78 Scientific American, December 2020MAGNETIC CAGE: ITER’s fusion plasma will be encased and
contained by a nest of magnets, including six ring-shaped
superconducting poloidal magnets ( shown here ) that will pile
on top of one another horizontally to surround the plasma.
In addition, 18 toroidal field coils will encircle the machine
vertically, and one large central solenoid will sit in the middle,
forming the largest superconducting magnet system ever built.
Superconductors allow electric current to flow without resistance,
enabling electrons to move freely to create intense magnetic fields.