Disclosed are techniques for initiating and sustaining a transport barrier within a magnetically confined plasma in a plasma fusion device. For a toroidal magnetic configuration, a characteristic region of the magnetic field can be established by generating a current within the plasma or by other means. The location of the characteristic region can be controlled to be suitably close to the interior walls of the plasma fusion device to allow a quantity of particles to be injected into the plasma at or inside the characteristic region. The quantity of particles can augment the density of the plasma and create a density gradient within the characteristic region, resulting in the formation of a transport barrier at or inside the characteristic region.

The present disclosure is directed to a method of generating a set of torsion-restricted free parameters which describe a design of one or more electromagnetic coils, such as for use in a stellarator. In some embodiments, the computing of the set of torsion-restricted free parameters describing the one or more substantially planar coils includes a parametrization which describes one or more non-planar coils.