On Wednesday 16 July 2008 12:04:26 s440697@stud.uni-goettingen.de wrote:
Hi, i have a print out of a talk (about XANES, XAFS and multiple scattering...) and i want to cite some figures (attached). Can anybody tell me the author etc...? I searched everywhere on the web (on several sites of XAFS-Summer Schools...). Unfortunately i do not have the talk as pdf-file only the print out. Maybe the talk is from Matt Newville? Maybe anybody recalls on this talk/slides or recognizes them?
Eckhard, I do not know the provenance of those figures, but I would recommend using the 3rd one with caution. The disorder term in the exafs equation, as it is conventionally expressed, is exp(-2 * k^2 * sigma^2). The author of these figures clearly got confused between the disorder and mean free path terms. At the very least, you should photoshop or the gimp to fix that. I also dislike the phrase "Debye-Waller factor" for the exafs disorder term. In crystallography, the Debye-Waller factor refers to disorder of atoms about their lattice positions. In exafs, the disorder is about the path length of the N-body configuration -- clearly not the same thing. I am, apparently, in the minority on this topic -- "Debye-Waller factor" is in wide use in the exafs literature. But, as everyone here knows, I often like to stand up on my soapbox and yell into the crowd. ;-) Another thing -- I don't quite understand the middle panel of the second figure. That is not the cartoon I would use to describe the operator in Fermi's golden rule. B -- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 My homepage: http://xafs.org/BruceRavel EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/