gcmotion.InitialConditions

class gcmotion.InitialConditions(species: SupportedSpecies, theta0: float | Quantity, zeta0: float | Quantity, psi0: Quantity, muB: Quantity, Pzeta0: Quantity, t_eval: QuantityArray)

Creates a set of initial conditions for a particle

Upon initialization, only the passed arguments are setup. When creating a particle, the Tokamak instance is is used internally to calculate the full set of initial conditions, such as \(\rho_0\), \(\psi_{p0}\), …, as well as the particle’s energy.

Parameters:

species{‘p’, ‘e’, ‘D’, ‘T’, ‘He3’, ‘He4’}

The particle’s species. This field is case-insensitive.

theta0float | Quantity

The particle’s initial \(\theta_0\).

zeta0float | Quantity

The particle’s initial \(\zeta_0\).

psi0: Quantity

The \(\psi_0\) initial values in dimensions of [Magnetic_flux] or [psi_wall]. [psi_wall] is a unit of Magnetic flux, where 1[psi_wall] is defined to be the Magnetic flux of the last closed surface. This way we can set the \(\psi_0\) initial value with respect to the tokamak’s \(\psi_{wall}\).

t_evalQuantity (1D array)

The time interval return values, [\(t_0, t_f, steps\)], in dimensions of [time].

muBQuantity

This parameter will be parsed differently depending on its dimensionality. If its dimensions are [energy], then it is parsed as the particle’s initial “perpandicular energy”, \(\mu B\). If its dimensions are [current][area] i.e. dimensions of magnetic moment, it is parsed as the particle’s magnetic moment, which is a Constant of motion.

Pzeta0Quantity

The particle’s initial \(P_{\zeta 0}\).

Examples

How to initialize an InitialConditions object.

>>> import gcmotion as gcm
>>> import numpy as np
>>>
>>> # Quantity Constructor
>>> Rnum = 1.65
>>> anum = 0.5
>>> B0num = 1
>>> species = "p"
>>> Q = gcm.QuantityConstructor(R=Rnum, a=anum, B0=B0num, species=species)
>>>
>>> init = gcm.InitialConditions(
...     species="p",
...     theta0=0,
...     zeta0=0,
...     psi0=Q(0.6, "psi_wall"),
...     muB=Q(0.5, "keV"),
...     Pzeta0=Q(-0.015, "NUCanonical_momentum"),
...     t_eval=Q(np.linspace(0, 1e-3, 1000), "seconds"),
... )

Methods