an external magnetic field, thus reducing power consumption. It
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Miniaturized ultra-narrowband HTS linear phase filter with CQ units sharing quarter-wavelength resonators Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-13 Liguo Zhou, Zhihe Long, Quanyuan Feng and Zhixiong Di
This paper proposes a method for designing a miniaturized ultra-narrowband high-temperature superconducting (HTS) linear phase filter based on the resonator-shared cascaded quadruplet (CQ) units constructed by the quarter-wavelength microstrip line. Two types of CQ unit with different coupling configurations are utilized to introduce transmission zeros and realize the linear phase. The introduction
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Numerical evaluation of the deformation of REBCO pancake coil, considering winding tension, thermal stress, and screening-current-induced stress Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-13 Hiroshi Ueda, Yuta Awazu, Keisuke Tokunaga and SeokBeom Kim
In recent years, the applications of high-field REBa 2 CuO y (REBCO) coils have remarkably progressed towards NMR MRIs, accelerators, and other such devices. In a REBCO coil, the magnetic field due to the screening current is generated in the direction opposite to the field by the transport current, thus reducing the magnetic field, deteriorating the field homogeneity, and affecting the time stability
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Multi-objective optimization for the superconducting bias coil of a saturated iron core fault current limiter using the T-A formulation Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-13 G dos Santos, F Sass, G G Sotelo, F Fajoni, C A Baldan and E Ruppert
The short-circuit levels have increased considerably in transmission and distribution systems in the last years. Fault current limiter (FCL) devices are a potential solution to this problem. Among several FCL topologies, this group has good experience in the use of superconducting fault current limiters (SFCL) to reduce the electrical current during short-circuits. The literature also presents studies
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Enhanced higher temperature irreversibility field and critical current density in MgB 2 wires with Dy 2 O 3 additions Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-13 Y Yang, M D Sumption, M Rindfleisch, M Tomsic and E W Collings
Bulk samples of magnesium diboride (MgB 2 ) doped with 0.5 wt% of the rare earth oxides (REOs) Nd 2 O 3 and Dy 2 O 3 (named B-ND and B-DY) prepared by standard powder processing, and wires of MgB 2 doped with 0.5 wt% Dy 2 O 3 (named W-DY) prepared by a commercial powder-in-tube processing were studied. Investigations included x-ray diffractometry, scanning- and transmission electron microscopy, magnetic
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Influence of strain-driven segregation in low-angle grain boundaries on critical current density of Y 0.9 Nd 0.1 Ba 2 Cu 3 O 7-d Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-12 Sang-il Kim and David C Larbalestier
Low-angle grain boundaries (GBs) constitute the most important current-limiting mechanism in the operation of biaxially textured YBa 2 Cu 3 O 7−d (YBCO)-coated conductors. Ca doping of YBCO is known to improve the critical current density J c across the GB because of carrier doping by anisovalent Ca 2+ substitution for Y 3+ and the strain relief induced by Ca segregation at the GB cores; however, the
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Superconducting NbN thin films for use in superconducting radio frequency cavities Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-12 S Leith, M Vogel, J Fan, E Seiler, R Ries and X Jiang
In recent years, renewed interest has been given to alternatives to bulk Nb for use in superconducting radio frequency (SRF) cavities. Much of this research has involved the use of thin films of Nb or other alternative high T c materials. Given the recent insights into the potential of single layer high ##IMG## [http://ej.iop.org/images/0953-2048/34/2/025006/sustabc73bieqn1.gif] {${{ - \kappa }}$}
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Advances in Nb 3 Sn superconducting radiofrequency cavities towards first practical accelerator applications Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-12 S Posen, J Lee, D N Seidman, A Romanenko, B Tennis, O S Melnychuk and D A Sergatskov
Nb 3 Sn is a promising next-generation material for superconducting radiofrequency cavities, with significant potential for both large scale and compact accelerator applications. However, so far, Nb 3 Sn cavities have been limited to continuous wave accelerating fields <18 MV m −1 . In this paper, new results are presented with significantly higher fields, as high as 24 MV m −1 in single cell cavities
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Optimum heat treatment to enhance the weak-link response of Y123 nanowires prepared by Solution Blow Spinning Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-12 Ana M Caffer, Davi A D Chaves, Alexsander L Pessoa, Claudio L Carvalho, Wilson A Ortiz, Rafael Zadorosny and Maycon Motta
Although the production of YBa 2 Cu 3 O 7-δ (Y123) has been extensively reported, there is still a lack of information on the ideal heat treatment to produce this material in the form of one dimension nanostructures. Thus, by means of the Solution Blow Spinning technique, metals embedded in polymer fibers were prepared. These polymer composite fibers were fired and then investigated by thermogravimetric
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Operation of parallel SNSPDs at high detection rates Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-09 Matthieu Perrenoud, Misael Caloz, Emna Amri, Claire Autebert, Christian Schönenberger, Hugo Zbinden and Félix Bussières
Recent progress in the development of superconducting nanowire single-photon detectors (SNSPD) has delivered excellent performance, and their increased adoption has had a great impact on a range of applications. One of the key characteristic of SNSPDs is their detection rate, which is typically higher than other types of free-running single-photon detectors. The maximum achievable rate is limited by
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First demonstration of high current canted-cosine-theta coils with Bi-2212 Rutherford cables Supercond. Sci. Technol. (IF 3.067) Pub Date : 2021-01-09 L Garcia Fajardo, T Shen, X Wang, C Myers, D Arbelaez, E Bosque, L Brouwer, S Caspi, L English, S Gourlay, A Hafalia, M Martchevskii, I Pong and S Prestemon
Future high energy physics colliders could benefit from accelerator magnets based on high-temperature superconductors, which may reach magnetic fields of up to 45 T at 4.2 K, twice the field limit of the two Nb-based superconductors. Bi 2 Sr 2 CaCu 2 O 8-x (Bi-2212) is the only high- T c cuprate material available as a twisted, multifilamentary and isotropic round wire. However, it has been hitherto
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Fluctuating Cooper pairs in FeSe at temperatures exceeding double T c Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-12-08 A L Solovjov, E V Petrenko, L V Omelchenko, E Nazarova, K Buchkov and K Rogacki
Temperature dependencies of excess conductivity, ##IMG## [http://ej.iop.org/images/0953-2048/34/1/015013/sustabc2acieqn1.gif] {$\sigma^{\prime}$} , have been studied in detail for three FeSe 0.94 textured polycrystalline samples prepared by partial melting and solid state reaction. It was revealed that both ##IMG## [http://ej.iop.org/images/0953-2048/34/1/015013/sustabc2acieqn2.gif] {$\sigma^{\prime}$}
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Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC ® wires Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-12-08 Xiaorong Wang, Dmytro Abraimov, Diego Arbelaez, Timothy J Bogdanof, Lucas Brouwer, Shlomo Caspi, Daniel R Dietderich, Joseph DiMarco, Ashleigh Francis, Laura Garcia Fajardo, William B Ghiorso, Stephen A Gourlay, Hugh C Higley, Maxim Marchevsky, Maxwell A Maruszewski, Cory S Myers, Soren O Prestemon, Tengming Shen, Jordan Taylor, Reed Teyber, Marcos Turqueti, Danko van der Laan and Jeremy D Weiss
Although the high-temperature superconducting (HTS) REBa 2 Cu 3 O x (REBCO, RE–rare earth elements) material has a strong potential to enable dipole magnetic fields above 20 T in future circular particle colliders, the magnet and conductor technology needs to be developed. As part of an ongoing development to address this need, here we report on our CORC ® canted cos θ magnet called C2 with a target
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Large enhancement of the in-field critical current density of YBCO coated conductors due to composite pinning landscape Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-12-01 K J Kihlstrom, L Civale, S Eley, D J Miller, U Welp, W K Kwok, P Niraula, A Kayani, G Ghigo, F Laviano, S Fleshler, M Rupich and M Leroux
YBa 2 Cu 3 O 7 -based coated conductors (CCs) achieve the highest critical current densities ( J c ) of any known superconductor and are a key technology for applications such as rotatory machines, high-field magnets and power transmission. Incorporation of nano-sized non-superconducting second phases as additional vortex pinning centers has been considered the most amenable route to further enhance
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Microwave measurements of the high magnetic field vortex motion pinning parameters in Nb 3 Sn Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-28 Andrea Alimenti, Nicola Pompeo, Kostiantyn Torokhtii, Tiziana Spina, René Flükiger, Luigi Muzzi and Enrico Silva
The high frequency vortex motion in Nb 3 Sn was analyzed in this work up to 12 T. We used a dielectric loaded resonator tuned at 15 GHz to evaluate the surface impedance Z of a Nb 3 Sn bulk sample (24.8 at.%Sn). From the field induced variation of Z , the high frequency vortex parameters (the pinning constant k p , the depinning frequency ν p and the flux flow resistivity ρ ff ) were obtained over
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BiFeO 3 nanoparticle doping effect on the growth and properties of Y–Ba–Cu–O superconductors Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-28 Guo-Zheng Li, Chao Chen and Miao Wang
The doping effect of BiFeO 3 (BFO) nanoparticles on the growth and properties of Y–Ba–Cu–O (YBCO) superconductors by the powder melt and infiltration growth technique is investigated. The results indicate that nano-BFO doping reduces the growth rate of the Y-123 crystal and finally leads to smaller grain size in the YBCO bulk. Superconducting property measurements prove that improved levitation force
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Learning cell for superconducting neural networks Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-28 Andrey Schegolev, Nikolay Klenov, Igor Soloviev and Maxim Tereshonok
An energy-efficient adiabatic learning neuro cell is proposed. The cell can be used for on-chip learning of adiabatic superconducting artificial neural networks. The static and dynamic characteristics of the proposed learning cell have been investigated. Optimization of the learning cell parameters was performed within simulations of the multi-layer neural network supervised learning with the resilient
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Pinning analyses of a BaHfO 3 -containing GdBa 2 Cu 3 O 7‐δ thin film grown by chemical solution deposition Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-26 Kazumasa Iida, Pablo Cayado, Hannes Rijckaert, Manuela Erbe, Jens Hänisch, Tatsunori Okada, Isabel Van Driessche, Satoshi Awaji and Bernhard Holzapfel
The electric transport properties of a GdBa 2 Cu 3 O ##IMG## [http://ej.iop.org/images/0953-2048/34/1/015009/sustabb205ieqn1.gif] {$_{7-\delta}$} thin film containing 12 mol% nano-sized BaHfO 3 (BHO) particles grown by chemical solution deposition were investigated in a wide range of temperatures (4.2 ≤ T ≤ 77 K) and magnetic fields up to ##IMG## [http://ej.iop.org/images/0953-2048/34/1/015009/sustabb205ieqn2
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Homogeneity of neutron transmission imaging over a large sensitive area with a four-channel superconducting detector Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-26 The Dang Vu, Hiroaki Shishido, Kenji M Kojima, Tomio Koyama, Kenichi Oikawa, Masahide Harada, Shigeyuki Miyajima, Takayuki Oku, Kazuhiko Soyama, Kazuya Aizawa, Mutsuo Hidaka, Soh Y Suzuki, Manobu M Tanaka, Alex Malins, Masahiko Machida and Takekazu Ishida
We previously proposed a method to detect neutrons by using a current-biased kinetic inductance detector (CB-KID), where neutrons are converted into charged particles using a 10 B conversion layer. The charged particles are detected based on local changes in kinetic inductance of X and Y superconducting meanderlines under a modest DC bias current. The system uses a delay-line method to locate the positions
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AC dynamic reorganization and critical phase transitions in superconducting vortex matter Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-25 G Pasquini, M Marziali Bermúdez and V Bekeris
Vortex matter in type-II superconductors is a model complex system belonging to the vast ensemble of disordered elastic media. In all these systems, depinning occurs when an external drive is increased beyond a critical force. The nature of the depinning transition, the connection with a non-equilibrium phase transition, and its relation with proliferation or annealing of topological defects has been
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Development and Understanding of Nb 3 Sn films for radiofrequency applications through a sample-host 9-cell cavity Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-25 T Spina, B M Tennis, J Lee, D N Seidman and S Posen
Nb 3 Sn is a promising advanced material under development for superconducting radiofrequency cavities. Past efforts have been focused primarily on small development-scale cavities, but large, often multi-celled cavities, are needed for particle accelerator applications. In this work, we report on successful Nb 3 Sn coatings on Nb in a 1 m-long 9-cell Nb sample-host cavity at Fermilab. The geometry
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Current limiting tests of a prototype 160 kV/1 kA resistive DC superconducting fault current limiter Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-19 Meng Song, Chao Sheng, Tao Ma, Yong Huang, Chao Yang, Ying Xin, Hui Jin, Tianhui Yang, Jialing Xiong, Chao Li, Quan Li, Changqi Wang, Bin Li, Leishi Xiao and Pandian Luo
High voltage direct current (HVDC) transmission technology has begun to play a great role in power transmission industry over the last decade. However, short-circuit fault seriously threatens the safety of an HVDC network. In order to reduce the fault current level of an HVDC network, utilizing a superconducting fault current limiter (SFCL) was proposed by researchers and engineers worldwide. Recently
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The effects of nonlinear thermal fluctuation and series junction array on high- T c superconducting terahertz mixer performance Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-19 Xiang Gao, Jia Du, Ting Zhang, Xiangyuan Bu and Jianping An
Sensitive high- T c superconducting (HTS) heterodyne receivers are envisioned as promising technologies for terahertz (THz) communication and sensing applications due to the lack of power efficient sources in the band. HTS device properties, particularly the noise temperature, are dependent on complicated factors that include multiple noise sources as well as the interaction between Josephson junction
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Approaching depairing current in dirty thin superconducting strip covered by low resistive normal metal Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-19 S S Ustavschikov, M Yu Levichev, I Yu Pashenkin, A M Klushin and D Yu Vodolazov
We experimentally demonstrate that a thin dirty superconducting (S) strip covered by low resistive normal metal (N) approaches closer to the depairing current than a single S strip, which makes its non-linear properties stronger. The obtained result comes from proximity-induced superconductivity in the N layer, its large contribution to the superconducting properties of the SN bilayer and larger sensitivity
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AC loss calculation in REBCO coils or stacks by solving the equation of motion for current using an integration approach Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-19 Lingfeng Lai and Chen Gu
The flux motion and its collective behaviour known as AC loss is the basic characteristic of high temperature superconducting (HTS) materials and controls the economic efficiency, stability and magnetic field uniformity of superconducting equipment. In so far, we have no method to calculate the AC loss of HTS devices in an efficient way. Normally, it will take days to simulate AC loss of HTS coils
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A 12-pole VHF band high selective high temperature superconducting filter Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-17 Xiao Yu, Weibin Xi, Songtao Wu and Peiguang Yan
A 12-pole VHF band high temperature superconducting (HTS) filter with a spiral quarter-wavelength resonator is introduced. The coupling characteristics of the proposed resonator, cross structure and external quality factor is analyzed in detail. The HTS filter is fabricated on a 3-inch-diameter double-sided DyBa 2 Cu 3 O 7 HTS thin film with a LAO substrate and measured with a low-temperature test
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A proposal for a lightweight, large current superconducting cable for aviation Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-17 Sataro Yamaguchi and Masae Kanda
More Electric Aircraft (MEA) is one of the most important subjects for designing the next generation of aircraft. Since we cannot ground the electric power systems of a flying aircraft and the air insulation voltage is lower at high altitude, a low voltage, direct current (DC) aircraft electrical system is preferable for a MEA. Since the current must be high to supply high power, we consider high temperature
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Enhancement of the lower critical field in FeSe-coated Nb structures for superconducting radio-frequency applications Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-13 Zefeng Lin, Mingyang Qin, Dong Li, Peipei Shen, Liping Zhang, Zhongpei Feng, Peng Sha, Jun Miao, Jie Yuan, Xiaoli Dong, Chao Dong, Qing Qin and Kui Jin
Bulk Nb superconducting radio-frequency (SRF) cavities are widely used in accelerators, and their accelerating gradient and general performance are limited by the superheating field ( B sh ). To push the theoretical limit of the B sh , new multilayer structures are required. We fabricated FeSe-coated Nb films using pulsed laser deposition, performed structural characterizations, and measured the transport
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Recent progress of superconducting fault current limiter in China Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-11 GuoMin Zhang, Haonan Wang, Qinggquan Qiu, Zhifeng Zhang, Liye Xiao and Liangzhen Lin
With the increase of electricity demand and the rapid development of renewable energy generation, it is becoming more and more important to ensure the safety and stability of power grid, where a superconducting fault current limiter (SFCL) could play an important role. In recent years, a lot of research work has been done in China on the application of high temperature superconducting (HTS) power technology
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Controlling magnetic flux penetration in low-T C superconducting films and hybrids Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-07 F Colauto, M Motta and W A Ortiz
In realistic situations, a typical scenario for applications of type II superconductors necessarily includes vortices, usually in the presence of currents. Under these circumstances, a Lorentz force acts on each individual vortex, propelling its dissipative movement across the superconducting medium, what increases the local temperature and, eventually, endangers the preservation of the superconducting
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Double-valued strong-coupling corrections to Bardeen–Cooper–Schrieffer ratios Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-03 E F Talantsev
The experimental discovery of near-room-temperature (NRT) superconductivity in highlycompressed H 3 S, LaH 10 and YH 6 has restored fundamental interest in the electron–phonon pairing mechanism in superconductors. One of the prerequisites of phonon-mediated NRT superconductivity in highly compressed hydrides is strong electron–phonon interactions, which can be quantified by dimensionless ratios of
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Reverse advance internal magnesium diffusion process to produce dense MgB 2 bulks and high J C wires through high pressure heat treatment Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-11-03 G Bovone, M Capra, C Bernini, F Loria, T Cetner, D Gajda, A Morawski, A Ballarino, S C Hopkins, M Tropeano, G Grasso, M Putti, C Ferdeghini, A S Siri and M Vignolo
Here we report a new versatile technique to manufacture MgB 2 massive samples, called reverse advance internal magnesium diffusion (r-AIMI). The idea focuses on the goal of obtaining dense bulk or wire samples depending on synthesis conditions. In respect to the traditional AIMI procedure, in which a central Mg rod is covered with a B corona, here a Mg tube is filled with B powder and clad in a Ti
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Persistent-mode operation and magnetization behavior of a solid-nitrogen-cooled MgB 2 small-scale test coil towards a tabletop 1.5-T osteoporosis MRI Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-30 Yoonhyuck Choi, Dongkeun Park, Yi Li, Hiromi Tanaka, Wooseung Lee, Juan Bascuñán and Yukikazu Iwasa
We present results—cool-down, energization, and persistent-mode operation—of a solid-nitrogen (SN2)-cooled, magnesium diboride (MgB 2 ) small-scale test coil. The test coil, immersed in a volume of solid nitrogen at 6 K, successfully operated in persistent-mode at 108 A for a period of 5 d. Although designated a ‘persistent-mode’ coil, its center field was measured to decay at a rate of <0.6 ppm h
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Numerical analysis of the screening current-induced magnetic field in the HTS insert dipole magnet Feather-M2.1-2 Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-30 L Bortot, M Mentink, C Petrone, J Van Nugteren, G Kirby, M Pentella, A Verweij and S Schöps
Screening currents are field-induced dynamic phenomena which occur in superconducting materials, leading to persistent magnetization. Such currents are of importance in ReBCO tapes, where the large size of the superconducting filaments gives rise to strong magnetization phenomena. In consequence, superconducting accelerator magnets based on ReBCO tapes might experience a relevant degradation of the
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Electrical transport measurements for superconducting sulfur hydrides using boron-doped diamond electrodes on beveled diamond anvil Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-30 Ryo Matsumoto, Mari Einaga, Shintaro Adachi, Sayaka Yamamoto, Tetsuo Irifune, Kensei Terashima, Hiroyuki Takeya, Yuki Nakamoto, Katsuya Shimizu and Yoshihiko Takano
A diamond anvil cell (DAC) has become an effective tool for investigating physical phenomena that occur at extremely high pressure, such as high-transition temperature superconductivity. Electrical transport measurements, which are used to characterize one of the most important properties of superconducting materials, are difficult to perform using conventional DACs. The available sample space in conventional
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Inelastic x-ray scattering studies of phonon dispersions in superconductors at high pressures Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-30 S M Souliou, A Bosak, G Garbarino and M Le Tacon
Electron–phonon interaction is of central importance for the electrical and heat transport properties of metals, and is directly responsible for charge-density-waves or (conventional) superconducting instabilities. The direct observation of phonon dispersion anomalies across electronic phase transitions can provide insightful information regarding the mechanisms underlying their formation. Here, we
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An approach to identifying unconventional superconductivity in highly-compressed superconductors Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-29 E F Talantsev
Since the milestone experimental discovery by Drozdov et al ( 2015 Nature 525 73–6) who reported the observation of near-room-temperature (NRT) superconductivity in highly-compressed sulphur hydride, the quest for room-temperature superconductivity is primarily focused on highly-compressed materials. Extreme conditions and space confinement inside a diamond anvil cell (DAC) dramatically limits the
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Transverse-pressure susceptibility of high- J c RRP and PIT types of Nb 3 Sn Rutherford cables for accelerator magnets Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-29 P Gao, M Dhallé, B Bordini, A Ballarino and H H J Ten Kate
In the frame of the High-Luminosity Large Hadron Collider construction and Future Circular Collider development program, the magnetic field in the accelerator dipole magnets is being enhanced to 11 T, and 15 T to 16 T level, respectively. Advanced Nb 3 Sn superconductors with a non-copper critical current density exceeding 2500 A mm −2 at 4.2 K and 12 T, are being developed using the Restacked-Rod-Process
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A record-high trapped field of 5.6 T in the stacking of MgB 2 /TiB 2 composite bulks prepared by an in-situ hot isostatic pressing method Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-29 Tomoyuki Naito, Yuhei Takahashi and Satoshi Awaji
We have studied the trapped field properties of triple and double stacking of ##IMG## [http://ej.iop.org/images/0953-2048/33/12/125004/sustabb203ieqn1.gif] {$\mathrm{MgB_2/TiB_2}$} composite superconductor bulks magnetized by field-cooled magnetization. The triple-stacked ##IMG## [http://ej.iop.org/images/0953-2048/33/12/125004/sustabb203ieqn2.gif] {$\mathrm{MgB_2/TiB_2}$} bulks trapped a magnetic
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Analysis of mechanical behavior in inhomogeneous high-temperature superconductors under pulsed field magnetization Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-29 Haowei Wu, Huadong Yong and Youhe Zhou
Melt-textured large, single-grain REBCO (RE: rare earth element or Y) bulk superconductors have growth sector boundaries (GSBs) and growth sector regions (GSRs). The critical current density is dependent on the GSBs and the GSRs, which will influence the electromagnetic field and the temperature field distributions. REBCO bulk superconductors are brittle materials and during the manufacturing process
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Superconducting properties of the ternary boride YRh 4 B 4 Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-29 Jumaeda Jatmika, Hiroshi Maruyama, Md Shahidur Rahman, Akito Sakai, Satoru Nakatsuji, Akira Iyo and Takao Ebihara
The low number of physical parameters for superconductivity has motivated researchers to perform bulk measurements in YRh 4 B 4 , discovered four decades ago, with superconducting transition temperature ( ##IMG## [http://ej.iop.org/images/0953-2048/33/12/125006/sustabbb18ieqn1.gif] {$T_{\textrm{c}}$} ) of approximately 11 K. We performed electrical resistivity, magnetic susceptibility, and specific
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Strong flux pinning and anomalous anisotropy of Sr 0.6 K 0.4 Fe 2 As 2 superconducting tapes Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-14 He Lin, Chiheng Dong, Xifeng Pan, Chao Yao, Xianping Zhang, Yong Zhao and Yanwei Ma
A comprehensive study on the resistivity, magnetization and microstructure is carried out to understand the superconductivity and flux pinning behavior of hot-pressed Sr 0.6 K 0.4 Fe 2 As 2 tapes. The Sr 0.6 K 0.4 Fe 2 As 2 tapes possess excellent properties of high T c = 36.2 K, large transport J c of ∼10 5 A cm −2 at 10 T and 4.2 K, and high pinning potential U 0 / k B with small field-dependence
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Nitrogen infusion R&D at DESY a case study on cavity cut-outs Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-14 Marc Wenskat, Christopher Bate, Arti Dangwal Pandey, Arno Jeromin, Thomas F Keller, Jens Knobloch, Julia Köszegi, Felix Kramer, Oliver Kugeler, Satish Kulkarni, Detlef Reschke, Jörn Schaffran, Guilherme Dalla Lana Semione, Sven Sievers, Lea Steder, Andreas Stierle and Nicholas Walker
A first series of nitrogen infusion runs of 1.3 GHz single-cell cavities at DESY resulted in an unexpected and severe deterioration observed during the vertical cold test. To investigate the origin of the deterioration, one of the cavities underwent extensive radio-frequency measurements and a temperature- and magnetic field-mapping was performed in collaboration with the Helmholtz-Zentrum Berlin.
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Electronically tunable quantum phase slips in voltage-biased superconducting rings as a base for phase-slip flux qubits Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-14 Ahmed Kenawy, Wim Magnus, Milorad V Milošević and Bart Sorée
Quantum phase slips represent a coherent mechanism to couple flux states of a superconducting loop. Since their first direct observation, there have been substantial developments in building charge-insensitive quantum phase-slip circuits. At the heart of these devices is a weak link, often a nanowire, interrupting a superconducting loop. Owing to the very small cross-sectional area of such a nanowire
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Design of high selectivity narrowband eight-order high-temperature superconducting sextaplexer Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-14 Li-Tian Wang, Ming He, Yang Xiong, Wei Zhang, Hai-Hua Chen and Lu Ji
A C-band high-temperature superconducting six-channel multiplexer (sextaplexer) is proposed in this paper. A distributed coupling scheme is introduced, with which the bandpass filter (BPF) in each channel can be designed individually. The computational complexity of the proposed method is linearly increased as the number of the channels is getting larger, which is much lower than the traditional method
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Resistivity of REBCO tapes in overcritical current regime: impact on superconducting fault current limiter modeling Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-13 N Riva, F Sirois, C Lacroix, W T B de Sousa, B Dutoit and F Grilli
A detailed knowledge of the resistivity of high-temperature superconductors in the overcritical current regime is important to achieve reliable numerical simulations of applications such as superconducting fault current limiters. We have previously shown that the combination of fast pulsed current measurements and finite element analysis allows accounting for heating effects occurring during the current
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Bi-SQUID: design for applications Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-07 Victor K Kornev, Nikolay V Kolotinskiy and Oleg A Mukhanov
A review of the theory of bi-SQUIDs and the experimental studies of bi-SQUID-based devices is presented. The reported output voltage linearity of the fabricated devices ( ##IMG## [http://ej.iop.org/images/0953-2048/33/11/113001/sustaba541ieqn1.gif] {$\sim{}$} 40 to 45 dB) is much higher than that observed for dc SQUIDs ( ##IMG## [http://ej.iop.org/images/0953-2048/33/11/113001/sustaba541ieqn2.gif]
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A new concept for developing a compact joint structure for reducing joint resistance between high-temperature superconductors (HTS) and low-temperature superconductors (LTS) Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-07 Nobuya Banno, Toshihisa Asano, Takeharu Kato and Hideaki Maeda
It is significantly difficult to develop a superconducting joint between REBCO and low-temperature superconductors (LTS) using a solder matrix replacement technique. This is because the REBCO superconducting layer is highly corrosive to Sn. In this work, TEM observations were first conducted on the reaction interface between the REBCO layer and Sn to reveal the reaction. Then, a new idea to create
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Analytical model of 2D electric potential and current transfer in superconducting tapes with a current flow diverter architecture Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-07 Jean-Hughes Fournier-Lupien, Patrick Del Vecchio, Christian Lacroix and Frédéric Sirois
This work presents a generalization of the concept of current transfer length (CTL) between the stabilizer and the superconducting layer of high temperature superconductor (HTS) coated conductor tapes with a current flow diverter (CFD) architecture. The CFD architecture consists in a non-uniform interfacial resistance between the two layers, namely a high interfacial resistance in the middle of the
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Evaluation of irradiation effects on the microstructure and properties of Ag-sheathed Bi-2212 superconducting round wire for future application in CFETR Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-07 Zuoguang Li, Hongmei Zhu, Changjun Qiu, Dongsheng Yang, Jinggang Qin and Chao Zhou
The Chinese Fusion Engineering Test Reactor (CFETR) is designed to build a fusion engineering Tokamak reactor generating fusion power of 200–1500 MW, and to test the breeding tritium during fusion reaction. This may require a maximum magnetic field up to 15 T in the central solenoid and toroidal field coils. New superconducting materials should be developed for satisfying the next-generation fusion
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Fast and efficient critical state modelling of field-cooled bulk high-temperature superconductors using a backward computation method Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-07 Kai Zhang, Mark Ainslie, Marco Calvi, Sebastian Hellmann, Ryota Kinjo and Thomas Schmidt
A backward computation method has been developed to accelerate modelling of the critical state magnetization current in a staggered-array bulk high-temperature superconducting (HTS) undulator. The key concept is as follows: (i) a large magnetization current is first generated on the surface of the HTS bulks after rapid field-cooling (FC) magnetization; (ii) the magnetization current then relaxes inwards
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VIPER: an industrially scalable high-current high-temperature superconductor cable Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-07 Zachary S Hartwig, Rui F Vieira, Brandon N Sorbom, Rodney A Badcock, Marta Bajko, William K Beck, Bernardo Castaldo, Christopher L Craighill, Michael Davies, Jose Estrada, Vincent Fry, Theodore Golfinopoulos, Amanda E Hubbard, James H Irby, Sergey Kuznetsov, Christopher J Lammi, Philip C Michael, Theodore Mouratidis, Richard A Murray, Andrew T Pfeiffer, Samuel Z Pierson, Alexi Radovinsky, Michael D
High-temperature superconductors (HTS) promise to revolutionize high-power applications like wind generators, DC power cables, particle accelerators, and fusion energy devices. A practical HTS cable must not degrade under severe mechanical, electrical, and thermal conditions; have simple, low-resistance, and manufacturable electrical joints; high thermal stability; and rapid detection of thermal runaway
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Vortex phase diagram in 12442-type RbCa 2 Fe 4 As 4 F 2 single crystal revealed by magneto-transport and magnetization measurements Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-10-05 Xiangzhuo Xing, Xiaolei Yi, Meng Li, Yan Meng, Gang Mu, Jun-Yi Ge and Zhixiang Shi
The recently discovered 12442-type ACa 2 Fe 4 As 4 F 2 (A = K, Rb, Cs) compounds are the only iron-based superconductors (IBSs) with double FeAs layers between neighboring insulating layers, analogous to the double CuO 2 layers in some high- T c cuprates. Here, we report the study of vortex phase diagram of RbCa 2 Fe 4 As 4 F 2 single crystal via magneto-transport and magnetization measurements. The
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Size reduction of boron particles by high-power ultrasound for optimization of bulk MgB 2 Supercond. Sci. Technol. (IF 3.067) Pub Date : 2020-09-30 Sai Srikanth Arvapalli, Muralidhar Miryala, Milos Jirsa and Masato Murakami
Critical current density, J c , in superconductors is strongly connected with size of defects in the material. Frequently, the smaller defects, the higher J c . In this work, we tried to reduce the size of cheap commercial boron precursor powder using high energy ultra-sonication in ethanol media. The resulting powder was then utilized in synthesizing bulk MgB 2 via sintering at 775 °C. Effect of boron
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