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Hello Ron,

At 4/4/2007 11:23 PM, you wrote:
>When is it possible to do a quantitative analysis on a probe with a
>rastered beam on an inhomogeneous sample?

I sometimes use a defocussed beam, but for the reason mentioned by 
Andy Buckley I stay away from rastering. The JEOL 8200 has a "beam 
diameter" parameter in its EOS setup, which is fairly accurate 
judging from materials that show the "burn" spot.

Right now I am engaged in a quantitative study how well that works 
for various alloys. One thing I am still missing is a probe that 
would allow me to measure the beam intensity across a defocussed 
beam, although I think it will be more uniform than across a raster.

Many years ago we also tried Li-borate fusion for rock analysis (on 
samples too small for our XRF), which seemed to work o.k., but didn't 
pursue it past the initial tests.

Alfred

Alfred Kracher
Ames Laboratory (USDOE)
Iowa State University
227 Wilhelm Hall
Ames, IA 50011-3020
Tel.: 515 294 7097