The 'Little Big Coil (LBC)' magnet test bed investigates key coated conductor characteristics in a high field and high stress environment by testing a REBCO coil in the bore of the NHMFL 31.1 T Bitter magnet. Indeed, LBC3 first demonstrated excessive screening current stress (SCS) resulting in wavy plastic conductor damage, while obtaining the record-high DC magnetic field of 45.5 T by...
The no-insulation technique in high-temperature superconducting (HTS) coils has significantly advanced HTS magnet technology by introducing an innovative approach to protection. This technique allows current redistribution between adjacent turns, enabling self-protection of the coils. However, it also introduces charging delays. To reduce the charging delay while maintaining self-protection...
High temperature superconductor (HTS) coils are widely acknowledged for having greater stability margins than low temperature superconductor (LTS) counterparts. In particular, no-insulation (NI) coils are often assumed to exhibit even greater stability owing to enhanced thermal conduction between turns and inherent current bypass capabilities. However, we hypothesize that this assumption may...
Advancements in high-temperature superconductors (HTS), particularly REBCO coated conductors, have catalyzed breakthroughs in ultra-high field magnet technology. However, significant challenges remain, with quench protection being a critical unresolved issue. The no-insulation (NI) winding technique offers a promising approach to mitigate these challenges. By allowing turn-to-turn bypass...
No-insulation (NI) high-temperature superconducting (HTS) coils have been shown to have improved thermal stability properties and an improved winding pack density over traditionally wound HTS coils. These improved properties have led to new design proposals for a wide range of applications, include some of the magnets of a fusion magnet system. However, further research still needs to be...
Parallel-wound no-insulation (PWNI) high-temperature superconducting (HTS) coil is a kind of pancake-shaped coil wound with parallel-stacked tapes, which is a promising technique with reduced ramping delay and enhanced thermal stability compared to conventional no-insulation coils wound with single tape (single-wound no-insulation (SWNI) coil). The turn-to-turn current redistribution...
Fast-ramping REBCO HTS magnets are required for the central solenoid and poloidal field coils of spherical tokamaks. Beyond fusion, this class of magnets has broad relevance to a range of emerging applications including motors and generators, space propulsion, manufacturing and other sectors. These magnets cannot adopt no-insulation (NI), which offer the most compact route to high fields using...
