Strong magnetic fields are required in many fields, such as medicine (magnetic resonance imaging), pharmacy (nuclear magnetic resonance), particle accelerators (such as the Large Hadron Collider) and fusion devices (for example, the International Thermonuclear Experimental Reactor, ITER), as well as for other diverse scientific and industrial uses. For almost two decades, 45 tesla has been the highest achievable direct-current (d.c.) magnetic field; however, such a field requires the use of a 31-megawatt, 33.6-tesla resistive magnet inside 11.4-tesla low-temperature superconductor coils1, and such high-power resistive magnets are available in only a few facilities worldwide2. By contrast, superconducting magnets are widespread owing to their low power requirements. Here we report a high-temperature superconductor coil that generates a magnetic field of 14.4 tesla inside a 31.1-tesla resistive background magnet to obtain a d.c. magnetic field of 45.5 tesla—the highest field achieved so far, to our knowledge. The magnet uses a conductor tape coated with REBCO (REBa2Cu3Ox, where RE = Y, Gd) on a 30-micrometre-thick substrate3, making the coil highly compact and capable of operating at the very high winding current density of 1,260 amperes per square millimetre. Operation at such a current density is possible only because the magnet is wound without insulation4, which allows rapid and safe quenching from the superconducting to the normal state5–10. The 45.5-tesla test magnet validates predictions11 for high-field copper oxide superconductor magnets by achieving a field twice as high as those generated by low-temperature superconducting magnets.A copper oxide high-temperature superconductor magnet generates a direct-current magnetic field of 45.5 tesla—the highest value reported so far—using a design that enables operation at high current densities.

中文翻译：

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高温超导磁铁产生的45.5特斯拉直流磁场

许多领域都需要强磁场，例如医学（磁共振成像）、制药（核磁共振）、粒子加速器（例如大型强子对撞机）和聚变装置（例如国际热核实验反应堆，ITER） ，以及其他不同的科学和工业用途。近二十年来，45 特斯拉一直是可达到的最高直流 (dc) 磁场；然而，这样的场需要在 11.4 特斯拉低温超导体线圈中使用 31 兆瓦、33.6 特斯拉的电阻磁铁1，而这种高功率电阻磁铁在全球只有少数设施可用2。相比之下，超导磁体由于其低功率要求而被广泛使用。在这里，我们报告了一个高温超导体线圈，它在 31.1 特斯拉的电阻背景磁铁内产生 14.4 特斯拉的磁场，以获得 45.5 特斯拉的直流磁场——据我们所知，这是迄今为止达到的最高磁场。磁铁在 30 微米厚的基板上使用涂有 REBCO（REBa2Cu3Ox，其中 RE = Y、Gd）的导体带3，使线圈非常紧凑，并且能够在每平方毫米 1,260 安培的极高绕组电流密度下运行. 在这样的电流密度下运行是可能的，因为磁体是在没有绝缘的情况下缠绕的，这允许从超导快速安全地淬火到正常状态 5-10。45.