freegs.coil.Coil

class freegs.coil.Coil(R, Z, current=0.0, turns=1, control=True, area=<freegs.coil.AreaCurrentLimit object>)

Bases: object

Represents a poloidal field coil

public members

R, Z - Location of the coil current - current in each turn of the coil in Amps turns - Number of turns control - enable or disable control system area - Cross-section area in m^2

The total toroidal current carried by the coil is current * turns

__init__(R, Z, current=0.0, turns=1, control=True, area=<freegs.coil.AreaCurrentLimit object>)

R, Z - Location of the coil

current - current in each turn of the coil in Amps turns - Number of turns. Total coil current is current * turns control - enable or disable control system area - Cross-section area in m^2

Area can be a fixed value (e.g. 0.025 for 5x5cm coil), or can be specified using a function which takes a coil as an input argument. To specify a current density limit, use:

area = AreaCurrentLimit(current_density)

where current_density is in A/m^2. The area of the coil will be recalculated as the coil current is changed.

The most important effect of the area is on the coil self-force: The smaller the area the larger the hoop force for a given current.

Methods

Br(R, Z)	Calculate radial magnetic field Br at (R,Z)
Bz(R, Z)	Calculate vertical magnetic field Bz at (R,Z)
__init__(R, Z[, current, turns, control, area])	R, Z - Location of the coil
calcPsiFromGreens(pgreen)	Calculate plasma psi from Greens functions and current
controlBr(R, Z)	Calculate radial magnetic field Br at (R,Z) due to a unit current
controlBz(R, Z)	Calculate vertical magnetic field Bz at (R,Z) due to a unit current
controlPsi(R, Z)	Calculate poloidal flux at (R,Z) due to a unit current
createPsiGreens(R, Z)	Calculate the Greens function at every point, and return array.
from_numpy_array(value)
getForces(equilibrium)	Calculate forces on the coils in Newtons
inShape(polygon)
plot([axis, show])	Plot the coil location, using axis if given
psi(R, Z)	Calculate poloidal flux at (R,Z)
to_numpy_array()	Helper method for writing output

Attributes

area	The cross-section area of the coil in m^2
dtype

Br(R, Z)

Calculate radial magnetic field Br at (R,Z)

Bz(R, Z)

Calculate vertical magnetic field Bz at (R,Z)

property area

The cross-section area of the coil in m^2

calcPsiFromGreens(pgreen)

Calculate plasma psi from Greens functions and current

controlBr(R, Z)

Calculate radial magnetic field Br at (R,Z) due to a unit current

controlBz(R, Z)

Calculate vertical magnetic field Bz at (R,Z) due to a unit current

controlPsi(R, Z)

Calculate poloidal flux at (R,Z) due to a unit current

createPsiGreens(R, Z)

Calculate the Greens function at every point, and return array. This will be passed back to evaluate Psi in calcPsiFromGreens()

dtype = dtype([('R', '<f8'), ('Z', '<f8'), ('current', '<f8'), ('turns', '<i8'), ('control', '?')])

classmethod from_numpy_array(value)

getForces(equilibrium)

Calculate forces on the coils in Newtons

Returns an array of two elements: [ Fr, Fz ]

Force on coil due to its own current:

Lorentz self-forces on curved current loops Physics of Plasmas 1, 3425 (1998); https://doi.org/10.1063/1.870491 David A. Garren and James Chen

inShape(polygon)

plot(axis=None, show=False)

Plot the coil location, using axis if given

The area of the coil is used to set the radius

psi(R, Z)

Calculate poloidal flux at (R,Z)

to_numpy_array()

Helper method for writing output