{"title":"Enhancing in-field performance of GdBCO coated conductors by cooperative irradiation with Ti ions and protons","authors":"Daxing Huang , Hao Dong , Tongxin Wang , Hao Yu , Kaigui Zhu , Hongwei Gu , 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 REBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-</sub><em><sub>δ</sub></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><sub>c</sub>) for GdBCO CCs using cooperative irradiation with Ti ions and protons. Remarkably, the in-field <em>J</em><sub>c</sub> 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}
SuperconductivityPub Date : 2024-07-30DOI: 10.1016/j.supcon.2024.100111
Yuan Wang , Jin Fang , Timothy Haugan , Rodney A. Badcock , James G. Storey , Zhenan Jiang
{"title":"Numerical simulations on the AC loss of REBCO stacks under rotating magnetic fields","authors":"Yuan Wang , Jin Fang , Timothy Haugan , Rodney A. Badcock , James G. Storey , 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><sub>tol</sub>) (with current) and magnetization loss (<em>Q</em><sub>m</sub>) (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><sub>tol</sub> and <em>Q</em><sub>m</sub>, 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><sub>m</sub> of a superconducting strip (BI-strip) are close to <em>Q</em><sub>m</sub> 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><sub>m</sub> 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><sub>m</sub> and <em>Q</em><sub>tol</sub> when asymmetric <em>J</em><sub>c</sub> (<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><sub>m</sub> under uniform RF while significantly impacts both <em>Q</em><sub>m</sub> and <em>Q</em><sub>tol</sub> 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}
SuperconductivityPub Date : 2024-07-18DOI: 10.1016/j.supcon.2024.100110
Kumud Singh , Janvin Itteera , Mahima , Vikas Tiwari , Himanshu Bisht , Sanjay Malhotra , R.R. Singh , Rajesh Jalan , Sanjay Howal , Rajesh Chimurkar , Sunil Kumar , S. Stoynev , M. Turenne , M. Yu , B. Hanna , J. Hayman , C. Boffo
{"title":"Electromagnetic design and performance of conduction cooled superconducting magnet for spoke resonator cryomodule for Proton Improvement Plan (PIP)-II","authors":"Kumud Singh , Janvin Itteera , Mahima , Vikas Tiwari , Himanshu Bisht , Sanjay Malhotra , R.R. Singh , Rajesh Jalan , Sanjay Howal , Rajesh Chimurkar , Sunil Kumar , S. Stoynev , M. Turenne , M. Yu , B. Hanna , J. Hayman , 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 T<sup>2</sup>m 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}
SuperconductivityPub Date : 2024-06-26DOI: 10.1016/j.supcon.2024.100101
Qianting Ran , Ze Jing , Lei Shen , Jun Zhou , Cong Liu , Zhiwei Zhang , Xingyi Zhang
{"title":"Suppression of flux avalanches in YBCO superconducting thin films by coating metal investigated using magneto-optical imaging","authors":"Qianting Ran , Ze Jing , Lei Shen , Jun Zhou , Cong Liu , Zhiwei Zhang , 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}
SuperconductivityPub Date : 2024-06-01DOI: 10.1016/j.supcon.2024.100099
Peiyao Qu , Huanli Liu , Xiangyu Zheng , Jiahong Yang , Liliang Ying , Jie Ren , Haihang You , Guangming Tang
{"title":"An energy-efficient 32-bit bit-parallel superconducting SFQ specialized processor","authors":"Peiyao Qu , Huanli Liu , Xiangyu Zheng , Jiahong Yang , Liliang Ying , Jie Ren , Haihang You , 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}
SuperconductivityPub Date : 2024-06-01DOI: 10.1016/j.supcon.2024.100100
Yunwu Han , Xihua Zong , Wei Xie
{"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 , Xihua Zong , 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}
SuperconductivityPub Date : 2024-04-30DOI: 10.1016/j.supcon.2024.100098
Shermane M. Benjamin
{"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>></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<sub>c</sub></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}
SuperconductivityPub Date : 2024-04-19DOI: 10.1016/j.supcon.2024.100096
Yuting Jiang , Xingyu Zhang , Hui Zhou , Xiaofu Zhang , Hao Li , Lixing You
{"title":"Superconducting nanostrip single photon detectors fabricated of aluminum thin-films","authors":"Yuting Jiang , Xingyu Zhang , Hui Zhou , Xiaofu Zhang , Hao Li , Lixing You","doi":"10.1016/j.supcon.2024.100096","DOIUrl":"10.1016/j.supcon.2024.100096","url":null,"abstract":"<div><p>We systematically investigated the detection performance of Al nanostrips for single photons at various wavelengths. The Al films were deposited using magnetron sputtering, and the sophisticated nanostructures and morphology of the deposited films were revealed through high-resolution transmission electron microscopy. The fabricated Al meander nanostrips, with a thickness of 4.2 nm and a width of 178 nm, exhibited a superconducting transition temperature of 2.4 K and a critical current of approximately 5 μA at 0.85 K. While the Al nanostrips demonstrated a saturated internal quantum efficiency for 405-nm photons, the internal detection efficiency exhibited an exponential dependence on bias current without any saturation tendency for 1550-nm photons. This behavior can be attributed to the relatively large diffusion coefficient and coherence length of the Al films. By further narrowing the nanostrip width, the Al-SNSPDs remain capable of effectively detecting single telecom photons to facilitate practical applications.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"10 ","pages":"Article 100096"},"PeriodicalIF":0.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000139/pdfft?md5=cc4de4e35457f3c41620e11c070c4e76&pid=1-s2.0-S2772830724000139-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140777496","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 modelling of electromechanical coupling behaviors in HTS coil with implementation of H formulation in FE software","authors":"Huadong Yong , Dong Wei , Yunkai Tang , Donghui Liu","doi":"10.1016/j.supcon.2024.100097","DOIUrl":"10.1016/j.supcon.2024.100097","url":null,"abstract":"<div><p>(Re)Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub> (REBCO) coated conductors (CCs) have attracted considerable concern because of their outstanding current carrying capacity in magnetic fields of high strengths. A huge electromagnetic force is generated in the superconducting coil when conducting large currents in strong magnetic field. Thus, management of stress and strain has become a key technical challenge for the stability and safety of superconducting coil during operation. To accurately predict the electro-magnetic and mechanical characteristics of superconducting coil in strong magnetic field, an electromechanical model on the basis of the H-formulation and arbitrary Lagrangian-Eulerian (ALE) method is proposed here with FE software. To verify the proposed model, the simulation outcomes of the coil during magnetization are compared with the experimental outcomes. The coupling effect of magnet at high field strengths is dependent on the position of the coil. To reduce the screening current effect, the overshoot method with plateau is found superior to the traditional overshoot method, and an increase in the stabilization time can decrease the maximum value of stress. Finally, the electromechanical behaviors of single winding coil and two-tapes co-winding coil are compared.</p></div>","PeriodicalId":101185,"journal":{"name":"Superconductivity","volume":"10 ","pages":"Article 100097"},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772830724000140/pdfft?md5=f0be644092e97573b6237099e2f8dee3&pid=1-s2.0-S2772830724000140-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140783356","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}