Tokamak Energy are developing large scale REBCO HTS magnets for application in spherical tokamaks for fusion energy. As part of our HTS technology development plan, a series of quality assessment (QA) coils have been manufactured and tested. These are non-insulated coils containing ~100 m of HTS tape. The manufacture and testing of these magnets has allowed us to assess the performance of HTS conductors from various worldwide suppliers, as well as to develop magnet construction techniques. Six different QA magnets have been made and tested in total. The magnets were tested using Tokamak Energy’s purpose-built cryogenic test rig, which provides conduction cooling at temperatures in the range 12 - 50 K and currents up to several kiloamps.
This talk discusses the tests conducted and presents a comparison of conductor performance (without identifying the products). The talk concludes with a summary of work on high field demonstrator magnets under way at Tokamak Energy. We aim to reveal the test results for a high field conduction cooled non-insulated HTS solenoid utilizing the novel coil construction methods demonstrated in QA coils.