Research to enable rapid development of High Temperature Superconducting magnets for fusion energy and other applications.

托卡马克能源有限公司是一家私营公司，目标是到2030年将聚变作为一种清洁安全的能源提供。该公司的目标是通过将球形托卡马克和高温超导(HTS)磁体相结合来实现这一点。球形托卡马克是一种磁约束聚变设备，高温超导(HTS)磁体可以在紧凑型设备中提供非常强的磁场。该公司认为，HTS球形托卡马克是快速交付商业聚变能源的关键途径。该项目旨在解决高温超导磁体技术领域的两个关键挑战，以加快聚变能源和其他应用的高温超导磁体的发展。第一个挑战是为高温超导导体的特性和质量保证(QA)制定技术和战略方法，然后在几年内采购的数百公里长的导体上实施这一方法。这里的关键困难在于，稀土氧铜(REBCO)高温超导导体的电流容量非常大，并且与温度、磁场强度、磁场方向和晶体的纳米结构有着非常复杂的依赖关系。由于所涉及的磁场和电流很大，测量聚变磁体在终端使用条件下的导体性能是非常具有挑战性的。因此，尽管磁铁设计主要依赖于他们的知识，但不能常规地进行完整的表征。该项目将建立必要的性能指标(平衡成本、风险和信息深度)，开发测量这些指标所需的方法，并在真正的导体上实施这些指标。第二个挑战是高温超导聚变磁体可拆卸线圈结构的开发。高温超导磁体可以在相对较高的温度(&gt；~20K)下工作，在该温度下，冷却系统可以容纳来自导体之间接头的大量热负荷。与传统的低温超导体(LTS)不同，高温下工作的高温超导导体具有极高的热稳定性，因此可以容忍其结构周围几个开尔文的温度变化。这使得能够考虑可拆卸线圈结构，其中在组装和拆卸期间，磁体的匝数可以彼此连接和断开。对于托卡马克磁铁来说，这是一种极具吸引力的设计方案，将一些线圈(例如，极向场线圈(PFS))穿入其他线圈组(例如，环形场线圈(TF))是非常有利的。如果线圈是可拆卸的，那么托卡马克更广泛的组装过程也会大大简化，例如真空室和中子屏的组装。可拆卸线圈的开发是一个多方面的问题，涉及开发新的低电阻连接方法、托卡马克会场环境中的实际实施方法以及设计更宽的磁体系统以容纳接头(包括绝缘方法和磁体工作原理)。

Tokamak Energy Ltd is a private company targeting the delivery of fusion as a clean and safe energy source by 2030. The company aims to do this by combining spherical tokamaks, which are a type of magnetic confinement fusion device, with high temperature superconducting (HTS) magnets, which can deliver very strong magnetic fields in compact devices. The company believes that HTS spherical tokamaks are the key route to delivering commercial fusion energy on a rapid timescale. This project aims to address two key challenges in the field of HTS magnet technology, in order to accelerate the development of HTS magnets for fusion energy and other applications. The first challenge is to develop a technical and strategic approach towards the characterisation and quality assurance (QA) of HTS conductors, then implement this on several hundred kilometres of conductor procured over a period of several years. The key difficulty here is that the current capacity of rare-earth barium copper oxide (REBCO) HTS conductors is extremely large and has a very complex dependence on temperature, magnetic field strength, field direction and the crystal's nanostructure. Measurement of conductor performance under the end-use conditions in fusion magnets is extremely challenging due to the high magnetic fields and currents involved. Therefore, complete characterisation cannot be carried out routinely despite magnet designs relying crucially on their knowledge. This project will establish the necessary performance indicators (balancing cost, risk and depth of information), develop the methods required to measure them, and implement this on the real conductor as it arrives. The second challenge is the development of dismantlable coil structures for HTS fusion magnets. HTS magnets can be operated at relatively high temperatures (>~20 K) at which substantial heat loads from joints between conductors can be accommodated by cooling systems. Unlike conventional low temperature superconductors (LTS), HTS conductors operated at high temperatures are extremely thermally stable and can therefore tolerate substantial temperature variations of several degrees Kelvin around their structures. This enables dismantlable coil structures to be considered, in which the turns of the magnet can be connected and disconnected from one another during assembly and disassembly. This is an extremely attractive design option for tokamak magnets, where it is advantageous for some coils (e.g. poloidal field coils (PFs) ) to be threaded inside other coil sets (e.g. the toroidal field coils (TFs)). The wider assembly process for tokamaks is also greatly simplified if the coils are dismantlable, for example the assembly of vacuum chambers and neutron shields. Development of dismantlable coils is a multifaceted problem involving development of novel low resistance jointing methods, practical implementation methods in a tokamak assembly hall environment, and design of the wider magnet system to accommodate the joints (including insulation methods and magnet operating principles).