desc.geometry.FourierRZToroidalSurface.from_near_axis

classmethod FourierRZToroidalSurface.from_near_axis(aspect_ratio, elongation, mirror_ratio, axis_Z, NFP=1)[source]

Create a surface from a near-axis model for quasi-poloidal/quasi-isodynamic.

Parameters:

  • aspect_ratio (float) – Aspect ratio of the geometry = major radius / average cross-sectional area.

  • elongation (float) – Elongation of the elliptical surface = major axis / minor axis.

  • mirror_ratio (float) – Mirror ratio generated by toroidal variation of the cross-sectional area. Must be < 2.

  • axis_Z (float) – Vertical extent of the magnetic axis Z coordinate. Coefficient of sin(2*phi).

  • NFP (int) – Number of field periods.

Returns:

surface (FourierRZToroidalSurface) – Surface with given geometric properties.