[Ifeffit] Distortion of transmission spectra due to particlesize

[Ravel, Bruce]

> I think you are correct in principle that more layers can reduce the
> thickness effect problem.  If harmonics were not an issue, eventually if
> you pile up enough random layers, the thickness will be uniform.
> Whether this is useful in practice is another matter, but suspect it may
> not be when single particle absorption is large.

I think I agree with this.  Among my beamline's users, a very common problem is preping samples that, as Matthew suggested, have boulders either on tape or in BN.  If the individual particles/agglomerates are 10's of absorption lengths (which *is* a common problem among my users) then ignoring harmonics and stackin' 'em up won't help.

So stacking as a solution to pinholes only works if the particles are small enough to begin with -- in which case it won't be that hard to make a good sample in the first place!

B

--
 Bruce Ravel  ----------------------------------- bravel at bnl.gov

 National Institute of Standards and Technology
 Synchrotron Methods Group at Brookhaven National Laboratory
 Building 535A
 Upton NY, 11973

 My homepage:    http://cars9.uchicago.edu/~ravel
 EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/
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