[Ifeffit] No background subtraction in some cases?

[Alexander Riskin]

Dear all,

Recently we've measured samples at the DUBBLE Beamline at ESRF for iron 
and molybdenum (K-edge). After measuring, the DUBBLE software generates 
a .dat file which must then be translated to other files (depending on 
the fact whether transmission or fluorescence is measured) using some 
script in linux. When we try to import some of these transformed files 
(for transmission measured) into Athena however, the program fails to 
subtract a background from mu(E), therefore no k and R-space plots are 
available (see project files MoPEL002 and MoPEL004, the original 
dat.sample files are included in the zip files). Other files however, 
work fine (both transmission and fluorescence measured ones).

After analyzing the structure of the .dat files, it was discovered which 
columns are the Io an It data and the correct ln(Io/It) could be 
manually generated. This manual procedure yields data sets identical to 
the ones in the dat.sample files, we named them dat.good files. When 
importing these files into Athena, the background subtraction works 
fine. It is the exact same data however...

Although the problem can be bypassed by processing the data manually, 
the fact that Athena processes some files correctly and others not seems 
very strange to us since they all come from the same beamline. We 
thought it would be interesting to let you all know.

Thanks for your time and for making such wonderful software,
Alexander Riskin

-- 
Alexander Riskin
Universiteit Hasselt
IMO - Inorganic and Physical Chemistry
Agoralaan – Building D
BE-3590 Diepenbeek / Belgium
tel. +32.(0)11.26.83.94
fax. +32.(0)11.26.83.23
email: alexander.riskin at uhasselt.be

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