radis.phys package

Submodules

• radis.phys.air module
  • Routine Listing
  • air2vacuum()
  • air_index_dispersion()
  • vacuum2air()
• radis.phys.blackbody module
  • planck()
  • planck_wn()
  • sPlanck()
• radis.phys.constants module
  • Av
  • Ry
  • a_0
  • c
  • c_CGS
  • eV
  • e_CGS
  • eps_0
  • h
  • h_CGS
  • hc_k
  • k_b
  • k_b_CGS
  • m_e
  • m_e_CGS
• radis.phys.convert module
  • J2K()
  • J2cm()
  • J2eV()
  • K2J()
  • K2cm()
  • K2eV()
  • atm2bar()
  • atm2torr()
  • bar2atm()
  • bar2torr()
  • cm2J()
  • cm2J_vaex()
  • cm2K()
  • cm2eV()
  • cm2hz()
  • cm2nm()
  • cm2nm_air()
  • dcm2dnm()
  • dcm2dnm_air()
  • dhz2dnm()
  • div_safe()
  • dnm2dcm()
  • dnm2dhz()
  • dnm_air2dcm()
  • eV2J()
  • eV2K()
  • eV2cm()
  • eV2nm()
  • hz2cm()
  • hz2nm()
  • nm2cm()
  • nm2eV()
  • nm2hz()
  • nm_air2cm()
  • torr2atm()
  • torr2bar()
  • zero2nan()
• radis.phys.morse module
  • morse_increment()
• radis.phys.units module
  • Unit()
  • conv2()
  • convert_emi2cm()
  • convert_emi2nm()
  • convert_rad2cm()
  • convert_rad2nm()
  • convert_universal()
  • is_homogeneous()
• radis.phys.units_astropy module
  • convert_and_strip_units()

Module contents

Physical constants and conversion.

planck(lambda_, T, eps=1, unit='mW/cm2/sr/nm')

Planck function for blackbody radiation.

\[\epsilon \frac{2h c^2}{{\lambda}^5} \frac{1}{\operatorname{exp}\left(\frac{h c}{\lambda k T}\right)-1}\]

Parameters:

• λ (np.array (nm)) – wavelength

• T (float (K)) – equilibrium temperature

• eps (grey-body emissivity) – default 1

• unit (output unit) – default ‘mW/sr/cm2/nm’

Returns:

np.array – equilibrium radiance

Return type:

(mW.sr-1.cm-2/nm)

See also

sPlanck(), planck_wn()

planck_wn(wavenum, T, eps=1, unit='mW/cm2/sr/cm-1')

Planck function for blackbody radiation, wavenumber version.

\[\epsilon 2h c^2 {\nu}^3 \frac{1}{\operatorname{exp}\left(\frac{h c \nu}{k T}\right)-1}\]

Parameters:

• wavenum (np.array (cm-1)) – wavenumber

• T (float (K)) – equilibrium temperature

• eps (grey-body emissivity) – default 1

• unit (str) – output unit. Default ‘mW/sr/cm2/cm-1’

Returns:

np.array – equilibrium radiance

Return type:

default (mW/sr/cm2/cm-1)

See also

sPlanck(), planck()

sPlanck(wavenum_min=None, wavenum_max=None, wavelength_min=None, wavelength_max=None, T=None, eps=1, wstep=0.01, medium='air', **kwargs)

Return a RADIS Spectrum object with blackbody radiation.

It’s easier to plug in a SerialSlabs() line-of-sight than the Planck radiance calculated by planck(). And you don’t need to worry about units as they are handled internally.

See Spectrum documentation for more information

Parameters:

• wavenum_min / wavenum_max (():math:cm^{-1})) – minimum / maximum wavenumber to be processed in \(cm^{-1}\).

• wavelength_min / wavelength_max ((\(nm\))) – minimum / maximum wavelength to be processed in \(nm\).

• T (float (K)) – blackbody temperature

• eps (float [0-1]) – blackbody emissivity. Default 1

Other Parameters:

• wstep (float (cm-1 or nm)) – wavespace step for calculation

• **kwargs (other keyword inputs) – all are forwarded to spectrum conditions. For instance you can add a ‘path_length=1’ after all the other arguments

Examples

Generate Earth blackbody:

s = sPlanck(wavelength_min=3000, wavelength_max=50000,
            T=288, eps=1)
s.plot()

Examples using sPlanck :

Blackbody radiation

Blackbody radiation

References

In wavelength:

\[\epsilon \frac{2h c^2}{{\lambda}^5} \frac{1}{\operatorname{exp}\left(\frac{h c}{\lambda k T}\right)-1}\]

In wavenumber:

\[\epsilon 2h c^2 {\nu}^3 \frac{1}{\operatorname{exp}\left(\frac{h c \nu}{k T}\right)-1}\]

Additional Reference: - [“Blackbody Radiation and Planck’s Law,” Optics Express] (https://opg.optica.org/oe/fulltext.cfm?uri=oe-14-18-8121&id=97928).

See also

planck(), planck_wn()