High temperature superconducting (HTS) tapes have crucial applications for generating high magnetic fields with minimal power input. Given a single tape has a limited current-carrying capacity, stacked tapes are common, fabricated through methods like solder soldering or epoxy impregnation requiring heat treatment. In this work, we have investigated the efficient region for vacuum heat treatment applicable of commercial HTS tapes, analysed the thermal degradation principles and accordingly proposed a controlled heat treatment process for stacked HTS tapes to achieve more precise regulation of the critical current (Ic). This heat treatment process was explored using a specialized multi-temperature zone vacuum system. Critical parameters in this process include heat treatment temperature, duration and pressure on the tape. A series of experiments were conducted at 77 K in a self-field to investigate how these parameters affect the superconductivity performance of stacked HTS tapes. Based on the experimental results, an optimal heat treatment process has been proposed. Under the current process, with the heat treatment temperature set at 200 °C, duration at 20 min, and pressure on the tape at 12 MPa, the samples exhibit favourable properties characterized by a smooth and neat appearance without defects such as pinholes or false soldering, and the superconductivity performance can be consistently maintained at more than 97%. The obtained measurements were compared with simulated results, demonstrating an error margin within 0.5%. Moreover, precise control of Ic is achieved, tailored to tape and stacking specifications, allowing manageable degradation as required. This heat treatment process for stacked HTS tapes holds significant importance, especially in the context of designing cable-in-conduit conductors fabricated with stacked HTS tapes. It serves as a valuable reference for further advancements in this field.
{"title":"Thermal degradation analysis and optimization of controlled heat treatment for stacked high temperature superconducting tapes","authors":"Shige Yang, Bohan Tang, Zhilai Yue, Hui Yu, Bowen Xie, Sicheng Li, Yanquan Chen, Rui Niu, Jun Zhao, Peng Zhou, Wenge Chen, Shili Jiang, Donghui Jiang, Guangli Kuang","doi":"10.1088/1361-6668/ad6ada","DOIUrl":"https://doi.org/10.1088/1361-6668/ad6ada","url":null,"abstract":"High temperature superconducting (HTS) tapes have crucial applications for generating high magnetic fields with minimal power input. Given a single tape has a limited current-carrying capacity, stacked tapes are common, fabricated through methods like solder soldering or epoxy impregnation requiring heat treatment. In this work, we have investigated the efficient region for vacuum heat treatment applicable of commercial HTS tapes, analysed the thermal degradation principles and accordingly proposed a controlled heat treatment process for stacked HTS tapes to achieve more precise regulation of the critical current (<inline-formula>\u0000<tex-math><?CDATA ${I_{text{c}}}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:msub><mml:mi>I</mml:mi><mml:mrow><mml:mtext>c</mml:mtext></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"sustad6adaieqn1.gif\"></inline-graphic></inline-formula>). This heat treatment process was explored using a specialized multi-temperature zone vacuum system. Critical parameters in this process include heat treatment temperature, duration and pressure on the tape. A series of experiments were conducted at 77 K in a self-field to investigate how these parameters affect the superconductivity performance of stacked HTS tapes. Based on the experimental results, an optimal heat treatment process has been proposed. Under the current process, with the heat treatment temperature set at 200 °C, duration at 20 min, and pressure on the tape at 12 MPa, the samples exhibit favourable properties characterized by a smooth and neat appearance without defects such as pinholes or false soldering, and the superconductivity performance can be consistently maintained at more than 97%. The obtained measurements were compared with simulated results, demonstrating an error margin within 0.5%. Moreover, precise control of <inline-formula>\u0000<tex-math><?CDATA ${I_{text{c}}}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:msub><mml:mi>I</mml:mi><mml:mrow><mml:mtext>c</mml:mtext></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"sustad6adaieqn2.gif\"></inline-graphic></inline-formula> is achieved, tailored to tape and stacking specifications, allowing manageable degradation as required. This heat treatment process for stacked HTS tapes holds significant importance, especially in the context of designing cable-in-conduit conductors fabricated with stacked HTS tapes. It serves as a valuable reference for further advancements in this field.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quench protection has always been challenging for high-temperature superconductor (HTS) coils. Fast current discharge after quench detection is important for a successful coil protection. The copper plates initially intended for cooling can significantly accelerate the discharging process for HTS coils through electromagnetic coupling between coils and copper plates. However, the underlying physical mechanism of this technique has not been studied thoroughly. Here we present a detailed study on the electromagnetic and thermal characteristics of HTS coils coupled with copper plates through experiments and simulations. The results show that a considerable current rebound occurs after an accelerating current drop in the early stage of the fast-discharging process. This coil current rebound is induced by temperature rise as well as the resistivity of copper plates, which are heated by induced eddy current. The heat transfer from copper plates can uniformly heat the whole coil rapidly, which speeds up the discharging process, meanwhile it can also induce overcurrent quench risk. A 30 T@20 K HTS magnet with 36 single pancakes is analyzed. The coupling copper plates can make the coil current drop to 36.9% within the initial 8 ms. The temperature rise induced by copper plates shows a considerable nonuniform distribution among the multiple coil systems. The protection can be enhanced by optimizing the resistivity of copper plates and magnetic coupling strength between plates and coils. This technique has great potential for the protection of insulated HTS magnets.
{"title":"Fast current discharging using self-coupling energy absorption for insulated high temperature superconductor magnets","authors":"Jingyi Liu, Zhen Lu, Yawei Wang, Qingqing Yang, Yutong Fu, Yue Zhao, Zhijian Jin","doi":"10.1088/1361-6668/ad6e26","DOIUrl":"https://doi.org/10.1088/1361-6668/ad6e26","url":null,"abstract":"Quench protection has always been challenging for high-temperature superconductor (HTS) coils. Fast current discharge after quench detection is important for a successful coil protection. The copper plates initially intended for cooling can significantly accelerate the discharging process for HTS coils through electromagnetic coupling between coils and copper plates. However, the underlying physical mechanism of this technique has not been studied thoroughly. Here we present a detailed study on the electromagnetic and thermal characteristics of HTS coils coupled with copper plates through experiments and simulations. The results show that a considerable current rebound occurs after an accelerating current drop in the early stage of the fast-discharging process. This coil current rebound is induced by temperature rise as well as the resistivity of copper plates, which are heated by induced eddy current. The heat transfer from copper plates can uniformly heat the whole coil rapidly, which speeds up the discharging process, meanwhile it can also induce overcurrent quench risk. A 30 T@20 K HTS magnet with 36 single pancakes is analyzed. The coupling copper plates can make the coil current drop to 36.9% within the initial 8 ms. The temperature rise induced by copper plates shows a considerable nonuniform distribution among the multiple coil systems. The protection can be enhanced by optimizing the resistivity of copper plates and magnetic coupling strength between plates and coils. This technique has great potential for the protection of insulated HTS magnets.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-21DOI: 10.1088/1361-6668/ad68d7
Kentaro Yamamoto, Yutaka Yoshida, Tomoya Horide
YBa2Cu3O7 coated conductors are a strategic material for superconducting applications such as high field magnets, fusion, and motors. Grain boundaries reduce the critical current density (Jc) even at a tilt angle as low as 5°, but the successful development of the highly oriented substrates seemed to overcome the weak link problem at grain boundaries. However, it reappears when we visit the homogeneity of the coated conductors. To suppress the weak link in the coated conductors, the Ca doping was investigated. The Ca-doped YBa2Cu3O7 films were fabricated on the moderately oriented substrates. While the grain boundaries in the moderately oriented substrates significantly degraded the Jc without Ca doping, the Ca doping improved the Jc especially at low temperature. This indicates that the tilt angle dependence of Jc was varied by the Ca doping. While the Jc for the moderately oriented substrate was 20 times smaller than that for the highly oriented substrate, the Ca doping restored 1/2 of the Jc for the highly oriented substrate at 40 K and 9 T. The vortex structure changed from Abrikosov Josephson vortices to the Abrikosov vortices with increasing the Ca content. The combination of Ca doping and moderate substrate texture is another design of coated conductors. The Ca doping can patch the local degradation of the substrate texture to mass produce the practical coated conductors with improved homogeneity.
YBa2Cu3O7 涂层导体是高磁场磁体、核聚变和发动机等超导应用的战略材料。晶界会降低临界电流密度（Jc），即使倾斜角低至 5°，但高取向基底的成功开发似乎克服了晶界的薄弱环节问题。然而，当我们考察涂层导体的均匀性时，弱链接问题再次出现。为了抑制涂层导体中的薄弱环节，研究人员对掺钙进行了研究。掺 Ca 的 YBa2Cu3O7 薄膜是在取向适中的基底上制作的。在没有掺杂 Ca 的情况下，适度取向基底中的晶界会显著降低 Jc 值，而掺杂 Ca 则会提高 Jc 值，尤其是在低温条件下。这表明 Jc 与倾斜角的关系因掺钙而异。虽然适度取向衬底的 Jc 比高度取向衬底小 20 倍，但在 40 K 和 9 T 条件下，掺杂钙后，高度取向衬底的 Jc 恢复了 1/2。钙掺杂与适度的基底纹理相结合是涂层导体的另一种设计。钙掺杂可以修补基底纹理的局部退化，从而批量生产出具有更好均匀性的实用涂层导体。
{"title":"Suppression of grain boundary weak link by Ca doping in YBa2Cu3O7 coated conductor","authors":"Kentaro Yamamoto, Yutaka Yoshida, Tomoya Horide","doi":"10.1088/1361-6668/ad68d7","DOIUrl":"https://doi.org/10.1088/1361-6668/ad68d7","url":null,"abstract":"YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub> coated conductors are a strategic material for superconducting applications such as high field magnets, fusion, and motors. Grain boundaries reduce the critical current density (<italic toggle=\"yes\">J</italic><sub>c</sub>) even at a tilt angle as low as 5°, but the successful development of the highly oriented substrates seemed to overcome the weak link problem at grain boundaries. However, it reappears when we visit the homogeneity of the coated conductors. To suppress the weak link in the coated conductors, the Ca doping was investigated. The Ca-doped YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub> films were fabricated on the moderately oriented substrates. While the grain boundaries in the moderately oriented substrates significantly degraded the <italic toggle=\"yes\">J</italic><sub>c</sub> without Ca doping, the Ca doping improved the <italic toggle=\"yes\">J</italic><sub>c</sub> especially at low temperature. This indicates that the tilt angle dependence of <italic toggle=\"yes\">J</italic><sub>c</sub> was varied by the Ca doping. While the <italic toggle=\"yes\">J</italic><sub>c</sub> for the moderately oriented substrate was 20 times smaller than that for the highly oriented substrate, the Ca doping restored 1/2 of the <italic toggle=\"yes\">J</italic><sub>c</sub> for the highly oriented substrate at 40 K and 9 T. The vortex structure changed from Abrikosov Josephson vortices to the Abrikosov vortices with increasing the Ca content. The combination of Ca doping and moderate substrate texture is another design of coated conductors. The Ca doping can patch the local degradation of the substrate texture to mass produce the practical coated conductors with improved homogeneity.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-21DOI: 10.1088/1361-6668/ad68d6
Zhuoyan Zhong, Wei Wu, Zhijian Jin
For no-insulation (NI) high-temperature superconducting (HTS) coils, a 3D electromagnetic model, which is fast and accurate, conducive to establish, and straightforward to multi-physics coupling, is still required. This paper introduces a polygon-anisotropic-resistivity (PAR) method for 3D FEM electromagnetic simulations of NI HTS coils. This model avoids dividing each tape into the specific HTS-tape layer and turn-to-turn contact layer, which yields: (1) a reduced computational burden; (2) improved convergence due to smaller element aspect ratios. The significance of the PAR method lies in its indispensable role in achieving a 3D anisotropic-resistivity model with high computing speed and accuracy. The proposed PAR model is rigorously evaluated through three types of simulations: (1) charge and discharge tests; (2) AC losses of the NI coil subjected to AC fields with a DC current supply; (3) heat-triggered quench and recovery scenarios. For these simulations, the PAR model is validated by comparisons with the full-element model, namely, the 3D FEM model that explicitly incorporates each specific HTS-tape layer and turn-to-turn contact layer in the H-formulation model, and is also validated by previous experimental data for AC losses. Good consistency is observed. The computing speed of the PAR model is tested to be 12–38 times that of the full-element model with the same accuracy. The PAR model achieves a 40% reduction in degrees of freedom compared to the full-element model, with the same mesh density along the HTS tape width and length, facilitating more precise and larger scale coil simulations within the same computational memory limits. Additionally, the PAR model entirely eliminates the inherent inaccuracies found in the conventional-anisotropic-resistivity 3D model, which stem from discrepancies between the arranged anisotropic-resistivity and the actual computed coil meshes. The proposed PAR model will enhance the prevalence of 3D electromagnetic analyses of NI HTS coils.
对于无绝缘（NI）高温超导（HTS）线圈，仍然需要一种快速准确、有利于建立并可直接进行多物理场耦合的三维电磁模型。本文介绍了用于 NI HTS 线圈三维有限元电磁模拟的多边形各向异性电阻率 (PAR) 方法。该模型避免了将每个磁带划分为特定的 HTS 磁带层和匝间接触层，从而：(1) 减轻了计算负担；(2) 由于元素纵横比更小，收敛性得到改善。PAR 方法的意义在于它在实现具有高计算速度和精度的三维各向异性电阻率模型方面发挥了不可或缺的作用。所提出的 PAR 模型通过三类模拟进行了严格评估：(1) 充电和放电测试；(2) 直流电源下 NI 线圈在交流场中的交流损耗；(3) 热触发淬火和恢复情景。在这些模拟中，PAR 模型通过与全元素模型（即在 H 型模型中明确包含每个特定 HTS 带层和匝间接触层的 3D FEM 模型）的比较进行了验证，并通过之前的交流损耗实验数据进行了验证。该模型具有良好的一致性。经测试，在精度相同的情况下，PAR 模型的计算速度是全元素模型的 12-38 倍。在 HTS 磁带宽度和长度网格密度相同的情况下，PAR 模型比全元素模型减少了 40% 的自由度，从而在相同的计算内存限制下，实现了更精确、更大规模的线圈模拟。此外，PAR 模型完全消除了传统各向异性电阻率三维模型中固有的不准确性，这种不准确性源于排列的各向异性电阻率与实际计算的线圈网格之间的差异。建议的 PAR 模型将提高 NI HTS 线圈三维电磁分析的普及率。
{"title":"Fast and accurate 3D FEM model for electromagnetic simulations of no-insulation HTS coils based on polygon-anisotropic-resistivity","authors":"Zhuoyan Zhong, Wei Wu, Zhijian Jin","doi":"10.1088/1361-6668/ad68d6","DOIUrl":"https://doi.org/10.1088/1361-6668/ad68d6","url":null,"abstract":"For no-insulation (NI) high-temperature superconducting (HTS) coils, a 3D electromagnetic model, which is fast and accurate, conducive to establish, and straightforward to multi-physics coupling, is still required. This paper introduces a polygon-anisotropic-resistivity (PAR) method for 3D FEM electromagnetic simulations of NI HTS coils. This model avoids dividing each tape into the specific HTS-tape layer and turn-to-turn contact layer, which yields: (1) a reduced computational burden; (2) improved convergence due to smaller element aspect ratios. The significance of the PAR method lies in its indispensable role in achieving a 3D anisotropic-resistivity model with high computing speed and accuracy. The proposed PAR model is rigorously evaluated through three types of simulations: (1) charge and discharge tests; (2) AC losses of the NI coil subjected to AC fields with a DC current supply; (3) heat-triggered quench and recovery scenarios. For these simulations, the PAR model is validated by comparisons with the full-element model, namely, the 3D FEM model that explicitly incorporates each specific HTS-tape layer and turn-to-turn contact layer in the <italic toggle=\"yes\">H</italic>-formulation model, and is also validated by previous experimental data for AC losses. Good consistency is observed. The computing speed of the PAR model is tested to be 12–38 times that of the full-element model with the same accuracy. The PAR model achieves a 40% reduction in degrees of freedom compared to the full-element model, with the same mesh density along the HTS tape width and length, facilitating more precise and larger scale coil simulations within the same computational memory limits. Additionally, the PAR model entirely eliminates the inherent inaccuracies found in the conventional-anisotropic-resistivity 3D model, which stem from discrepancies between the arranged anisotropic-resistivity and the actual computed coil meshes. The proposed PAR model will enhance the prevalence of 3D electromagnetic analyses of NI HTS coils.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-14DOI: 10.1088/1361-6668/ad637e
Evgeny F Talantsev, Vasiliy V Chistyakov
For seven decades, when referring to A-15 superconductors, we meant metallic A<sub>3</sub>B alloys (where A is a transition metal, and B is group IIIB and IVB elements) discovered by Hardy and Hulm (1953 <italic toggle="yes">Phys. Rev.</italic> <bold>89</bold> 884). Nb<sub>3</sub>Ge exhibited the highest superconducting transition temperature, <italic toggle="yes">T<sub>c</sub></italic> = 23K, among these alloys. One of these alloys, Nb<sub>3</sub>Sn, is the primary material in modern applied superconductivity. Recently, Guo <italic toggle="yes">et al</italic> (2024 <italic toggle="yes">Natl Sci. Rev.</italic> nwae149, <ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1093/nsr/nwae149">https://doi.org/10.1093/nsr/nwae149</ext-link>) extended the family of superconductors where the metallic ions are arranged in the beta tungsten (A-15) sublattice by observation of <italic toggle="yes">T<sub>c</sub></italic><sub>,zero</sub> = 81K in the La<sub>4</sub>H<sub>23</sub> phase compressed at <italic toggle="yes">P</italic> = 118 GPa. Despite the fact that La<sub>4</sub>H<sub>23</sub> has much lower <italic toggle="yes">T<sub>c</sub></italic> in comparison with the near-room-temperature superconducting LaH<sub>10</sub> phase (<italic toggle="yes">T<sub>c</sub></italic><sub>,zero</sub> = 250K at <italic toggle="yes">P</italic> ∼ 200 GPa) discovered by Drozdov <italic toggle="yes">et al</italic> (2019 <italic toggle="yes">Nature</italic> <bold>569</bold> 531), La<sub>4</sub>H<sub>23</sub> holds the record for the highest <italic toggle="yes">T<sub>c</sub></italic> within the A-15 family. Cross <italic toggle="yes">et al</italic> (2024 <italic toggle="yes">Phys. Rev.</italic> B <bold>109</bold> L020503) confirmed the high-temperature superconductivity in compressed La<sub>4</sub>H<sub>23</sub>. In this paper, we analyzed available experimental data measured in La<sub>4</sub>H<sub>23</sub> and found that this superconductor exhibits a nanograined structure, 5.5 nm ⩽ <italic toggle="yes">D</italic> ⩽ 35 nm, low crystalline strain, <inline-formula> <tex-math><?CDATA $left| {{varepsilon }} right|$?></tex-math><mml:math overflow="scroll"><mml:mrow><mml:mrow><mml:mo>|</mml:mo><mml:mrow><mml:mrow><mml:mi>ε</mml:mi></mml:mrow></mml:mrow><mml:mo>|</mml:mo></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href="sustad637eieqn1.gif"></inline-graphic></inline-formula> ⩽ 0.003, strong electron–phonon interaction, 1.5 ⩽ λ<sub>e-ph</sub>⩽ 2.55, and a moderate level of nonadiabaticity, 0.18 ⩽ Θ<italic toggle="yes"><sub>D</sub></italic>/<italic toggle="yes">T</italic><sub>F</sub> ⩽ 0.22 (where Θ<italic toggle="yes"><sub>D</sub></italic> is the Debye temperature, and <italic toggle="yes">T</italic><sub>F</sub> is the Fermi temperature). We found that the derived Θ<italic toggle="yes"><sub>D</sub></italic>/<italic toggle="yes">T</italic><sub>F</sub> and <italic toggle="yes">T<sub>c</sub></italic>/<italic toggle="yes">T</italic><sub>F</sub> values for the La<sub>
{"title":"The A-15-type superconducting hydride La4H23: a nanograined structure with low strain, strong electron-phonon interaction, and a moderate level of nonadiabaticity","authors":"Evgeny F Talantsev, Vasiliy V Chistyakov","doi":"10.1088/1361-6668/ad637e","DOIUrl":"https://doi.org/10.1088/1361-6668/ad637e","url":null,"abstract":"For seven decades, when referring to A-15 superconductors, we meant metallic A<sub>3</sub>B alloys (where A is a transition metal, and B is group IIIB and IVB elements) discovered by Hardy and Hulm (1953 <italic toggle=\"yes\">Phys. Rev.</italic> <bold>89</bold> 884). Nb<sub>3</sub>Ge exhibited the highest superconducting transition temperature, <italic toggle=\"yes\">T<sub>c</sub></italic> = 23K, among these alloys. One of these alloys, Nb<sub>3</sub>Sn, is the primary material in modern applied superconductivity. Recently, Guo <italic toggle=\"yes\">et al</italic> (2024 <italic toggle=\"yes\">Natl Sci. Rev.</italic> nwae149, <ext-link ext-link-type=\"uri\" xlink:href=\"https://doi.org/10.1093/nsr/nwae149\">https://doi.org/10.1093/nsr/nwae149</ext-link>) extended the family of superconductors where the metallic ions are arranged in the beta tungsten (A-15) sublattice by observation of <italic toggle=\"yes\">T<sub>c</sub></italic><sub>,zero</sub> = 81K in the La<sub>4</sub>H<sub>23</sub> phase compressed at <italic toggle=\"yes\">P</italic> = 118 GPa. Despite the fact that La<sub>4</sub>H<sub>23</sub> has much lower <italic toggle=\"yes\">T<sub>c</sub></italic> in comparison with the near-room-temperature superconducting LaH<sub>10</sub> phase (<italic toggle=\"yes\">T<sub>c</sub></italic><sub>,zero</sub> = 250K at <italic toggle=\"yes\">P</italic> ∼ 200 GPa) discovered by Drozdov <italic toggle=\"yes\">et al</italic> (2019 <italic toggle=\"yes\">Nature</italic> <bold>569</bold> 531), La<sub>4</sub>H<sub>23</sub> holds the record for the highest <italic toggle=\"yes\">T<sub>c</sub></italic> within the A-15 family. Cross <italic toggle=\"yes\">et al</italic> (2024 <italic toggle=\"yes\">Phys. Rev.</italic> B <bold>109</bold> L020503) confirmed the high-temperature superconductivity in compressed La<sub>4</sub>H<sub>23</sub>. In this paper, we analyzed available experimental data measured in La<sub>4</sub>H<sub>23</sub> and found that this superconductor exhibits a nanograined structure, 5.5 nm ⩽ <italic toggle=\"yes\">D</italic> ⩽ 35 nm, low crystalline strain, <inline-formula>\u0000<tex-math><?CDATA $left| {{varepsilon }} right|$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mrow><mml:mo>|</mml:mo><mml:mrow><mml:mrow><mml:mi>ε</mml:mi></mml:mrow></mml:mrow><mml:mo>|</mml:mo></mml:mrow></mml:mrow></mml:math><inline-graphic xlink:href=\"sustad637eieqn1.gif\"></inline-graphic></inline-formula> ⩽ 0.003, strong electron–phonon interaction, 1.5 ⩽ λ<sub>e-ph</sub>⩽ 2.55, and a moderate level of nonadiabaticity, 0.18 ⩽ Θ<italic toggle=\"yes\"><sub>D</sub></italic>/<italic toggle=\"yes\">T</italic><sub>F</sub> ⩽ 0.22 (where Θ<italic toggle=\"yes\"><sub>D</sub></italic> is the Debye temperature, and <italic toggle=\"yes\">T</italic><sub>F</sub> is the Fermi temperature). We found that the derived Θ<italic toggle=\"yes\"><sub>D</sub></italic>/<italic toggle=\"yes\">T</italic><sub>F</sub> and <italic toggle=\"yes\">T<sub>c</sub></italic>/<italic toggle=\"yes\">T</italic><sub>F</sub> values for the La<sub>","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-14DOI: 10.1088/1361-6668/ad68d4
Emilio Bellingeri, Cristina Bernini, Federico Loria, Andrea Traverso, Alessandro Leveratto, Valeria Braccini, Amalia Ballarino, Andrea Malagoli
Iron-based superconductors (IBSs) are promising for high-field applications due to their exceptional characteristics, like ultrahigh upper critical field and minimal electromagnetic anisotropy. Creating multifilamentary superconducting wires with elevated transport critical current density is essential for practical use. The Powder in Tube (PIT) technique is commonly used for this purpose, but achieving optimal results requires careful exploration of powder microstructural properties. This is particularly crucial for superconductors like (Ba,K)122, the IBS most promising from an applicative point of view, where factors such as reactivity, volatility, and toxicity of constituent elements affect phase formation. Potassium volatility often leads to nonstoichiometric conditions, introducing excess potassium in the formulation. This study focuses on the impact of potassium excess δ on the microstructural properties of the ‘optimally doped’ (Ba0.6K0.4+δ)Fe2As2 phase (0 ⩽ δ ⩽ 0.08). Using techniques like Scanning Electron Microscopy, x-ray diffraction, and temperature-dependent magnetization measurements, we demonstrate the ability to produce nearly pure powders of the superconducting phase with controlled grain size. Our findings are relevant for PIT wire fabrication, where grain size strongly affects mechanical deformation. Grain size also influences transport properties, as observed in previous studies, where reducing grain size enhanced current-carrying capability at high magnetic fields.
{"title":"Effects of K excess in microstructure of (Ba0.6K0.4)Fe2As2 superconducting powders","authors":"Emilio Bellingeri, Cristina Bernini, Federico Loria, Andrea Traverso, Alessandro Leveratto, Valeria Braccini, Amalia Ballarino, Andrea Malagoli","doi":"10.1088/1361-6668/ad68d4","DOIUrl":"https://doi.org/10.1088/1361-6668/ad68d4","url":null,"abstract":"Iron-based superconductors (IBSs) are promising for high-field applications due to their exceptional characteristics, like ultrahigh upper critical field and minimal electromagnetic anisotropy. Creating multifilamentary superconducting wires with elevated transport critical current density is essential for practical use. The Powder in Tube (PIT) technique is commonly used for this purpose, but achieving optimal results requires careful exploration of powder microstructural properties. This is particularly crucial for superconductors like (Ba,K)122, the IBS most promising from an applicative point of view, where factors such as reactivity, volatility, and toxicity of constituent elements affect phase formation. Potassium volatility often leads to nonstoichiometric conditions, introducing excess potassium in the formulation. This study focuses on the impact of potassium excess <italic toggle=\"yes\">δ</italic> on the microstructural properties of the ‘optimally doped’ (Ba<sub>0.6</sub>K<sub>0.4+<italic toggle=\"yes\">δ</italic></sub>)Fe<sub>2</sub>As<sub>2</sub> phase (0 ⩽ <italic toggle=\"yes\">δ</italic> ⩽ 0.08). Using techniques like Scanning Electron Microscopy, x-ray diffraction, and temperature-dependent magnetization measurements, we demonstrate the ability to produce nearly pure powders of the superconducting phase with controlled grain size. Our findings are relevant for PIT wire fabrication, where grain size strongly affects mechanical deformation. Grain size also influences transport properties, as observed in previous studies, where reducing grain size enhanced current-carrying capability at high magnetic fields.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-11DOI: 10.1088/1361-6668/ad6a9c
T Bagni, C Calzolaio, G Bovone, J Ferradas-Troitino, C Barth, A Ballarino and C Senatore
Future high-field magnets for particle accelerators hinge on the crucial development of advanced Nb3Sn wires engineered to withstand the large stresses generated during magnet assembly and operation. The superconducting properties of Nb3Sn enable the design of compact accelerator-quality magnets above 10 T, but at the same time the brittleness and strain sensitivity of the material impose careful consideration of the mechanical limits. In addition, accelerator magnets are wound using Rutherford cables and the cabling process generates deformations in the wire that can affect its electro-mechanical performance. This paper reports on the impact of the rolling deformation on the transverse stress tolerance of high-performance restacked-rod-process (RRP®) and powder-in-tube (PIT) Nb3Sn wires. Rolling deformation was used to mimic the effect of cabling on the wire shape. Deformed samples were compared to reference round wires in term of stress dependence and irreversible limit (σirr) of the critical current (Ic) under transverse compressive loads up to 240 MPa. Experiments were performed at 4.2 K, 19 T, on resin-impregnated single wires that imitate the operating conditions in a Rutherford cable of an accelerator magnet. The results show that rolling deformation has a detrimental effect on the initial Ic of PIT wires, but it does not influence the behavior of the wire under stresses above 70 MPa. On the other hand, the deformation of RRP® wires leads to an improved σirr without affecting the initial Ic. Additionally, a 2D-mechanical finite element method model of the RRP® wire was developed to investigate the impact of the wire geometry on the plastic deformation of the copper matrix, which induces residual stresses on Nb3Sn and is the main cause for the permanent reduction of Ic. Based on the model results, an alternative layout of the wire was proposed that improves its stress tolerance without affecting its electrical transport properties.
未来用于粒子加速器的高磁场磁体取决于先进 Nb3Sn 线材的关键开发，这些线材必须能够承受磁体组装和运行过程中产生的巨大应力。Nb3Sn 的超导特性使我们能够设计出 10 T 以上的紧凑型加速器级磁体，但与此同时，这种材料的脆性和应变敏感性也要求我们仔细考虑其机械限制。此外，加速器磁体是使用卢瑟福线缆绕制的，而绕线过程会使线缆产生变形，从而影响其电子机械性能。本文报告了轧制变形对高性能重组棒工艺 (RRP®) 和管中粉末 (PIT) Nb3Sn 线材横向应力耐受性的影响。轧制变形用于模拟布线对金属丝形状的影响。在高达 240 兆帕的横向压缩载荷下，将变形样品与参考圆线进行了应力依赖性和临界电流 (Ic) 不可逆极限 (σirr)方面的比较。实验在 4.2 K、19 T 条件下对树脂浸渍单线进行，模仿加速器磁体卢瑟福电缆的工作条件。结果表明，滚动变形对 PIT 线材的初始 Ic 有不利影响，但在 70 兆帕以上的应力下不会影响线材的行为。另一方面，RRP® 线材的变形可改善 σirr 而不影响初始 Ic。此外，还开发了 RRP® 金属丝的二维机械有限元法模型，以研究金属丝几何形状对铜基体塑性变形的影响，塑性变形会在 Nb3Sn 上产生残余应力，是导致 Ic 永久性降低的主要原因。根据模型结果，提出了另一种线材布局方案，在不影响其电气传输特性的情况下提高了线材的应力耐受性。
{"title":"Investigating the effect of rolling deformation on the electro-mechanical limits of Nb3Sn wires produced by RRP® and PIT technologies","authors":"T Bagni, C Calzolaio, G Bovone, J Ferradas-Troitino, C Barth, A Ballarino and C Senatore","doi":"10.1088/1361-6668/ad6a9c","DOIUrl":"https://doi.org/10.1088/1361-6668/ad6a9c","url":null,"abstract":"Future high-field magnets for particle accelerators hinge on the crucial development of advanced Nb3Sn wires engineered to withstand the large stresses generated during magnet assembly and operation. The superconducting properties of Nb3Sn enable the design of compact accelerator-quality magnets above 10 T, but at the same time the brittleness and strain sensitivity of the material impose careful consideration of the mechanical limits. In addition, accelerator magnets are wound using Rutherford cables and the cabling process generates deformations in the wire that can affect its electro-mechanical performance. This paper reports on the impact of the rolling deformation on the transverse stress tolerance of high-performance restacked-rod-process (RRP®) and powder-in-tube (PIT) Nb3Sn wires. Rolling deformation was used to mimic the effect of cabling on the wire shape. Deformed samples were compared to reference round wires in term of stress dependence and irreversible limit (σirr) of the critical current (Ic) under transverse compressive loads up to 240 MPa. Experiments were performed at 4.2 K, 19 T, on resin-impregnated single wires that imitate the operating conditions in a Rutherford cable of an accelerator magnet. The results show that rolling deformation has a detrimental effect on the initial Ic of PIT wires, but it does not influence the behavior of the wire under stresses above 70 MPa. On the other hand, the deformation of RRP® wires leads to an improved σirr without affecting the initial Ic. Additionally, a 2D-mechanical finite element method model of the RRP® wire was developed to investigate the impact of the wire geometry on the plastic deformation of the copper matrix, which induces residual stresses on Nb3Sn and is the main cause for the permanent reduction of Ic. Based on the model results, an alternative layout of the wire was proposed that improves its stress tolerance without affecting its electrical transport properties.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-11DOI: 10.1088/1361-6668/ad6a9d
Jeseok Bang, Griffin Bradford, Kwangmin Kim, Jonathan Lee, Anatolii Polyanskii and David Larbalestier
Recent reports on screening current stress simulations of high-field REBCO magnets frequently present peak stresses over 1 GPa. However, this result is probably an unrealistic artifact of purely elastic calculations, considering the macroscopic yield and fracture stresses of approximately 900 MPa and less than 1.1 GPa for Hastelloy substrate-coated conductors. Here, we evaluate elastic-plastic conductor damage at over 0.4% strain using a high-stress REBCO coil exposed to a high field to explore this elastic-plastic regime. The coil was located off-center in a low-temperature superconductor magnet so as to induce a significant screening current in the enhanced radial field. Voltage taps, a Hall sensor, and two strain gauges were used for the instrumentation. We obtained strains exceeding 0.4% near the outward edge during the coil current charge from 350 A to 390 A, where the coil was exposed to external axial and radial magnetic fields of 13 T and 0.5 T. Post mortem results showed wavy plastic deformation, electrical damage, and REBCO defects. An elastic-plastic simulation reproduced the measured strains and predicted that ∼1 GPa stress is sufficient to induce ∼0.9% strain, thus validating our initial concerns with purely elastic models. This paper provides our experimental and simulation results.
最近关于高磁场 REBCO 磁体屏蔽电流应力模拟的报告经常显示峰值应力超过 1 GPa。然而，考虑到哈氏合金基材涂层导体的宏观屈服应力和断裂应力分别约为 900 兆帕和小于 1.1 GPa，这一结果很可能是纯弹性计算中不切实际的假象。在此，我们使用暴露在高场中的高应力 REBCO 线圈来评估应变超过 0.4% 的弹塑性导体损伤，以探索这种弹塑性机制。线圈位于低温超导体磁体的偏心位置，以便在增强的径向磁场中产生显著的屏蔽电流。仪器使用了电压抽头、霍尔传感器和两个应变计。在线圈电流从 350 A 充至 390 A 期间，我们在外缘附近获得了超过 0.4% 的应变，线圈暴露在 13 T 和 0.5 T 的外部轴向和径向磁场中。弹塑性模拟再现了测量到的应变，并预测 1 GPa 的应力足以引起 0.9% 的应变，从而验证了我们最初对纯弹性模型的担忧。本文提供了我们的实验和模拟结果。
{"title":"Elastic-plastic conductor damage evaluation at over 0.4% strain using a high-stress REBCO coil","authors":"Jeseok Bang, Griffin Bradford, Kwangmin Kim, Jonathan Lee, Anatolii Polyanskii and David Larbalestier","doi":"10.1088/1361-6668/ad6a9d","DOIUrl":"https://doi.org/10.1088/1361-6668/ad6a9d","url":null,"abstract":"Recent reports on screening current stress simulations of high-field REBCO magnets frequently present peak stresses over 1 GPa. However, this result is probably an unrealistic artifact of purely elastic calculations, considering the macroscopic yield and fracture stresses of approximately 900 MPa and less than 1.1 GPa for Hastelloy substrate-coated conductors. Here, we evaluate elastic-plastic conductor damage at over 0.4% strain using a high-stress REBCO coil exposed to a high field to explore this elastic-plastic regime. The coil was located off-center in a low-temperature superconductor magnet so as to induce a significant screening current in the enhanced radial field. Voltage taps, a Hall sensor, and two strain gauges were used for the instrumentation. We obtained strains exceeding 0.4% near the outward edge during the coil current charge from 350 A to 390 A, where the coil was exposed to external axial and radial magnetic fields of 13 T and 0.5 T. Post mortem results showed wavy plastic deformation, electrical damage, and REBCO defects. An elastic-plastic simulation reproduced the measured strains and predicted that ∼1 GPa stress is sufficient to induce ∼0.9% strain, thus validating our initial concerns with purely elastic models. This paper provides our experimental and simulation results.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-11DOI: 10.1088/1361-6668/ad6adc
L Zhang, Y L Zhong, J J Xie, H Jin, W B Zhao, W Peng, L Chen and Z Wang
In this research, we have studied the structural and electrical properties of NbTiN films deposited on MgO and SiO2/Si substrates by reactive dc sputtering. The formation of stoichiometric NbTiN is very sensitive to N concentration and can be easily adjusted by changing the discharge current and Ar: N2 ratio along the current–voltage curves (IVCs) of the NbTi target. Excessive or insufficient N concentration in NbTiN leads to sublattice expansion or distortion, resulting in a decrease in critical temperature Tc. At Ar: N2 ratio of 30:4 and discharge current of 2.2 A, Tc as high as 15.8 K and 15.3 K has been obtained for 200 nm thick NbTiN/MgO and NbTiN/SiO2/Si samples, respectively. In addition, the critical density Jc of the 4 μm-wide and 7 nm-thick NbTiN film grown on MgO substrate at 2 K reaches 19.2 MA cm−2, which is approximately twice as high as the 10.9 MA cm−2 of the same-sized NbTiN film grown on SiO2/Si substrate. Therefore, by further fine-tuning the N concentration in combination with the IVCs of the target, high-quality stoichiometric NbTiN can be obtained.
在这项研究中，我们研究了通过反应直流溅射沉积在氧化镁和二氧化硅/硅基底上的铌钛氮薄膜的结构和电气特性。化学计量铌钛氮的形成对 N 浓度非常敏感，可以通过改变放电电流和 Ar：通过沿 NbTi 靶材的电流-电压曲线 (IVC) 改变放电电流和 Ar：N2 比率，可以很容易地调整 NbTiN 的形成。NbTiN 中的 N 浓度过高或过低都会导致亚晶格膨胀或变形，从而降低临界温度 Tc。在 Ar：在 Ar：N2 比率为 30：4 和放电电流为 2.2 A 的条件下，200 nm 厚的 NbTiN/MgO 和 NbTiN/SiO2/Si 样品的临界温度分别高达 15.8 K 和 15.3 K。此外，在 2 K 下，生长在氧化镁衬底上的 4 μm 宽、7 nm 厚的铌钛氮薄膜的临界密度 Jc 达到 19.2 MA cm-2，约为生长在 SiO2/Si 衬底上的相同尺寸铌钛氮薄膜的 10.9 MA cm-2 的两倍。因此，通过结合靶材的 IVC 进一步微调氮浓度，可以获得高质量的化学计量铌钛氮。
{"title":"Effect of nitrogen content on the structure and superconductivity of reactive sputtered NbTiN thin films","authors":"L Zhang, Y L Zhong, J J Xie, H Jin, W B Zhao, W Peng, L Chen and Z Wang","doi":"10.1088/1361-6668/ad6adc","DOIUrl":"https://doi.org/10.1088/1361-6668/ad6adc","url":null,"abstract":"In this research, we have studied the structural and electrical properties of NbTiN films deposited on MgO and SiO2/Si substrates by reactive dc sputtering. The formation of stoichiometric NbTiN is very sensitive to N concentration and can be easily adjusted by changing the discharge current and Ar: N2 ratio along the current–voltage curves (IVCs) of the NbTi target. Excessive or insufficient N concentration in NbTiN leads to sublattice expansion or distortion, resulting in a decrease in critical temperature Tc. At Ar: N2 ratio of 30:4 and discharge current of 2.2 A, Tc as high as 15.8 K and 15.3 K has been obtained for 200 nm thick NbTiN/MgO and NbTiN/SiO2/Si samples, respectively. In addition, the critical density Jc of the 4 μm-wide and 7 nm-thick NbTiN film grown on MgO substrate at 2 K reaches 19.2 MA cm−2, which is approximately twice as high as the 10.9 MA cm−2 of the same-sized NbTiN film grown on SiO2/Si substrate. Therefore, by further fine-tuning the N concentration in combination with the IVCs of the target, high-quality stoichiometric NbTiN can be obtained.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.1088/1361-6668/ad6d9e
Guangxian Zhu, Yirong Kan, Renyuan Zhang, Yasuhiko Nakashima, Wenhui Luo, N. Takeuchi, Nobuyuki Yoshikawa, O. Chen
This paper introduces SuperSIM, a benchmarking framework tailored for neural networks using superconducting Josephson devices, specifically focusing on Adiabatic Quantum Flux Parametron (AQFP) based Processing-in-Memory (PIM) architectures. Our framework offers in-depth architecture-level simulations and performance assessments to enhance AQFP PIM chip development. It supports single and multi-bit PIM designs, various AQFP memory cell types, and diverse clocking methods. Additionally, it integrates circuit-level models for precise energy, delay, and area measurements, ensuring accurate performance evaluation. The framework includes application, device, and architectural layers for versatile configurations and cycle-accurate energy, latency, and area simulations. Experiments validate our framework, with case studies on algorithm and architecture-level features, examining data precision, crossbar size, operating frequency and clocking scheme impacts on computational accuracy, energy use, overall latency and hardware cost.
{"title":"SuperSIM: A comprehensive benchmarking framework for neural networks using superconductor josephson devices","authors":"Guangxian Zhu, Yirong Kan, Renyuan Zhang, Yasuhiko Nakashima, Wenhui Luo, N. Takeuchi, Nobuyuki Yoshikawa, O. Chen","doi":"10.1088/1361-6668/ad6d9e","DOIUrl":"https://doi.org/10.1088/1361-6668/ad6d9e","url":null,"abstract":"\u0000 This paper introduces SuperSIM, a benchmarking framework tailored for neural networks using superconducting Josephson devices, specifically focusing on Adiabatic Quantum Flux Parametron (AQFP) based Processing-in-Memory (PIM) architectures. Our framework offers in-depth architecture-level simulations and performance assessments to enhance AQFP PIM chip development. It supports single and multi-bit PIM designs, various AQFP memory cell types, and diverse clocking methods. Additionally, it integrates circuit-level models for precise energy, delay, and area measurements, ensuring accurate performance evaluation. The framework includes application, device, and architectural layers for versatile configurations and cycle-accurate energy, latency, and area simulations. Experiments validate our framework, with case studies on algorithm and architecture-level features, examining data precision, crossbar size, operating frequency and clocking scheme impacts on computational accuracy, energy use, overall latency and hardware cost.","PeriodicalId":21985,"journal":{"name":"Superconductor Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141925321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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