Improvement of l=2 Stellarator and Torsatron

抄録

Magnetic field systems with l=2 helical windings of fairly short pitch have large rotational transform and high shear. This high shear promises the formation of average magnetic well, when a vertical field is externally applied.
A hybrid field having mainly l=2 and l=3 helical fields can be produced by deforming l=2 helical windings. This field has a deep well and its current system is very simple.
Numerical calculations using Biot-Savart’s law show that these improvements are realized in practice.