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@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/