Problem with Pb characteristic radiation

Dear FLUKA experts.

I attempt to calculate the Lα and Lβ photon spectrum of X-ray characteristic radiation from lead atoms irradiated with a beam of monoenergetic photons of energy 60keV. In principle, I identified most of the lines characteristic of Pb. Some of the lines are not visible, but this can still be OK. On the other hand, I have a problem because I have a line in the spectrum with an energy of ~12.65keV and I can’t identify it meaningfully. The lead transition table doesn’t show anything with that energy, and it shows everything that has been identified in the area (Table of Isotopes decay data).

I attach all the files from the calculations.

test.flair (5.2 KB)
test.inp (1.4 KB)

Dear AdamW

1- The data in the TOI is old (1999) and some of it was changed

this table has the values

I found one updated 2009

Any how let us analysis the problem
XRF for lead must have 2 strong X-ray lines as in figure

it can has also other lines but these liens weaker!!! (not has the same or bigger intensity.)

the next table can help. It can gives the energy of X-rays with its intensities

also the pdf file contain a good tables for this

I suggest that, you first find all the X-ray lines (found in modern references) with their intensity ratios first. Take into account that it is possible to find some lines as sum peaks, such as:
12.7913 keV= 10.449 + 2.3423,
14.797 keV=12.1432 + 2.6538
and then after you are sure that the calculations are good, and the strongest lines is ok with its intensities. You start examining what belongs to you or not.
This is because I searched alot and I couldn’t fiend any relation to the 12.65 keV
Best Regards
Mohamed Fayez

Dear @AdamW ,

The following table summarizes the origin of the various lines you’re witnessing, detailing the subshell where the vacancy was left (as well as its binding energy in FLUKA), the subshell from which an electron transitioned to fill the vacancy (as well as its binding energy in FLUKA), the resulting x-ray line energy and its spectroscopic labeling (following table 2 of this reference). I’ve just focused on the two lines immediately at ~12.65 keV:

Vacancy subshell Binding energy (keV) Subshell from which e- transitions Binding energy (keV) Gamma energy (keV) Transition
L2 15.251 M4 2.5947 12.6563 L \beta_1
L3 13.04 N5 0.41249 12.62751 L \beta_2

What you’re witnessing are differences at the level of mere 10s of eV (!) in atomic (sub)shell binding energies among various references, which should not be an issue provided lines energies are self-consistently determined from energy level differences.

To have an idea of what’s in the market, see the second paragraph of page 3 of this NIST database manual.



Dear Profile - mohammed.fayiz - FLUKA User Forum and Profile - cesc - FLUKA User Forum.
Thank you very much for your help.
Best regards
Adam W.