Absorption length
Revision as of 13:35, 6 June 2014 by KevinYager (talk | contribs)
The absorption length or attenuation length in x-ray scattering is the distance over which the x-ray beam is absorbed. By convention, the absorption length λ is defined as the distance into a material where the beam flux has dropped to 1/e of its incident flux.
Absorption
The absorption follows a simple Beer-Lambert law:
The attenuation coefficient (or absorption coefficient) is simply the inverse of the absorption length;
Calculating
The absorption length arises from the imaginary part of the atomic scattering factor, f2. It is closely related to the absorption cross-section, and the mass absorption coefficient. Specifically, the atomic photoabsorption cross-section can be computed via:
