Dear Mengling,

 

As Caroline Peacock from Leeds has successfully done Tl L3 microXAFS on some samples on I18 at diamond, I Have a little experience.

She has a paper on the work currently in review.

As Matt says if you have Pb in the sample your data is limited to just under 350 eV (10 k). Micro EXAFS past 10 k is quite hard but feasible and the big advantage is your localised concs. are possibly (probably?) a lot higher than for the bulk. If the Tl was equally distributed at 13 ppm max then micro Xanes might work, XAFS wont – but i think that’s not likely. Thus with a local high concentration you might with time get 12 k XAFS from the Tl.

 

As for using a total yield detector the big advantage is that they are count rate unlimited so you  don’t have to worry about count rate saturating your detector and can have it dead close to the sample to get the maximum Tl counts. Even with Al attenuation which will remove the Fe signal quicker than the Tl you are throwing away some Tl counts. Hence for XANES in particular it may be advantageous.

 

Cheers

Fred

 

 

Prof.  J F W Mosselmans

Principal Beamline Scientist I18

Diamond Light Source

Diamond House

Harwell Campus

Didcot

Oxon

OX11 ODE

UK

 

T 00 44 1235 778568

M 00 44 7785510211

E fred.mosselmans@diamond.ac.uk

F 00 44 1235 778448

 

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