What's important is not only maximum current, but magnitude of the magnetic field. Yes, these quantities are closely related, but fusion reactors are interested

What's important is not only maximum current, but magnitude of the magnetic field. Yes, these quantities are closely related, but fusion reactors are interested in dense magnetic field, and superconductors often break down after some magnetic field. For example, according to this site, the record is 17.6 Tesla - http://www.kings.cam.ac.uk/news/2014/world-superconductor-record.html http://www.kings.cam.ac.uk/news/2014/world-superconductor-re...