Re-use of this resource is governed by a Creative Commons Attribution-
NonCommercial-ShareAlike 4.0 International
https://creativecommons.org/licenses/by-nc-sa/4.0/
creative commons DoITPoMS logo
The scattering vector is perpendicular to the planes of interest.
This is the standard symmetric reflection geometry
Now the planes, and hence the scattering vector are offset .
To measure the diffraction peak the sample is rotated by the offset. Now ω is not equal to θ. This is called an asymmetric reflection
How do we collect reflections from these planes?
This transmission mode is only possible when the X-rays can penetrate the sample, i.e. a low enough absorption coefficient. Typically this is possible in polymers.