Superconductivity最新文献

{"title":"Analytical model for coupling loss in filamentized high-temperature superconducting tapes","authors":"F. Gömöry ,&nbsp;J. Šouc ,&nbsp;M. Solovyov ,&nbsp;S. Landvogt ,&nbsp;M. Pekarčíková ,&nbsp;C.R.H. Bahl ,&nbsp;A.C. Wulff","doi":"10.1016/j.supcon.2025.100193","DOIUrl":"10.1016/j.supcon.2025.100193","url":null,"abstract":"<div><div>Composite wires containing superconducting filaments embedded in a metallic matrix are used in various applications. In the presence of time-varying magnetic fields, electrical currents are induced in the loops where superconductor and normal metal regions are connected in series, causing energy dissipation known as coupling loss. Commonly accepted analytical formulas provide a basic understanding of this phenomenon. Recently, tape-shaped conductors containing a single layer of high-temperature superconductor striated in several parallel filaments have gained attention for use in nuclear fusion reactors, particle accelerators, and motors. It was found that, in spite of a dissimilar geometry, the analytical formulas deduced for round composites provide a fair qualitative interpretation of the experimental data obtained for this new kind of conductor. However, because of the used postulation of uniform local magnetic field, these models cannot correctly predict the dissipation near the peak in frequency dependence. We derived an analytical model starting from the assumption of an exponential decrease of magnetic field from the tape ends towards its center. This model is free of fitting parameters, with the peak dissipation controlled by the tape width only. Compared to previous models, it predicts <span><math><mo>∼</mo></math></span>40% lower peak loss. We demonstrate its decent agreement with experiments.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100193"},"PeriodicalIF":6.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Critical current degradation of REBCO coated conductor tapes caused by multiple cracks under tensile loading","authors":"Zhirong Yang ,&nbsp;Peng Song ,&nbsp;Feng Feng ,&nbsp;Timing Qu","doi":"10.1016/j.supcon.2025.100185","DOIUrl":"10.1016/j.supcon.2025.100185","url":null,"abstract":"<div><div>REBa₂Cu₃O_x (REBCO) coated conductors exhibit irreversible critical current (<span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>) degradation under tensile strain beyond the irreversible strain (<span><math><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>irr</mi></mrow></msub></math></span>). While this degradation is attributed to cracking, the specific crack evolution process and its quantitative relation to <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> degradation remain unclear. Here, the multiplication of cracks in REBCO tapes under tensile is characterized. It was found that surface particles disrupt continuous crack propagation, causing fragmentation of the REBCO layer. A shear lag model describes how the stress distribution evolves with fragmentation spacing. A probabilistic fracture model then predicts the two-regime spacing reduction as a function of applied strain. The discontinuous crack network acts as the residual flow channel for current once strain exceeds <span><math><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>irr</mi></mrow></msub></math></span>. Crack spacing determines the remaining <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> in this regime. An analytical model is thus proposed to capture the <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> degradation behavior based on the quantified fragmentation process. Additionally, this study suggests approaches to obtain a wider safe operating strain range through tailoring of the fracture behavior, expanding the practical application limits. This work provides new insights into the progressive cracking mechanisms governing irreversible <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> degradation in strained REBCO tapes.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100185"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144712905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High performance multifactorial designs based on a refined analytical method for HTS maglev systems","authors":"Xiaoning Liu ,&nbsp;Zigang Deng ,&nbsp;Zhihao Ke ,&nbsp;Yuqiong Wang ,&nbsp;Xiangyu Tian","doi":"10.1016/j.supcon.2025.100190","DOIUrl":"10.1016/j.supcon.2025.100190","url":null,"abstract":"<div><div>YBa<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Cu<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>δ</mi></mrow></msub></math></span> high-temperature superconductors (HTS) exhibit remarkable passive levitation over permanent magnet guideways (PMG), but the strong nonlinearity poses significant challenges for developing analytical models for HTS maglev systems. This paper presents a refined analytical method for calculating the electromagnetic force in such systems. The method incorporates critical factors, including the complex properties of the superconductors, the Halbach PMG geometry, and various operation conditions. The derived analytical expressions explicitly reveal the interplay between system parameters and levitation performance. Experimental and numerical validation confirms the model’s high prediction accuracy in magnetic fields, levitation and guidance forces. A sensitivity analysis further identifies the most influential parameters such as thickness of the magnet, levitation height, Halbach wavelength. Moreover, this paper calculates and provides the recommended structural parameters for both rare-earth and rare-earth-free PMG. The potential of HTS maglev systems for heavy-haul applications is explored, demonstrating the capability to achieve significant levitation force (about 50 ton/m) under constrained geometric conditions. This work provides critical insights for minimizing permanent magnet consumption in HTS maglev systems and circumventing rare-earth material constraints.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100190"},"PeriodicalIF":6.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A low-resistance joint of REBCO stacked cable for large-scale superconducting magnets","authors":"Jialong Zhang ,&nbsp;Peng Song ,&nbsp;Binbin Wang ,&nbsp;Yulong Liu ,&nbsp;Cedric Korte ,&nbsp;Timing Qu","doi":"10.1016/j.supcon.2025.100191","DOIUrl":"10.1016/j.supcon.2025.100191","url":null,"abstract":"<div><div>The integration of REBCO superconducting coils into compact tokamak toroidal field magnets represents a transformative advancement in fusion technology. In the fabrication of these magnets, electrical connections between pancake coils are typically established through a transverse bridging joint, the performance of which critically impacts device efficiency. To address the demand for enhanced connectivity, this study presents a novel bridge-type “stacked joint” utilizing a superconducting-copper composite structure, optimized for inter-coil connections of stacked REBCO cables. Leveraging a modular stacking approach and low-temperature soldering, this design achieves a resistance as low as 1 <span><math><mrow><mi>n</mi><mi>Ω</mi></mrow></math></span> over a 10 cm length alongside a soldering resistivity below 25 <span><math><mrow><mi>n</mi><mi>Ω</mi><mspace></mspace><msup><mrow><mi>cm</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span> in a liquid nitrogen (77 K) self-field environment. The study further investigates the impact of tape length and quantity on joint electrical performance under this configuration. Rigorous testing, including 10 thermal cycles (77 K to room temperature) and pressure loads up to 30 MPa, confirms the joint’s structural reliability and the consistency of the fabrication process, underscoring its potential for fusion applications.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100191"},"PeriodicalIF":6.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High temperature superconductor coated conductors: A highly complex system where the only way is ‘ups’","authors":"J.L. MacManus-Driscoll","doi":"10.1016/j.supcon.2025.100189","DOIUrl":"10.1016/j.supcon.2025.100189","url":null,"abstract":"","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100189"},"PeriodicalIF":6.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superconducting fault current limiter for multi-terminal HVDC grid protection","authors":"Wenxin Li ,&nbsp;Ying Xin","doi":"10.1016/j.supcon.2025.100195","DOIUrl":"10.1016/j.supcon.2025.100195","url":null,"abstract":"<div><div>With the global energy transition, the proportion of renewable energy power generation in total electricity production has exceeded 30% and continues to rise, even the ratio is higher in China. Multi-terminal high-voltage direct-current (MT-HVDC) transmission systems have advantages of integration of distributed renewable energy sources, dynamic grid interconnections, and reliable islanding operation capabilities, being critical for next-generation power grid. Current limiting technologies are pivotal in maintaining grid safety and stability, especially for HVDC systems without natural zero-crossing point in fault currents. In this perspective, a superconducting fault current limiter (SFCL) with combination of resistance and inductance is necessary and more effective solution in protecting MT-HVDC transmission systems.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100195"},"PeriodicalIF":6.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of rare earth (RE) mixing in REBa2Cu3O7−x thin films, including RE2O3 nanoparticle formation, on in-field critical current density at 20K","authors":"M.H. Lai ,&nbsp;I. Kim ,&nbsp;J.P. Feighan ,&nbsp;T. Bedford ,&nbsp;J. Shen ,&nbsp;M.T. Moceri ,&nbsp;J. Huang ,&nbsp;X.T. Nguyen ,&nbsp;G. Di Martino ,&nbsp;H. Wang ,&nbsp;S.H. Moon ,&nbsp;A. Kursumovic ,&nbsp;J.L. MacManus-Driscoll","doi":"10.1016/j.supcon.2025.100171","DOIUrl":"10.1016/j.supcon.2025.100171","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The factors that influence high-field, low-temperature current carrying performance of coated conductors are complex. Using epitaxial thin films grown by pulsed laser deposition (PLD) made from (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Y&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;RE’&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;RE”&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;)Ba&lt;sub&gt;2&lt;/sub&gt;Cu&lt;sub&gt;3&lt;/sub&gt;\u0000 O&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; (YREBCO), where RE = rare earth targets, with and without liquid (L) additions, this work decouples the different complex effects (both positive and negative) of RE mixing. In doing so, we understand the outcomes of the separate effects of this mixing, and the incidental formation of (Y,RE’,RE”)&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; nanoparticles. The YREBCO composition is chosen because it permits growth conditions to be the same and near-optimum for all the targets, &lt;em&gt;i.e.&lt;/em&gt;, at the optimum temperature as for the growth of pure YBCO, the reference composition, to enable effective comparison of compositions. We find that a high RE ion size variance increases the RE&lt;sub&gt;2&lt;/sub&gt;O&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; fraction but that &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; (20 K, 8 T) is decreased, owing to the associated atomic disorder. On the other hand, we find that for moderate variance (and moderate RE&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; nanoparticle formation), &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; (20 K, 8 T) is increased. A liquid phase needs to be included to ensure minimal microstructural disorder of the YREBCO lattice caused by the RE&lt;sub&gt;2&lt;/sub&gt;O&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; nanoparticle inclusions. Of the wide range of PLD target compositions explored, (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Y&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Gd&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Yb&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;)Ba&lt;sub&gt;2&lt;/sub&gt;Cu&lt;sub&gt;3&lt;/sub&gt;O&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; is determined to have the optimum moderate ion size variance. An approximate doubling of &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; (20 K, 8 T) compared to pure YBCO films results. Thus, the (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;Y&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Gd&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;Yb&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"15 ","pages":"Article 100171"},"PeriodicalIF":5.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Split pulsed magnet combining high peak central magnetic field and long rise time for pulsed field magnetization of high temperature superconductors","authors":"Juntong Hu ,&nbsp;Wenjiang Yang ,&nbsp;Difan Zhou ,&nbsp;Peng Zhao ,&nbsp;Mingliang Bai ,&nbsp;Juzhuang Yan ,&nbsp;Haoran Jiang ,&nbsp;Tianxin Lan","doi":"10.1016/j.supcon.2025.100166","DOIUrl":"10.1016/j.supcon.2025.100166","url":null,"abstract":"<div><div>Split pulsed magnets are widely employed in high temperature superconducting (HTS) motor armature winding as magnetizing coils to implement in-situ pulsed field magnetization (PFM) for HTS field pole magnets. We have designed and developed a compact and portable split pulsed magnet, that balances a peak central magnetic field of nearly 7 T and a rise time of 24 ms, making it particularly suitable for PFM of HTS materials at lower temperatures. Single and two-step PFM experiments of HTS GdBa ₂Cu₃O<span><math><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>δ</mi></mrow></msub></math></span> (GdBCO) bulk in different temperature ranges are conducted and the maximum trapped fields <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span> are observed to be <span><math><mrow><mo>&gt;</mo><mn>3</mn></mrow></math></span> T in the 40–50 K temperature range and nearly 4 T at 30 K in a 30 mm diameter GdBCO bulk. The trapped field results validate the excellent PFM ability of this designed split pulsed magnet and indicate a high trapped field (close to 4 T) can also be obtained in a coreless double armature. Moreover, multi-physical field responses of the split pulsed magnet during discharge are analyzed by a 3D field-circuit coupling model, which manifests that the split pulsed magnet is in a stable and safe operating state even under the highest charge voltage. Finally, this study may provide a novel clue for the development of coreless HTS bulk motors and suggest that HTS coreless motors can maintain a high air gap magnetic field while avoiding losses and thrust or torque fluctuations caused by iron core saturation under high magnetic fields.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100166"},"PeriodicalIF":5.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hysteresis loss scaling of round REBCO cable towards 20 T","authors":"Arend Nijhuis ,&nbsp;Ruben Lubkemann ,&nbsp;Gulio Annaballi ,&nbsp;Huan Jin ,&nbsp;Zichuan Guo ,&nbsp;Jinggang Qin ,&nbsp;Chao Zhou","doi":"10.1016/j.supcon.2025.100165","DOIUrl":"10.1016/j.supcon.2025.100165","url":null,"abstract":"<div><div>High Temperature Superconductor (HTS) cables are considered for use in tokamaks such as DEMO (EU) and Chinese next generation fusion device (CN) or compact fusion machines. HTS cables offer the advantage of increased operating temperature and field strength of the magnet coils. In particular for Central Solenoid (CS) coils, the HTS high current cabled conductor windings are exposed to fast ramping AC magnetic fields inducing AC losses. The AC loss in HTS cables for fusion is mainly explored at low magnetic field amplitudes due to lack of testing facilities at higher fields. However, since the operating field in CS coils may be up to 20 T, it is essential to obtain quantitative knowledge on the AC losses for the entire applied field range with reasonable accuracy. This is important for thermohydraulic analysis of the operating temperature margin in coil designs. A method is used here to scale the hysteresis loss of a REBCO cable without transport current, measured up to only 1.4 T, to the entire field and temperature range up to 20 T and 50 K respectively. The field shielding and penetration effects of a multi-layer REBCO CORC®-like cable are quantified by measurements on stacked tape samples with a Vibrating Sample Magnetometer (VSM) up to fields significantly higher than the round cable’s full penetration field, found to be at 4.2 T. For higher fields, using measured critical current (<span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>) data up to 19 T and an <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>(<em>B</em>,<em>T</em>) scaling law for field (<em>B</em>) and temperature (<em>T</em>) serve to cover the required range of data within the window of coil operation parameters. Basic well-known theory on AC loss, particularly on the relation between hysteresis loss and critical current density against magnetic field, serves as a validation for this work.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100165"},"PeriodicalIF":5.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-gap two-band superconductivity well above the Pauli limit in non-centrosymmetric TaIr2B2","authors":"J. Kačmarčík ,&nbsp;Z. Pribulová ,&nbsp;T. Shiroka ,&nbsp;F. Košuth ,&nbsp;P. Szabó ,&nbsp;M.J. Winiarski ,&nbsp;S. Królak ,&nbsp;J. Jaroszynski ,&nbsp;T. Shang ,&nbsp;R.J. Cava ,&nbsp;C. Marcenat ,&nbsp;T. Klein ,&nbsp;T. Klimczuk ,&nbsp;P. Samuely","doi":"10.1016/j.supcon.2025.100167","DOIUrl":"10.1016/j.supcon.2025.100167","url":null,"abstract":"<div><div>Non-centrosymmetric superconducting materials represent an exciting class of novel superconductors featuring a variety of unconventional properties, including mixed-parity pairing and very high upper critical fields. Here, we present a comprehensive study of TaIr<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>B<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> (with <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>5</mn><mo>.</mo><mn>1</mn></mrow></math></span>\u0000 <!--> <!-->K), using a set of complementary experimental methods, including bulk- and surface-sensitive techniques. We provide evidence that this system is a two-band, yet it behaves as a single-gap superconductor with a strong coupling. The upper critical field of TaIr<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>B<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> significantly exceeds the Pauli limit and exhibits a nearly linear temperature dependence down to the lowest temperatures. This behavior, rarely seen in superconductors, is discussed in terms of anti-symmetric spin–orbit interaction, two-band-, and strong-coupling effects, as well as disorder.</div></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"14 ","pages":"Article 100167"},"PeriodicalIF":5.6,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}