Abstract
The present paper discusses the diffusion approximation of the linear Boltzmann equation in cases where the collision frequency is not uniformly large in the spatial domain. Our results apply for instance to the case of radiative transfer in a composite medium with optically thin inclusions in an optically thick background medium. The equation governing the evolution of the approximate particle density coincides with the limit of the diffusion equation with infinite diffusion coefficient in the optically thin inclusions.
| Original language | English |
|---|---|
| Pages (from-to) | 641-671 |
| Number of pages | 31 |
| Journal | Communications in Mathematical Sciences |
| Volume | 13 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1 Jan 2015 |
Keywords
- Diffusion approximation
- Linear Boltzmann equation
- Neutron transport equation
- Radiative transfer equation