Hi Bruce, Thanks for your help, it's really appreciated. I was trying to keep it simple but it seems I'm just messing around.
What I am trying to do is to perform a new developed self-absorption correction using collected fluorescence absorption coefficient data on a CuSO4 (pentahydrate) capillar (cylinder) and spherical sample with Cu as absorber, having different values of molarity and penetration depth. The correction expression requires these measured quantity: μX(E) : the absorption coefficient due to a given core excitation of the absorbing atom - I used the background function for this ( bkg(E)) μo = μ(E) : photoelectric total linear absorption coefficient of the sample at incident energy E - I used the xmu(E) for this μh = μ(E) :photoelectric total linear absorption coefficient of the sample at fluorescence emission Ef - I used the xmu(Ef) with Ef the K absorption edge of Cu ( 8.9789 eV) χ: and here I used the chi(E) values of the exported ascii .xmu file Hope it's clear now. Matteo 2016-04-02 19:00 GMT+02:00 <ifeffit-requ...@millenia.cars.aps.anl.gov>: > Send Ifeffit mailing list submissions to > ifeffit@millenia.cars.aps.anl.gov > > To subscribe or unsubscribe via the World Wide Web, visit > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > or, via email, send a message with subject or body 'help' to > ifeffit-requ...@millenia.cars.aps.anl.gov > > You can reach the person managing the list at > ifeffit-ow...@millenia.cars.aps.anl.gov > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Ifeffit digest..." > > > Today's Topics: > > 1. Re: Ifeffit Digest, Vol 158, Issue 1 (Matt Newville) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 1 Apr 2016 15:56:29 -0500 > From: Matt Newville <newvi...@cars.uchicago.edu> > To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov> > Subject: Re: [Ifeffit] Ifeffit Digest, Vol 158, Issue 1 > Message-ID: > <CA+7ESbrsbsFQGMGLwGNPJmVO= > fgzksbv1sezr3m5prkxann...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Matteo, > > > On Fri, Apr 1, 2016 at 8:35 AM, Matteo Busi <baseb...@gmail.com> wrote: > > > Hi Bruce, > > Now this is clear. > > In my case the correction I have to perform requires these > > measured/evaluated parameters: chi, mu (not sure if it's better to work > > with normmu here) and the background function. > > Is it physically meaningless to have the mu(k) and bkg(k) data? If that > is > > not the case I would like to have these two columns exported in the ascii > > chi(k) file. > > So then I can perform the correction and re-import the new corrected > > chi(k) and make comparison with the uncorrected. > > > > Kind regards, > > Matteo > > > > > It would certainly help (and by that I mean "help you get the answers > you're looking for") if you gave us more details about what you're trying > to do rather than ask for how to what you think you want to do. > > Just to be clear: Converting from E to k does not involve a Fourier > transform, just > k = sqrt((2m*e/hbar**2)*(E-E0)) > > for k in Ang^-1 and E in eV, that's k ~= sqrt(0.262468*(E-E0)) > > I'm not sure what you're trying, but I would image you want to use > normalized mu(E) or at least pre-edge subtracted mu(E). That is, what we > call mu(E) is typically really -ln(I/I0) > where I and I0 are not the actual intensities before and after the sample, > but counts or counts per time in some detector that samples the flux. > These values include more or less arbitrary scale factors (amplifier gains, > etc) included. That means that (unless you very careful) mu(E) does not > have meaningful units, certainly not cm^-1 or cm^2/gram. > > Normalized mu(E) doesn't have such units either, but it's an easier place > to start. > > --Matt > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20160401/658d433a/attachment-0001.html > > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit > > > ------------------------------ > > End of Ifeffit Digest, Vol 158, Issue 3 > *************************************** >
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