Physica C-superconductivity and Its Applications最新文献_第9页

A high-voltage SFQ-to-DC driver for wide-range digital SQUID magnetometer based on flux quanta counting scheme 基于磁通量子计数方案的宽量程数字SQUID磁强计高压sfq - dc驱动器

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-06-15 Epub Date: 2025-04-08 DOI: 10.1016/j.physc.2025.1354708

Mengfei Zhao , Yongliang Wang , Pusheng Yuan , Shuna Wang , Lingyun Li , Lixing You

{"title":"A high-voltage SFQ-to-DC driver for wide-range digital SQUID magnetometer based on flux quanta counting scheme","authors":"Mengfei Zhao , Yongliang Wang , Pusheng Yuan , Shuna Wang , Lingyun Li , Lixing You","doi":"10.1016/j.physc.2025.1354708","DOIUrl":"10.1016/j.physc.2025.1354708","url":null,"abstract":"<div><div>Superconducting quantum interference devices (SQUIDs) exhibit flux-modulated current–voltage characteristics and are widely used as magnetometers for ultra-low noise magnetic field measurements in biomagnetism and geophysics. Compared to the conventional flux-locked loop (FLL) readout scheme, the flux quanta counting (FQC) scheme offers a wider flux measurement range and a higher slew rate. The challenge of the FQC scheme lies in the matching of voltage levels and response speeds between the SQUID and room-temperature circuits. Typically, the FQC scheme utilizes an SFQ-to-DC converter (Q2D) for signal conversion. However, the output voltage of Q2D is only a few hundred microvolts, which prevents it from operating at high speeds and limits the slew rate of the magnetometer. Moreover, the low amplitude output of Q2D also increases the burden on the subsequent semiconductor amplifiers. Therefore, a high-voltage, high-speed SFQ-to-DC driver is essential for the application of FQC schemes. We developed an SFQ-to-DC driver with high voltage output for the asynchronous FQC scheme. This driver is designed to capture voltage pulses from the DC-SQUID and convert them into DC voltages for reading by semiconductor digital devices. The asynchronous FQC scheme based on this driver was introduced and simulated, and the quantized flux counting signal closely matches the input flux signal with a quantization error of <span><math><mrow><mn>1</mn><msub><mrow><mi>Φ</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></math></span>. The test results of the driver demonstrate an output swing of up to 6.9 mV and an operating speed of up to 15 Gbps. This is promising for the wide-range and high-slew-rate digital SQUID magnetometer for geophysics, which faces challenges in the airborne platform due to the Earth’s magnetic field.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"633 ","pages":"Article 1354708"},"PeriodicalIF":1.3,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of the superconducting solenoid for the compact laser plasma accelerator for proton therapy 质子治疗激光等离子体加速器超导螺线管的研制

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-04-07 DOI: 10.1016/j.physc.2025.1354702

Xu Zhang , Kedong Wang , Kai Wang , Yingjie Li , Jie Li , Xinlin Yang , Feiyu Wu , Xueqing Yan , Kun Zhu

{"title":"Development of the superconducting solenoid for the compact laser plasma accelerator for proton therapy","authors":"Xu Zhang , Kedong Wang , Kai Wang , Yingjie Li , Jie Li , Xinlin Yang , Feiyu Wu , Xueqing Yan , Kun Zhu","doi":"10.1016/j.physc.2025.1354702","DOIUrl":"10.1016/j.physc.2025.1354702","url":null,"abstract":"<div><div>Laser plasma accelerators have become a new kind of particle accelerator in recent years. Peking University has built the world’s first compact laser plasma accelerator, CLAPA I, which has an energy of 15 MeV and can adjust its energy spread to 5%. Currently, CLAPA II is being built. Its main use is for proton therapy. The beam transport system of CLAPA II can handle proton beams with energies from 40 to 230 MeV and an energy spread of less than 5% at the end. The laser interacts with the target to create an initial proton beam that has a large spread of angles and energy. This beam is first captured and focused by three superconducting solenoids. Then, the beam is sent into horizontal and vertical beamlines for treatment. This paper focuses on the three superconducting solenoids in the beam collection section. The magnetic design was completed based on beam dynamics requirements. The central magnetic fields of the three solenoids are 7.8 T, 3.2 T, and 7.8 T, respectively. A three-dimensional magnetic field measurement platform was used to measure the integral field homogeneity and magnetic center. The integral field homogeneity meets the design requirement of <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math></span>, confirming the magnetic design’s validity. Considering the magnetic center deviation, the alignment and installation of the three superconducting solenoids were conducted using a laser tracker, achieving an installation accuracy of less than 0.3 mm. The three superconducting solenoids are working well now, and experiments with high-power lasers impinging on the targets are about to start.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354702"},"PeriodicalIF":1.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal transmittance measurements of niobium at cryogenic temperatures 铌在低温下的热透射率测量结果

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-03-12 DOI: 10.1016/j.physc.2025.1354694

Marc Wenskat , Leon King , Lasse Koch , Cem Saribal , Anton Lorf , Isabel González Díaz-Palacio , Cornelius Martens , Robert Zierold , Wolfgang Hillert

{"title":"Thermal transmittance measurements of niobium at cryogenic temperatures","authors":"Marc Wenskat , Leon King , Lasse Koch , Cem Saribal , Anton Lorf , Isabel González Díaz-Palacio , Cornelius Martens , Robert Zierold , Wolfgang Hillert","doi":"10.1016/j.physc.2025.1354694","DOIUrl":"10.1016/j.physc.2025.1354694","url":null,"abstract":"<div><div>The first <span><math><mi>O</mi></math></span>(100snm) of the inner surface Niobium-based superconducting RF (SRF) cavities are crucial to achieve high accelerating fields and a low surface resistance. Recent treatments aim to improve superconducting properties by tailoring the interstitial atom concentration or by depositing thin superconducting films. Yet, no investigation of the thermal characteristics of those surfaces after such treatments has been done, although this is a crucial property to cool the induced RF losses away and to maintain the superconducting state while high surface magnetic fields are applied. In this contribution, a newly developed experimental set-up is described, which allowed the first ever measurement of the thermal transmittance of Mid-T heat treated and Superconductor-Insulator-Superconductor (SIS) coated niobium samples. The results show that the SIS samples perform the same as standard niobium and that Mid-T heat treated samples have an improved thermal transmittance of 30%.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354694"},"PeriodicalIF":1.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Magneto-thermal stability analysis of Nb3Sn multifilament superconducting wires in rotating magnetic fields 旋转磁场中Nb3Sn多丝超导丝的磁热稳定性分析

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-04-07 DOI: 10.1016/j.physc.2025.1354684

An He , Yu Jia , Wei Liu

{"title":"Magneto-thermal stability analysis of Nb3Sn multifilament superconducting wires in rotating magnetic fields","authors":"An He , Yu Jia , Wei Liu","doi":"10.1016/j.physc.2025.1354684","DOIUrl":"10.1016/j.physc.2025.1354684","url":null,"abstract":"<div><div>Superconducting wires in superconducting motors typically operate in environments with strong magnetic fields and high currents, which may trigger flux jumps accompanied by rapid temperature rises. This can lead to a decrease in the wire’s current-carrying capacity and even result in a quench. In this study, the Nb<sub>3</sub>Sn superconducting wire, consisting of multiple superconducting filaments and copper, was modeled by constraining the net current of each filament to be zero in order to simulate the three-dimensional twisting characteristics. The magneto-thermal stability of the superconducting wire under rotating magnetic fields was investigated. The effects of the magnetic field amplitude and frequency on the flux jump behavior of the Nb<sub>3</sub>Sn superconducting wire were analyzed. As the magnetic field amplitude increased, the frequency range of flux jumps initially increased and then decreased. We examine the effect of different ratios of rotational to alternating fields <span><math><mi>k</mi></math></span> on flux jumps. At lower frequencies, the number of flux jumps increased with <span><math><mi>k</mi></math></span>, at higher frequencies, the number of flux jumps initially increased and then decreased. Subsequently, the effects of the Cu/SC ratio and the number of filaments on flux jumps were studied. For a fixed frequency, the number of flux jumps and the temperature rise exhibited non-monotonic variations with the magnetic field amplitude. When the magnetic field amplitude fixed, both the number of flux jumps and the temperature rise decreased with increasing frequency. Finally, the variation in the number of flux jumps with the Cu/SC ratio and <span><math><mi>k</mi></math></span> was discussed.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354684"},"PeriodicalIF":1.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling and analysis of torque characteristics for an axial HTS magnetic coupler 轴向高温超导磁力耦合器转矩特性建模与分析

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-04-07 DOI: 10.1016/j.physc.2025.1354704

Liwang Ai , Pengfei Ma , Haichao Feng , Siyuan Jiang , Caixia Gao , Xiaozhuo Xu

{"title":"Modeling and analysis of torque characteristics for an axial HTS magnetic coupler","authors":"Liwang Ai , Pengfei Ma , Haichao Feng , Siyuan Jiang , Caixia Gao , Xiaozhuo Xu","doi":"10.1016/j.physc.2025.1354704","DOIUrl":"10.1016/j.physc.2025.1354704","url":null,"abstract":"<div><div>The theoretical modeling of torque for an axial high-temperature superconductor (HTS) magnetic coupler (AHTSMC) is challenging due to the dual-rotor motion system with large relative displacement and the nonlinear <em>E</em>-<em>J</em> relationship of the HTS. In this paper, the models of torque calculation for AHTSMC are developed using numerical and analytical methods, and a comparative analysis is carried out to investigate the torque characteristics of AHTSMC. Firstly, the structure and operational principle of AHTSMC are described, and 2-D numerical simulations are performed based on the <strong><em>H</em></strong>-<em>φ</em> formulation. Also, experimental tests verified the simulation model. Then, the frozen-image model is improved by introducing two dipoles that represent the hysteresis of the HTS under an AC magnetic field, and by modifying the rule of frozen dipole. Based on the improved frozen-image model, the lateral force of the HTS- permanent magnets (PMs) system and the torque of the AHTSMC can be calculated. The results of the analytical calculations are basically in agreement with the numerical simulation results. Finally, the study showed that the AHTSMC can operate both asynchronously and synchronously. In asynchronous operation, the AHTSMC remains capable of transmitting torque, but there is significant fluctuation. In synchronous operation, the AHTSMC outputs a stable torque, and the magnitude of the torque is determined by the relative position angle between the PM rotor and the HTS rotor.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354704"},"PeriodicalIF":1.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thoughts about boosting superconductivity 关于提高超导性的想法

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-03-11 DOI: 10.1016/j.physc.2025.1354688

Dirk van der Marel

引用次数: 0

Quantum criticality of type-I and critically tilted Dirac semimetals i型和临界倾斜狄拉克半金属的量子临界性

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-03-12 DOI: 10.1016/j.physc.2025.1354687

Huanzhi Hu , Frank Krüger

{"title":"Quantum criticality of type-I and critically tilted Dirac semimetals","authors":"Huanzhi Hu , Frank Krüger","doi":"10.1016/j.physc.2025.1354687","DOIUrl":"10.1016/j.physc.2025.1354687","url":null,"abstract":"<div><div>We investigate the universality of an Ising symmetry breaking phase transition of tilted two-dimensional Dirac fermions, in the type-I phase as well as at the Lifshitz transition between a type-I and a type-II semimetal, where the Fermi surface changes from point-like to one with electron and hole pockets that touch at the overtilted Dirac cones. We compute the Landau damping of long-wavelength order parameter fluctuations by tilted Dirac fermions and use the resulting IR propagator as input for a renormalisation-group analysis of the resulting Gross–Neveu–Yukawa field theory. We first demonstrate that the criticality of tilted type-I fermions is controlled by a line of fixed points along which the poles of the renormalised Green function correspond to an untilted Dirac spectrum with varying anisotropy of Fermi velocities. At the phase transition the Lorentz invariance is restored, resulting in the same critical exponents as for conventional Dirac systems. The multicritical point is given by the endpoint of the fixed-point line. It can be approached along any path in parameter space that avoids the fixed point line of the critical type-I semimetal. We show that the critical exponents at the Lifshitz point are different and that Lorentz invariance is broken.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354687"},"PeriodicalIF":1.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Origin of the reentrant tetragonal phase in hole-doped Fe-pnictide superconductors: Role of intersite Coulomb interaction 空穴掺杂铁镍超导体中可重入四方相的起源：场间库仑相互作用的作用

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-03-22 DOI: 10.1016/j.physc.2025.1354699

Hao Luo, Huan Li, Xing Ming, Xiao-Jun Zheng

{"title":"Origin of the reentrant tetragonal phase in hole-doped Fe-pnictide superconductors: Role of intersite Coulomb interaction","authors":"Hao Luo, Huan Li, Xing Ming, Xiao-Jun Zheng","doi":"10.1016/j.physc.2025.1354699","DOIUrl":"10.1016/j.physc.2025.1354699","url":null,"abstract":"<div><div>Using mean-field approaches within the extended five-orbital Hubbard model, we reveal that intersite Coulomb interactions play a crucial role in determining the distinct magnetic phases of iron-based superconductors. We demonstrate that the reentrant tetragonal (<span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>) phase, which is a spin charge density wave (SCDW) phase, is a combination of the stripe-like antiferromagnetic phase (str-AFM) and the charge density wave (CDW) phase. We prove that SCDW is the ground state in the hole-doped Fe-pnictides as long as the intersite Coulomb interaction (<span><math><mi>V</mi></math></span>) increases with doping concentration. Our work not only provides a numerical realization of the reentrant <span><math><msub><mrow><mi>C</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> state but also emphasizes the significant role of intersite interactions in the emergence of this phase, offering a deep understanding into the complex diagram phase of iron-based materials.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354699"},"PeriodicalIF":1.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electromagnetic design and performance analysis of a 20 MW-class high temperature superconducting induction/synchronous motor for electric aircraft applications using a self-assembling design method 应用自组装设计方法对电动飞机用20mw级高温超导感应/同步电机进行电磁设计与性能分析

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-04-07 DOI: 10.1016/j.physc.2025.1354690

Masayoshi Yamamoto, Taketsune Nakamura

引用次数: 0

Motion characteristics of a self-driven HTS bulk maglev under the composite magnetic field 复合磁场下自驱动高温超导体磁浮的运动特性

IF 1.3 3区物理与天体物理

Physica C-superconductivity and Its Applications Pub Date : 2025-05-15 Epub Date: 2025-04-07 DOI: 10.1016/j.physc.2025.1354686

Yonghai Zhao , Jun Zheng , Xuanbo Wang

{"title":"Motion characteristics of a self-driven HTS bulk maglev under the composite magnetic field","authors":"Yonghai Zhao , Jun Zheng , Xuanbo Wang","doi":"10.1016/j.physc.2025.1354686","DOIUrl":"10.1016/j.physc.2025.1354686","url":null,"abstract":"<div><div>High temperature superconducting (HTS) maglev has the advantages of levitation-guidance integration and low magnetic resistance due to pinning effects. Currently, most HTS maglev systems adopt linear motors for propulsion, requiring the installation of the mover on the maglev vehicle and the stator on the track separately. It is potential to establish the composite pancake coil magnetic field based on permanent magnet guideway (PMG), which can bring HTS bulks the original levitation and guidance force generated and driving force. Based on the self-development micro levitation force test device, the paper explores the feasibility of using coils to drive HTS bulks. At a working height (WH) of 12 mm and a coil current of 15 A, the maximum driving force can reach 0.2 N. The driving force can be increased by reducing the WH or increasing the field cooling height (FCH). Based on the COMSOL Multiphysics software, the three-dimensional finite element simulation model of HTS bulks combined with the motion equation was established. Qualitative analysis of the free movement characteristics of the HTS bulk driven by the coils was performed, and the differences between different current directions were compared. In addition, the paper built a driving principal model to analyze the movement characteristics of HTS bulks driven by coils. Consistent with the simulation results, the levitation height increases, and positive pitch angle occurs when driven by the positive current, while the levitation height decreases, and negative pitch angle occurs when driven by the negative current.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"632 ","pages":"Article 1354686"},"PeriodicalIF":1.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0