研究人员使用新方法来克服下一代超导体的关键障碍

来自北卡罗来纳州立大学的研究人员开发了一种新的计算方法，以改善特定设计应用的超导材料的实用性 - 并使用该方法来解决下一代超导材料YTTrium Yttrium Yttrium Yttrium Yttrium Yttrium Copper Oxide（YBCO）的关键研究障碍。

超导体是一种可以携带电力而不会损失的材料 - 例如，没有任何能量被耗散为热量。超导材料目前用于医疗MRI技术，预计将在新兴的电力技术（例如储能或高效风力涡轮机）中发挥重要作用。

想要设计使用超导材料的技术的系统工程师面临的一个问题是，它们是根据现有材料的特性设计产品所需的。但是NC国家研究人员提出了一种方法，该方法将使产品设计师能够直接与创建超导材料（例如电线）的行业进行互动，以创建超导体，从而更加准确地符合成品的需求。

“我们正在介绍这样的想法，即电线制造商在此过程中与系统工程师合作，利用计算机模型更快地创建更好的材料。”该过程的论文首席作者贾斯汀·施瓦茨（Justin Schwartz）博士说，科比钢铁（Kobe Steel）of NC State’s Department of Materials Science and Engineering. “This approach moves us closer to the ideal of having materials engineering become part of the product design process.”

为了证明该过程的实用性，研究人员解决了下一代YBCO超导体面临的问题。YBCO导体很有希望，因为它们非常强大并且具有高的超导电流密度 - 这意味着它们可以处理大量的电力。但是它们的广泛使用存在障碍。

One of these key obstacles is how to handle “quench.” Quench is when a superconductor suddenly loses its superconductivity. Superconductors are used to store large amounts of electricity in a magnetic field – but a quench unleashes all of that stored energy. If the energy isn’t managed properly, it will destroy the system – which can be extremely expensive. “Basically, the better a material is as a superconductor, the more electricity it can handle, so it has a higher energy density, and that makes quench protection more important, because the material may release more energy when quenched,” Schwartz says.

为了解决该问题，研究人员探索了七个不同的变量，以确定如何最好地设计YBCO导体，以优化性能并最大程度地降低淬火风险。例如，增加YBCO的厚度是否增加或降低了淬火风险？事实证明，它实际上降低了淬火风险。其他许多变量也发挥了作用，但是新方法有效地帮助研究人员确定有意义的解决淬火风险的方法。

“The insight we’ve gained into YBCO quench behavior, and our new process for designing better materials, will likely accelerate the use of YBCO in areas ranging from new power applications to medical technologies – or even the next iteration of particle accelerators,” Schwartz says.

“This process is of particular interest given the White House’s Materials Genome Initiative,” Schwartz says. “The focus of that initiative is to expedite the process that translates new discoveries in materials science into commercial products – and I think our process is an important step in that direction.”

The paper, “三维Micrometer-Scale Modeling of Quenching in High-Aspect-Ratio YBa2Cu3O7-dCoated Conductor Tapes—Part II: Influence of Geometric and Material Properties and Implications for Conductor Engineering and Magnet Design,” was co-authored by Dr. Wan Kan Chan, a research associate at NC State. The paper is available online fromIEEE在应用超导性上的交易。该研究由空军研究实验室资助。

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Note to Editors:The study abstract follows.

“Three-Dimensional Micrometer-Scale Modeling of Quenching in High-Aspect-Ratio YBa2Cu3O7-dCoated Conductor Tapes—Part II: Influence of Geometric and Material Properties and Implications for Conductor Engineering and Magnet Design”

作者: Wan Kan Chan and Justin Schwartz, North Carolina State University

Published:在线,IEEE在应用超导性上的交易

Abstract:YBa2Cu3O7-d(YBCO) coated conductors (CCs) show great promise for applications, but due to a very slow normal-zone propagation velocity (NZPV), quench detection and protection in YBCO magnets may be difficult. Present YBCO CCs have been developed with a primary focus on maximizing the critical current density for elevated-temperature low-field or low-temperature high-field applications. As the market for magnet applications progresses, it becomes important to consider design parameters such as the thicknesses and properties of all YBCO CC components, with the intent of considering quench-related behaviors as an integral part of the conductor and magnet design processes. Thus, it is important to know the impacts of conductor parameters on quench behavior. Considering that the YBCO layer itself is on the order of a micrometer in thickness, quench behavior must also be considered at this scale length. Here, the highly accurate experimentally validated micrometer-scale 3-D tape model reported in Part I is used to study how variations in CC geometry and material properties affect quench behavior, including the NZPV, hot-spot temperature, and minimum quench energy. The parametric variations focus on quantities that can be most readily modified by CC manufacturers. Based on simulation results, the relative sensitivities of the quench quantities to the parametric variations are calculated to identify which CC design parameters are most impactful on quench behavior. The implications of these results for quench detection and protection are discussed.