It's a big ring of magnetic coil, superconducting coil, and it makes a magnetic field in a ring like this, and the hot gas in the middle, which is called a plasma, is trapped.
To je velika prstenasta magnetska zavojnica, supravodljiva zavojnica koja stvara magnetsko polje u ovakvom prstenu, a vrući plin u sredini zvan plazma je zarobljen u prstenu.