Re: [Ifeffit] crystal analyzer and microprobe

Something to consider would be modelling the entire thing in Penepma. In theory you could create a lookup table of observed ratios vs actual ratios, and then use that once you take your measurements to try to get back to the actual ratio. I'm replying to you directly because it's Friday afternoon and I'm worried that I may have misunderstood something about your question. Regards, Ash PS: Some links to get you started, if not already familiar with Penepma. http://www.geology.wisc.edu/~johnf/AGU-2007_JHF.pdf http://pypenelope.sourceforge.net/code/penelopetools/api/program/penepma.htm... http://www.probesoftware.com/Technical.htm On 16/08/2013 19:36, Matthew Marcus wrote:

Yup, the idea is indeed to get an absolute ratio. Not only that, but these are particles of size greater than the absorption depth of the Ni fluorescence in the Fe matrix, but not MUCH greater. The approach we've taken here is to plot the count ratio va. Fe counts as we move on the sample, and extrapolate to 0 counts. I'll pass the info to the interested parties. mam

On 8/16/2013 11:04 AM, Matt Newville wrote:

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Hi Matthew,

On Aug 16, 2013 11:53 AM, "Matthew Marcus" mailto:mamarcus@lbl.gov> wrote:

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I know that this is somewhat off-topic, but the list reaches all

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the Ni/Fe ratio is particles of Fe-rich material. This ratio is << 1, and they need a non-destructive probe. A microprobe with a crystal analyzer would do the job nicely. Here at ALS, we have the microprobe, but not the analyzer. Can anyone recommend a beamline

the right people. I have some collaborators who are looking to measure that has both?

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I'm pretty sure there's at least one at APS; a beamline number and a name would help a lot. Thanks. mam _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov mailto:Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

Both GSE (13 IDE) and PNC (20 IDC) have wavelength dispersive spectrometers that could work. Was the idea to get an absolute ratio? That can be challenging for large dynamic ranges with any detector, but can be done.

--Matt

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-- --- Ashley Norris Department of Earth Sciences South Parks Road, Oxford, UK ----------------