Superconductivity最新文献

{"title":"Optimisation of pulsed laser deposited Ba1-xKxBiO3 thin films with tunable superconducting properties by control of K doping level, x","authors":"A. Kursumovic ,&nbsp;J. Prestigiacomo ,&nbsp;M. de h-Óra ,&nbsp;W. Li ,&nbsp;J. Feighan ,&nbsp;V. Smolyaninova ,&nbsp;I. Smolyaninov ,&nbsp;M. Osofsky ,&nbsp;J.L. MacManus-Driscoll","doi":"10.1016/j.supcon.2024.100115","DOIUrl":"10.1016/j.supcon.2024.100115","url":null,"abstract":"<div><p>The mid-<em>T</em>_C superconductor Ba_1-XK_XBiO₃ (BKBO) exhibits different superconducting mechanisms depending on x, in the range ∼ 0.35–0.65. The optimal doping for the highest <em>T</em>_C is reported to be around x  = 0.4. To understand more about the dependence of the superconducting mechanism on x, high quality and reproducible epitaxial films with controlled x are needed. This has been challenging owing to the volatility of K and (to a lesser extent) Bi. In this work, we use pulsed laser deposition (PLD) with several novel process steps to achieve high-quality films in a reproducible way. These include a modified method for target preparation, a low NO₂ growth pressure, and precise positioning of substrates in the PLD plume. Optimum <em>T</em>_C films (32 K onset) were grown from an x  = 0.4 target, i.e. with no excess K, as is normally used. Stable, higher K content films (made from an x = 0.45 target), were also grown. These x = 0.45 films had a lower <em>T</em>_C (22.5 K onset), as expected for (K) overdoped films, with very high upper critical field, <em>H</em>_C2 (0 K), and irreversibility field, <em>H</em>_irr (0 K), values, from linear extrapolation, of ∼ 31.7 T and ∼ 28.8 T, respectively. The growth methodology demonstrated in this work is highly beneficial for fundamental mechanistic studies of this complex superconductor on which there is renewed interest, and where controlled compositions and crystalline quality are currently limited.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"11 ","pages":"Article 100115"},"PeriodicalIF":5.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000322/pdfft?md5=6e44af9fc754192ef1aabc09fd102f6e&pid=1-s2.0-S2772830724000322-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancements in dynamic characteristics analysis of superconducting electrodynamic suspension systems: Modeling, experiment, and optimization","authors":"Huan Huang ,&nbsp;Haitao Li ,&nbsp;Tim Coombs ,&nbsp;Hanlin Zhu ,&nbsp;Yougang Sun ,&nbsp;Guobin Lin ,&nbsp;Junqi Xu ,&nbsp;Jun Zheng","doi":"10.1016/j.supcon.2024.100114","DOIUrl":"10.1016/j.supcon.2024.100114","url":null,"abstract":"<div><p>Superconducting electrodynamic suspension (EDS) presents numerous advantages, including large suspension gaps, high lift-to-drag ratios, and lower requirements for track irregularities. Recent advancements in superconducting materials have further enhanced the feasibility of this technology, and hence multiple research institutions are actively developing and improving this high-speed rail technology. Superconducting EDS achieves passive suspension and guidance by the interaction between ground null-flux coils and onboard superconducting magnets, forming an electromechanical coupled system. Thus, electromechanical coupling modeling and equivalent experimental methods are essential in evaluating and optimizing this system. This article reviews the research on dynamic characteristics analysis of superconducting EDS, focusing on modeling and experimental methods. Firstly, it revisits the development history of superconducting EDS and the new opportunities brought by advancements in superconducting materials. Secondly, it discusses various modeling approaches for the suspension system, emphasizing their benefits and limitations. Thirdly, it describes equivalent experimental methods and their respective application scenarios. Then, it reviews important conclusions and possible optimization methods related to dynamic performance and electromechanical coupling research. Additionally, the sliding window method is introduced to improve computational efficiency in vehicle dynamics modeling. This article provides insights into the current state and future directions of superconducting EDS research, serving as a valuable reference for researchers and engineers.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"11 ","pages":"Article 100114"},"PeriodicalIF":5.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000310/pdfft?md5=46adfaf16db0cf7aa63b9000768c6fbc&pid=1-s2.0-S2772830724000310-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142148836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superconducting materials − tools to combat with climate change","authors":"Muralidhar Miryala","doi":"10.1016/j.supcon.2024.100113","DOIUrl":"10.1016/j.supcon.2024.100113","url":null,"abstract":"","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"11 ","pages":"Article 100113"},"PeriodicalIF":5.6,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000309/pdfft?md5=fc498a98f267c4d5329bcb672a91fd77&pid=1-s2.0-S2772830724000309-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing in-field performance of GdBCO coated conductors by cooperative irradiation with Ti ions and protons","authors":"Daxing Huang ,&nbsp;Hao Dong ,&nbsp;Tongxin Wang ,&nbsp;Hao Yu ,&nbsp;Kaigui Zhu ,&nbsp;Hongwei Gu ,&nbsp;Fazhu Ding","doi":"10.1016/j.supcon.2024.100112","DOIUrl":"10.1016/j.supcon.2024.100112","url":null,"abstract":"<div><p>Irradiation can accurately manipulate defects and adjust pinning landscapes within REBa₂Cu₃O_7-<em>_δ</em> (REBCO, RE: rare earths) coated conductors (CCs). This study reports a productive method to dramatically boost the in-field critical current density (<em>J</em>_c) for GdBCO CCs using cooperative irradiation with Ti ions and protons. Remarkably, the in-field <em>J</em>_c of commercial CCs can be almost doubled at a wide range of temperatures and magnetic fields. Defects of various sizes induced by cooperative irradiation are more uniform distribution through the entire GdBCO film to improve the vortex pinning characteristics, thereby enhancing the in-field performance of the GdBCO CC. This method highlights how combining different particle irradiation types can tailor defect size and distribution, optimizing pinning landscapes for commercial REBCO CCs.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"11 ","pages":"Article 100112"},"PeriodicalIF":5.6,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000292/pdfft?md5=1d8a1e8656a36c52fb889d3851377434&pid=1-s2.0-S2772830724000292-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulations on the AC loss of REBCO stacks under rotating magnetic fields","authors":"Yuan Wang ,&nbsp;Jin Fang ,&nbsp;Timothy Haugan ,&nbsp;Rodney A. Badcock ,&nbsp;James G. Storey ,&nbsp;Zhenan Jiang","doi":"10.1016/j.supcon.2024.100111","DOIUrl":"10.1016/j.supcon.2024.100111","url":null,"abstract":"<div><p>AC loss presents a significant challenge for high-temperature superconducting (HTS) rotating machines. To date, the behaviour of total AC loss (<em>Q</em>_tol) (with current) and magnetization loss (<em>Q</em>_m) (without current) in a single HTS tape under rotating magnetic fields (RF) have been explored. However, a research gap remains in understanding how these findings translate to the more complex HTS windings of rotating machines. Further exploration is needed to understand the loss behaviour of more complex HTS structures, such as HTS stacks. In this work, <em>Q</em>_tol and <em>Q</em>_m, in the HTS stacks under RF and a perpendicular AC standing wave magnetic field are numerically investigated. Two different RF models are considered: one is the Uni-RF model, characterized by a uniform field with equal field amplitudes and phases at each position, and the other is a non-uniform field created by a rotating Halbach array, referred to as the Hal-RF model. The dependence of AC loss on parameters such as the number of tapes in the stacks, tape width (2a), and the inclination angle (<em>α</em>) of tapes, which refers to the angle between the normal direction of the stack and the vertical direction, have been explored. The number of tapes in the stacks ranges from 1 to 16, <em>α</em> ranges from 0° to 90°, and the tape width includes 4 mm and 40 mm. Additionally, different rotating field directions are also considered. Interestingly, the analytical values from Brandt and Indenbom equation for <em>Q</em>_m of a superconducting strip (BI-strip) are close to <em>Q</em>_m results of the stacks under the standing wave at high fields, while they are over twice as high as those in the Hal-RF model at 1 T. This suggests the BI-strip equation is not reliable for predicting <em>Q</em>_m under RF at high fields. We also show in the Hal-RF model that different rotation directions of the field lead to varying <em>Q</em>_m and <em>Q</em>_tol when asymmetric <em>J</em>_c (<em>B</em>, <em>θ</em>) data are applied. Moreover, it has been observed that the inclination angle has no impact on <em>Q</em>_m under uniform RF while significantly impacts both <em>Q</em>_m and <em>Q</em>_tol in the Hal-RF model.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"11 ","pages":"Article 100111"},"PeriodicalIF":5.6,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000280/pdfft?md5=e488a162ac5d6460d16d0da22359d19b&pid=1-s2.0-S2772830724000280-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromagnetic design and performance of conduction cooled superconducting magnet for spoke resonator cryomodule for Proton Improvement Plan (PIP)-II","authors":"Kumud Singh ,&nbsp;Janvin Itteera ,&nbsp;Mahima ,&nbsp;Vikas Tiwari ,&nbsp;Himanshu Bisht ,&nbsp;Sanjay Malhotra ,&nbsp;R.R. Singh ,&nbsp;Rajesh Jalan ,&nbsp;Sanjay Howal ,&nbsp;Rajesh Chimurkar ,&nbsp;Sunil Kumar ,&nbsp;S. Stoynev ,&nbsp;M. Turenne ,&nbsp;M. Yu ,&nbsp;B. Hanna ,&nbsp;J. Hayman ,&nbsp;C. Boffo","doi":"10.1016/j.supcon.2024.100110","DOIUrl":"10.1016/j.supcon.2024.100110","url":null,"abstract":"<div><p>The Proton Improvement Plan (PIP)-II project is part of Fermilab’s upgrade of its proton accelerator complex, to provide a powerful, high-intensity proton beam to the laboratory’s upcoming research program. The project includes an 800 MeV superconducting (SC) linear accelerator (linac), with five flavours of cavities and cryomodules. The medium energy section of the linac contains two types of superconducting Single Spoke Resonator (SSR) RF cavities (SSR1 and SSR2), which are interleaved with strong solenoid focusing lenses. A unified design of the solenoid has been developed, with one solenoid design satisfying both SSR1 and SSR2 requirements. The integral focusing strength requirement of 4.5 T²m with a full width half maximum (FWHM) of 180 mm indicates the peak field strength ∼ 6.8 T in the magnet aperture, necessitating a superconducting design within the limits of NbTi as magnet wire strand. These are complex combined units that include one focusing solenoid with bucking coils to minimize fringe fields and four corrector coils each, with independent current leads to produce dipole and quadrupole fields. To simplify the current lead design and reduce complexity, the project opted conduction cooling for these magnets, thus requiring a redesign compared to previous prototype bath cooled units. Existing designs for high energy accelerators adopt bath cooled design of the solenoid focusing lenses for medium energy cryomodules. The present design explores a unique and technically superior solution for the cryomodule operation by decoupling the magnet and cavity cooling to certain extent. Reliability in cryomodule operations shall be studied after integration of magnets in the Linac beamline. Here we discuss the design requirements, challenges, electromagnetic design, superconducting wire selection and the results from magnetic measurements of the first pre-series units.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"11 ","pages":"Article 100110"},"PeriodicalIF":5.6,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000279/pdfft?md5=3f1c2ac3d4e64c36fa32de681de29e03&pid=1-s2.0-S2772830724000279-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141839735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suppression of flux avalanches in YBCO superconducting thin films by coating metal investigated using magneto-optical imaging","authors":"Qianting Ran ,&nbsp;Ze Jing ,&nbsp;Lei Shen ,&nbsp;Jun Zhou ,&nbsp;Cong Liu ,&nbsp;Zhiwei Zhang ,&nbsp;Xingyi Zhang","doi":"10.1016/j.supcon.2024.100101","DOIUrl":"https://doi.org/10.1016/j.supcon.2024.100101","url":null,"abstract":"<div><p>Flux avalanches, prevalently existing in superconducting thin films, can cause catastrophic breakdowns of electromagnetic properties and even irreversible damage to superconducting materials. Metal coating is an effective way to suppress the flux avalanches in superconducting thin films. Nevertheless, it is difficult to reveal the suppression mechanisms due to the challenge of effectively separating the simultaneous eddy currents and heat exchange in the metal coating. In this work, the eddy currents and heat exchange in the Ag metal coating are separated by setting a thermal insulation layer, and its inhibiting effect on the flux avalanches of the YBCO superconducting thin films is elucidated. The results indicate that eddy currents play an important part in suppressing magnetic flux avalanches, and their effect strengthens with increasing Ag thickness. Meanwhile, employing the double-exposure method, the flux avalanche velocity of YBCO superconducting thin films was measured, revealing a significant decrease in the magnetic flux avalanche velocity due to suppression by eddy currents. Moreover, a theoretical model was established to investigate the influence of eddy currents on the motion of a single vortex, and the calculated results showed good agreement with the experiments. These findings provide a better understanding of the flux avalanches and their suppression in YBCO superconducting thin films.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"11 ","pages":"Article 100101"},"PeriodicalIF":5.6,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000188/pdfft?md5=b062012277351a09b14b89621753db2a&pid=1-s2.0-S2772830724000188-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141595690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An energy-efficient 32-bit bit-parallel superconducting SFQ specialized processor","authors":"Peiyao Qu ,&nbsp;Huanli Liu ,&nbsp;Xiangyu Zheng ,&nbsp;Jiahong Yang ,&nbsp;Liliang Ying ,&nbsp;Jie Ren ,&nbsp;Haihang You ,&nbsp;Guangming Tang","doi":"10.1016/j.supcon.2024.100099","DOIUrl":"https://doi.org/10.1016/j.supcon.2024.100099","url":null,"abstract":"<div><p>As the demand for energy efficiency rises, researchers are increasingly prioritizing the quest for energy-efficient chip design. Superconducting SFQ circuit technology has garnered attention due to its ultra-high speed and low power consumption characteristics. In this paper, we propose a layout method called Maximum Operating Frequency Constraint (MOFC) for SFQ circuit design. Using this method, we demonstrated a 32-bit bit-parallel string-matching processor fabricated based on SIMIT-Nb03P technology, which holds practical value. The MOFC method focuses on achieving high bit-width processor design within constrained area cost in SFQ circuits, contributing to less energy consumption. To the best of our knowledge, this represents the first demonstrated instance of a superconducting SFQ chip achieving successful internal 32-bit data parallel processing. Our chip has been fabricated and tested, revealing not only its capability for 32-bit bit-parallel processing at a high speed of 12 GHz but also its achievement of an energy efficiency ratio of up to 251 GOPS/W.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"10 ","pages":"Article 100099"},"PeriodicalIF":5.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000164/pdfft?md5=aa71c13957b87a6be9f561c349209d28&pid=1-s2.0-S2772830724000164-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141485617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cooling system for China’s 35 kV/2.2kA/1.2 km high-temperature superconducting cable achieves two-year successful operation","authors":"Yunwu Han ,&nbsp;Xihua Zong ,&nbsp;Wei Xie","doi":"10.1016/j.supcon.2024.100100","DOIUrl":"https://doi.org/10.1016/j.supcon.2024.100100","url":null,"abstract":"<div><p>In December 2021, a 1.2 km high-temperature superconducting (HTS) cable, Xuhui HTS Cable Project, was completed and installed in Xuhui district, Shanghai, China. A cooling system with three refrigerators and two liquid nitrogen (LN2) pumps was developed for this km-class cable. Now, this cooling system has worked successfully for two years without faults. This is a great progress for km-class HTS power cable technique, which is validating the reliability and commercial value of HTS power transmission.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"10 ","pages":"Article 100100"},"PeriodicalIF":5.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000176/pdfft?md5=81de7fb49873487b49e6c65a9bc789db&pid=1-s2.0-S2772830724000176-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141485618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pressurization, intercalation, doping, and elements: An empirical study of superconductivity near perturbation onsets","authors":"Shermane M. Benjamin","doi":"10.1016/j.supcon.2024.100098","DOIUrl":"https://doi.org/10.1016/j.supcon.2024.100098","url":null,"abstract":"<div><p>Superconductivity is a phenomenon arising from cooperative electron behavior. However, correlations among (1) the minimum tuning parameter required for emergence, (2) the superconducting transition temperature resulting from minimal tuning, and (3) the host’s physical/chemical properties still elude the scientific community. Recent empirical investigations, such as those revealing ideal gas-like correlations at the onset of superconductivity in intercalated superconductors, motivate this study. Our investigation reports similar findings in systems (<em>&gt;</em>170 compounds) exhibiting superconductivity through other perturbative means, such as single-element doping. In general, statistical measures, including distance correlation analyses (≠ linear regression fit) of thermodynamic variables, indicate the presence of empirical relationships near the superconducting onset of systematically tuned compounds. These relations involve unit cell volume (<em>V</em>), the number of valence electrons (<em>N</em>), and the superconducting transition temperature (<em>T_c</em>). Note: The author’s primary aim is not to validate or challenge BCS theory; it is instead to focus on leveraging methodology led by available data to enhance the exploration and development of innovative and cost-effective superconductors.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"10 ","pages":"Article 100098"},"PeriodicalIF":0.0,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000152/pdfft?md5=0438704b7762dcde9406e6b3c8539992&pid=1-s2.0-S2772830724000152-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140951792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}