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Equilibrium

dexter.Equilibrium(qfactor: Qfactor, current: Current, bfield: Bfield, *, perturbation: Optional[Perturbation] = Perturbation([]), geometry: Optional[Geometry] = None, species: ParticleSpecies = 'Proton')

An Equilibrium.

Contains all the necessary equilibrium objects, defines conversions to SI and provides plots.

For conveniently constructing a numerical equilibrium from a netCDF file, see numerical_equilibrium

Parameters:

  • qfactor (Qfactor) –

    The equilibrium's qfactor.

  • current (Current) –

    The equilibrium's current.

  • bfield (Bfield) –

    The equilibrium's bfield.

  • perturbation (Optional[Perturbation], default: Perturbation([]) ) –

    todo: The equilibrium's perturbation, if they exist. Defaults to None (unperturbed equilibrium).

  • geometry (Optional[Geometry], default: None ) –

    The equilibrium's geometry. This field is not required for calculations. Defaults to None.

  • species (ParticleSpecies, default: 'Proton' ) –

    The particle species under study. This only affects unit conversions to SI. Defaults to "Proton".

Example
Equilibrium creation
>>> eq = Equilibrium(
...     geometry=dex.LarGeometry(baxis=2, raxis=1.75, rlast=0.5),
...     qfactor=dex.ParabolicQfactor(1.1, 3.9, dex.LastClosedFluxSurface("Toroidal", 0.45)),
...     current=dex.LarCurrent(),
...     bfield=dex.LarBfield(),
... )

Methods:

  • quantity –

    Constructs a Quantity

  • plot_b –

    Plots a contour plot of the magnetic field strength for a numerical equilibrium.

  • plot_db –

    Plots contour plots of the magnetic field's derivatives for a numerical equilibrium.

  • plot_flux_surfaces –

    Plots the flux surfaces of a numerical equilibrium.

  • plot_boozer_theta –

    Plots the \(\theta_B = const\) lines on a numerical equilibrium.

  • plot_midplane –

    Plots \(B\), \(dB/d(\psi/\psi_p)\) and \(dB/d\theta\) on the midplane.

Attributes:

  • geometry (Geometry) –

    The equilibrium 'Geometry'.

  • qfactor (Qfactor) –

    The equilibrium 'Qfactor'.

  • current (Current) –

    The equilibrium 'Current'.

  • bfield (Bfield) –

    The equilibrium 'Bfield'.

  • perturbation (Perturbation) –

    The equilibrium 'Perturbation'.

  • psi_last (float) –

    The value of the last closed toroidal flux surface, \(\psi_{LCFS}\).

  • psip_last (float) –

    The value of the last closed poloidal flux surface, \(\psi_{p,LCFS}\).

  • baxis (float) –

    The magnetic field strength on the axis, \(B_{axis}\).

  • raxis (float) –

    The device's major radius, \(R_{axis}\).

  • rlast (float) –

    The radial coordinate's value at the last closed flux surface, \(r_{LCFS}\).

dexter.Equilibrium.geometry: Geometry property

The equilibrium 'Geometry'.

dexter.Equilibrium.qfactor: Qfactor property

The equilibrium 'Qfactor'.

dexter.Equilibrium.current: Current property

The equilibrium 'Current'.

dexter.Equilibrium.bfield: Bfield property

The equilibrium 'Bfield'.

dexter.Equilibrium.perturbation: Perturbation property writable

The equilibrium 'Perturbation'.

dexter.Equilibrium.psi_last: float property

The value of the last closed toroidal flux surface, \(\psi_{LCFS}\).

dexter.Equilibrium.psip_last: float property

The value of the last closed poloidal flux surface, \(\psi_{p,LCFS}\).

dexter.Equilibrium.baxis: float property

The magnetic field strength on the axis, \(B_{axis}\).

dexter.Equilibrium.raxis: float property

The device's major radius, \(R_{axis}\).

dexter.Equilibrium.rlast: float property

The radial coordinate's value at the last closed flux surface, \(r_{LCFS}\).

dexter.Equilibrium.quantity(value: float | ArrayLike, units: str) -> PlainQuantity

Constructs a Quantity

dexter.Equilibrium.plot_b(levels: int = 20, units: UnitSystem = 'SI', show: bool = True) -> Canvas

Plots a contour plot of the magnetic field strength for a numerical equilibrium.

Parameters:

  • levels (int, default: 20 ) –

    The number of contour levels. Defaults to 20.

  • units (UnitSystem, default: 'SI' ) –

    The unit system of the magnetic field magnitude. Defaults to "SI".

  • show (bool, default: True ) –

    Whether or not to call plt.show(). Defaults to True.

Returns:

  • Canvas –

    The produced Figure and Ax.

dexter.Equilibrium.plot_db(levels: int = 20, show: bool = True) -> MultiCanvas

Plots contour plots of the magnetic field's derivatives for a numerical equilibrium.

Parameters:

  • levels (int, default: 20 ) –

    The number of contour levels. Defaults to 20.

  • show (bool, default: True ) –

    Whether or not to call plt.show(). Defaults to True.

Returns:

dexter.Equilibrium.plot_flux_surfaces(number: int = 20, show: bool = True) -> Canvas

Plots the flux surfaces of a numerical equilibrium.

Parameters:

  • number (int, default: 20 ) –

    The number of flux surfaces to (try to) plot. Defaults to 20.",

  • show (bool, default: True ) –

    Whether or not to call plt.show(). Defaults to True.

Returns:

  • Canvas –

    The produced Figure and Ax.

dexter.Equilibrium.plot_boozer_theta(number: int = 80, show: bool = True) -> Canvas

Plots the \(\theta_B = const\) lines on a numerical equilibrium.

Parameters:

  • number (int, default: 80 ) –

    The number of lines to (try to) plot. Defaults to 80.",

  • show (bool, default: True ) –

    Whether or not to call plt.show(). Defaults to True.

Returns:

  • Canvas –

    The produced Figure and Ax.

dexter.Equilibrium.plot_midplane(show: bool = True) -> Canvas

Plots \(B\), \(dB/d(\psi/\psi_p)\) and \(dB/d\theta\) on the midplane.

The midplane is defined as two \(\theta=const\) lines:

  • \(\theta = \pi\) and \(\psi=[0, \psi_{LCFS}]\) (or \(\psi_p=[0, \psi_{p,LCFS}]\))
  • \(\theta = 0\) and \(\psi=[0, \psi_{LCFS}]\) (or \(\psi_p=[0, \psi_{p,LCFS}]\))

Parameters:

  • show (bool, default: True ) –

    Whether or not to call plt.show(). Defaults to True.

Returns:

  • Canvas –

    The produced Figure and Ax.

dexter.numerical_equilibrium(path: str, interp1d_type: Interp1DType, interp2d_type: Interp2DType, *, padding: int = 15) -> Equilibrium

Constructs a numerical equilibrium from a netCDF file.

Perturbations are not constructed, but can be added manually in the Equilibrium object.

Parameters:

  • path (str) –

    Path to netCDF file.

  • interp1d_type (Interp1DType) –

    The 1D interpolation type.

  • interp2d_type (Interp2DType) –

    The 2D interpolation type.

  • padding (int, default: 15 ) –

    The left-right \(\theta\) (per-side) padding width of the \(B\) array. Defaults to 15.

Returns: