desc.coils.FourierXYCoil.compute_Bnormal

FourierXYCoil.compute_Bnormal(surface, eval_grid=None, source_grid=None, vc_source_grid=None, params=None, basis='rpz', chunk_size=None, B_plasma_chunk_size=None)Source

Compute Bnormal from self on the given surface.

Parameters:

  • surface (Surface or Equilibrium) – Surface to calculate the magnetic field’s Bnormal on. If an Equilibrium is supplied, will use its boundary surface, and also include the contribution from the equilibrium currents using the virtual casing principle.

  • eval_grid (Grid, optional) – Grid of points on the surface to calculate the Bnormal at, if None defaults to a LinearGrid with twice the surface poloidal and toroidal resolutions points are in surface angular coordinates i.e theta and zeta

  • source_grid (Grid, int or None) – Grid used to discretize MagneticField object if calculating B from Biot-Savart. Should NOT include endpoint at 2pi.

  • vc_source_grid (LinearGrid) – LinearGrid to use for the singular integral for the virtual casing principle to calculate the component of the normal field from the plasma currents. Must have endpoint=False and sym=False and be linearly spaced in theta and zeta, with nodes only at rho=1.0

  • params (list or tuple of dict, optional) – parameters to pass to underlying field’s compute_magnetic_field function. If None, uses the default parameters for each field. If a list or tuple, should have one entry for each component field.

  • basis ({"rpz", "xyz"}) – basis for returned coordinates on the surface cylindrical “rpz” by default

  • chunk_size (int or None) – Size to split Biot-Savart computation into chunks of evaluation points. If no chunking should be done or the chunk size is the full input then supply None.

  • B_plasma_chunk_size (int or None) – Size to split singular integral computation for B_plasma into chunks. If no chunking should be done or the chunk size is the full input then supply None. Default is chunk_size.

Returns:

  • Bnormal (ndarray) – The normal magnetic field to the surface given, as an array of size grid.num_nodes.

  • coords (ndarray) – the locations (in specified basis) at which the Bnormal was calculated, given as a (grid.num_nodes , 3) shaped array.