REBCO tapes exhibit considerable potential for application in high magnetic field devices such as compact fusion reactors and particle accelerators; next-generation electric machines such as high-efficiency industrial motors and high-power wind turbine generators; and electric aircraft. Our group had previously demonstrated an advanced metal organic chemical vapor deposition (A-MOCVD) method to produce 50-meter-long REBCO tapes with film thickness over 4 µm in a single pass, and a uniform critical current ( Ic ) over 1,750 A/12 mm at 65 K, 0.25 T. Further, for high magnetic field applications, 40-meter-long tapes have been made by A-MOCVD with an Ic over 4,000 A/12 mm at 4.2 K and 13 T, as well as over 1,400 A/12 mm at 20 K and 20 T. A laminar vapor path design in the A-MOCVD reactor enabled the growth of thick REBCO films with a high precursor-to-film conversion efficiency up to 45% (4x the conversion efficiency of conventional MOCVD of REBCO tapes). Subsequent advancements in the A-MOCVD process enabled simultaneous deposition of REBCO films on both sides of a double-sided buffered substrate, in a single pass. This yielded double-sided, 30-cm-long REBCO tapes with 3.4-µm-thick films on each side, which showed Ic over 530 A/4 mm at 20 K, 20 T. This paper reports our recent work on next-generation A-MOCVD design to scale up double-sided REBCO tapes to long lengths, with superior performance and an increased precursor-to-film conversion efficiency beyond 70%. Tape heating and precursor delivery methods incorporated in the new design aims to facilitate the scale-up of A-MOCVD for multi-track deposition for higher tape throughput.
{"title":"Next-Generation Advanced MOCVD for Long REBCO Tapes","authors":"Vishnu Pullanikkat;Manoj Thevalappilly Paulose;Sajith Rajamohan;Robert Schmidt;Sarthak Diwan;Goran Majkic;Venkat Selvamanickam","doi":"10.1109/TASC.2024.3514600","DOIUrl":"https://doi.org/10.1109/TASC.2024.3514600","url":null,"abstract":"REBCO tapes exhibit considerable potential for application in high magnetic field devices such as compact fusion reactors and particle accelerators; next-generation electric machines such as high-efficiency industrial motors and high-power wind turbine generators; and electric aircraft. Our group had previously demonstrated an advanced metal organic chemical vapor deposition (A-MOCVD) method to produce 50-meter-long REBCO tapes with film thickness over 4 µm in a single pass, and a uniform critical current (\u0000<italic>I<sub>c</sub></i>\u0000) over 1,750 A/12 mm at 65 K, 0.25 T. Further, for high magnetic field applications, 40-meter-long tapes have been made by A-MOCVD with an \u0000<italic>I<sub>c</sub></i>\u0000 over 4,000 A/12 mm at 4.2 K and 13 T, as well as over 1,400 A/12 mm at 20 K and 20 T. A laminar vapor path design in the A-MOCVD reactor enabled the growth of thick REBCO films with a high precursor-to-film conversion efficiency up to 45% (4x the conversion efficiency of conventional MOCVD of REBCO tapes). Subsequent advancements in the A-MOCVD process enabled simultaneous deposition of REBCO films on both sides of a double-sided buffered substrate, in a single pass. This yielded double-sided, 30-cm-long REBCO tapes with 3.4-µm-thick films on each side, which showed \u0000<italic>I<sub>c</sub></i>\u0000 over 530 A/4 mm at 20 K, 20 T. This paper reports our recent work on next-generation A-MOCVD design to scale up double-sided REBCO tapes to long lengths, with superior performance and an increased precursor-to-film conversion efficiency beyond 70%. Tape heating and precursor delivery methods incorporated in the new design aims to facilitate the scale-up of A-MOCVD for multi-track deposition for higher tape throughput.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938248","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 : 2024-12-23DOI: 10.1109/TASC.2024.3520943
Yu Suetomi;Kwangmin Kim;Todd Adkins;Hongyu Bai;Iain R. Dixon
Screening current induced stress (SCIS) causes conical deformation in REBCO pancake coils. In an actual ultra-high field magnet, a REBCO pancake coil is subjected to axial pressure from upper pancake coils, in addition to SCIS. This axial pressure likely enhances the conical deformation and hoop strain. In this study, we developed a test scheme, referred to as the combined axial pressure and tape tilting (CATT) test, to investigate the degree of strain enhancement caused by axial pressure. As a result of the test, a 50% increase of hoop strain was observed at an axial load of 180 kN, leading to yielding of the REBCO tapes. Buckling deformation due to compressive hoop strain was also observed during the charging test with current in negative direction under a background field.
{"title":"Combined Axial Pressure and Screening Current Induced Stress Test on REBCO Pancake Coils","authors":"Yu Suetomi;Kwangmin Kim;Todd Adkins;Hongyu Bai;Iain R. Dixon","doi":"10.1109/TASC.2024.3520943","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520943","url":null,"abstract":"Screening current induced stress (SCIS) causes conical deformation in REBCO pancake coils. In an actual ultra-high field magnet, a REBCO pancake coil is subjected to axial pressure from upper pancake coils, in addition to SCIS. This axial pressure likely enhances the conical deformation and hoop strain. In this study, we developed a test scheme, referred to as the combined axial pressure and tape tilting (CATT) test, to investigate the degree of strain enhancement caused by axial pressure. As a result of the test, a 50% increase of hoop strain was observed at an axial load of 180 kN, leading to yielding of the REBCO tapes. Buckling deformation due to compressive hoop strain was also observed during the charging test with current in negative direction under a background field.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-7"},"PeriodicalIF":1.7,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938166","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 : 2024-12-23DOI: 10.1109/TASC.2024.3515969
T. Fujita;K. Sakuma;R. Tanaka;K. Toshima;N. Sekiya
We developed a split-type radio frequency (RF) coil using a high-temperature superconductor (HTS) for nuclear magnetic resonance (NMR). The coil does not have HTS thin film on substrates in the area closest to the cylindrical sample. Thus, the coil suppressed the distortion of the static magnetic field. The decreasing quality factor of the coil when a sample was loaded was suppressed because the electric-field-concentration area was placed far from the sample. The measured quality factor of the coil cooled to 11 K was 20 times higher than that of the cooled copper RF coil when D 2 O was loaded. The measured maximum distortion of the static magnetic field when the split-type HTS coil was implemented was suppressed to about 37% of that when the conventional HTS coil was implemented.
{"title":"Development of Split-Type RF Coil Using High-Temperature Superconductor for NMR","authors":"T. Fujita;K. Sakuma;R. Tanaka;K. Toshima;N. Sekiya","doi":"10.1109/TASC.2024.3515969","DOIUrl":"https://doi.org/10.1109/TASC.2024.3515969","url":null,"abstract":"We developed a split-type radio frequency (RF) coil using a high-temperature superconductor (HTS) for nuclear magnetic resonance (NMR). The coil does not have HTS thin film on substrates in the area closest to the cylindrical sample. Thus, the coil suppressed the distortion of the static magnetic field. The decreasing quality factor of the coil when a sample was loaded was suppressed because the electric-field-concentration area was placed far from the sample. The measured quality factor of the coil cooled to 11 K was 20 times higher than that of the cooled copper RF coil when D\u0000<sub>2</sub>\u0000O was loaded. The measured maximum distortion of the static magnetic field when the split-type HTS coil was implemented was suppressed to about 37% of that when the conventional HTS coil was implemented.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-4"},"PeriodicalIF":1.7,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938167","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 : 2024-12-23DOI: 10.1109/TASC.2024.3513942
Manoj Thevalappilly Paulose;Jithin Sai Sandra;Md Abu Sayeed;Venkat Selvamanickam
Rare Earth Barium Copper Oxide (REBCO) superconducting thin films on dielectric substrates are being developed for microwave and radio frequency applications such as transmission lines for quantum computing. Our group previously demonstrated the growth of REBCO thin films on short, flexible, yttria-stabilized-zirconia (YSZ) substrates. In this study, we report high-quality REBCO films on 12-cm-long flexible YSZ substrates. We planarized the surface of 40-µm-thick flexible YSZ substrate by vertical dip coating in n-propanol solution to achieve average surface roughness R a <1>3 (LMO) cap layer. The out-of-plane and in-plane texture values of the LMO films were 3.9° and 6.9° respectively. REBCO films of a thickness of 350 nm were grown on these 12-cm-long flexible YSZ substrates by metal organic chemical vapor deposition (MOCVD) and a critical current density ( J c ) of 1.06 MA/cm 2 was achieved at 77 K, 0 T. We are also developing an electrically conductive buffer architecture for defect-tolerant REBCO tapes, to shunt current from the REBCO film to substrate. This buffer architecture is based on conductive titanium nitride buffer on Hastelloy C276 substrate, with an oxide cap layer deposited by magnetron sputtering. REBCO films, about 350 nm thick, have been grown by MOCVD on this buffer architecture with a J c greater than 1 MA/cm 2 at 77 K, self-field. Texture, microstructure, composition and critical current density of REBCO tapes on electrically conductive buffers will be presented.
{"title":"Development of REBCO Thin Films Using MOCVD on Non-Standard Buffers and Substrates","authors":"Manoj Thevalappilly Paulose;Jithin Sai Sandra;Md Abu Sayeed;Venkat Selvamanickam","doi":"10.1109/TASC.2024.3513942","DOIUrl":"https://doi.org/10.1109/TASC.2024.3513942","url":null,"abstract":"Rare Earth Barium Copper Oxide (REBCO) superconducting thin films on dielectric substrates are being developed for microwave and radio frequency applications such as transmission lines for quantum computing. Our group previously demonstrated the growth of REBCO thin films on short, flexible, yttria-stabilized-zirconia (YSZ) substrates. In this study, we report high-quality REBCO films on 12-cm-long flexible YSZ substrates. We planarized the surface of 40-µm-thick flexible YSZ substrate by vertical dip coating in n-propanol solution to achieve average surface roughness \u0000<italic>R</i>\u0000 \u0000<sub>a</sub>\u0000<1>3</sub>\u0000 (LMO) cap layer. The out-of-plane and in-plane texture values of the LMO films were 3.9° and 6.9° respectively. REBCO films of a thickness of 350 nm were grown on these 12-cm-long flexible YSZ substrates by metal organic chemical vapor deposition (MOCVD) and a critical current density (\u0000<italic>J</i>\u0000 \u0000<sub>c</sub>\u0000) of 1.06 MA/cm\u0000<sup>2</sup>\u0000 was achieved at 77 K, 0 T. We are also developing an electrically conductive buffer architecture for defect-tolerant REBCO tapes, to shunt current from the REBCO film to substrate. This buffer architecture is based on conductive titanium nitride buffer on Hastelloy C276 substrate, with an oxide cap layer deposited by magnetron sputtering. REBCO films, about 350 nm thick, have been grown by MOCVD on this buffer architecture with a \u0000<italic>J</i>\u0000 \u0000<sub>c</sub>\u0000 greater than 1 MA/cm\u0000<sup>2</sup>\u0000 at 77 K, self-field. Texture, microstructure, composition and critical current density of REBCO tapes on electrically conductive buffers will be presented.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938137","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}
As a novel form of energy storage, large-capacity flywheels offer a promising solution for supporting the efficient operation of new energy grid connection and advanced power system. In order to ensure the stable operation of the flywheel rotor, the introduction of superconducting maglev bearings (SMBs), characterized by stable levitation without the need for an origin, low energy losses, and high rotational speeds, can significantly enhance the performance of large-capacity flywheel. This article focuses on a 100-kW·h flywheel energy storage system, where the axial load requirement for the heavy-duty bearing system is set at 8 t. A rotor-excited SMB system is designed, with reference to the stator-excited SMB designed by the Japan Institute of Iron and Steel Technology, to investigate the levitation performance of both SMB configurations at different temperatures. Furthermore, the levitation force and stiffness are calculated under optimal parameter combinations to compare the mechanical performances of the two configurations. The mechanical properties of the bearing system are compared. The results reveal that, due to structural differences, the rotor-excited and stator-excited SMBs exhibit distinct levitation characteristics and mechanical properties, each offering specific advantages and disadvantages for the operation of large-capacity flywheels. These findings provide valuable insights and solutions for further performance optimization of such systems.
{"title":"Comparison of Heavy-Load Superconducting Maglev Bearings for High-Capacity Flywheel","authors":"Wei Liu;Wenhao Zhao;Huang Zhou;Peiyu Zhong;Kangqiang Deng;Hailian Jing;Xiao Fang;Lei Zhao","doi":"10.1109/TASC.2024.3521505","DOIUrl":"https://doi.org/10.1109/TASC.2024.3521505","url":null,"abstract":"As a novel form of energy storage, large-capacity flywheels offer a promising solution for supporting the efficient operation of new energy grid connection and advanced power system. In order to ensure the stable operation of the flywheel rotor, the introduction of superconducting maglev bearings (SMBs), characterized by stable levitation without the need for an origin, low energy losses, and high rotational speeds, can significantly enhance the performance of large-capacity flywheel. This article focuses on a 100-kW·h flywheel energy storage system, where the axial load requirement for the heavy-duty bearing system is set at 8 t. A rotor-excited SMB system is designed, with reference to the stator-excited SMB designed by the Japan Institute of Iron and Steel Technology, to investigate the levitation performance of both SMB configurations at different temperatures. Furthermore, the levitation force and stiffness are calculated under optimal parameter combinations to compare the mechanical performances of the two configurations. The mechanical properties of the bearing system are compared. The results reveal that, due to structural differences, the rotor-excited and stator-excited SMBs exhibit distinct levitation characteristics and mechanical properties, each offering specific advantages and disadvantages for the operation of large-capacity flywheels. These findings provide valuable insights and solutions for further performance optimization of such systems.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 2","pages":"1-7"},"PeriodicalIF":1.7,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938282","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}
To expand the application of NbTi superconducting strand, this study investigates the microstructure evolution after heat treatment and drawing of samples with higher Critical Current Density 709 A/mm 2 at (4.2 K, 9 T). The experimental results indicate that the combined action of heat treatment and drawing influences the final performance. Beginning the 1st heat treatment, there are a few irregular particle precipitates on the matrix. The precipitates increase with the heat treatment times, and it significantly increases up to 19.7% after heat treatment. After every heat treatment, the original precipitates grow larger, and simultaneously, new precipitates are generated. With the final drawing, the precipitates become strips. The J c (4.2 K, 9 T) is more than 700 A/mm 2 with the proper final strain, compared with the normal NbTi superconducting wire with the J c (4.2 K, 9 T) of approximately 580 A/mm 2 .
{"title":"Study on the Heat Treatment Microstructure Evolution of High Field NbTi Superconducting Strand","authors":"Yanmin Zhu;Qiang Guo;Pingxiang Zhang;Kailin Zhang;Ruilong Wang;Zijing Zhou;Luyang Han;Shuai Wang;Bo Wu;Jianfeng Li;Xianghong Liu;Yong Feng","doi":"10.1109/TASC.2024.3517571","DOIUrl":"https://doi.org/10.1109/TASC.2024.3517571","url":null,"abstract":"To expand the application of NbTi superconducting strand, this study investigates the microstructure evolution after heat treatment and drawing of samples with higher Critical Current Density 709 A/mm\u0000<sup>2</sup>\u0000 at (4.2 K, 9 T). The experimental results indicate that the combined action of heat treatment and drawing influences the final performance. Beginning the 1st heat treatment, there are a few irregular particle precipitates on the matrix. The precipitates increase with the heat treatment times, and it significantly increases up to 19.7% after heat treatment. After every heat treatment, the original precipitates grow larger, and simultaneously, new precipitates are generated. With the final drawing, the precipitates become strips. The \u0000<italic>J</i>\u0000c (4.2 K, 9 T) is more than 700 A/mm\u0000<sup>2</sup>\u0000 with the proper final strain, compared with the normal NbTi superconducting wire with the \u0000<italic>J</i>\u0000c (4.2 K, 9 T) of approximately 580 A/mm\u0000<sup>2</sup>\u0000.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938183","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}
The development of high-current high-temperature superconducting (HTS) cables is a key technology for high-field accelerator magnets of 16 T or more. Recently, a flexible HTS round cable, consisting of many rare-earth barium copper oxide (REBCO) coated conductors helically wound in multiple layers on a metal core, have been manufactured by Advanced Conductor Technologies LLC as the conductor on round core (CORC). When a commercially available coated conductor with a substrate thickness of 30 µm is applied to the CORC, the minimum core diameter is approximately 2.4 mm without any degradation in the critical current ( I c ). Because the engineering current density of the CORC is highly dependent on the core diameter, the cable with a smaller core is desirable to achieve compact coil windings for high-field accelerator magnets. In this study, a stack conductor, made by soldering two coated conductors with their REBCO layers facing each other, was applied to the round cable instead of the commercially available single coated conductor. This stack conductor allows the REBCO layer to be closer to the neutral axis of the conductor, thereby reducing the strain induced in the REBCO layer by winding the conductor on the core. As a result, the stack conductor can be wound on a smaller core than the CORC, allowing for higher current densities. This paper presents the cable I c measured at 77 K and the strain of the REBCO layer calculated as a function of the core diameter. The cable I c at 20 T and 4.2 K was estimated using the measured magnetic field dependent I c of the coated conductor at 4.2 K.
{"title":"Critical Current Measurements on Round Cables Made With a REBCO Stack Conductor","authors":"Xudong Wang;Kiyosumi Tsuchiya;Akio Terashima;Suguru Tanabe;Nobuyuki Negishi;Akihiro Kikuchi","doi":"10.1109/TASC.2024.3520940","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520940","url":null,"abstract":"The development of high-current high-temperature superconducting (HTS) cables is a key technology for high-field accelerator magnets of 16 T or more. Recently, a flexible HTS round cable, consisting of many rare-earth barium copper oxide (REBCO) coated conductors helically wound in multiple layers on a metal core, have been manufactured by Advanced Conductor Technologies LLC as the conductor on round core (CORC). When a commercially available coated conductor with a substrate thickness of 30 µm is applied to the CORC, the minimum core diameter is approximately 2.4 mm without any degradation in the critical current (\u0000<italic>I</i>\u0000<sub>c</sub>\u0000). Because the engineering current density of the CORC is highly dependent on the core diameter, the cable with a smaller core is desirable to achieve compact coil windings for high-field accelerator magnets. In this study, a stack conductor, made by soldering two coated conductors with their REBCO layers facing each other, was applied to the round cable instead of the commercially available single coated conductor. This stack conductor allows the REBCO layer to be closer to the neutral axis of the conductor, thereby reducing the strain induced in the REBCO layer by winding the conductor on the core. As a result, the stack conductor can be wound on a smaller core than the CORC, allowing for higher current densities. This paper presents the cable \u0000<italic>I</i>\u0000<sub>c</sub>\u0000 measured at 77 K and the strain of the REBCO layer calculated as a function of the core diameter. The cable \u0000<italic>I</i>\u0000<sub>c</sub>\u0000 at 20 T and 4.2 K was estimated using the measured magnetic field dependent \u0000<italic>I</i>\u0000<sub>c</sub>\u0000 of the coated conductor at 4.2 K.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","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":"142938209","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 : 2024-12-20DOI: 10.1109/TASC.2024.3520937
Yi Zhang;Daoyu Hu;Jitan Wu;Xuyang Liu;Kai Mao
High-temperature superconducting (HTS) persistent-current switch (PCS) is an essential device for on-board HTS magnets achieving the closed-loop operation mode. This work proposed a type of the heater-triggered HTS-PCS operated in SN 2 environment. The thermal structure of the HTS-PCS is introduced in detailed. The thermal characteristics including switch OFF time, switch ON time, and temperature rise of the HTS-PCS operated in SN 2 environment are studied via experimental tests and simulation analysis. The used simulation model is a thermal simulation model constructed based on the finite element method. The effect of the solid-solid and solid-liquid phase transitions of nitrogen has been taken into account. The effectiveness of the simulation model is verified by the experimental tests. The research results show that the HTS-PCS with ∼0.53 Ω off-resistance can be switched OFF within 5 min and switched ON within 25 min in SN 2 environment, and the outermost layer temperature does not exceed 65 K. This study provides useful information for the design of the HTS-PCS operated in SN 2 environment.
{"title":"Experimental and Simulation Research on High-Temperature Superconducting Persistent-Current Switch Operated in Solid-Nitrogen Environment","authors":"Yi Zhang;Daoyu Hu;Jitan Wu;Xuyang Liu;Kai Mao","doi":"10.1109/TASC.2024.3520937","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520937","url":null,"abstract":"High-temperature superconducting (HTS) persistent-current switch (PCS) is an essential device for on-board HTS magnets achieving the closed-loop operation mode. This work proposed a type of the heater-triggered HTS-PCS operated in SN\u0000<sub>2</sub>\u0000 environment. The thermal structure of the HTS-PCS is introduced in detailed. The thermal characteristics including switch OFF time, switch ON time, and temperature rise of the HTS-PCS operated in SN\u0000<sub>2</sub>\u0000 environment are studied via experimental tests and simulation analysis. The used simulation model is a thermal simulation model constructed based on the finite element method. The effect of the solid-solid and solid-liquid phase transitions of nitrogen has been taken into account. The effectiveness of the simulation model is verified by the experimental tests. The research results show that the HTS-PCS with ∼0.53 Ω off-resistance can be switched OFF within 5 min and switched ON within 25 min in SN\u0000<sub>2</sub>\u0000 environment, and the outermost layer temperature does not exceed 65 K. This study provides useful information for the design of the HTS-PCS operated in SN\u0000<sub>2</sub>\u0000 environment.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 2","pages":"1-8"},"PeriodicalIF":1.7,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142937825","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 : 2024-12-20DOI: 10.1109/TASC.2024.3520535
Francesco Mimmi;Emiliano Guerra;Mattia Simonazzi;Antonio Morandi;Umberto Melaccio;Christian-Eric Bruzek
The European project SCARLET is dedicated to advancing the integration and application of superconducting technologies for medium voltage direct current (MVDC) systems. One of the main innovations within SCARLET is the development of a dual-purpose infrastructure that combines the transmission of bulk electricity and liquid hydrogen. The MgB 2 superconducting cable, operating at around 20 K, finds its suitable environment within the pipeline for liquid hydrogen transport. This integration promises a compact and economically attractive solution for the simultaneous distribution of hydrogen and electricity. In this paper, we present various designs of the MgB 2 cable core, showcasing results from electro-thermal simulations and highlighting the strengths and potential challenges. The intent of this work is to help identify the most effective cable configuration that meets the requirements of energy efficiency and compactness, while also considering the constraints associated with the production phase. In addition, to enhance the sensitivity to the thermal behaviour, a thermal model was developed and presented.
{"title":"Comparative Analysis of MgB2 Cable Layouts for 1 GW Superconducting Transmission-Insights From the SCARLET Project","authors":"Francesco Mimmi;Emiliano Guerra;Mattia Simonazzi;Antonio Morandi;Umberto Melaccio;Christian-Eric Bruzek","doi":"10.1109/TASC.2024.3520535","DOIUrl":"https://doi.org/10.1109/TASC.2024.3520535","url":null,"abstract":"The European project SCARLET is dedicated to advancing the integration and application of superconducting technologies for medium voltage direct current (MVDC) systems. One of the main innovations within SCARLET is the development of a dual-purpose infrastructure that combines the transmission of bulk electricity and liquid hydrogen. The MgB\u0000<sub>2</sub>\u0000 superconducting cable, operating at around 20 K, finds its suitable environment within the pipeline for liquid hydrogen transport. This integration promises a compact and economically attractive solution for the simultaneous distribution of hydrogen and electricity. In this paper, we present various designs of the MgB\u0000<sub>2</sub>\u0000 cable core, showcasing results from electro-thermal simulations and highlighting the strengths and potential challenges. The intent of this work is to help identify the most effective cable configuration that meets the requirements of energy efficiency and compactness, while also considering the constraints associated with the production phase. In addition, to enhance the sensitivity to the thermal behaviour, a thermal model was developed and presented.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"35 5","pages":"1-12"},"PeriodicalIF":1.7,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905959","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 : 2024-12-20DOI: 10.1109/TASC.2024.3520542
C. Nguyen Thanh Dao;A. Torre;L. Zani;G. Jiolat;Q. Le Coz;V. Corato;M. Ortino;C. Zhou;C. Dai;J. Qin
The EU-DEMO baseline follows the path towards a large-scale tokamak demonstrator. The unmatched size stands as one of the biggest challenge to overcome. Toroidal field magnets are no exception and the expanding performance and limits require the development of new conductor designs. In this regard, CEA design team has been working on the scaling-up of ITER-like conductor technology, with the design, manufacture and test of a square-in-square 100 kA-class conductor called DEMOTF-WP3. It has now been tested in SULTAN and this article presents preliminary results. The sample is composed by two legs containing the same 3.5 m long CICC for redundancy purpose. Voltage taps and temperature sensors are installed along both legs following a symmetrical scheme. This sample also contains a twinbox joint prototype connecting the two legs together at the bottom of the sample thanks to a thin layer of compacted indium. Furthermore, the need expressed at EU-DEMO Gate 1 review to investigate round-in-round geometry permitting the use of radial plates, triggered the CEA design team to propose another Nb 3 Sn conductor design (DEMOTF-WP4), with operating current of 116 kA and peak field of 12.5 T. This conductor is composed of 721 SC strands and 1108 copper strands cabled together within a round stainless steel jacket with a diameter of 55 mm. The detailed design is presented along with the prototype manufactured that will be used for the qualification tests to be held at SULTAN facility at CRPP in 2025.
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