1. Absorption Corrections Spencer Howells
1 Basics
2 Paalman-Pings
3 Monte Carlo

2. Basics Neutron paths in and out Transmission exp(-n*sigma*l)
Scattering point
Neutron paths in and out
Transmission exp(-n*sigma*l)
measured, calculated
Input
Shape – flat plate, cylinder, annulus
Sample parameters – cross-sections & density
Wavelength – for both paths
Scattering angles

3. scattering absorption As,s sample sample Ac,c container container
Paalman-Pings
Takes into account both sample and container
scattering absorption
As,s sample sample
Ac,c container container
As,sc sample sample & container
Ac,sc container sample & container
Correction is (sample – container*Ac,sc/Ac,c)/As,sc
Could extend to sample environment
Sample volume divided up
Input from diffraction, indirect with elastic, direct

6. Only calculates As,s and Ac,c Applied as an approximation
Monte Carlo
Scattering point generated at random
Added beam size
Only calculates As,s and Ac,c
Applied as an approximation
Awaiting version for P-P