niobium-titanium · wire
NbTi
A ductile niobium-titanium alloy, and the only superconductor that can be drawn into wire on machinery a copper mill would recognize.
NbTi in numbers
- Transition temperature
- 9.2 K
- Made as
- wire
- Nitrogen line
- Below 77 K
What NbTi runs in today
MRI magnets; the LHC main dipoles; ITER’s poloidal field coils.
Source: Textbook value; CERN LHC Design Report vol. 1; ITER magnet system documentation
Why engineers choose NbTi
Every other conductor on this list is chosen in spite of how it is made. NbTi is chosen because of it. The alloy takes cold work. A billet of niobium-titanium rods packed in a copper matrix can be extruded and drawn in one continuous process, down to filaments a few microns across. No reaction furnace in the middle. No strain limit the winder has to design the magnet around. A coil shop can wind it, twist it, joint it and repair it. The cheapest superconducting wire in the world is also the one inside most of the MRI scanners installed today. A hospital magnet is a procurement decision rather than a physics program.
Where NbTi stops
It runs out of field long before it runs out of anything else. Past the operating point a modern high-field magnet asks for there is no margin left in the alloy, and a machine that needs more does not get there by winding more turns. It changes material, which is the entire reason the industry tolerates the conductor listed next to it.
Fields built on NbTi
- MRIMost scanners are superconducting magnets. More than 30,000 are installed.
- Particle therapyA superconducting gantry brought a heavy-ion treatment room from 600 tonnes down to about 300.
- NMR spectrometersThe magnet that resolves a protein structure runs at a few kelvin.
- Magnetic energy storageCurrent parked in a loop and handed back in milliseconds, for power quality.
- MaglevJapan’s superconducting maglev reached 603 km/h on a test track.
- Particle accelerators1,232 superconducting dipoles bend the beam around 27 km at CERN.
- Fusion magnetsTwenty tesla, and the reason a compact tokamak is credible at all.
- Magnetic separationHigh-gradient magnets pull iron out of clay at industrial rates.
NbTi and the other wire conductors
Terms used on this page about NbTi
SuperMatics is a platform infrastructure company for superconducting devices: software that finds the material and the process, lab work that makes and measures it, and pilot manufacturing with industrial partners.If a conductor on this page stops short of what your device needs, tell us about it.