IEEE Transactions on Applied Superconductivity最新文献

{"title":"IEEE Transactions on Applied Superconductivity Information for Authors","authors":"","doi":"10.1109/TASC.2026.3719788","DOIUrl":"https://doi.org/10.1109/TASC.2026.3719788","url":null,"abstract":"","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"0003001-0003001"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11663554","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Screening Behavior of Hybrid High-Temperature Superconducting Screens Subjected to Successive Excitation Cycles: Experiments and Numerical Study","authors":"Nicolas Rotheudt;Jean-François Fagnard;Tomas Hlasek;Jan Plechacek;Philippe Vanderbemden","doi":"10.1109/TASC.2025.3646984","DOIUrl":"10.1109/TASC.2025.3646984","url":null,"abstract":"Combining high-temperature superconducting bulks and jointless closed-loop coated conductors recently demonstrated promising magnetic shielding/screening properties when they are zero-field cooled andsubjected to an inhomogeneous applied field. The present work focuses on studying how their screening properties evolve if several magnetic field excitation cycles are applied, as it is the case in practical applications. This study is carried out both experimentally and numerically. The main result is that more than 95% of the field attenuation (screening factor SF) obtained after the first ramp still remain after 300 cycles. This result is explained by using the numerically computed current density distribution in the bulk alone. The slight decrease in SF after several cycles is found to be smaller than the field attenuation arising from conventional current relaxation (or flux creep) if the magnetic field is kept constant after the first increasing ramp. These results demonstrate the potential of such superconducting screens for practical applications with a large number of excitation applied field cycles.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-6"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polycrystalline Phase Formation of Co-Doped BaFe2As2 Studied by In-Situ 4D-STEM","authors":"Yiming Ma;Yusuke Shimada;Hongye Gao;Yuta Hasegawa;Shinnosuke Tokuta;Akiyasu Yamamoto;Akinori Yamanaka;Satoshi Hata","doi":"10.1109/TASC.2025.3649784","DOIUrl":"10.1109/TASC.2025.3649784","url":null,"abstract":"For polycrystalline cobalt-doped BaFe₂As₂ (Ba122:Co) superconductors, controlling their microstructure, such as grain size, crystallographic texture, is crucial for achieving high critical current densities (<italic>J</i>_c). A prevailing academic view holds that heat treatment is a key step in forming a desired crystallographic texture. This study performed in-situ heating and four-dimensional scanning transmission electron microscopy (4D-STEM) observation to characterize microstructural evolution in precursor Ba122:Co powders prepared by high-energy ball milling and subsequent spark plasma sintering. A formation path for the Ba122 phase was revealed: a crystallographic orientation relationship was recognized between fine Ba122 grains and adjacent larger FeAs grains in the precursor powders, which suggests epitaxial growth of the Ba122 phase from the FeAs phase. However, in the subsequent in-situ heating process, the microstructural changes in the thin foil specimens of the precursor powders exhibited a different trend from that of bulk specimens of the precursor powders: the fine Ba122 grains did not coarsen but exhibit grain refinement and amorphization. The observed results described above were discussed from the viewpoints of the microstructural control of polycrystalline Ba122:Co.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-5"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Filament Structure in NbTi Superconducting Wires in WST","authors":"Zhang Kailin;Guo Qiang;Jiang Longtao;Han Luyang;Wang Han;Zhao Jiajun;Li Hengchao;Zhu Yanmin;Yan Lingxiao;Wang Ruilong;Zhou Zijing;Wang Shuai;Liu Xianghong;Feng Yong;Li Jianfeng;Zhang Pingxiang","doi":"10.1109/TASC.2026.3652108","DOIUrl":"10.1109/TASC.2026.3652108","url":null,"abstract":"This study optimized the structural design of NbTi superconducting wires using the analysis method combining finite element simulation with experiments. By adjusting the matrix material of the NbTi mono-filament billet, the overall deformation uniformity of the filaments was significantly improved. Considering both the optimal structural parameters obtained from simulations and the practical requirements of assembly feasibility and processing yield, the final design has been confirmed, with the matrix material of the NbTi mono-filament billet being Cu2Mn, and the spacing-to-diameter ratio (S/D) parameter and filament spacing of the NbTi multi-filament billet being 0.50 and 5.20 mm, respectively. Based on this design, NbTi multi-filament wire with 24 filaments and a copper-to-non-copper ratio of 7 was fabricated using conventional drawing and aging heat treatment processes. The wire was finally drawn to a diameter of 1.0 mm and subjected to superconducting performance tests. The results showed that, under 4.2 K and 4 T, the optimized design achieved a critical current density (<italic>J_c</i>) of 3804 A/mm², representing an 11.8% improvement compared with 3400 A/mm² for the existing structure.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-5"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Edge Geometry and Interface Characteristics on Delamination Strength of REBCO Tapes Under Transverse Tension Using Anvil Method","authors":"Richard Pascua;Michael de Leon;Sang Heon Lee;Hyung-Seop Shin","doi":"10.1109/TASC.2025.3649790","DOIUrl":"10.1109/TASC.2025.3649790","url":null,"abstract":"Multilayer REBCO-coated conductor (CC) tapes undergo various stresses and strains when utilized in superconducting devices such as high-field magnets and coils. The stresses encountered by REBCO tapes include radial transverse tensile stresses from Lorenz forces and thermal stresses arising from differences in the thermal expansion coefficients of the constituent layers during quenching. These stresses can cause delamination at multiple interfaces within the REBCO CC tape’s multilayer architecture, compromising its integrity and leading to catastrophic failure of the superconducting device. Meanwhile, the Cu stabilizer surrounding the CC tape plays a key role in preventing delamination failure by binding multiple constituent layers with different mechanical properties and maintaining structural stability against transverse external forces. However, the effect of slit edges created during CC tape manufacturing on delamination resistance under transverse loading remains unclear. To address this critical research gap, we conducted comprehensive delamination tests using the anvil method. We compared the effects of the slit edge geometry and the Cu layer at the edges on the mechanical delamination strength of REBCO CC tapes. By conducting a comprehensive analysis, we aimed to examine the roles of edge geometry and interfacial properties in the delamination behavior of REBCO CC tapes. This will offer valuable insights for optimizing the design and fabrication of these high-field coils, contributing to the development of more robust and reliable superconducting devices.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-5"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation of Critical Current in Superconducting Structures Based on Quasi-Static A-ϕ Formulation","authors":"Hongbo Yang;Sijian Wang;Huadong Yong","doi":"10.1109/TASC.2026.3658272","DOIUrl":"10.1109/TASC.2026.3658272","url":null,"abstract":"The critical current is a key factor for the stable operation of superconducting structures. Therefore, it is imperative to employ precise and efficient numerical methods for evaluating the critical current in complex superconducting structures, thereby ensuring their operational safety and reliability. Several numerical approaches based on the finite element method have been proposed by researchers. However, when evaluating the critical current, the computational demand of the time-dependent calculation method is exceedingly high. Therefore, it is necessary to adopt a quasi-static methodology for the computation of superconducting critical currents. In this paper, it is assumed that the current in the superconductor is stable and the induced current caused by magnetic field variation has been fully dissipated. The critical current is predicted in different structures based on the quasi-static A-<italic>ϕ</i> formulation and <italic>E</i>-<italic>J</i> constitutive law. The numerical results are compared between the quasi-static A-<italic>ϕ</i> formulation and experimental data as well as the H formulation. Due to its significant computational efficiency, the quasi-static A-<italic>ϕ</i> formulation holds potential as an effective method for optimizing superconductor structures.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-10"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146223664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Series-Arc Analysis Using a Normalized FFT Harmonic Energy Ratio in Power Distribution Systems With SFCL","authors":"Min-Ho Yoon;Seung-Su Choi;Sung-Hun Lim","doi":"10.1109/TASC.2026.3664364","DOIUrl":"10.1109/TASC.2026.3664364","url":null,"abstract":"Detecting series arc faults in motor-connected distribution systems is challenging due to the dynamic impedance of induction motors. The inclusion of a Resistive Superconducting Fault Current Limiter (SFCL) further complicates detection by potentially dampening the high-frequency arc signatures required for identification. This paper experimentally investigates whether a harmonic-based detection metric remains robust under the combined influence of motor inrush dynamics and SFCL resistive operation We utilize a three-cycle sliding Fast Fourier Transform (FFT) to compute a band-limited harmonic energy ratio, H(k) over the 200–2000 Hz band. Tests compare wye and delta starting methods and two arc locations: the main feeder (Case 1) and the motor branch (Case 2). Experimental results show that under the same line voltage, the delta connection produced a larger natural inrush(<inline-formula><tex-math>$ approx 65$</tex-math></inline-formula>A) compared to the wye connection (<inline-formula><tex-math>$ approx 26$</tex-math></inline-formula>A). The SFCL effectively functioned as a soft-starter, limiting the delta inrush to 35 A via a resistive quench(<inline-formula><tex-math>$ approx 80$</tex-math></inline-formula>V). Although this resistive damping attenuated the absolute arc current spectra, the normalized metric H(k) successfully distinguished arc faults. In Case 1, H(k) consistently exceeded the baseline by a factor of 3 to 8. In Case 2, despite a masking effect caused by the parallel resistive load under wye starting, the metric remained reliable, showing a distinct 5-fold increase in the delta configuration and a gradual rise at the motor terminals. This study validates that the proposed harmonic-energy metric provides a practical, connection-aware indicator for series arc detection, capable of overcoming the signal suppression introduced by the SFCL.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-6"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148484439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of Superconducting Power Transmission in Long-Term Commercial Railway Operation Over One Year","authors":"M. Tomita;Y. Fukumoto;A. Ishihara;T. Akasaka;T. Onji","doi":"10.1109/TASC.2026.3660621","DOIUrl":"10.1109/TASC.2026.3660621","url":null,"abstract":"Using superconducting cables as feeders in railway electrification systems can significantly reduce voltage drops, offering benefits such as reduced transmission losses, improved regeneration efficiency, and fewer substations. We have begun research and development of superconducting cables for railway electrification systems, and have accumulated data under various conditions on commercial lines. With technical confirmation, we had obtained government approval for commercial operation of passenger transport using superconducting feeder cable system, superconducting power transmission had achieved a stable power supply to every trains, under train operating conditions and seasonal temperature fluctuations in spring, summer, autumn and winter. One year has passed since the start of commercial operation, we have reported on the operational results of superconducting power transmission.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-4"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148484789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progress Toward a 10-kA Superconducting Power Supply for Levitated Dipole Reactors","authors":"Bradley Leuw;Rodney A. Badcock;Eleanor V. W. Chambers;Joshua P. M. Ellingham;Piet Guersen;Kent Hamilton;Joseph Jones;Matt Lynch;Jack Morris;Les Meadows;James H. P. Rice;Mohammad Siamaki;Sam Schimanski;Joe Todd;Sriharsha Venuturumilli;Ratu C. Mataira","doi":"10.1109/TASC.2026.3654477","DOIUrl":"10.1109/TASC.2026.3654477","url":null,"abstract":"OpenStar Technologies is a private fusion company in New Zealand, developing a fusion reactor based on the levitated dipole. The levitated dipole has a stable magnetic configuration, which provides the basis for the design of a fusion concept. Levitated dipole-based fusion reactors will require large-scale high-field high temperature superconductor (HTS) magnets operating with consistent “quasi-persistent” current while levitating. Quasi-persistent currents in levitating magnets can only be supplied by on-board power supplies that continuously replenish the energy lost from magnet operation. OpenStar has designed, built, and validated an HTS rectifier which to date has charged a 0.53 H non-insulated HTS magnet to 824 A. The initial charging of this magnet to 180 kJ over 60 hours demonstrates the first integration of a large scale HTS magnet with an embedded HTS rectifier. In October 2024, this enabled OpenStar to reach the milestone of first plasma.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-6"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148485585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HTS Dynamo Modeling Comparison Using the J-A-$phi$ and H-A Formulations Considering Two Distinct Operating Scenarios","authors":"Gabriel dos Santos;Mark Ainslie;Rui Du","doi":"10.1109/TASC.2026.3672433","DOIUrl":"10.1109/TASC.2026.3672433","url":null,"abstract":"High-temperature superconducting (HTS) dynamos enable contact-free injection of large direct currents into superconducting circuits, and their multiphysics electromagnetic–thermal coupling and practical circuit interactions requires models that are both accurate and computationally efficient. This work implements a hybrid J–A–<inline-formula><tex-math>$phi$</tex-math></inline-formula> formulation coupled to thermal model. It solves the scalar magnetic potential <inline-formula><tex-math>$phi$</tex-math></inline-formula>, the magnetic vector potential <inline-formula><tex-math>$mathbf {A}$</tex-math></inline-formula>, the current density <inline-formula><tex-math>$mathbf {J}$</tex-math></inline-formula>, and the temperature <inline-formula><tex-math>$T$</tex-math></inline-formula>. To consider the temperature dependence, the critical current density is a function of temperature that is computed by a thermal model. Two operating scenarios are examined: (i) an open-circuit case with zero-net transport current and (ii) a charging case in which the HTS tape is coupled to a series <inline-formula><tex-math>$R$</tex-math></inline-formula>–<inline-formula><tex-math>$L$</tex-math></inline-formula> circuit. Simulations at 10 Hz and 500 Hz evaluate global variables: instantaneous voltage between the terminal of tape <inline-formula><tex-math>$V_{text{sc}}$</tex-math></inline-formula>, cumulative time-averaged voltage <inline-formula><tex-math>$V_{text{DC}}$</tex-math></inline-formula>, average temperature <inline-formula><tex-math>$T_{text{av}}$</tex-math></inline-formula>, and charging current <inline-formula><tex-math>$I_{text{sc}}$</tex-math></inline-formula> using a segregated <inline-formula><tex-math>$H$</tex-math></inline-formula>-formulation as the reference and benchmarking against <bold>J-A</b>, <bold>H-A</b> and <bold>J-A</b>-<inline-formula><tex-math>$phi$</tex-math></inline-formula> formulations. The J–A–<inline-formula><tex-math>$phi$</tex-math></inline-formula> formulation delivers substantial reductions in computational cost marked decreases the time footprint relative to <bold>H-A</b> while preserving the accuracy of the reference solution. These results indicate that J–A–<inline-formula><tex-math>$phi$</tex-math></inline-formula> is a reliable and efficient tool for design-oriented studies of HTS dynamos.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"36 5","pages":"1-6"},"PeriodicalIF":1.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11433398","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148487881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}