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
) – Astr
orParticle
instance representing an element, isotope, or ion; or an integer representing the atomic number of an element.ionic_fractions (
ndarray
,list
,tuple
, orQuantity
; 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 oftol
if dimensionless. Alternatively, this argument may be aQuantity
that represents the number densities of each neutral/ion. This argument cannot be specified whenparticle
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 byisclose
when testing normalizations and making comparisons. Defaults to1e-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
andn_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
Return the electron temperature.
Return the mean integer charge
Return a
list
of the integer charges with the highest ionic fractions.Return the root mean square integer charge.
Return the atomic number of the element.
Return the symbol of the element or isotope.
Return the atomic symbol of the element.
Return an array with the integer charges.
Return the ionic fractions, where the index corresponds to the integer charge.
Return the ionic symbols for all charge states.
Return the isotope symbol for an isotope, or
None
if the particle is not an isotope.Return the kappa parameter for a kappa distribution function for electrons.
Return the electron number density assuming a single species plasma.
Return the total number density of neutrals and all ions.
Return the number densities for each state.
Return the absolute tolerance for comparisons.
Methods Summary
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.
-
kappa
¶ Return the kappa parameter for a kappa distribution function for electrons.
The value of
kappa
must be greater than1.5
in order to have a valid distribution function. Ifkappa
equalsinf
, 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 ----------------------------------------------------------------