Challenges of high field large bore superconducting “outserts” for research magnets.

The development of high temperature superconductors (HTS), with high critical fields at 4.2 Kelvin (K), has opened up a new experimental space: the investigation of the properties of matter within static magnetic fields > 22 Tesla (T). This has driven the requirement for large bore, high field “outsert” solenoid magnets, using more conventional NbTi and Nb3Sn conductors to provide the background field, within which an HTS coil can operate. We will discuss the challenges which have to be met to provide such compact, high field superconducting magnets, including quench energy management, coil interactions, mechanical support, eddy current forces and cryogen handling, and how they have been successfully overcome with the development of 19T, 150mm bore (Hochfeld-Magnetlabor Dresden, HLD) and 15T, 250mm bore systems (All superconducting 32 Tesla program at the National High Field Magnet Laboratory, Florida, NHMFL). We will also discuss where this emerging technology can be further developed for the next generation of experiments.

高温超导体（high temperature superconductors，HTS）凭借其在4.2开尔文（Kelvin，K）下的高临界磁场特性，开辟了全新的实验研究领域：探究22特斯拉（Tesla，T）以上静磁场环境中的物质属性。这一技术进展推动了对大口径高场外插螺线管磁体的需求——这类磁体采用更为常规的铌钛（NbTi）与铌三锡（Nb3Sn）导体来提供背景磁场，高温超导体线圈即可在该磁场环境中运行。我们将探讨研制此类紧凑高场超导磁体所需攻克的各类挑战，包括失超能量管理、线圈间相互作用、机械支撑、涡流作用力以及低温工质操控，并介绍依托19T、150毫米口径的德累斯顿高场磁体实验室（Hochfeld-Magnetlabor Dresden，HLD）装置，以及15T、250毫米口径的美国佛罗里达国家高场磁体实验室（National High Field Magnet Laboratory, Florida, NHMFL）全超导32特斯拉项目装置，如何成功克服了上述难题。此外，我们还将探讨该新兴技术可如何针对下一代实验进行进一步的优化与拓展。