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%matplotlib inline


# Braginskii coefficients¶

A short example of how to calculate classical transport coefficients from Bragiński's theory.

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from astropy import units as u

from plasmapy.formulary import ClassicalTransport


We'll use some sample ITER data, without much regard for whether the regime is even fit for classical transport theory:

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thermal_energy_per_electron = 8.8 * u.keV
electron_concentration = 10.1e19 / u.m ** 3

thermal_energy_per_ion = 8.0 * u.keV
ion_concentration = electron_concentration
ion = "D+"  # a crude approximation

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braginskii = ClassicalTransport(
thermal_energy_per_electron,
electron_concentration,
thermal_energy_per_ion,
ion_concentration,
ion,
)


These variables are calculated during initialization and can be referred to straight away:

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print(braginskii.coulomb_log_ei)
print(braginskii.coulomb_log_ii)
print(braginskii.hall_e)
print(braginskii.hall_i)


These quantities are not calculated during initialization and can be referred to via methods. To signify the need to calculate them, we call them via ().

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print(braginskii.resistivity)
print(braginskii.thermoelectric_conductivity)
print(braginskii.electron_thermal_conductivity)
print(braginskii.ion_thermal_conductivity)


They also change with magnetization:

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mag_braginskii = ClassicalTransport(
thermal_energy_per_electron,
electron_concentration,
thermal_energy_per_ion,
ion_concentration,
ion,
B=0.1 * u.T,
)

print(mag_braginskii.resistivity)
print(mag_braginskii.thermoelectric_conductivity)
print(mag_braginskii.electron_thermal_conductivity)
print(mag_braginskii.ion_thermal_conductivity)

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all_direction_braginskii = ClassicalTransport(
thermal_energy_per_electron,
electron_concentration,
thermal_energy_per_ion,
ion_concentration,
ion,
B=0.1 * u.T,
field_orientation="all",
)

print(all_direction_braginskii.resistivity)
print(all_direction_braginskii.thermoelectric_conductivity)
print(all_direction_braginskii.electron_thermal_conductivity)
print(all_direction_braginskii.ion_thermal_conductivity)


The viscosities return arrays:

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print(braginskii.electron_viscosity)
print(mag_braginskii.electron_viscosity)
print(braginskii.ion_viscosity)
print(mag_braginskii.ion_viscosity)