The flux from the spots fall off as the square as well. Assuming that
flux at the detector is linear with respect to measured intensity, I'm
not sure where the benefit would be. I'm also assuming an ideal beam
and ignoring other sources of noise.
James
On Nov 23, 2009, at 2:54 PM, Richard Gillilan wrote:
It seems to be widely known and observed that diffuse background
scattering decreases more rapidly with increasing detector-to-sample
distance than Bragg reflections. For example, Jim Pflugrath, in his
1999 paper (Acta Cryst 1999 D55 1718-1725) says "Since the X-ray
background falls off as the square of the distance, the expectation
is that a larger crystal-to-detector distance is better for
reduction of the x-ray background. ..."
Does anyone know of a more rigorous discussion of why background
scatter fades while Bragg reflections remain collimated with distance?
Richard Gillilan
MacCHESS
