IEEE Transactions on Applied Superconductivity最新文献

Low-AC-Loss Nb3Sn Validation Model Coil in Solid Nitrogen for a Fast-Switching-Field MRI Magnet Prototype. 用于快速开关场MRI磁体原型的低交流损耗Nb3Sn在固体氮中的验证模型线圈。

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-05-01 Epub Date: 2025-09-26 DOI: 10.1109/tasc.2025.3614571

Jintao Hu, Junseong Kim, Liangjun Shao, Juan Bascuñán, Yukikazu Iwasa, Jerome L Ackerman, Dongkeun Park

In this paper, we present the design and test results of a low-AC-loss Nb3Sn model coil developed to validate key enabling technologies for a fast-switching-field magnetic resonance imaging (MRI) magnet concept that can change the magnetic field very quickly in time, within 1 second, between significantly different field strengths: a high field (3 T) for relaxometry and prepolarization and a low field (0.5 T) for spectroscopy and imaging. While conventional MRI magnets require a static magnetic field, we expect that our proposed superconducting magnet with rapidly changing fields can provide opportunities for novel contrast mechanisms, which include level-crossing between spin-1/2 and quadrupolar nuclei, accelerated spin-lattice relaxation, and adiabatic demagnetization/remagnetization, by permitting differential relaxometry enabled by a large field strength difference, and ratiometric molecular/superthermal imaging. We have developed and demonstrated an innovative magnet design that uses a very low-AC-loss Nb3Sn coil and a novel cooling technology featuring highly heat-conductive thermal links between the coil and solid nitrogen surrounding the coil. These thermal links in solid nitrogen are anchored at one end to the cryocooler cold head. This design enables rapid switching between two magnetic fields in the superconducting magnet without inducing quench. The paper provides details on the construction, test results, and an analysis of the maximum temperature rise in the coil of the small-scale fast-switching-field magnet system.

在本文中，我们介绍了一种低交流损耗Nb3Sn模型线圈的设计和测试结果，该线圈旨在验证快速开关场磁共振成像（MRI）磁体概念的关键使能技术，该磁体可以在1秒内快速改变磁场，在显著不同的场强之间：用于松弛测量和预极化的高场（3 T）和用于光谱和成像的低场（0.5 T）。虽然传统的MRI磁体需要静态磁场，但我们希望我们提出的具有快速变化磁场的超导磁体可以为新的对比机制提供机会，包括自旋1/2和四极核之间的平交、加速自旋晶格弛豫和绝热退磁/再磁化，通过允许由大场强差实现的微分弛豫测量，以及比例分子/超热成像。我们已经开发并展示了一种创新的磁体设计，它使用了极低交流损耗的Nb3Sn线圈和一种新颖的冷却技术，在线圈和线圈周围的固体氮之间具有高导热的热链接。固体氮中的这些热链接固定在制冷机冷头的一端。这种设计可以在超导磁体的两个磁场之间快速切换，而不会引起猝灭。本文详细介绍了小型快速开关磁场磁体系统的结构、测试结果和线圈最大温升的分析。

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引用次数: 0

Cooldown and Ramp Test of a Low-Cryogen, Lightweight, Head-Only 7T MRI Magnet. 低低温、轻量、仅头部的7T MRI磁体的冷却和斜坡试验。

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-05-01 Epub Date: 2025-10-09 DOI: 10.1109/tasc.2025.3619470

Anbo Wu, Justin Ricci, Minfeng Xu, Vijay Soni, Gene Conte, Chris Van Epps, Michael Parizh, Wolfgang Stautner, Yihe Hua, Seung-Kyun Lee, Mark Vermilyea, Desmond Tb Yeo, Thomas Kf Foo

A compact 7.0 T MRI system (C7T) has been successfully constructed, cooled down, and ramped (energized) to 7.01 T at GE HealthCare Technology and Innovation Center. The C7T magnet is designed for a B0-field homogeneity of <1.0 ppm over a 26-cm field-of-view, dedicated for MRI brain imaging. The C7T magnet applies a fully closed-loop cryogenic cooling system which condenses only 12 liters of liquid helium at 4.2 K from high pressure helium gas charged at room temperature. The helium is permanently sealed inside the cooling system even after a quench. This newly developed 7.0 T MRI has similar size and stray magnetic field as a clinical whole-body 3.0 T MRI magnet, it can be easily installed in a 3T scanner bay. This C7T MRI system can greatly improve the access to high performance 7T brain imaging for more patients. The cooldown, ramp and quench protection performance of the compact 7T MRI magnet prototype is reported in this paper.

在GE医疗保健技术和创新中心，一个紧凑的7.0 T MRI系统（C7T）已成功构建、冷却并提升（通电）到7.01 T。C7T磁体设计用于b0场均匀性

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引用次数: 0

Contact Resistivity Between REBCO Tapes With (Pr0.8Sm0.2)0.6Ca0.4CoO3 Smart-Insulation Layer 具有（Pr0.8Sm0.2）0.6Ca0.4CoO3智能绝缘层的REBCO带之间的接触电阻率

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-20 DOI: 10.1109/TASC.2026.3655248

Kyosuke Sakurai;Yuji Tsuchiya;Masahiro Tahashi;Hideo Goto;Satoshi Awaji

A smart-insulation (SI) approach employing a metal–insulator transition (MIT) material has been investigated for improving the thermal stability and charging characteristics of REBCO coils. In this study, we investigated a coating method for REBCO tapes using a material (Pr_0.8Sm_0.2)_0.6Ca_0.4CoO₃ (PSCCO) which exhibits a MIT around 74 K. PSCCO powder, synthesized by the sol–gel method and then ball-milled, was dispersed in N-methyl-2-pyrrolidone (NMP) to form a slurry, which was subsequently coated onto the REBCO tape. The contact resistivity (ρ_ct) between REBCO tapes was measured from 10 K to 270 K under uniaxial pressures. The ρ_ct decreased monotonically from 1.9 × 10⁸ μΩ·cm² at 10 K to 7.0 × 10³ μΩ·cm² at 270 K. However, the ρ_ct did not show a sharp MIT-like transition as observed in bulk PSCCO. Magnetization measurements confirmed that the transition became significantly broadened in the coated layer. Finally, the temperature rise of a coil employing the PSCCO coating was estimated based on the previous reported theory, suggesting that a temperature increase up to around 90 K can be expected during magnet operation. These results suggest that PSCCO is a promising turn-to-turn insulation material for realizing SI coils.

研究了一种采用金属-绝缘体过渡（MIT）材料的智能绝缘（SI）方法，以改善REBCO线圈的热稳定性和充电特性。在这项研究中，我们研究了一种REBCO带的涂层方法，该方法使用的材料（Pr0.8Sm0.2）0.6Ca0.4CoO3 (PSCCO)，其MIT在74 K左右。采用溶胶-凝胶法合成PSCCO粉末，然后进行球磨，将其分散在n -甲基-2-吡咯烷酮（NMP）中形成浆料，随后将浆料涂覆在REBCO胶带上。在10 ~ 270 K的单轴压力范围内测量了REBCO带间的接触电阻率ρct。ρct从10 K时的1.9 × 108 μΩ·cm2单调下降到270 K时的7.0 × 103 μΩ·cm2。然而，在块状PSCCO中，ρct没有表现出明显的mit样转变。磁化测量证实，在涂覆层中转变变得明显变宽。最后，根据先前报道的理论估计了采用PSCCO涂层的线圈的温升，这表明在磁铁操作期间可以预期温度升高至约90k。这些结果表明，PSCCO是一种很有前途的匝间绝缘材料，用于实现SI线圈。

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引用次数: 0

Achieving High and Isotropic Pinning in Multilayer BaZrO3/YBa2Cu3O7-x Films 在多层BaZrO3/YBa2Cu3O7-x薄膜中实现高各向同性钉钉

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-19 DOI: 10.1109/TASC.2026.3651418

Aafiya;Victor Ogunjimi;Mary Ann Sebastian;Mohan Panth;Benson Tsai;Abhijeet Chowdhury;Jialong Huang;Timothy Haugan;Haiyan Wang;Judy Wu

In a recently developed multilayer (ML) scheme, two or more 10-nm thick Ca_0.3Y_0.7Ba₂Cu₃O_7-x spacers were inserted into BaZrO₃-doped YBa₂Cu₃O_7-x (BZO/YBCO) films to enable dynamic diffusion of Ca ions from the spacers to BZO/YBCO layers. In these ML BZO/YBCO nanocomposite films, significantly enhanced pinning has been attributed to Ca/Cu substitution on the Cu-O planes of YBCO, leading to reduced lattice mismatch and hence defects at the BZO/YBCO interface. In this work, we further probe the Ca diffusion in the five-layer ML films by varying the thickness of the two Ca_0.3Y_0.7Ba₂Cu₃O_7-x spacers in the range of 1 nm-10 nm and also the thickness of the three BZO/YBCO layers in the range of 50–330 nm. Ca diffusion has been found highly effective if the spacer layer thickness exceeds 2 nm and can diffuse through large BZO/YBCO thicknesses up to 330 nm (total film thickness ∼ 1 µm) along the BZO/YBCO interface. The critical current density exhibits enhanced and almost thickness-independent trends in the ML BZO/YBCO nanocomposite films. Significantly enhanced pinning is illustrated in up to 5 folds enhancement of J_c at 65 K and 9.0 T. At lower temperatures, the enhanced pinning extends to a broad range of the orientations of magnetic field (B). At 20 K and 9.0 T, the I_c is up to 654 A/cm-width at B//c, which is close to 753 A/cm-width at B//ab due to the intrinsic pinning, has been achieved. This result suggests that the ML scheme provides an interesting approach to improve pinning in nanocomposite films.

在最近开发的多层（ML）方案中，将两个或多个10 nm厚的Ca0.3Y0.7Ba2Cu3O7-x间隔层插入到bazro3掺杂的YBa2Cu3O7-x （BZO/YBCO）薄膜中，使Ca离子从间隔层动态扩散到BZO/YBCO层。在这些ML BZO/YBCO纳米复合薄膜中，YBCO的Cu- o平面上的Ca/Cu取代显著增强了钉住作用，导致晶格失配减少，从而减少了BZO/YBCO界面上的缺陷。在这项工作中，我们通过改变两个Ca0.3Y0.7Ba2Cu3O7-x间隔层的厚度在1 nm-10 nm范围内，以及三个BZO/YBCO层的厚度在50-330 nm范围内，进一步探讨了Ca在五层ML膜中的扩散。如果间隔层厚度超过2 nm， Ca的扩散就会非常有效，并且可以沿着BZO/YBCO界面扩散到330 nm（总膜厚度约1 μ m）。在ML - BZO/YBCO纳米复合薄膜中，临界电流密度表现出增强且几乎与厚度无关的趋势。在65 K和9.0 t的温度下，Jc的钉住作用增强了5倍，在较低的温度下，钉住作用扩展到很宽的磁场方向范围(B)。在20 K和9.0 T下，Ic在B//c处高达654 A/cm-宽度，由于固有引脚，在B//ab处接近753 A/cm-宽度。这一结果表明，ML方案提供了一种有趣的方法来改善纳米复合膜中的钉住。

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引用次数: 0

Preparation and Properties of High Performance MgB2/Ni Superconducting Wire With Improved Internal Magnesium Diffusion Process 改进镁内扩散法制备高性能MgB2/Ni超导线及其性能

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-16 DOI: 10.1109/TASC.2026.3654478

Yiming Wang;Qingyang Wang;Zhenyu Chen;Dan Xi;Hongli Hou;Shengnan Zhang;Jianqing Feng;Jianfeng Li;Pingxiang Zhang

MgB₂ superconducting wires made with internal magnesium diffusion (IMD) process have reached an excellent performance than other routes. However, the incomplete Mg/B reaction has been the core problem of IMD process. In this study, MgB₂/Ni IMD superconducting monofilament wires were prepared using the improved IMD process. By exploring annealing processes during fabrication, we improved the ductility of the wires and ensured the uniform continuity of the central Mg core filaments. The optimal heat treatment process for MgB₂/Ni IMD wires was ascertained by micro structural morphology analysis, phase structure analysis, superconducting property analysis. The study demonstrates that this processing technique leads to a more complete reaction between Mg and B after heat treatment. The critical current density of MgB₂/Ni super-conducting wires was measured at 4.2 K, demonstrating high current-carrying capabilities, particularly at high magnetic fields. This research provides valuable insights for the processing and heat treatment of MgB₂/Ni multi-core superconducting wires in the future.

采用内镁扩散（IMD）工艺制备的MgB2超导线具有较好的性能。然而，Mg/B反应不完全一直是IMD工艺的核心问题。本研究采用改进的IMD工艺制备了MgB2/Ni超导单丝。通过在制造过程中探索退火工艺，我们提高了线材的延展性，并确保了中央Mg芯丝的均匀连续性。通过显微组织形貌分析、相结构分析、超导性能分析，确定了MgB2/Ni IMD丝的最佳热处理工艺。研究表明，该工艺使Mg和B在热处理后反应更完全。测量到MgB2/Ni超导导线的临界电流密度为4.2 K，显示出高载流能力，特别是在高磁场下。该研究为未来MgB2/Ni多芯超导线的加工和热处理提供了有价值的见解。

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引用次数: 0

Random-Number Generation Using Chaos in RF-Irradiated Stacked Intrinsic Josephson Junction 利用混沌在射频辐照堆叠本征约瑟夫森结中产生随机数

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-14 DOI: 10.1109/TASC.2025.3650523

Dai Oikawa;Hirokazu Komatsu;Keita Tsuzuki;Hiroya Andoh

The configuration of a robust, high-security system has become increasingly important because, as computer processing speeds continue to improve, the vulnerabilities of cryptographic systems that rely on conventional pseudo-random-numbers have raised concerns regarding potential leaks of confidential information. To establish such a secure system, high-quality and high-speed random numbers are essential. Here, high-quality random-numbers are defined as statistically unbiased, non-reproducible, and unpredictable values. One approach to generating such numbers is to exploit physical random phenomena, such as chaos. In particular, chaos in Josephson junctions (JJs) under radio-frequency (RF) irradiation has been identified as a suitable mechanism for random-number generation. In this study, we considered RF-biased intrinsic Josephson junctions (IJJs) in a mesa-type Bi

$_{2}$

Sr

$_{2}$

CaCu

$_{2}$

O

$_{8+delta }$

single crystal. Since the interactions among stacked IJJs must be considered, it is insufficient to evaluate their properties using the conventional resistively and capacitively shunted junction (RCSJ) circuit model. Instead, we numerically investigated the chaotic voltage of an IJJ stack irradiated with higher frequencies than those typically used in conventional RF systems, employing the capacitively coupled JJ model with diffusion current, which incorporates interlayer interactions. Based on the time-series output voltage of the IJJ, we then generated random-numbers and evaluated their quality using statistical tests.

配置一个健壮的、高安全性的系统变得越来越重要，因为随着计算机处理速度的不断提高，依赖传统伪随机数的加密系统的漏洞已经引起了人们对机密信息泄露的潜在担忧。为了建立这样一个安全的系统，高质量和高速的随机数是必不可少的。在这里，高质量随机数被定义为统计上无偏的、不可重复的和不可预测的值。产生这些数字的一种方法是利用物理随机现象，比如混沌。特别是，在射频（RF）照射下，约瑟夫森结（JJs）中的混沌已被确定为随机数产生的合适机制。在这项研究中，我们考虑了台型Bi $_{2}$ Sr$_{2}$CaCu $_{2}$ O$_{8+delta}$单晶中rf偏置的内禀约瑟夫森结（IJJs）。由于必须考虑堆叠ijs之间的相互作用，因此使用传统的电阻和电容分流结（RCSJ）电路模型来评估其性能是不够的。相反，我们采用包含层间相互作用的扩散电流电容耦合JJ模型，数值研究了比传统射频系统中通常使用的频率更高的IJJ堆栈的混沌电压。基于IJJ的时间序列输出电压，我们生成随机数，并使用统计检验评估它们的质量。

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引用次数: 0

Development of Premix Internal-Magnesium-Diffusion MgB2 Wire Using a Data-Driven Approach 基于数据驱动方法的预混镁扩散MgB2钢丝的研制

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-14 DOI: 10.1109/TASC.2026.3652546

Akiyoshi Matsumoto;Akimitsu Ishii;Rei Kawasaki;Takahiro Hosokawa;Akiyasu Yamamoto

Optimizing various fabrication parameters is one of the major challenges in the development of superconducting wires, often resulting in prolonged transition periods from fundamental research to practical applications. Additionally, escalating costs for essential resources such as liquid helium have amplified the difficulty of experimental work, further underscoring the importance of data-driven research approaches. In this study, we focus on magnesium diboride (MgB₂) wires and demonstrate the effectiveness of Bayesian optimization in efficiently searching complex parameter spaces to identify optimal fabrication conditions. Specifically, we investigate the internal magnesium diffusion (IMD) process, employing Bayesian optimization and the BOXVIA visualization tool to explore key heat-treatment parameters—namely, heat-treatment time and temperature—with the aim of maximizing the engineering critical current density (

$J_{mathrm{e}}$

). Our results show that, under conventional conditions, the highest Je was achieved at approximately 700 °C with a short holding time of less than one hour. Moreover, our process informatics approach enabled the discovery of optimal conditions even under unconventional parameter settings. This methodology substantially reduces the number of experimental iterations required and enhances the performance of superconducting wires. Overall, our data-driven optimization strategy offers a promising route for faster, more efficient wire fabrication and the accelerated commercialization of superconducting technologies.

优化各种制造参数是超导导线发展的主要挑战之一，往往导致从基础研究到实际应用的过渡时间延长。此外，液氦等基本资源的成本不断上升，加大了实验工作的难度，进一步强调了数据驱动研究方法的重要性。在本研究中，我们重点研究了二硼化镁（MgB2）线，并证明了贝叶斯优化在有效搜索复杂参数空间以确定最佳制造条件方面的有效性。具体来说，我们研究了内部镁扩散（IMD）过程，采用贝叶斯优化和BOXVIA可视化工具来探索关键热处理参数，即热处理时间和温度，目的是最大化工程临界电流密度（$J_{ mathm {e}}$）。我们的研究结果表明，在常规条件下，在大约700°C的温度下，在不到一小时的短时间内，可以获得最高的乙脑。此外，我们的过程信息学方法即使在非常规参数设置下也能发现最佳条件。这种方法大大减少了所需的实验迭代次数，提高了超导导线的性能。总的来说，我们的数据驱动优化策略为更快、更高效的电线制造和加速超导技术的商业化提供了一条有前途的途径。

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引用次数: 0

Research on Solder Joints Process between Bi-2212 Round Wire and Other Superconducting Materials Bi-2212圆线与其他超导材料的焊点工艺研究

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-14 DOI: 10.1109/TASC.2026.3653561

Lei Yu;Zhen Fang;Qingbin Hao;Hang Zhao;Zhipeng Jiang;Jianyuan Xu;Hangwei Ding;Yuyang Shi;Pengcheng Huang;Zhiyou Chen;Wenge Chen

As the only high-temperature superconducting material that can be prepared into isotropic round wires, Bi-2212 has important application value in the high magnetic field domain. This study investigates the manufacturing process of connection joints between a Bi-2212 round wire and other superconducting materials. First, pure tin is used to dissolve the sheath materials of the outer layers of each superconducting material, and then the superconducting solder PbBi alloy is used to replace the nonsuperconducting tin. During this process, the influence of time on the dissolution of different metal sheath by the solder was compared and analyzed, and the more appropriate soldering temperature and time are preliminarily given. Second, joints between Bi-2212 and NbTi, Nb₃Sn, as well as Bi-2223 were successfully prepared by applying this process, and the current-carrying capacity test was carried out at 4.2 K and 0–1.2 T. Finally, elemental analysis of the joints was performed by using a scanning electron microscope (SEM), confirming the good bonding performance between the PbBi alloy and the base metal.

Bi-2212作为目前唯一可以制备成各向同性圆导线的高温超导材料，在高磁场领域具有重要的应用价值。本文研究了Bi-2212圆线与其他超导材料连接接头的制造工艺。首先用纯锡溶解各超导材料外层的护套材料，然后用超导焊料PbBi合金代替非超导锡。在此过程中，比较分析了时间对焊料对不同金属护套溶解的影响，初步给出了较为适宜的焊接温度和焊接时间。其次，利用该工艺成功制备了Bi-2212与NbTi、Nb3Sn以及Bi-2223的接头，并在4.2 K和0-1.2 t下进行了载流能力测试。最后，通过扫描电镜（SEM）对接头进行了元素分析，证实了PbBi合金与母材的良好结合性能。

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引用次数: 0

Serial Arc Risk Analysis in HTS Tapes for Electric Aircraft 电动飞机HTS胶带电弧风险分析

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-14 DOI: 10.1109/TASC.2026.3652114

Cécile Weulersse;Jean Rivenc;Ivan Revel;Pedro Barusco;Emelie Nilsson

High Temperature Superconducting (HTS) cables developed for superconducting powertrains for electric aircrafts have to demonstrate their robustness, especially towards electric arcs. We propose here a methodology to evaluate HTS cable vulnerability to serial arcs following a quench. First, the arc voltage threshold of an HTS tape is measured under cryogenic temperatures. Then, a model is proposed to predict the peak of the transient voltage developed at the breaking point in case one of the HTS tapes in the cable is broken. This model depends on self and mutual inductances and on current variation dI/dt. A good correlation is obtained between the model and experiments using a simplified setup at room temperature. The comparison between the predicted transient voltage induced in representative HTS cables when one tape is broken with the arc voltage threshold will allow to assess the arcing risk in specific topologies of HTS cable.

为电动飞机的超导动力系统开发的高温超导电缆必须证明其坚固性，特别是对电弧的坚固性。我们在这里提出了一种方法来评估高温超导电缆在淬火后对串行电弧的脆弱性。首先，在低温下测量了高温超导胶带的电弧电压阈值。然后，提出了一个模型来预测在断口处的瞬态电压峰值，如果电缆中的一个高温超导带断裂。该模型依赖于自感和互感以及电流变化dI/dt。在简化的室温条件下，模型与实验结果有很好的相关性。通过将典型高温超导电缆中一根胶带断裂时的预测瞬态电压与电弧电压阈值进行比较，可以评估高温超导电缆在特定拓扑结构中的电弧风险。

引用次数: 0

Development of Microwave SQUID Multiplexer for Readout of Transition-Edge Sensor Array 过渡边缘传感器阵列读出用微波SQUID多路复用器的研制

IF 1.8 3区物理与天体物理 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

IEEE Transactions on Applied Superconductivity

Pub Date : 2026-01-14 DOI: 10.1109/TASC.2026.3653239

Zhi-Fa Feng;Xian-Feng Zhou;Wen Zhang;Zheng Wang;Qing-Xiao Ma;Pei-Zhan Li;Jia-Qiang Zhong;Wei Miao;Yuan Ren;Qi-Jun Yao;Valery Koshelets;Lyudmila Filippenko;Michael Fominsky;Jing Li;Sheng-Cai Shi

Superconducting transition-edge sensors (TESs) with high sensitivity can detect electromagnetic wave radiations from millimeter/submillimeter, optical to x/γ rays, and have been successfully used in many fields. To improve detection efficiency and sensitivity, large-scale TES arrays are required in combination with multiplexing readout electronics. Compared to other multiplexing schemes, microwave SQUID multiplexing (μMUX), consisting of high-quality microwave superconducting resonators and RF SQUIDs, is most suitable since it provides a wider bandwidth (GHz) and consequently higher multiplexing factor. We designed two types of circuits with different mutual inductances (

${{M}_{mathrm{T}}}$

) between the resonator and the RF SQUID: 2.3 pH for the weak-coupling channel and 6.5 pH for the strong-coupling channel. The resonator and RF SQUID washers made of 150 nm Nb are first fabricated by magnetron-sputtering and reactive ion etching, followed by the deposition of Nb/Al–AlOx/Nb trilayer and definition of the Josephson junctions of the RF SQUIDs. This work presents a μMUX demonstration chip with five channels with

${{Q}_{mathrm{l}}}$

values of 787 and 3626, and the measured frequency shifts (

$Delta {{f}_{text{pp}}}$

) of ∼500 kHz and 4 MHz for the weak- coupling and strong-coupling channels, respectively. The open-loop equivalent noise current, obtained from the measured phase noise and resonator responsivity, is

$sim 80text{pA}/sqrt {text{Hz}} $

with the strong-coupling channel.

超导过渡边缘传感器（TESs）具有高灵敏度，可以探测从毫米/亚毫米、光学到x/γ射线的电磁波辐射，并已成功地应用于许多领域。为了提高检测效率和灵敏度，需要大规模TES阵列与多路读出电子设备相结合。与其他复用方案相比，由高质量微波超导谐振器和RF SQUID组成的微波SQUID复用方案（μMUX）具有更宽的带宽（GHz）和更高的复用系数，因此是最合适的。我们在谐振器和RF SQUID之间设计了两种不同互感的电路（${{M}_{mathrm{T}}}$）：弱耦合通道为2.3 pH，强耦合通道为6.5 pH。首先采用磁控溅射和反应离子刻蚀法制备了150nm Nb材料的谐振腔和RF SQUID衬垫，然后沉积了Nb/ Al-AlOx /Nb三层，并定义了RF SQUID的Josephson结。本工作提出了一个μMUX演示芯片，该芯片具有5个通道，${{Q}_{mathrm{l}}}$值分别为787和3626，弱耦合和强耦合通道的测量频移（$Delta {{f}_{text{pp}}}$）分别为～ 500 kHz和4 MHz。在强耦合通道下，由测量的相位噪声和谐振腔响应度得到的开环等效噪声电流为$sim 80text{pA}/sqrt {text{Hz}} $。

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引用次数: 0