IonizationState¶

class plasmapy.particles.IonizationState(particle: plasmapy.particles.particle_class.Particle, ionic_fractions=None, *, T_e: Unit("K") = <Quantity nan K>, kappa: numbers.Real = inf, n_elem: Unit("1 / m3") = <Quantity nan 1 / m3>, tol: Union[float, int] = 1e-15)¶

Bases: object

Representation of the ionization state distribution of a single element or isotope.

Parameters

particle (ParticleLike) – A str or Particle instance representing an element, isotope, or ion; or an integer representing the atomic number of an element.
ionic_fractions (ndarray, list, tuple, or Quantity; optional) – The ionization fractions of an element, where the indices correspond to integer charge. This argument should contain the atomic number plus one items, and must sum to one within an absolute tolerance of tol if dimensionless. Alternatively, this argument may be a Quantity that represents the number densities of each neutral/ion. This argument cannot be specified when particle is an ion.
T_e (Quantity, keyword-only, optional) – The electron temperature or thermal energy per electron.
n_elem (Quantity, keyword-only, optional) – The number density of the element, including neutrals and all ions.
tol (float or integer, keyword-only, optional) – The absolute tolerance used by isclose when testing normalizations and making comparisons. Defaults to 1e-15.

Raises

ParticleError – If the ionic fractions are not normalized or contain invalid values, or if number density information is provided through both ionic_fractions and n_elem.
InvalidParticleError – If the particle is invalid.

Examples

>>> states = IonizationState('H', [0.6, 0.4], n_elem=1*u.cm**-3, T_e=11000*u.K)
>>> states.ionic_fractions[0]  # fraction of hydrogen that is neutral
0.6
>>> states.ionic_fractions[1]  # fraction of hydrogen that is ionized
0.4
>>> states.n_e  # electron number density
<Quantity 400000. 1 / m3>
>>> states.n_elem  # element number density
<Quantity 1000000. 1 / m3>

If the input particle is an ion, then the ionization state for the corresponding element or isotope will be set to 1.0 for that ion. For example, when the input particle is an alpha particle, the base particle will be He-4, and all He-4 particles will be set as doubly charged.

>>> states = IonizationState('alpha')
>>> states.base_particle
'He-4'
>>> states.ionic_fractions
array([0., 0., 1.])

Initialize an IonizationState instance.

Attributes Summary

`T_e`	Return the electron temperature.
`Z_mean`	Return the mean integer charge
`Z_most_abundant`	Return a `list` of the integer charges with the highest ionic fractions.
`Z_rms`	Return the root mean square integer charge.
`atomic_number`	Return the atomic number of the element.
`base_particle`	Return the symbol of the element or isotope.
`element`	Return the atomic symbol of the element.
`integer_charges`	Return an array with the integer charges.
`ionic_fractions`	Return the ionic fractions, where the index corresponds to the integer charge.
`ionic_symbols`	Return the ionic symbols for all charge states.
`isotope`	Return the isotope symbol for an isotope, or `None` if the particle is not an isotope.
`kappa`	Return the kappa parameter for a kappa distribution function for electrons.
`n_e`	Return the electron number density assuming a single species plasma.
`n_elem`	Return the total number density of neutrals and all ions.
`number_densities`	Return the number densities for each state.
`tol`	Return the absolute tolerance for comparisons.

Methods Summary

`normalize`()	Normalize the ionization state distribution (if set) so that the sum of the ionic fractions becomes equal to one.
`summarize`([minimum_ionic_fraction])	Print quicklook information for an `IonizationState` instance.

Attributes Documentation

T_e¶: Return the electron temperature.

Z_mean¶: Return the mean integer charge

Z_most_abundant¶

Return a list of the integer charges with the highest ionic fractions.

Examples

>>> He = IonizationState('He', [0.2, 0.5, 0.3])
>>> He.Z_most_abundant
[1]
>>> Li = IonizationState('Li', [0.4, 0.4, 0.2, 0.0])
>>> Li.Z_most_abundant
[0, 1]

Z_rms¶: Return the root mean square integer charge.

atomic_number¶: Return the atomic number of the element.

base_particle¶: Return the symbol of the element or isotope.

element¶: Return the atomic symbol of the element.

integer_charges¶: Return an array with the integer charges.

ionic_fractions¶

Return the ionic fractions, where the index corresponds to the integer charge.

Examples

>>> hydrogen_states = IonizationState('H', [0.9, 0.1])
>>> hydrogen_states.ionic_fractions
array([0.9, 0.1])

ionic_symbols¶: Return the ionic symbols for all charge states.

isotope¶: Return the isotope symbol for an isotope, or None if the particle is not an isotope.

kappa¶

Return the kappa parameter for a kappa distribution function for electrons.

The value of kappa must be greater than 1.5 in order to have a valid distribution function. If kappa equals inf, then the distribution function reduces to a Maxwellian.

n_e¶: Return the electron number density assuming a single species plasma.

n_elem¶: Return the total number density of neutrals and all ions.

number_densities¶: Return the number densities for each state.

tol¶: Return the absolute tolerance for comparisons.

Methods Documentation

normalize() → None ¶

Normalize the ionization state distribution (if set) so that the sum of the ionic fractions becomes equal to one.

This method may be used, for example, to correct for rounding errors.

summarize(minimum_ionic_fraction: numbers.Real = 0.01) → None ¶

Print quicklook information for an IonizationState instance.

Parameters: minimum_ionic_fraction (Real) – If the ionic fraction for a particular ionization state is below this level, then information for it will not be printed. Defaults to 0.01.

Example

>>> He_states = IonizationState(
...     'He',
...     [0.941, 0.058, 0.001],
...     T_e = 5.34 * u.K,
...     kappa = 4.05,
...     n_elem = 5.51e19 * u.m ** -3,
... )
>>> He_states.summarize()
IonizationState instance for He with Z_mean = 0.06
----------------------------------------------------------------
He  0+: 0.941    n_i = 5.18e+19 m**-3
He  1+: 0.058    n_i = 3.20e+18 m**-3
----------------------------------------------------------------
n_elem = 5.51e+19 m**-3
n_e = 3.31e+18 m**-3
T_e = 5.34e+00 K
kappa = 4.05
----------------------------------------------------------------