发表机构
National High Magnetic Field Laboratory（美国国家高磁场实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文报告了大型REBCO线圈中因电磁应力导致的分层现象，通过测试和显微镜观察确认了气泡状分层，并讨论了其对未来磁体设计的影响及缓解方法。
AI 中文摘要
REBCO涂层导体已用于凝聚态物理研究、核聚变、粒子加速器和核磁共振应用中的超高场磁体。然而，众所周知，由于其固有的层状结构，它们在抗分层方面机械强度不足。因此，分层问题已成为REBCO磁体线圈的主要设计挑战之一。作为美国国家高磁场实验室40 T全超导磁体开发的一部分，采用双线并绕REBCO导体并带有匝间绝缘的大型线圈被设计并在4.2 K、11.4 T背景磁场下进行了测试。在测试过程中，我们发现了绕组内部和交叉接头处的REBCO性能退化。事后检查发现，退化是由分层引起的。分层以气泡形式出现在导体表面，随后通过显微镜进行了研究。此外，通过扭矩磁力测量在短样品上也发现了类似的气泡。这支持了线圈中发现的分层气泡是由电磁应力引起的推断。在本文中，我们介绍了这些发现。将讨论这些发现对未来磁体设计的影响以及缓解方法。
英文摘要
REBCO coated conductors have been used in ultrahigh field magnets for condensed matter physics research, nuclear fusion, particle accelerators, and NMR applications. It is well known, however, that they are not mechanically strong against delamination due to their intrinsic layered structures. As a result, the delamination issue has become one of the major design challenges of REBCO magnet coils. As a part of the development of the 40 T all-superconducting magnet at the National High Magnetic Field Laboratory, USA, large-scale coils wound by two-in-hand REBCO conductor with turn-to-turn insulation was designed and tested at 4.2 K in an 11.4 T background magnetic field. We found REBCO degradations within the windings and at the crossover joints during the tests. The postmortem inspection found that the degradation was caused by delamination. The delamination appears on the surface of the conductor as bubbles which were subsequently studied by microscopy. Additionally, a similar bubble was found on a short sample by torque magnetometry. This supports the inference that the delamination bubbles found in coils are due to electromagnetic stress. In this paper, we present these findings. The implication of these findings for future magnet designs and the method of mitigation will be discussed.
Comments7 figures, 1 table, 5 pages
