def refraction_index_O(wave_freq, density, squared=False):
"""
Calculate the refraction index of an O mode wave in a medium.
Parameters
----------
wave_freq : number or ndarray
Frequency of the wave entering the medium.
density : number or ndarray
Density of the medium.
squared : bool, optional
If squared is True, return the square of the refraction index. Otherwise
return the real part of the refractive index. Default is False.
Returns
-------
number
The refraction index.
"""
n_squared = 1 - np.power(plasma_frequency(density) / wave_freq, 2.)
if squared:
return n_squared
else:
# don't allow negative refractive indexes
return np.sqrt(np.maximum(n_squared, 0))
def refraction_index_X(wave_freq, density, magnetic_field, squared=False):
"""
Calculate the refraction index of an O mode wave in a medium.
Parameters
----------
wave_freq : number or ndarray
Frequency of the wave entering the medium.
density : number or ndarray
Density of the medium.
magnetic_field : number or ndarray
Magnetic field present in the medium.
squared : bool, optional
If squared is True, return the square of the refraction index. Otherwise
return the real part of the refractive index. Default is False.
Returns
-------
number
The refraction index.
"""
fce2 = np.power(cyclotron_frequency(magnetic_field), 2.)
fpe2 = np.power(plasma_frequency(density), 2.)
fwav2 = np.power(wave_freq, 2.)
n_squared = 1 - (fpe2 / fwav2) * (fwav2 - fpe2) / (fwav2 - fpe2 - fce2)
if squared:
return n_squared
else:
# don't allow negative refractive indexes
return np.sqrt(np.maximum(n_squared, 0))
def cutoff_freq_X(density, magnetic_field):
"""
Calculate the cut-off frequencies of X mode.
The cut-off frequencies for X mode are given by
:math:`f_{L,R}=\\sqrt{f_{pe}^2 + f_{ce}^2/4}\\ \mp f_{ce} / 2` .
Parameters
----------
density : number or ndarray
Density/ies of the medium.
magnetic_field : number or ndarray
Magnetic field(s) present.
Returns
-------
number or ndarray
Left cut-off frequency/ies.
number or ndarray
Right cut-off frequency/ies.
"""
fpe = plasma_frequency(density)
fce = cyclotron_frequency(magnetic_field)
f_temp = np.sqrt(np.power(fpe, 2.) + np.power(fce, 2.) / 4)
cutoff_left = f_temp - fce / 2
cutoff_right = f_temp + fce / 2
return cutoff_left, cutoff_right
def cutoff_freq_O(density):
"""
Calculates the cut-off frequency of O mode.
The cut-off frequency for O mode is the plasma frequency.
Parameters
----------
density : number or ndarray
Density/ies of the medium.
Returns
-------
number or ndarray
Cut-off frequency/ies.
"""
return plasma_frequency(density)
def N2O(wave_freq, density):
"""
Calculate the refraction index of an O mode wave in a medium.
Parameters
----------
wave_freq : number or ndarray
Frequency of the wave entering the medium.
density : number or ndarray
Density of the medium.
squared : bool, optional
If squared is True, return the square of the refraction index. Otherwise
return the real part of the refractive index. Default is False.
Returns
-------
nsquared : number or ndarray
The refraction index, squared.
"""
nsquared = 1 - np.power(plasma_frequency(density) / wave_freq, 2.)
return nsquared