X-Ray Characteristic Emission Lines - Too Narrow?


My simulation uses an electron beam incident on a tantalum target to output an x-ray spectrum at the desired electron beam energy. I’m expecting my k_alpha characteristic emission lines to be in ratio 2:1 between k_alpha1 and k_alpha2, but this ratio is only achieved at a plot step size of 0.1 eV, which is a lot smaller than the expected 100 eV energy bandwidth of these lines. Has anyone found this in their work? Is there a way to set up my simulation to account for spectral broadening of emission lines from the uncertainty principle?

For context, I have found this issue with Penelope, EM4 and Livermore physics lists using a range cutoff of 5 um.

Any help would be appreciated! Thank you,