Pub Date : 2024-12-20DOI: 10.1109/TASC.2024.3521006
Yue Wu;Liye Xiao;Siyuan Han;Jiamin Chen
The magnetoresistance-superconducting composited magnetic sensor is a novel high-sensitivity weak magnetic sensor with significant application potential in fields such as biomedical science and geological exploration. However, the current superconducting flux concentrators face the issue of saturation in magnetic field amplification, which limits further improvement in the magnetic field resolution of the composited sensors. This article proposes a new type of magnetoresistance-superconducting-soft-magnetic composited sensor, which utilizes a superconducting planar gradient coil combined with soft magnetic plates to form a composite flux concentration structure. This design not only enhances the magnetic field amplification but also suppresses the interference of magnetic fields in nondetection directions. Theoretical simulations and experimental results indicate that the magnetic field sensitivity of this novel composited sensor is 3.2 times higher than that of magnetoresistance-superconducting composited sensors. This work is of great significance for the research on magnetoresistance sensors.
{"title":"High-Performance Magnetoresistance-Superconducting-Soft-Magnetic Composited Magnetic Sensor","authors":"Yue Wu;Liye Xiao;Siyuan Han;Jiamin Chen","doi":"10.1109/TASC.2024.3521006","DOIUrl":"https://doi.org/10.1109/TASC.2024.3521006","url":null,"abstract":"The magnetoresistance-superconducting composited magnetic sensor is a novel high-sensitivity weak magnetic sensor with significant application potential in fields such as biomedical science and geological exploration. However, the current superconducting flux concentrators face the issue of saturation in magnetic field amplification, which limits further improvement in the magnetic field resolution of the composited sensors. This article proposes a new type of magnetoresistance-superconducting-soft-magnetic composited sensor, which utilizes a superconducting planar gradient coil combined with soft magnetic plates to form a composite flux concentration structure. This design not only enhances the magnetic field amplification but also suppresses the interference of magnetic fields in nondetection directions. Theoretical simulations and experimental results indicate that the magnetic field sensitivity of this novel composited sensor is 3.2 times higher than that of magnetoresistance-superconducting composited sensors. This work is of great significance for the research on magnetoresistance sensors.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 2","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938219","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}
Aircraft equipment needs to maintain stable operation in low-temperature and low-pressure environments. This study assesses the feasibility of operating a developed machine under such conditions. Rotational tests were conducted in an environment that simulated the conditions required for aircraft-mounted equipment. The synchronous machine was installed in a thermostatic chamber that was set to a temperature of −55 °C and pressure of 11 kPa, which mimics the conditions at an altitude of 15,000 m. The machine demonstrated stable operation at a rotational speed of 180 rpm, with a field current of 50 A and an armature current amplitude of 100 A at a frequency of 3 Hz. The synchronous machine was tested in generator mode at ground level under no-load and three-phase short-circuit conditions to evaluate its rated operation under a normal environment. In the no-load test, the field current and rotational speed were increased from 10 A to 110 A and 100 rpm to 2,500 rpm, respectively, and the maximum line voltage was 590 V. In the three-phase short-circuit test, the U, V, and W phases exhibited maximum short-circuit currents of 490 A with a field current of 45 A and rotational speed of 100 rpm. These results confirm that the synchronous machine operated stably at 2,500 rpm with an output of 250 kW in generator mode. The stable performance of the machine under these conditions suggests its potential for enhancing the efficiency, power density, and reliability of electric propulsion systems in aviation.
{"title":"Performance Testing of 400 kW-Rated REBCO Superconducting Synchronous Machine in Low-Temperature and Low-Pressure Environments","authors":"H. Miyazaki;M. Iwakuma;Y. Emori;R. Konishi;K. Yoshida;S. Sato;H. Sasa;S. Miura;I. Sagara;Y. Suzuki;M. Konno;H. Hirai;A. Kawagoe;T. Izumi","doi":"10.1109/TASC.2024.3520532","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520532","url":null,"abstract":"Aircraft equipment needs to maintain stable operation in low-temperature and low-pressure environments. This study assesses the feasibility of operating a developed machine under such conditions. Rotational tests were conducted in an environment that simulated the conditions required for aircraft-mounted equipment. The synchronous machine was installed in a thermostatic chamber that was set to a temperature of −55 °C and pressure of 11 kPa, which mimics the conditions at an altitude of 15,000 m. The machine demonstrated stable operation at a rotational speed of 180 rpm, with a field current of 50 A and an armature current amplitude of 100 A at a frequency of 3 Hz. The synchronous machine was tested in generator mode at ground level under no-load and three-phase short-circuit conditions to evaluate its rated operation under a normal environment. In the no-load test, the field current and rotational speed were increased from 10 A to 110 A and 100 rpm to 2,500 rpm, respectively, and the maximum line voltage was 590 V. In the three-phase short-circuit test, the U, V, and W phases exhibited maximum short-circuit currents of 490 A with a field current of 45 A and rotational speed of 100 rpm. These results confirm that the synchronous machine operated stably at 2,500 rpm with an output of 250 kW in generator mode. The stable performance of the machine under these conditions suggests its potential for enhancing the efficiency, power density, and reliability of electric propulsion systems in aviation.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938162","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}
Pub Date : 2024-12-19DOI: 10.1109/TASC.2024.3520079
V. Reynaud;S. Farinon;M. Janitschke;E. Ravaioli;A.P. Verweij;G. Willering;U. van Rienen
Electrical short-circuits in the coil winding pack of a superconducting magnet can severely impact the magnet's performance and safety during operation. Hence, finding ways to detect and assess these non-conformities is essential. Measurements of the complex impedance as a function of the frequency are a promising method to investigate such non-conformities more closely. The complex impedance of one HL-LHC recombination dipole magnet was recently measured at the CERN magnet test facility. Moreover, to mimic an inter-turn short in the coils, resistances at warm were connected externally to the voltage taps and the complex impedance of the magnet was measured. The acquired measurements are used to validate a developed lumped-element network model, reproducing the electromagnetic behaviour of the HL-LHC recombination dipole magnet in the frequency domain. The simulation results are compared to the measurements without artificial short circuits and are in good agreement up to a frequency of 10 kHz. The simulated effects of short circuits across a few turns in the frequency domain are compared to the measurements performed on the magnet. Since good agreement between measurements and simulations was obtained, these models can be used to predict the electromagnetic effects of any inter-turn short in the HL-LHC recombination dipole magnet or similar types of accelerator magnets.
{"title":"Evaluating the Electro-Magnetic Effects of Electrical Short-Circuits in a Nb-Ti Accelerator Magnet","authors":"V. Reynaud;S. Farinon;M. Janitschke;E. Ravaioli;A.P. Verweij;G. Willering;U. van Rienen","doi":"10.1109/TASC.2024.3520079","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520079","url":null,"abstract":"Electrical short-circuits in the coil winding pack of a superconducting magnet can severely impact the magnet's performance and safety during operation. Hence, finding ways to detect and assess these non-conformities is essential. Measurements of the complex impedance as a function of the frequency are a promising method to investigate such non-conformities more closely. The complex impedance of one HL-LHC recombination dipole magnet was recently measured at the CERN magnet test facility. Moreover, to mimic an inter-turn short in the coils, resistances at warm were connected externally to the voltage taps and the complex impedance of the magnet was measured. The acquired measurements are used to validate a developed lumped-element network model, reproducing the electromagnetic behaviour of the HL-LHC recombination dipole magnet in the frequency domain. The simulation results are compared to the measurements without artificial short circuits and are in good agreement up to a frequency of 10 kHz. The simulated effects of short circuits across a few turns in the frequency domain are compared to the measurements performed on the magnet. Since good agreement between measurements and simulations was obtained, these models can be used to predict the electromagnetic effects of any inter-turn short in the HL-LHC recombination dipole magnet or similar types of accelerator magnets.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10807401","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938204","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}
To further explore the physics beyond the capabilities of the LHC and its High-Luminosity Upgrade (HL-LHC), particle physicists are studying advanced accelerators in order to perform finer measurements and/or reach higher energies. Upon the recommendation of the Updated European Strategy for Particle Physics (ESPP), an International Muon Collider Collaboration has been established to investigate the feasibility of a muon collider facility with a center-of-mass energy of 10 TeV. This endeavor is confronted with several technical challenges, primarily arising from the brief muon lifetime at rest, which is only 2.2 ${mu }$ s. Addressing this stringent constraint necessitates the deployment of innovative technologies, including challengingmagnets, RF systems, targets, shielding, and cooling methodologies. This paper focuses on optimizing the electromagnetic and mechanical aspects of high-temperature superconducting (HTS) dipoles with large rectangular aperture for the accelerator ring, with a bore field up to 10 T, using finite element techniques. The objectives include ensuring a precise control over magnetic field uniformity and a preliminary evaluation of the mechanical behaviour of the HTS coils. The study is aligned with the priority set by ESPP on technological advancements, notably in high-field superconducting magnets, crucial components for any forthcoming circular collider.
{"title":"Magnetic and Mechanical Design of the Large Aperture HTS Superconducting Dipoles for the Accelerator Ring of the Muon Collider","authors":"F. Levi;L. Alfonso;L. Balconi;A. Bersani;L. Bottura;B. Caiffi;S. Fabbri;S. Farinon;A. Gagno;T. Maiello;F. Mariani;S. Mariotto;D. Novelli;A. Pampaloni;C. Santini;S. Sorti;M. Statera","doi":"10.1109/TASC.2024.3520073","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520073","url":null,"abstract":"To further explore the physics beyond the capabilities of the LHC and its High-Luminosity Upgrade (HL-LHC), particle physicists are studying advanced accelerators in order to perform finer measurements and/or reach higher energies. Upon the recommendation of the Updated European Strategy for Particle Physics (ESPP), an International Muon Collider Collaboration has been established to investigate the feasibility of a muon collider facility with a center-of-mass energy of 10 TeV. This endeavor is confronted with several technical challenges, primarily arising from the brief muon lifetime at rest, which is only 2.2 \u0000<inline-formula><tex-math>${mu }$</tex-math></inline-formula>\u0000s. Addressing this stringent constraint necessitates the deployment of innovative technologies, including challengingmagnets, RF systems, targets, shielding, and cooling methodologies. This paper focuses on optimizing the electromagnetic and mechanical aspects of high-temperature superconducting (HTS) dipoles with large rectangular aperture for the accelerator ring, with a bore field up to 10 T, using finite element techniques. The objectives include ensuring a precise control over magnetic field uniformity and a preliminary evaluation of the mechanical behaviour of the HTS coils. The study is aligned with the priority set by ESPP on technological advancements, notably in high-field superconducting magnets, crucial components for any forthcoming circular collider.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142940924","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}
Pub Date : 2024-12-19DOI: 10.1109/TASC.2024.3520080
E. Bianchi;S. Farinon;E. Felcini;A. Gagno;L. Gentini;I. Georgiadis;E. O. Kavoura;C. Kokkinos;F. Levi;R. Musenich;A. Pampaloni;D. Perini;M. Prioli;M. Pullia;L. Rossi;C. Santini;R. U. Valente
In ion therapy, gantries play a crucial role in minimizing damage to healthy tissue and enabling treatment from diverse angles. The introduction of superconducting magnets results in a substantial reduction in the overall weight and the power required to operate of these otherwise huge structures. The Superconducting Ion Gantry (SIG) project represents the contribution of INFN (Istituto Nazionale di Fisica Nucleare) to the EuroSIG collaboration, which includes CERN, CNAO (Centro Nazionale di Adroterapia Oncologica), and MedAustron. The primary goal is to design, manufacture, and test a demonstrator for a curved superconducting dipole with costheta-type NbTi coils for a 430 MeV/u carbon ion gantry. The magnet is designed with a 1.65 m radius of curvature and an 80 mm aperture, aiming to generate a magnetic field up to 4 T, with a ramp rate of about 0.4 T/s, without the option of utilizing a direct cooling system. The winding, assembly, and testing of the magnet will be carried out in Milan, at LASA (Laboratorio Acceleratori e Superconduttività Applicata). However, the available press is insufficient in size compared to the dimensions of the magnet. To overcome this limitation, an alternative method has been devised for the assembly of the iron yoke, relying on a steel system of clamps and vertical tie rods. These clamps have the purpose of securely fastening the two yoke halves together. This study presents the final design of the mechanical structure cross-section, derived through finite element analyses, highlighting the optimization of mechanical contacts between components while adhering to structural limits. Additionally, a preliminary 3D design based on this optimized cross-section is introduced.
{"title":"Consolidated 2D Mechanical Design and Preliminary 3D Design Phase of the Superconducting Ion Gantry (SIG) Dipole for Hadrontherapy","authors":"E. Bianchi;S. Farinon;E. Felcini;A. Gagno;L. Gentini;I. Georgiadis;E. O. Kavoura;C. Kokkinos;F. Levi;R. Musenich;A. Pampaloni;D. Perini;M. Prioli;M. Pullia;L. Rossi;C. Santini;R. U. Valente","doi":"10.1109/TASC.2024.3520080","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520080","url":null,"abstract":"In ion therapy, gantries play a crucial role in minimizing damage to healthy tissue and enabling treatment from diverse angles. The introduction of superconducting magnets results in a substantial reduction in the overall weight and the power required to operate of these otherwise huge structures. The Superconducting Ion Gantry (SIG) project represents the contribution of INFN (Istituto Nazionale di Fisica Nucleare) to the EuroSIG collaboration, which includes CERN, CNAO (Centro Nazionale di Adroterapia Oncologica), and MedAustron. The primary goal is to design, manufacture, and test a demonstrator for a curved superconducting dipole with costheta-type NbTi coils for a 430 MeV/u carbon ion gantry. The magnet is designed with a 1.65 m radius of curvature and an 80 mm aperture, aiming to generate a magnetic field up to 4 T, with a ramp rate of about 0.4 T/s, without the option of utilizing a direct cooling system. The winding, assembly, and testing of the magnet will be carried out in Milan, at LASA (Laboratorio Acceleratori e Superconduttività Applicata). However, the available press is insufficient in size compared to the dimensions of the magnet. To overcome this limitation, an alternative method has been devised for the assembly of the iron yoke, relying on a steel system of clamps and vertical tie rods. These clamps have the purpose of securely fastening the two yoke halves together. This study presents the final design of the mechanical structure cross-section, derived through finite element analyses, highlighting the optimization of mechanical contacts between components while adhering to structural limits. Additionally, a preliminary 3D design based on this optimized cross-section is introduced.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142940916","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}
Pub Date : 2024-12-19DOI: 10.1109/TASC.2024.3520099
Uijong Bong;Thanatheepan Balachandran;Yiming Zhao;Kiruba S. Haran
Cryogen-free ultra-high field superconducting electric motor (CRUISE Motor) project, initiated in 2022 with ARPA-E funding, aims to develop a 10 MW, 3000 rpm machine with a power density exceeding 40 kW/kg. This paper presents a detailed progress report on the field winding development as part of the CRUISE motor project. To achieve the motor's high power density target, a field winding consisting of two no-insulation (NI) REBCO double pancake racetrack coils per pole was designed, aiming for an operating conductor current density of 500 A/mm $^{2}$ at 50 K. As part of the experimental validation, prototype racetrack coils were fabricated using an in-house winding machine and tested at both 50 K and 77 K. Based on the insights gained from the prototype coils, the coil designs were further refined and applied to the full-scale racetrack coil design. Additionally, the quench behavior of the prototype coil was experimentally investigated to verify its robustness under fault conditions.
{"title":"No-Insulation REBCO Field Winding Assembly for CRUISE Motor","authors":"Uijong Bong;Thanatheepan Balachandran;Yiming Zhao;Kiruba S. Haran","doi":"10.1109/TASC.2024.3520099","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520099","url":null,"abstract":"Cryogen-free ultra-high field superconducting electric motor (CRUISE Motor) project, initiated in 2022 with ARPA-E funding, aims to develop a 10 MW, 3000 rpm machine with a power density exceeding 40 kW/kg. This paper presents a detailed progress report on the field winding development as part of the CRUISE motor project. To achieve the motor's high power density target, a field winding consisting of two no-insulation (NI) REBCO double pancake racetrack coils per pole was designed, aiming for an operating conductor current density of 500 A/mm\u0000<inline-formula><tex-math>$^{2}$</tex-math></inline-formula>\u0000 at 50 K. As part of the experimental validation, prototype racetrack coils were fabricated using an in-house winding machine and tested at both 50 K and 77 K. Based on the insights gained from the prototype coils, the coil designs were further refined and applied to the full-scale racetrack coil design. Additionally, the quench behavior of the prototype coil was experimentally investigated to verify its robustness under fault conditions.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905777","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}
Fully superconducting rotating machines with superconducting armature and field coils hold significant potential as electric propulsion systems for aircraft owing to their high power density (kg/kW). To support large current capacities in the superconducting armature coils of these motors, a multi-strand parallel conductor design was developed. Further, this study aimed to develop an optimum conductor design capable of incorporating any number of parallel conductors. To achieve this, three-strand parallel conductors were used. It was demonstrated that a uniform current distribution can be achieved using a novel transposition method within the winding. Herein, the winding process for this transposition method was developed to apply the desired configuration. The experimentally obtained current distributions of 33.4%, 35.2%, and 31.4% confirm the effectiveness of this method.
{"title":"Experimental Evaluation of Transposed Three-Parallel Conductors to Achieve Uniform Current in Armature Coils of Superconducting Motors","authors":"Goki Kawasaki;Kazuki Nakamura;Yudai Kimura;Tomohiro Inoue;Yohei Masuda;Shun Miura;Hiroshi Miyazaki;Akifumi Kawagoe;Masataka Iwakuma","doi":"10.1109/TASC.2024.3520549","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520549","url":null,"abstract":"Fully superconducting rotating machines with superconducting armature and field coils hold significant potential as electric propulsion systems for aircraft owing to their high power density (kg/kW). To support large current capacities in the superconducting armature coils of these motors, a multi-strand parallel conductor design was developed. Further, this study aimed to develop an optimum conductor design capable of incorporating any number of parallel conductors. To achieve this, three-strand parallel conductors were used. It was demonstrated that a uniform current distribution can be achieved using a novel transposition method within the winding. Herein, the winding process for this transposition method was developed to apply the desired configuration. The experimentally obtained current distributions of 33.4%, 35.2%, and 31.4% confirm the effectiveness of this method.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938163","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}
Pub Date : 2024-12-18DOI: 10.1109/TASC.2024.3520092
Weican Huang;Xiaohua Jiang;Guolin Chai;Xianrui Huang;Qingyu Zou;Ye Li
A 14 T actively shielded animal MRI magnet has been designed and is currently under construction. The magnet has a warm bore of 175 mm diameter and consists of Nb 3 Sn and NbTi solenoid coils. This paper presents the results of electromagnetic, structural and quench protection designs of the magnet. The magnetic field homogeneity is 0.9 ppm within a 60 mm diameter of spherical volume. The distance of 5 Gauss line from the magnet center is 2.4 m radially and 2.9 m axially. Stress analysis shows that the maximum axial and circumferential stresses in the coils are −73 MPa and 144 MPa, respectively. Under the worst quench scenarios, the maximum hotspot temperature and inter-layer voltage in the coils are constrained to 169 K and 720 V, respectively.
{"title":"Design of a 14 T Actively Shielded Superconducting Magnet for Animal MRI","authors":"Weican Huang;Xiaohua Jiang;Guolin Chai;Xianrui Huang;Qingyu Zou;Ye Li","doi":"10.1109/TASC.2024.3520092","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520092","url":null,"abstract":"A 14 T actively shielded animal MRI magnet has been designed and is currently under construction. The magnet has a warm bore of 175 mm diameter and consists of Nb\u0000<sub>3</sub>\u0000Sn and NbTi solenoid coils. This paper presents the results of electromagnetic, structural and quench protection designs of the magnet. The magnetic field homogeneity is 0.9 ppm within a 60 mm diameter of spherical volume. The distance of 5 Gauss line from the magnet center is 2.4 m radially and 2.9 m axially. Stress analysis shows that the maximum axial and circumferential stresses in the coils are −73 MPa and 144 MPa, respectively. Under the worst quench scenarios, the maximum hotspot temperature and inter-layer voltage in the coils are constrained to 169 K and 720 V, respectively.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912480","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}
Pub Date : 2024-12-18DOI: 10.1109/TASC.2024.3520094
Ao Shimada;Atsushi Ishiyama;Tsun Him Chong;Mitsuhiro Fukuda;So Noguchi;Hiroshi Ueda
We are developing a high-temperature superconducting skeleton cyclotron (HTS-SC), that is, an ultracompact, high-intensity accelerator. The coil system of the skeleton cyclotron consists of air-core no-insulation (NI) REBCO coils without an iron core, which is conventionally adopted, and can allow variable output energy. In parallel, we have been developing an NI-REBCO coil system for the electron cyclotron resonance ion source for the HTS-SC. It is necessary to change the magnetic-field configuration according to the operation frequencies: 2.45 and 10 GHz. Although both high thermal stability and high current density can be achieved by adopting NI-REBCO winding technology, the screening current-induced in the REBCO-coated conductor generates an irregular magnetic field. In addition, there is an excitation delay caused by a current flowing in the radial direction with coil excitation in the NI coil winding, which reduces the magnetic-field accuracy. In this paper, we focus on the accuracy of the spatial distribution of the generated magnetic field and present the results of evaluations based on experiments and numerical analysis. A newly developed screening current-induced field analysis method for NI-REBCO coils based only on circuit analysis was used for numerical simulations.
{"title":"Evaluation of Screening Current-Induced Field Generated by No-Insulation REBCO Coil System for Multi-Frequency ECR Ion Source","authors":"Ao Shimada;Atsushi Ishiyama;Tsun Him Chong;Mitsuhiro Fukuda;So Noguchi;Hiroshi Ueda","doi":"10.1109/TASC.2024.3520094","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520094","url":null,"abstract":"We are developing a high-temperature superconducting skeleton cyclotron (HTS-SC), that is, an ultracompact, high-intensity accelerator. The coil system of the skeleton cyclotron consists of air-core no-insulation (NI) REBCO coils without an iron core, which is conventionally adopted, and can allow variable output energy. In parallel, we have been developing an NI-REBCO coil system for the electron cyclotron resonance ion source for the HTS-SC. It is necessary to change the magnetic-field configuration according to the operation frequencies: 2.45 and 10 GHz. Although both high thermal stability and high current density can be achieved by adopting NI-REBCO winding technology, the screening current-induced in the REBCO-coated conductor generates an irregular magnetic field. In addition, there is an excitation delay caused by a current flowing in the radial direction with coil excitation in the NI coil winding, which reduces the magnetic-field accuracy. In this paper, we focus on the accuracy of the spatial distribution of the generated magnetic field and present the results of evaluations based on experiments and numerical analysis. A newly developed screening current-induced field analysis method for NI-REBCO coils based only on circuit analysis was used for numerical simulations.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938208","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}
Pub Date : 2024-12-18DOI: 10.1109/TASC.2024.3520067
E. Ravaioli;D. Araujo;B. Auchmann;A. Verweij;M. Wozniak
A 13 T Nb3Sn common-coil accelerator-type magnet is being developed at the Paul Scherrer Institute (PSI). The magnet cross-section features an innovative design with asymmetric elements and effective stress-management. Thanks to the asymmetric design narrow pole racetrack coils are not required in proximity of the magnet apertures to improve the field quality. Its magnetic design achieves adequate margin with respect to the short-sample limit while utilizing two available cables. This choice accelerates the completion of the 0.8 m long demonstrator magnet, but limits the flexibility of the conductor grading and makes the magnet quench protection more challenging. In this contribution, the strategy to limit the hot-spot temperature and peak voltage to ground reached in the magnet conductor after a quench is discussed. The electro-magnetic and thermal transients occurring during a quench discharge are simulated with the STEAM-LEDET program. Quench detection based on differential-voltage monitoring is proposed, and the expected quench detection times are evaluated in the case of quenches occurring in different coil locations. Furthermore, the performances of various quench protection systems, including energy-extraction based either on a resistor or a varistor, a CLIQ (Coupling-Loss Induced Quench) system, or combinations of these are assessed. It is shown that while energy-extraction is a viable option to protect the magnet, acceptable performance can be achieved with CLIQ while achieving a significantly lower peak voltage to ground. The lowest hot-spot temperature is obtained by combining energy extraction and CLIQ.
Paul Scherrer研究所（PSI）正在开发一种13t Nb3Sn共圈加速器型磁铁。磁体横截面采用创新设计，具有不对称元素和有效的应力管理。由于不对称设计，窄极赛道线圈不需要在磁铁孔附近，以提高磁场质量。它的磁性设计在利用两根可用电缆的同时，在短样品限制方面达到了足够的裕度。这种选择加速了0.8 m长演示磁铁的完成，但限制了导体分级的灵活性，并使磁铁淬火保护更具挑战性。在这篇文章中，讨论了限制磁体导体在淬火后到达地的热点温度和峰值电压的策略。用STEAM-LEDET程序模拟了淬火放电过程中的电磁瞬变和热瞬变。提出了基于差分电压监测的失稳检测方法，并对不同线圈位置发生失稳情况下的预期失稳检测时间进行了计算。此外，还评估了各种淬火保护系统的性能，包括基于电阻器或压敏电阻的能量提取，CLIQ（耦合损耗诱导淬火）系统或这些系统的组合。结果表明，虽然能量提取是保护磁体的可行选择，但使用CLIQ可以实现可接受的性能，同时实现对地峰值电压显著降低。采用能量提取和CLIQ相结合的方法获得了最低的热点温度。
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