The above Penepma calculations were very short (3600 sec each) and the uncertainties were larger than the intensities (at the 1, 2 and 4 um distances), so here is another calculation utilizing PAR files calculated by Penfluor down to 200 eV.
The Penfluor/Fanal model assumes pure Fe as the beam incident material and pure carbon as the boundary material and instead of using MC to calculate the fluorescence effects, Fanal uses an analytical model which provides better precision in a fraction of the time:
But the SF curve is very steep for this highly absorbing system so we might expect some differences between the MC and analytical modeling.
Note also that because the Penfluor calculation depends only on composition and density, once this is calculated (~10 hours for each composition), one can run multiple models in seconds with various beam energies, take off angles and distance from the boundary as seen here where the takeoff angle was modified from 40 to 35 degrees:
And here is the same calculation but where the beam incident material is Fe90Ni10 as opposed to pure Fe:
Remember: to perform Penfluor/fanal couple modeling for secondary fluorescence effects at energies lower than 1 keV, one must set the PenepmaMinimumElectronEnergy keyword to the value in keV. So for the above modeling I had to run the Fe and C materials through Penfluor using a PenepmaMinimumElectronEnergy set to 0.2 (or 200 eV) as seen below.
[software]
PenepmaMinimumElectronEnergy="0.2"
To facilitate modeling with these low energy PAR files, I have attached a number of them below.