{"title":"Misaligned Analysis of the 15 T Magnet in Super-X Facility","authors":"Yongsheng Wu;Houxiang Han;Lei Wu;Yi Shi;Yu Wu;Jinggang Qin","doi":"10.1109/TASC.2025.3543771","DOIUrl":"https://doi.org/10.1109/TASC.2025.3543771","url":null,"abstract":"The Super-X facility for testing large size superconducting conductors is making significant progress. However, the magnetic force between two coils arises when the centers of their respective magnetic fields do not coincide. Coil misalignment is nearly unavoidable during the installation of magnets which will lead to this eccentric force. In particular, for suspended background magnet in Super-X facility, the eccentric force amplifies the stress on structural components, thereby potentially compromising the magnet's safe operation. Therefore, it is imperative to evaluate its impact on the structural components of the magnet. The pull rope structure of the background magnet is elaborated upon in this article, followed by the analysis of the electromagnetic force generated under different eccentricities of the magnet. Subsequently, the stresses on the structural components of the magnet with and without the pull rope structure are analyzed separately. The results demonstrate that the presence of a pull rope structure is crucial for withstanding magnet eccentricity. Thus far, it can be concluded that the mechanical performance of the magnet still meets the design requirements, taking into account coil misalignment.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 3","pages":"1-6"},"PeriodicalIF":1.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601875","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":"A Quench Behavior Predictive Model for High Temperature Superconducting Magnet Based on Deep-Learning Neural Network","authors":"Pai Peng;Yutong Fu;Weihang Peng;Yawei Wang","doi":"10.1109/TASC.2025.3543793","DOIUrl":"https://doi.org/10.1109/TASC.2025.3543793","url":null,"abstract":"No-insulation (NI) high temperature superconduct-ing (HTS) coils show higher stability than traditionally insulated HTS coils. However, quench remains one of the most crucial issues affecting the safe operation of NI magnets. The quench behaviors in NI coils exhibit inherent complexity since turn-to-turn current redistribution. Low normal zone propagation speed of HTS materials makes it difficult to detect the local hotspot in the early stage of quench, which potentially leads to irreversible damage. In this study, a multi-physical quench behavior predictive model based on Long Short-Term Memory (LSTM) network for HTS NI coils is proposed. Quench data is obtained from an electromagnetic-thermal coupled numerical model with different quench initial locations. By leveraging multi-physical signals as input, the model can predict the dynamic quench behaviors over a future period of time, including temperature, azimuthal current, radial current density and magnetic field. Additionally, the model is capable of predicting quench behaviors at different spatial locations within the coil, achieving a prediction speed of 0.002 seconds and a prediction error below 0.2%. This method demonstrates promise for early quench detection using multi-physical signals and for enabling a timely protection system response.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-6"},"PeriodicalIF":1.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621625","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":"Highly Sensitive DC SQUID Arrays for the Readout of Optical TES at mK Temperatures","authors":"Matthias Schmelz;Vitaliy Shvab;Katja Peiselt;Jürgen Kunert;Vyacheslav Zakosarenko;Thomas Stöhlker;Gregor Oelsner;Ronny Stolz","doi":"10.1109/TASC.2025.3543941","DOIUrl":"https://doi.org/10.1109/TASC.2025.3543941","url":null,"abstract":"In this article, we present advancements of our submicrometer cross-type <inline-formula><tex-math>$text{Nb}/ text{AlO}_{x}/ text{Nb}$</tex-math></inline-formula> Josephson junction technology by implementing an additional highly conductive resistive layer, e.g., for thermalization structures. This allows for shifting the typically observed thermal decoupling of shunt resistors of highly sensitive dc superconducting quantum interference devices (SQUIDs) and SQUID arrays down to temperatures in the millikelvin range. We show results on the technological integration, device design of series SQUID arrays, and their characterization at 4.2 K down to 65 mK. Measurements were performed in an adiabatic demagnetization refrigerator. As an application scenario, we have successfully implemented them as readout circuitry for optical transition edge sensors operated at 150 mK requiring both low-noise and large bandwidth of the readout implemented in a flux-locked loop configuration.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 3","pages":"1-4"},"PeriodicalIF":1.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570680","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":"Evaluating Magnetization Losses in 3-D CORC Tapes With Integral and Finite-Element Methods","authors":"Francesco Lucchini","doi":"10.1109/TASC.2025.3544512","DOIUrl":"https://doi.org/10.1109/TASC.2025.3544512","url":null,"abstract":"The complex electromagnetic behavior of conductor on round core (CORC), compounded by the high aspect ratio of superconducting tapes and the microscale thickness of REBCO layers, necessitates robust 3-D numerical tools. This article compares 3-D finite-element methods (FEMs) and integral equation methods (IEMs) for analyzing magnetization losses in superconducting tapes of CORC cables. Specifically, state-of-the-art FEM formulations, including the <inline-formula><tex-math>$H$</tex-math></inline-formula>, <inline-formula><tex-math>$H-varphi _{m}$</tex-math></inline-formula>, and <inline-formula><tex-math>$T-A$</tex-math></inline-formula> methods, are benchmarked against a surface-based IEM approach. The numerical implementation strategies, computational efficiency, and performance of these methods are examined, emphasizing their strengths and limitations in addressing critical phenomena such as ac losses.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 3","pages":"1-8"},"PeriodicalIF":1.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601874","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":"Manufacturing and Testing HTS Coils for Magnetic Mirror","authors":"Grant Kristofek;Alexi Radovinsky;Alexander Zhukovsky;Nick Kelton;Sergey Kuznetsov;Robert Mumgaard;Jeremy Hollman;Nicoli Ames;P. Brandon Carroll;Jeff Howell;Ben Nottingham;Daniel Sullivan","doi":"10.1109/TASC.2025.3542351","DOIUrl":"https://doi.org/10.1109/TASC.2025.3542351","url":null,"abstract":"Commonwealth Fusion Systems (CFS) completed the design, construction, assembly, and full field dual magnet factory acceptance testing of two identical compact (< 2 ton), high-field (20 T on tape, 17 T in warm bore) HTS REBCO magnets for a magnetic mirror in an axial fusion device. The CFS magnets will serve as the high field end coils for the ARPA-E funded project, “An HTS Axisymmetric Magnetic Mirror on a Faster Path to Lower Cost Fusion Energy.” CFS is a subrecipient of the ARPA-E BETHE Fusion Grant with the University of Wisconsin-Madison.The CFS magnets are DC magnets which will operate in the presence of other magnetic coils. The magnets use partial insulation pancake design. They are conduction cooled by cryocoolers to a nominal design operating temperature of 20 K. Field-induced mechanical stresses in the winding pack are managed such that the tape is constrained within allowable stress and strain during magnet operation. The winding pack is mechanically supported and thermally isolated in the cryostat by a set of high strength, low thermal conductivity supports. The cold mass supports are designed to sustain over 60 tons of axial loading during peak operating conditions. Results of the magnet tests and commissioning are presented below.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143676123","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":"Fabrication of a Nb-Ti Superconducting Closed-Loop Coil for the Next-Generation 45 GHz ECR Ion Source MARS-D","authors":"Lianrong Xu;Janilee Benitez;Jaime Cruz Duran;Paolo Ferracin;Mariusz Juchno;Larry Phair;Damon Todd;Li Wang;Daniel Xie;Ye Yang","doi":"10.1109/TASC.2025.3542743","DOIUrl":"https://doi.org/10.1109/TASC.2025.3542743","url":null,"abstract":"Electron Cyclotron Resonance Ion Sources (ECRISs) that utilize Nb-Ti superconducting coils for 28 GHz frequencies have been operating effectively for over twenty years. However, transitioning to higher frequencies demands stronger magnetic fields, and the conventional racetrack-and-solenoid ECRIS structures have reached their maximum capability with Nb-Ti. To address this, a Mixed Axial and Radial field System Demonstrator (MARS-D) is being developed at Lawrence Berkeley National Laboratory (LBNL). This system features an innovative Closed-Loop Coil (CLC) design that optimizes the use of the conductor fields, enabling the application of Nb-Ti in the next-generation 45 GHz ECRISs. The fabrication of the hexagonal CLC is particularly challenging due to its complex winding path and shape, the stiffness of the Nb-Ti superconducting wire, and the small bending radius. To address these challenges, a series of unique fixtures and tools, as well as a pre-over-bending method, were developed for winding the CLC. To validate the winding fixtures, tools, procedures, and materials used in the coil assembly, a 4-layer practice CLC was wound, epoxy-impregnated, and then cold-tested using liquid nitrogen. The full-size MARS-D CLC is in the process of winding. This paper presents the structure of the MARS-D CLC, the winding fixtures and tools, the winding procedures, the quality control, the impregnation, the test results, and the potential future improvements.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564207","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":"Design and Preliminary Test at 77 K of a 5 T / 34 mm REBCO Dipole Magnet Insert for a 15 T Full-Service-Field Testing Facility","authors":"Ziyang Xu;Peng Song;Mingzhi Guan;Yulong Liu;Canjie Xin;Mianjun Xiao;Liangjun Shao;Timing Qu","doi":"10.1109/TASC.2025.3543334","DOIUrl":"https://doi.org/10.1109/TASC.2025.3543334","url":null,"abstract":"A new testing facility employing a 15 T transverse field to evaluate the full-service-field characteristics of superconducting materials is now under development in China. A primary objective involves producing a large bore 15 T dipole magnet to serve as the source of the transverse magnetic field load. In this study, we designed and constructed a compact high-temperature superconducting (HTS) dipole magnet insert, comprising six block-type double pancake (DP) coils wound with REBCO tapes. The insert features a user bore of 34 mm and an outer diameter of 110 mm, expected to generate a 5 T field at 4.2 K with an operating current of 278 A, within a 10 T low-temperature superconducting (LTS) background dipole magnet. According to numerical simulations, the sextupole coefficient <inline-formula><tex-math>$b_{mathrm{3}}$</tex-math></inline-formula> is less than <inline-formula><tex-math>$5times 10^{-3}$</tex-math></inline-formula> and the operating point <inline-formula><tex-math>$I_{text{op}}/I_{mathrm{c}}$</tex-math></inline-formula> is below 0.6 considering the screening current. Circumferential reinforcement structures were externally integrated to the REBCO coil assembly to mitigate electromagnetic stress under high background fields. The magnet was successfully charged to 43 A, achieving a central field of 0.71 T at 77 K, validating the winding process and joint techniques. The no-insulation characteristics were analyzed based on the test data. This work is important for advancing practical high-field HTS dipole magnets with high stability and field uniformity.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601920","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":"Critical Current Evaluation of REBCO Tapes Across Entire Temperatures and Magnetic Fields up to 25 T Using a 5 kA Pulsed Current Supply","authors":"Y. Tsuchiya;K. Mizuno;Y. Kohama;S. Awaji","doi":"10.1109/TASC.2025.3543148","DOIUrl":"https://doi.org/10.1109/TASC.2025.3543148","url":null,"abstract":"In this study, we developed a measurement method for the temperature and magnetic field dependences of the critical currents in full-width REBCO tapes using a 5 kA pulsed current. The confined space in high magnetic field environments and limited cooling power under variable temperature conditions give rise to challenges, particularly due to heat generation in the current leads under DC large currents. While microbridge processing is commonly used to limit current, it is less reliable due to the inhomogeneity of the REBCO tapes, making it necessary to measure the characteristics of full-width REBCO tapes. Therefore, we have addressed these challenges by using pulsed currents. By configuring supercapacitors and current regulators, a stable 5 kA pulsed power supply was developed. Using this power supply, the temperature and field dependences of the critical currents in REBCO tapes with full-widths were measured, including at 4.2 K under self-field condition. The suppression of mechanical vibrations reduced noise levels to several µV/cm, even under a magnetic field of 25 T. This approach provides a reliable method for evaluation of the performance of full-width REBCO tapes in high-field and variable-temperature environments.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601883","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}
Samuele Mariotto;Simone Busatto;Ciro Calzolaio;Lucio Rossi;Stephane Sanfilippo;Stefano Sorti
{"title":"Study of HTS Energy-Saving Superconducting Magnet Options for the PSI Particle Beam Lines","authors":"Samuele Mariotto;Simone Busatto;Ciro Calzolaio;Lucio Rossi;Stephane Sanfilippo;Stefano Sorti","doi":"10.1109/TASC.2025.3543325","DOIUrl":"https://doi.org/10.1109/TASC.2025.3543325","url":null,"abstract":"In recent years, particle accelerator facilities have become more aware of the sustainability of their scientific research activity investing in new energy-efficient technologies and energy management of their infrastructure. To address this issue, focusing on medium- to high-energy range proton and heavy ion beamlines, a growing interest in using superconducting magnets instead of energy-demanding resistive configurations has been observed. The proposed study, conducted by the research team from the University of Milan and the Istituto Nazionale di Fisica Nucleare (INFN), Milano, Laboratorio di Acceleratori e Superconduttività Applicata (LASA) lab, focuses on the development of steady-state magnet designs based on high-temperature superconductor (HTS) ReBCO (rare earth copper oxide) tapes. The paper presents a comparative analysis of energy consumption reduction in superferric dipole case studies for the Paul Scherrer Institut (PSI) accelerator complex, focusing on replacing conventional resistive coils with HTS windings optimized at 50 K in a window frame or h-type iron yoke. The outcomes of the proposed designs are compared against the existing resistive magnet performances, showing a strong advantage of this innovative approach for large-scale research facilities in terms of energy consumption and cost-effectiveness.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621637","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":"Modular Multi-Level Converter Model for the Analysis, the Design and the Optimization of DC Power Systems Involving Superconducting Power Cables Cooled by Liquid Hydrogen","authors":"E. Guerra;M. Simonazzi;F. Mimmi;A. Morandi;M. Bocchi;A. Musso;G. Angeli;L. Martini;A. Bertinato;P. Steckler;C. Creusot","doi":"10.1109/TASC.2025.3542742","DOIUrl":"https://doi.org/10.1109/TASC.2025.3542742","url":null,"abstract":"DC power transmission technologies have achieved significant advancements, gaining widespread adoption within modern electrical systems. The use of superconducting cables in Magnesium Diboride (MgB<sub>2</sub>) cooled by liquid hydrogen (LH2) could drastically increase the performance of DC grids, enabling higher power transport capacity and extending transmission distance, while reducing energy loss and land occupation. Today, the transport of DC electrical energy is enabled through modular muti-level converters (MMCs) capable of effectively controlling currents, voltages and power flow. Designing an optimal DC power system, along with appropriate superconducting cable design and protection apparatus, needs accurate, yet simplified, models of the converters. This study presents simplified models that apply during the fault, able to adapt to any pre-fault scenario without a need to implement complex control systems. The developed model can be easily integrated, along with a model of a superconducting MgB<sub>2</sub> cable, in EMT power system simulators for analysing their mutual interaction during faults and for optimizing the cable design and its protection system.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-6"},"PeriodicalIF":1.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10891523","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621675","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}