Spectral impurity lines

JNNT

Hello Forum

Is there a convenient way to include spectral impurities, i.e. Kb and La1 lines for Cu radiation, into the refinement?

Currently the diffractometer set-up looks like this:

LP_Factor(!th2_monochromator, 0)
CuKa2(0.0001)

Thanks in advance,
J

rowlesmr

Replace your CuKa2(0.0001) with

   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 @ 0.01    lo 1.3922160 lh 0.5502872 'Cu Kb
      la @ 0.01    lo 1.477     lh 0.5       'W La

Your current macro CuKa2(0.0001) is equivalent to the first 4 lines above. You can then add the Cu Kb1 peak and the W La1 peak as other emission lines. Their intensity, la, needs to be refined for your instrument, and may change with time. Do this on a standard sample with a high intensity peak, corundum or quartz are good choices, although make sure there is no cristobalite in your quartz, as W La1 quartz overlaps with Cu Ka1 quartz.

I got the Cu Kb values from the Kb emission profile from TOPAS, and the W emission line from my XRF slide chart. Feel free to substitute your own.

JNNT

rowlesmr

Thanks for your detailed answer, this was very helpful and exactly what I was looking for!