Re: [Ifeffit] status of self-absorption corrections

Hi Mauro, I haven't done anything about self-absorption corrections besides read a few of the papers and look at Booth's and Haskel's code and docs. Your assessment that there was 'no conclusion' from the previous discussions seems correct to me. I believe SixPack has incorporated Booth's algorithm already, so perhaps Sam or someone who has used this in SixPack can comment on it. Booth's and Haskel's programs are available, of course. I'd prefer to have a single procedure that could correct both XANES and EXAFS, and took into account sample thickness, incident angle and the range of exit angles as separate parameters. It seems that enough people have published partial solutions that it could be done 'right'. I was hoping someone would come up with something more definitive. It seems like a good project for a student. For what it's worth, if you're using a Ge detector, the deadtime corrections might also be important. --Matt On Fri, 30 Apr 2004 mauro@rulp.org wrote:

Hi to all,

I would like to ask you which is the status of the discussion on the self-absorption corrections to fluorescence EXAFS.

I'm working on Mo/Si multilayers, studied by standing-wave-assisted EXAFS. My data are collected at grazing incidence (phi + theta = 90 deg) with a Ge (13 elements) detector. I have done data analysis without self-absorption corrections and I have found good results, except for the amplitude (S_0^2) that is very low (~0.50). I think this low value is due to self-absorption, so I would like to demonstrate it.

My dilemma is: Troger's approach or Booth's one?

I personally think that Booth's (simple) approach, could be used in this particular case (Ge detector, phi+theta=90deg), but my tutor told me that I can't assume a neglectable solid angle for a Ge detector so I have to use the Troeger's (quite difficult) approach.

...

From the mailing-list archive, I have read your discussion about this topic but I haven't found something like a "conclusion". Is there anyone who use Booth's approach with good results? Have you already done "tests" of this method? Is it possible to improve it?

Finally, what about the software status? Matt, have you done something on Booth's Fortran code?

Thanks, Mauro

-- Mauro Rovezzi - Physics student University of Rome "Tor Vergata", ESRF Beamline BM8 - GILDA _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit