toroidal plasma

A toroidal plasma is a doughnut-shaped configuration of charged particles used in nuclear-fusion research for magnetic confinement. The most common type is the tokamak, which uses a combination of toroidal (long way around) and poloidal (short way around) magnetic fields to keep the plasma stable and contained within a vacuum chamber. These magnetic fields prevent the plasma from drifting to the walls and developing instabilities.12

The toroidal field is generated by external coils, while the poloidal field is created by an electric current flowing within the plasma itself. Techniques like radio-frequency current drive or neutral-beam injection can sustain this current, though a natural phenomenon called the bootstrap current can also contribute. The ultimate goal of these devices is to achieve the extreme temperatures and densities needed for fusion reactors to generate power.13