The Helical Heliotron field for plasma confinement

The Helical Heliotron field of the first kind is composed of a helical field, vertical field and toroidal solenoid field. The helical field is produced by a current carrying single helical conductor which is wound around the minor axis and closes on itself after making l-circuits around the major axis. By using a computer, the authors have traced the helical lines of force and computed the rotational transform, the shear and the well depth. The complex behaviour of the separatrix is also clarified. In the l=2 case, the Helical Heliotron field of the first kind has large rotational transform and strong shear simultaneously, and also has a magnetic well.