Physica C-superconductivity and Its Applications最新文献

{"title":"Experimental study on fatigue properties of REBCO copper bonding joints under cyclic tensile loading at 77 K","authors":"Guoxiang Wang ,&nbsp;Yuwei Zhou ,&nbsp;Zequn Ke ,&nbsp;Zhen Huang","doi":"10.1016/j.physc.2025.1354798","DOIUrl":"10.1016/j.physc.2025.1354798","url":null,"abstract":"<div><div>In practical applications, second-generation (2G) high-temperature superconducting (HTS) tapes are inevitably subjected to cyclic loads caused by mechanical, thermal, and electromagnetic forces. As critical components in large-scale HTS magnets, joints are prone to fatigue failure under cyclic loading, making their fatigue performance a key factor for system reliability. Copper bonding joint is a novel joining technology that provides easy fabrication and low joint resistance, offering benefits for designing and manufacturing large-scale HTS magnets. Therefore, examining the fatigue properties of copper bonding joints is essential. This paper first examined the uniaxial tensile properties of the joints and determined their irreversible force based on the criterion of 95 % initial critical current recovery. Subsequently, the influence of maximum forces, stress ratios, and fatigue frequencies on the critical current degradation of the joints was studied at 77 K. Finally, fatigue performance was compared among the original tapes, copper bonding joints, and soldered joints under identical maximum forces. The results showed that copper bonding joints exhibited better fatigue performance compared to the soldered joints.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"638 ","pages":"Article 1354798"},"PeriodicalIF":1.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268727","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":"Study on the levitation height dynamic performance under the current variation starting mode in pinning maglev","authors":"Wei Hong ,&nbsp;Changqi Wang ,&nbsp;Wenxin Li","doi":"10.1016/j.physc.2025.1354797","DOIUrl":"10.1016/j.physc.2025.1354797","url":null,"abstract":"<div><div>The self-stabilizing characteristics of magnetic pinning levitation offer significant potential for near-ground high-speed transportation systems. This article focuses on levitation height regulation during the starting procedure using the Current Variation Starting Mode (CVSM) within electromagnetic guideway (EMG). Through quasi-static experiments examining excitation current, initial levitation position, and load mass influences, the study establishes fundamental principles governing levitation height. A predictive mathematical model derived via empirical curve fitting yields a generalized analytical expression for levitation height calculation. The validated framework demonstrates applicability to static control strategies in maglev systems, particularly for height correction of train body at stations and the starting height estimation.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"638 ","pages":"Article 1354797"},"PeriodicalIF":1.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268726","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":"Foreword for the special issue of Physica C “Quantum matter” dedicated to Jan Zaanen","authors":"","doi":"10.1016/j.physc.2025.1354799","DOIUrl":"10.1016/j.physc.2025.1354799","url":null,"abstract":"","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"638 ","pages":"Article 1354799"},"PeriodicalIF":1.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269173","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":"Dynamic response of high-temperature superconducting magnetic levitation under real seismic wave excitation","authors":"Weifeng Pan ,&nbsp;Jun Zheng ,&nbsp;Yonghai Zhao ,&nbsp;Le Xu","doi":"10.1016/j.physc.2025.1354801","DOIUrl":"10.1016/j.physc.2025.1354801","url":null,"abstract":"<div><div>The high-temperature superconducting (HTS) pinning magnetic levitation (maglev) system achieves passive and stable levitation through the coupling between HTS bulks and permanent magnet guideway (PMG), which gives it great development potential in the field of high-speed rail transit. Nevertheless, safety considerations are also crucial for the HTS maglev transportation system. Currently, there is a lack of research on the operational safety of HTS maglev trains during some extreme situation like earthquakes. Thus, this paper uses an experimentally-verified electromagnetic-thermal-mechanical model to simulate and study the variation law of the temperature rise of HTS bulks under the action of the Trinidad seismic waves (including the individual actions of longitudinal waves and transverse waves, as well as their combined action). The results show that a temperature rise of approximately 0.09 K occurs in the left and right bulk materials when longitudinal waves act alone. The comprehensive effect will cause a lateral drift of 0.6 mm. When transverse waves act alone, the temperature rise of the left and right bulks reaches 0.15 K. Compared with vertical vibration, lateral vibration increases the likelihood of the bulks experiencing a quench, thereby posing a risk of the bulks hitting the PMG. When longitudinal and transverse waves act simultaneously, the temperature rise of the left and right bulks is 0.18 K, which is significantly lower than the 92 K critical temperature for quenching. Thus, under seismic wave conditions, the temperature rise of the bulks in HTS maglev system is extremely small, with a maximum of only 0.18 K. In the existing bath cooling mode of HTS pinning maglev, this temperature rise will not cause HTS bulks to quench. However, it is essential to prevent the decline in levitation performance caused by the change in temperature rise, as this decline may lead to the risk of the bulks hitting the PMG. These findings offer valuable insights into thermal stability, which are beneficial for the future practical implementation of HTS maglev systems.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"638 ","pages":"Article 1354801"},"PeriodicalIF":1.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222722","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":"Measurement and analysis on the levitation and guidance force of HTS bulks under permanent magnet guideway fluctuating magnetic field","authors":"Boyi Zhao,&nbsp;Hao Yang,&nbsp;Bo Yang,&nbsp;Zhichuan Huang,&nbsp;Yiming Zhou,&nbsp;Zigang Deng","doi":"10.1016/j.physc.2025.1354800","DOIUrl":"10.1016/j.physc.2025.1354800","url":null,"abstract":"<div><div>High-temperature superconducting (HTS) pinning maglev technology has attracted considerable attention in the field of high-speed maglev transportation. In practical applications, HTS bulks are subjected to a complex electromagnetic environment due to various external excitations, including the unevenness of permanent magnet guideway (PMG), aerodynamic effects, and normal disturbance of the motor etc. These factors induce variations in the levitation performance of the bulks. In this paper, an air cylinder vibration table with adjustable amplitude and frequency was constructed, and the SCML-01 system was employed to conduct real-time force measurements on the HTS bulks. Experimental results indicate that the levitation force attenuation of HTS bulks increases nonlinearly with the amplitude and frequency of the fluctuating magnetic field (FMF). A resonance phenomenon emerges at 8 Hz, where the levitation force attenuation rate reaches 9.51 %—significantly higher than that at other frequencies. In comparison with the control group, after exposure to the FMF of the PMG, the guidance force of HTS bulks increases significantly, while the unrecoverable distance decreases. This work clarifies the laws governing the influence of the amplitude and frequency of the FMF on the electromagnetic force characteristics of HTS bulks. These findings provide valuable insights for guiding the future development and application of HTS pinning maglev technology.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"638 ","pages":"Article 1354800"},"PeriodicalIF":1.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269171","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":"Belief in thermodynamics has provoked false thermodynamics of superconductors","authors":"A.V. Nikulov","doi":"10.1016/j.physc.2025.1354791","DOIUrl":"10.1016/j.physc.2025.1354791","url":null,"abstract":"<div><div>Belief in thermodynamics has forced superconductivity experts to forget basics of thermodynamics due to a contradiction of superconductivity phenomena to laws of thermodynamics. Because of this belief no one drew reader’s attention during many years that the conventional theory of superconductivity contradicts to the second law of thermodynamics. The common belief that the superconducting transition occurs when the free energy of the superconducting state becomes less than of the normal state has provoked a false claim that a power source of a solenoid creates the energy of magnetization rather than of magnetic field. The authors of only a few books on superconductivity, mostly future Nobel prize winners, did not follow this false claim. No one for many years has noticed that the equality of free energies at the superconducting transition in the critical magnetic field cannot be obtained without contradicting the second law of thermodynamics. The Meissner effect violates the second law of thermodynamics because of the negative surplus work performed in the closed Gorter cycle. The desire to avoid contradiction of superconductivity phenomena with the second law of thermodynamics provoked the false thermodynamics of superconductors, contradicting the law of conservation of energy.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"638 ","pages":"Article 1354791"},"PeriodicalIF":1.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099157","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":"Analysis of the influence of axial mass eccentricity on polar axis offset characteristics in superconducting rotors of magnetic levitation system","authors":"Quansheng Sun ,&nbsp;Chunyan Cui ,&nbsp;Xinning Hu ,&nbsp;Xian Yi ,&nbsp;Yuan Zhang ,&nbsp;Feifei Niu ,&nbsp;Qiuliang Wang","doi":"10.1016/j.physc.2025.1354790","DOIUrl":"10.1016/j.physc.2025.1354790","url":null,"abstract":"<div><div>The superconducting rotor magnetic levitation system has great potential in high-precision angular velocity sensing, but its accuracy and stability are limited by the coupling of multiple physical fields. To address the unresolved synergistic interaction between axial mass eccentricity and aspheric factors, this study systematically quantifies how material heterogeneity affects axial mass eccentricity. On this basis, a multi-field coupling dynamic model of superconducting rotor is established, and the dynamic characteristics of polar axis offset under the single action of axial mass eccentricity and its synergistic effect with aspheric factors such as centrifugal deformation are deeply analyzed, and quantitatively characterizes the nonlinear increase in drift velocity arising from their coupling. The results show that axial mass eccentricity is the core interference source of polar axis drift. The proposed quantitative models of material-induced eccentricity and its coupling with deformation offer a new theoretical foundation for drift prediction, compensation control, and structural optimization of high-precision superconducting rotors.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"638 ","pages":"Article 1354790"},"PeriodicalIF":1.0,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269172","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":"Quench stability simulation of the CFETR CSMC at 47 kA","authors":"Yu Chen ,&nbsp;Yanlan Hu ,&nbsp;Yezheng Xiao ,&nbsp;Qing Yan ,&nbsp;Hui Lu ,&nbsp;Huaichao Liu ,&nbsp;Jilin Zhang ,&nbsp;Xinxin Zhu ,&nbsp;Qicai Ni","doi":"10.1016/j.physc.2025.1354786","DOIUrl":"10.1016/j.physc.2025.1354786","url":null,"abstract":"<div><div>The Central Solenoid Model Coil (CSMC) is a critical component of the China Fusion Engineering Test Reactor (CFETR), responsible for generating a peak magnetic field of up to 12 T This is essential for ensuring the proper operation of the fusion reactor's confinement system. To verify the stable operation of the CSMC magnet, a quench stability analysis is conducted on each coil of the CSMC when the peak magnetic field is reached. This paper provides a detailed study of the magnetic field distribution of the CSMC under the operating current of 47 kA. Additionally, the CryoSoft code THEA is used to estimate the minimum quench energy (MQE) and temperature margin for each coil of the CSMC magnet system under electromagnetic disturbances, corresponding to the maximum magnetic field condition. A comparison of the minimum quench energy and temperature margin of the five coils is made, leading to the identification of the most susceptible coil to quench. Additional analyses further reveal that the disturbance length and its axial location along the cooling channel significantly affect local quench sensitivity.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"637 ","pages":"Article 1354786"},"PeriodicalIF":1.0,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010278","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":"Multiphysics modeling of no-insulation HTS energy storage coils: Enhanced T-A formulation for electromagnetic-mechanical coupling under sequential excitation","authors":"Bingxu Su ,&nbsp;Wenhai Zhou ,&nbsp;Wei Liu ,&nbsp;Rongli Jia ,&nbsp;Nipeng Wang ,&nbsp;Tingliang Chen ,&nbsp;Rui Liang","doi":"10.1016/j.physc.2025.1354785","DOIUrl":"10.1016/j.physc.2025.1354785","url":null,"abstract":"<div><div>Numerical calculation method has become a key tool to study the electric-magnetic-mechanical coupling characteristics of high temperature superconducting (HTS) Energy Storage Coils, especially in the multi-physics field coupling environment. In this paper, the T-A formulation of Maxwell's equations is used due to its high computational efficiency, strong adaptability and low resource requirement. The mechanical-electromagnetic coupling behavior of a 32T fully superconducting magnet in three typical excitation modes is analyzed in depth. Aiming at the limitation of the azimuthal shunt problem of no-insulation (NI) coils on the application of the algorithm, this study adopts the weak form equations to weaken Faraday's electromagnetic induction law which characterizes the relationship between the electric field and the magnetic field. The coupling solution method of current vector potential <em>T</em> and magnetic vector potential <em>A</em> is innovatively adopted. And the Lagrange multipliers and global equations are introduced to improve the conventional Neumann boundary conditions, thus effectively modeling the complex current distribution in HTS NI coils. In addition, based on the discrete coupling model, the COMSOL Multiphysics sub-region coupling modeling method is utilized combining the tilt angle of the tape and the strain-dependent characteristics of the critical current. The accurate quantitative analysis of the hoop stress-strain and tilt angle distribution characteristics of the NI coil is realized. The research results provide an important theoretical basis and technical support for the design and optimization of high-performance NI superconducting magnets.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"637 ","pages":"Article 1354785"},"PeriodicalIF":1.0,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010277","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":"Analysis of mechanical and quench behavior in high-temperature superconductors for energy storage coils","authors":"Lin Xu ,&nbsp;Qunwu Pei ,&nbsp;Jing Gao","doi":"10.1016/j.physc.2025.1354787","DOIUrl":"10.1016/j.physc.2025.1354787","url":null,"abstract":"<div><div>Superconducting materials exhibit superior electromagnetic properties, such as zero electrical resistance and the Meissner effect. These characteristics endow superconducting materials with extensive application potential across contemporary sectors including energy, transportation, electric power, healthcare, telecommunications, and aerospace. However, superconducting materials typically operate within a sophisticated environment characterized by extremely low temperatures, intense magnetic fields, and significant current levels. Under the slight thermal, mechanical, electrical and magnetic disturbances, quenching is easy to occur, potentially endangering the stability and security of the system. For this reason, in order to reduce the damage to the superconducting system caused by quench, the multi-field coupling characteristics and thermoplastic response of superconducting composites and structures during quench are theoretically studied in this paper. Firstly, utilizing the geometric configuration of the high-temperature superconducting (HTS) energy storage coil, a finite element model of the multi-layer composite structure of the superconducting tape is established. Secondly, the quench behavior resulting from local thermal disturbances at various temperatures is investigated through the coupling of transient electromagnetic field equations and heat conduction equations. Studies indicate that the instantaneous evolution of strain is closely correlated with temperature changes during the quenching process. At positions laterally distant from the heat source, the strain exhibits an initial decreasing trend followed by an increase, characterized by a distinct minimum point on the strain curve. However, at locations proximal to the heat source, the strain demonstrates a characteristic of continuous growth. Besides, with the further development of quenching, the growth rate of tensile strain in the unquenched region is obviously accelerated. That is, the thermal expansion in the quenched region can be transmitted to the unquenched regions through the interlayer, resulting in mechanical deformation in these regions. This phenomenon can provide a new perspective and technical approach for quench detection of high temperature superconducting structures.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"637 ","pages":"Article 1354787"},"PeriodicalIF":1.0,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010279","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}