# Pn scattering order

1. Sep 13, 2011

### Stephan_doc

I use some computational codes.I must to enter Pn scattering order for some materials.What means that? For example what is difference betwen P1,P2,P3 order?

2. Sep 13, 2011

### Astronuc

Staff Emeritus
Assuming one is familiar with discrete ordinates methods and spherical harmonics, the n in Pn refers to the number (n+1) of Legendre polynomials with which one expands the angular flux in transport problems, usually in slab geometry.