Account for tungsten radiation

hanna

Dear all,

Our in-house diffractometer gives peaks from tungsten radiation. Is there a simple way to account for this in the refinements in TOPAS?

Apologies if this is something that I could have found out myself with some more searching, but I am in a pre-beamtime rush.

Thanks in advance and best wishes,
Hanna

johnsoevans

This used to be "spot the error problem 8" on the Durham Rietveld school!

You have to add a line to the emission profile. Replace your CuKa2(0.0001) line with something like:

lam 
      ymin_on_ymax 0.0001 
      la 0.653817 lo 1.540596  lh 0.501844  
      la 0.346183 lo 1.544493  lh 0.626579  
'	la @  0.02980 lo 1.39222   lh 0.5      'CU KB 
      la @  0.00540` lo 1.47639   lh 0.5      'W LA

It won't be perfect, but should be ok for a pre-beamtime rush!

hanna

Thanks John, that is very helpful!