celinem
Hi,
I am trying to run quantitative rietvelt analysis from synchrotron data.
For reasons which are irrelevant here, we were working without monochromator and have contamination from higher harmonics. To make it even less simple, we were working in asymmetric reflection geometry with very small incident angles (from tens of degree to 2 degrees) to minimize the penetration. For the same reasons, we took the fundamental energy close to the edge so the absorption ratio between fundamental and higher harmonics is dramatic.
My question is: is there a way to apply different absorption corrections for the two beam energies simultaneously with Topas v6?
Thanks
Céline
alancoelho
Hi Celine
To incorporate the right absorption correction then use two phases and give each its own emission profile; your INP file should look something like:
xdd...
str...
lam la 1 lo 0.9 lh .01
scale s 0.0001
str...
lam la @ 1 lo 0.8 lh .01
scale s 0.0001
In the above we have two phases each with its own emission profile and each with the correct absorption. In your case the structures will be identical except for the emission profile.
You could either have one scale parameter and refine on one of the la parameters (as shown), or refine on two scale parameters and fix the la parameters.
alan