Computation of Radiative Transfer

initial intensity

I

0

1

source intensity

S

0

3

path length

s

4

gas density ρ

opacity κ

The equation of radiative transfer describes the propagation of radiation and the effects of emission, absorption, and scattering through a medium. This Demonstration shows the simple case of an initial intensity through a volume of gas with no scattering, constant opacity, gas density, and source function intensity. The differential equation is solved and the intensity

I

ν

as a result of the radiative transfer through the gas volume is computed as a function of optical depth. The intensity approaches the source function intensity

S

0

for optically thick cases (

τ≫1

) and the initial intensity of the background source

I

0

for optically thin cases (

τ≪1

).