[Ifeffit] Is good EXAFS data possible with 0.01 transmission coefficient

[Scott Calvin]

Hi Damon,

So you're saying you expect the total absorption of the sample to be less than 0.01 absorption lengths? In other words, if the detectors and electronics were identical, you would expect It = I0 exp(-0.01)?

While possible to measure in transmission, such a sample would normally be measured in fluorescence. If done that way, the measurement is routine. 

Or am I misunderstanding your description? (I am not entirely sure what you mean by "transmission coefficient.")

--Scott Calvin
Sarah Lawrence College

On Jul 25, 2013, at 4:07 PM, Damon Turney <dturney at ccny.cuny.edu> wrote:

> Hi IFEFFIT community,
> 
> I will make measurements soon at Brookhaven's NSLS to do EXAFS, and my
> sample is a powder mixture of carbon powder, MnO2 powder, and
> potassium hydroxide liquid.  The transmission coefficient of 6.5keV
> x-rays (the Mn K edge is at ~6.5keV) through the sample is ~0.001 to
> 0.01.  I am told that the ionization chamber detectors can easily
> detect the x-ray beam after this ~0.01 transmission loss (by
> increasing the gain on the detector), but I would like to ask the
> IFEFFIT community if there will be other problems with the EXAFS
> technique when the transmission coefficient is so low.  Does anybody
> have comments?
> 
> Much thanks -- if you have any info I greatly appreciate it!
> Damon Turney
> City College of New York
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