microphysics

microphysics.hydrogen_cross_section(wavelength=None, energy=None)[source]

Compute the photoionization cross-section of hydrogen in function of wavelength or energy.

Parameters
wavelength (``float`` or ``numpy.ndarray``, optional):

Wavelength in unit of angstrom. Default is None. If None, energy cannot be None.

energy (``float`` or ``numpy.ndarray``, optional):

Energy in unit of electron-volt. Default is None. If None, wavelength cannot be None.

Returns
a_lambda (float or numpy.ndarray):

Cross-section in function of wavelength and in unit of cm ** 2. Only returned if wavelength was input.

a_nu (float or numpy.ndarray):

Cross-section in function of energy and in unit of cm ** 2. Only returned if energy was input.

microphysics.helium_singlet_cross_section(wavelength)[source]

Compute the photoionization cross-section of helium singlet in function of wavelength.

Parameters
wavelength (``float`` or ``numpy.ndarray``):

Wavelength in unit of angstrom.

Returns
a_lambda_1 (float or numpy.ndarray):

Cross-section in function of wavelength and in unit of cm ** 2.

microphysics.helium_triplet_cross_section()[source]

Compute the photoionization cross-section of helium triplet in function of wavelength.

Returns
wavelength (numpy.ndarray):

Wavelength in which the cross-section was sampled in Norcross (1971).

a_lambda_3 (numpy.ndarray):

Cross-section in function of wavelength and in unit of cm ** 2.

microphysics.he_3_properties()[source]

Returns the central wavelengths in air, oscillator strengths and the Einstein coefficient of the helium triplet in 1.083 microns. The values were taken from the NIST database: https://www.nist.gov/pml/atomic-spectra-database

Returns
lambda_0 (float):

Central wavelength in air of line 0 in unit of m.

lambda_1 (float):

Central wavelength in air of line 1 in unit of m.

lambda_2 (float):

Central wavelength in air of line 2 in unit of m.

f_0 (float):

Oscillator strength of line 0 (unitless).

f_1 (float):

Oscillator strength of line 1 (unitless).

f_2 (float):

Oscillator strength of line 2 (unitless).

a_ij (float):

Einstein coefficient of the whole triplet in unit of 1 / s.