"""
Defines the core Plasma class used by PlasmaPy to represent plasma properties.
"""
__all__ = ["PlasmaBlob"]
import warnings
import astropy.units as u
from plasmapy.formulary import coupling_parameter, quantum_theta
from plasmapy.formulary.misc import _grab_charge
from plasmapy.particles import particle_mass
from plasmapy.plasma.plasma_base import GenericPlasma
from plasmapy.utils import code_repr
from plasmapy.utils.decorators import validate_quantities
from plasmapy.utils.exceptions import CouplingWarning
[docs]
class PlasmaBlob(GenericPlasma):
"""
Class for describing and calculating plasma parameters without
spatial/temporal description.
"""
@validate_quantities(T_e=u.K, n_e=u.m**-3)
def __init__(self, T_e, n_e, Z=None, particle="p+") -> None:
"""
Initialize plasma parameters.
The most basic description is composition (ion), temperature,
density, and ionization.
"""
self.T_e = T_e
self.n_e = n_e
self.particle = particle
self.Z = _grab_charge(particle, Z)
# extract mass from particle
self.ionMass = particle_mass(self.particle)
def __str__(self) -> str:
"""
Fetch regimes for easy printing.
Examples
--------
>>> print(PlasmaBlob(1e4 * u.K, 1e20 / u.m**3, particle="p+"))
PlasmaBlob(T_e=10000.0*u.K, n_e=1e+20*u.m**-3, particle='p+', Z=1)
Intermediate coupling regime: Gamma = 0.01250283...
Thermal kinetic energy dominant: Theta = 109690.5...
"""
return self.__repr__() + "\n" + "\n".join(self.regimes())
def __repr__(self) -> str:
"""
Return a string representation of this instance.
Returns
-------
str
Examples
--------
>>> import astropy.units as u
>>> PlasmaBlob(1e4 * u.K, 1e20 / u.m**3, particle="p+")
PlasmaBlob(T_e=10000.0*u.K, n_e=1e+20*u.m**-3, particle='p+', Z=1)
"""
argument_dict = {
"T_e": self.T_e,
"n_e": self.n_e,
"particle": self.particle,
"Z": self.Z,
}
return code_repr.call_string(PlasmaBlob, (), argument_dict)
@property
def electron_temperature(self):
return self.T_e
@property
def electron_density(self):
return self.n_e
@property
def ionization(self):
return self.Z
@property
def composition(self):
return self.particle
[docs]
def regimes(self):
"""
Generate a comprehensive description of the plasma regimes
based on plasma properties and consequent plasma parameters.
"""
coupling = self.coupling()
quantum_theta = self.quantum_theta()
if coupling <= 0.01:
coupling_str = f"Weakly coupled regime: Gamma = {coupling}."
elif coupling >= 100:
coupling_str = f"Strongly coupled regime: Gamma = {coupling}."
else:
coupling_str = f"Intermediate coupling regime: Gamma = {coupling}."
if quantum_theta <= 0.01:
quantum_theta_str = (
f"Fermi quantum energy dominant: Theta = {quantum_theta}"
)
elif quantum_theta >= 100:
quantum_theta_str = (
f"Thermal kinetic energy dominant: Theta = {quantum_theta}"
)
else:
quantum_theta_str = (
f"Both Fermi and thermal energy important: Theta = {quantum_theta}"
)
return [coupling_str, quantum_theta_str]
[docs]
def coupling(self):
"""
Ion-ion coupling parameter to determine if quantum/coupling effects
are important. This compares Coulomb potential energy to thermal
kinetic energy.
"""
couple = coupling_parameter(
self.T_e, self.n_e, (self.particle, self.particle), self.Z
)
if couple < 0.01:
warnings.warn(
f"Coupling parameter is {couple}, you might have strong coupling effects",
CouplingWarning,
)
return couple
[docs]
def quantum_theta(self):
"""
Quantum theta parameter, which compares Fermi kinetic energy to
thermal kinetic energy to check if quantum effects are important.
"""
return quantum_theta(self.T_e, self.n_e)
[docs]
@classmethod
def is_datasource_for(cls, **kwargs) -> bool:
return "T_e" in kwargs and "n_e" in kwargs