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Degradation of critical current in Bi2212 composite wire under compression load

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Applied Mathematics and Mechanics(English Edition) 2017年第12期38卷 1773-1784页

作者： Zhiyang WANG Huadong YONG Youhe ZHOU Key Laboratory of Mechanics on Environment and Disaster in Western China College of Civil Engineering and MechanicsLanzhou UniversityLanzhon 730000China

Since Bi2Sr2Ca1Cu2O8＋x（Bi2212） wires are subject to mechanical loadings, degradation of critical current will occur. The effect of compressive loadings on the critical current of Bi2212 wire is studied by considering micro-buckling of filament. A Bi2212 wire is regarded as a unidirectional filament-reinforced composite in the theoretical analysis. By considering the influence of inclusion, the micro-buckling wavelength can be derived by using a two-dimensional model. Based on the experimental results, the critical current is fitted as a function of buckling wavelength. It is found that the decrease of the critical current is directly proportional to the reciprocal of square of the buckling wavelength. Change of micro-buckling wavelength with material parameters is discussed. A critical strain in the wire with a filament bridge is analyzed using the finite element method.

关键词： micro-buckling Bi2Sr2Ca1Cu2O8+x(Bi2212) wire wavelength critical current

Status and Progress on an HTS Strand with Quasi-isotropic critical current

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CSEE Journal of Power and Energy Systems 2021年第1期7卷 150-155页

作者： Jian Du Jianlong Sun Yang Nie Siming Mo Yuan Cai Huijuan Chen Wen Yuan Yinshun Wang the State Grid Jiangsu Electric Power Co. Ltd.Economic Research InstituteNanjing 210008China the Key Laboratory of HV and EMC Beijing North China Electric Power UniversityNorth China Electric Power UniversityBeijing 102206China the Jiangsu Etern Company Limited Suzhou 215211China the Eastern Superconducting Science&Technology(Suzhou)Co.Ltd Suzhou 215200China

The coated conductors(CCs),also known as the second-generation high-temperature superconducting(2G HTS)tape,has attractive potential applications in transmissions at low magnetic field/liquid nitrogen temperatures and high-field applications at low temperatures due to their excellent critical current density and mechanical *** critical current density has strong anisotropy,particularly at 77 *** the single tape has limited capacity of carrying current,the cable or strand making of multi-tapes,stacked in parallel,is *** recent years,several cables,such as the Roebel cable,CORC cable,TSTC cable,TS cable,and the HTSCroCo cable,were *** paper presents a status and progress on a type of HTS strand made from REBCO *** quasi-isotropic critical current is experimentally confirmed for liquid nitrogen temperature,mechanical characteristics,AC losses,thermal stability,and quench characterizations are also ***,the feasible process for the production of practical length of such strand is described by processing 10 m long sample,which is promising for applications of high fields or power transmission.

关键词： AC loss critical current mechanical characteristics quasi-isotropic strand stability

Characteristics of Bi-2223 HTS Tapes Under Short-Circuit current Impacts in Hybrid Energy Transmission Pipelines

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 736-745页

作者： Yuguang Sun Chao Yin Weizhen Li Xinyang Li Xiaohua Jiang Department of Electric Engineering Tsinghua UniversityBeijing 100084China

A hybrid energy transmission pipeline is proposed with the aim of long-distance cooperative transmission of electricity and chemical fuels, which is composed of an inner high-temperature superconducting (HTS) power cable and outer liquefied natural gas (LNG) pipeline. The flowing LNG could maintain the operating temperature of the inner HTS power cable within the range of 85 K-90 K, thus the Bi-2223 superconductors in the HTS power cable produce little Joule loss with the transmission current below the critical current. Owing to the advantages of high power density, low transmission losses and economical manufacturing costs, the hybrid energy transmission pipeline is expected to be widely utilized in the near future. In order to ensure the safety of the HTS power cable and explosive LNG in case of short-circuit faults, this paper tests and analyzes the characteristics of Bi-2223 HTS tapes of the Type HT-CA, Type HT-SS and Type H models under short-circuit current impacts at the LNG cooling temperature (85 K-90 K). An experimental platform is designed and established for the ampacity tests of HTS tapes above LN2 cooling temperature (77 K). The AC over-current impact tests at 85 K-90 K are carried out on each sample of Bi-2223 tapes respectively, and the experimental results are analyzed and compared to evaluate their performances under different operating conditions. The results indicate that the Type HT-CA tape can withstand 50 Hz short-circuit current impact with the amplitude of 1108 A (10 times of critical current Ic ) for 100 ms at 90 K, and its resistance is the smallest of the three tested samples under similar current impacts. Therefore, the Type HT-CA Bi-2223 tape is the optimal superconductor of the HTS power cable in the hybrid energy transmission pipeline.

关键词： Bi-2223 high-temperature superconducting(HTS)tape critical current hybrid energy transmission pipeline liquefied natural gas(LNG)cooling temperature short-circuit current impact characteristics

Evaluation of temperature dependent vortex pinning properties in strongly pinned YBa_(2)Cu_(3)O_(7-δ)thin films with Y_(2)BaCuO_(5)nanoinclusions

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Superconductivity 2024年第1期9卷 95-105页

作者： Alok K.Jha Kaname Matsumoto Tomoya Horide Shrikant Saini Ataru Ichinose Paolo Mele Yutaka Yoshida Satoshi Awaji Department of Materials Science and Engineering Kyushu Institute of TechnologyTobata-kuKitakyushu 804-8550Japan Department of Mechanical and Control Engineering Kyushu Institute of TechnologyTobata-kuKitakyushu 804-8550Japan Central Research Institute of Electrical Power Industry YokosukaKanagawa 240-0196Japan College of Engineering-Innovative Global Program Shibaura Institute of TechnologyMinuma-kuSaitama 337-8570Japan Department of Energy Engineering and Science Nagoya UniversityChikusa-kuNagoya 464-8603Japan Institute for Materials Research Tohoku UniversityAoba-kuSendai 980-8577Japan

The pinning of quantized magnetic vortices in superconducting YBa_(2)Cu_(3)O_(7-δ)(YBCO or Y123)thin films with Y_(2)BaCuO_(5)(Y211)nanoinclusions have been investigated over wide temperature range(4.2-77 K).The concentration of Y211 nanoinclusions has been systematically varied inside YBCO thin films prepared by laser ablation technique using surface modified target *** pinning force density values(Fp∼0.5 TNm^(−3)at 4.2 K,9 T)have been observed for the YBCO film with moderate concentration of Y211 nanoinclusions(3.6 area%on ablation target).In addition,uniform enhancement in critical current density(J_(c))was observed in the angular dependent J_(c)measurement of YBCO+Y211 nanocomposite films.Y211 nanoinclusions have been found to be very efficient in pinning the quantized vortices thereby enhancing the in‐field J_(c)values over a wide range of *** the concentration of Y211 secondary phase into Y123 film matrix results into agglomeration of Y211 phase and observed as increased Y211 nanoparticle *** larger secondary phase nanoparticles are not as efficient pinning centers at lower temperatures as they are at higher temperatures due to substantial reduction of the coherence length at lower *** of the temperature dependence of J_(c)for YBCO+Y211 nanocomposite films has been conducted and possible vortex pinning mechanism in these nanocomposite films has been discussed.

关键词： YBCO thin film critical current Vortex pinning Nanoscale APCs

Biomass-derived carbon doping to enhance the current carrying capacity and flux pinning of an isotopic Mg^(11)B_(2)superconductor

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Journal of Magnesium and Alloys 2022年第7期10卷 1868-1877页

作者： M.Shahbazi Y.Hao D.Patel H.Liang Y.Yamauchi M.S.A.Hossain QUT Centre for Materials Science and School of Chemistry and Physics Queensland University of Technology(QUT)BrisbaneQLD 4001Australia School of Mechanical and Mining Engineering Faculty of EngineeringArchitecture and Information Technology(EAIT)The University of QueenslandBrisbaneQLD 4072Australia Australian Institute for Bioengineering and Nanotechnology(AIBN) The University of QueenslandBrisbaneQLD 4072Australia JST-ERATO Yamauchi Materials Space-Tectonics Project and International Center for Materials Nanoarchitectonics(WPI-MANA) National Institute for Materials Science(NIMS)1-1 NamikiTsukubaIbaraki 305-0044Japan

Low activation isotopic boron(11B)based magnesium diboride(Mg^(11)B_(2))superconductors doped with biomass-derived activated carbon were synthesized using11B and magnesium powder via solid-state *** effect of carbon doping on the lattice structure and superconducting properties of Mg^(11)B_(2)bulks were evaluated using X-ray powder diffraction,high resolution transmission electron microscopy,scanning electron microscopy and magnetization *** refinement of structural parameters indicates successful substitution of carbon in Mg^(11)B_(2)*** critical current density(Jc)of carbon doped Mg^(11)B_(2)synthesized at 650℃was enhanced more than two times compared with the pure Mg^(11)B_(2)*** improvement was observed for the Mg^(11)B_(2)bulks heat-treated at 800℃.This enhancement is due to successful substitution of biomass-derived carbon with high surface area into Mg^(11)B_(2)*** flux pinning mechanism of pure and doped Mg^(11)B_(2)bulks were investigated using the Dew-Hughes *** study provides information regarding enhancement of the Jc of low activation Mg^(11)B_(2)superconductors suitable for next-generation fusion magnets.

关键词： Magnesium diboride critical current Flux pinning mechanism Fusion reactor applications

Vortex pinning and rectification effect in a nanostructured superconducting film with a square array of antidot triplets

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Chinese Physics B 2018年第5期27卷 458-463页

作者：何安薛存周又和 College of Science Chang'an University School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical University Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China and Department of Mechanics and Engineering SciencesLanzhou University School of Aeronautics Northwestern Polytechnical University

We study the stability of vortices pinning and dynamics in a superconducting thin strip containing a square array of antidot triplets by using the nonlinear Ginzburg–Landau（GL） theory. Compared with the regular square array of circular holes, the vortices are no longer pinned inside the circular holes, but instead stabilized at the center of the antidot triplets depending on the geometry parameters. Moreover, the influences of the geometry parameters and the polarity of the applied current on the current–voltage（I–V） characteristics are also studied. The critical current for the sample turning into a normal state becomes smaller when the hole diameter D is smaller and the spacing B between the holes is larger. Due to the asymmetric pinning sites, our numerical simulations demonstrate that the positive and negative rectified voltages appear alternately in the resistive state of the sample under an ac current of square pulses.

关键词： matching effect antidot triplets current-voltage characteristic critical current

Fabrication and properties of the meander nanowires based on ultra-thin Nb films

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Chinese Physics B 2014年第8期23卷 521-526页

作者：赵璐金贻荣李洁邓辉郑东宁 Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences

We report the fabrication and the study of superconducting properties of ultra-thin Nb superconducting meander nanowires, which can be used as superconducting nanowire single-photon detectors （SNSPDs）. The ultra-thin （about 7- nm thick） Nb films are patterned into micro-bridges, and 100-nm wide meander nanowires by using e-beam lithography （EBL）. The average transition temperature （Tc） of the nanowires is about 4.8 K and the critical current density jc is about 2.8 × 10^6 A/cm2. Superconducting characteristics of the specimens at different applied magnetic fields up to 8 T （parallel or perpendicular to the specimen） are systematically investigated. The normalized temperature t （= T/Tc） dependences of the parallel critical field （HcⅡ） for both the micro-bridge and the meander nanowire are almost the same, following the Ginzburg and Landau （GL） formalism for ultra-thin films. However, in perpendicular field and in the vicinity of Tc （〉 0.95Tc）, the critical field Hc⊥ of the nanowire exhibits a down-turn curvature nonlinear temperature dependence while the micro-bridge displays a linear temperature dependence. The nonlinear behavior of Hc⊥ in the nanowire is believed to be due to the fact that in the vicinity of Tc the coherence length becomes larger than the line width. Additionally, the localization of carriers in the nanowire could also contribute to the nonlinear behavior. The resistive transitions could be described by the phase-slip model for quasi-one-dimensional system. Moreover, the hysteresis in I-V curve of the meander nanowires can be illustrated by a simple model of localized normal hotspot maintained by Joule heating.

关键词： Nb meander nanowire critical temperature critical field critical current

MAGNETOELASTIC BENDING AND STABILITY OF current-CARRYING COIL STRUCTURES

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Acta Mechanica Sinica 1997年第3期13卷 253-263页

作者：郑晓静周又和 Department of Mechanics Lanzhou UniversityLanzhou 730000China

As a results of magnetoelastic interaction, the mechanical behavior of current-carrying coil structures, such as deformation and instability, is a key problem in the design of strong held magnets. In this paper, a nonlinear mathematical model is presented to describe the deformation and buckling of D-type current-carrying coils, based on the Biot-Savart law and the bending theory of curved beams. The bending deformation, the critical value of current for the magnetoelastic buckling of the current-carrying coil, and the effects of the type and number of supports at middle part of the bending coil on the critical value are quantitatively investigated by a semi-analytical and semi-numerical method. The numerical results are shown to be in good agreement with the experimental data.

关键词： D-type coil magnetoelastic coupling interaction nonlinear equation critical current semi-analytical method

Study of Nb/Nb_xSi_(1-x)/Nb Josephson junction arrays

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Chinese Physics B 2015年第12期24卷 526-529页

作者：曹文会李劲劲钟源贺青 National Institute of Metrology

Owing to the adjustable characteristics and superior etching properties of co-sputtered Nbx Si1-x film, we are trying to fabricate Nb/Nbx Si1-x/Nb Josephson junction arrays for voltage standard. It is important to find the suitable Nbx Si1-x barrier for the junctions. Josephson junctions with different barrier content are fabricated. current–voltage characteristics are measured and analyzed. It is demonstrated in this paper that critical current can be adjusted by using different barrier content and thickness. Shapiro steps of five hundred junctions in series are observed.

关键词： Josephson junctions critical current voltage standard