Activity in copper foils

Dear FLUKA experts,
I’m trying to reproduce the results presents in the article “A new and simple calibration-independent method for measuring the beam energy of a cyclotron” (doi:10.1016/j.apradiso.2010.09.012).
The geometry contain two copper foils with an aluminium foil between them.
They used SRIM code and obtained a curve of the activity ratio between first and second copper foil in function of the proton beam energy, varying the aluminium thickness. The figure above shows that my results was higher than those presents in the article.
I attached my .flair file. beam_energy.flair (20.5 KB)
Could you help me to understand these different in ratios? Did I make a mistake?
Thanks in advanced.


I have no deeper knowledge of SRIM but if you have a look at the paper then you see that the way the calculation is done is not the same. While FLUKA uses a fully integrated nuclear interaction model to directly determine the activation products, the authors of the paper did this differently. Their activity is indirectly inferred from the energy deposition with which they select the energy range of the x-section that they consider to calculate the activity products.

If you look at the X-section data of IAEA (natCu(p,x)63Zn) you can see that uncertainties in that energy range are quite considerable. Just as a brief example, at 15 MeV IAEA considers around 220 mbarn while for example the models used in the TENDL library predict around 138 mbarn. So in overall a match/divergence within a factor of 2 with respect to models used in FLUKA does not necessarily surprise me either.

If you really want to reproduce the calculation data in the paper, then you might think about using the same approach based on energy deposition and manual convolution with the same x-sections that the authors have used.


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