The chamber where the 'sun fire' is intended to burn has to be large enough to avoid premature extinction of the discharge due to losses at the walls.

Heating by the plasma current (transformer) is supplemented by:

- Injection of fast (neutral) particles
- Microwaves (acceleration of charged particles).

The charged plasma particles generated at start-up of the transformer current are captured by the magnetic field, they 'gyrate' around the field lines.