Protons with energy under PART-THR minimum appearing in spectrum

Dear FLUKA experts,

I am trying to score the proton spectra in a water phantom at several depths using USRYIELD. For my study, I need to set up a proton transport threshold of 15 MeV, which I do using the PART-THR card.

When I graph these spectra, I still find protons under this energy of 15 MeV. Why is this the case?

I am aware that (as per the manual): “for thresholds lower than 100 MeV, the particle is not stopped, but is ranged out to rest in an approximate way”, do these contribute to the scorer?

If so, can you raise the production threshold so that no protons with energies higher than 15 MeV are produced?

I attach the flair file and a couple of examples of the spectra. Thank you very much for your time in advance!

Best regards,
Daniel
boxwater.flair (39.1 KB)
spectra-codes-z=3.9867549668874176.eps|attachment (118.9 KB)
spectra-codes-z=10.963576158940398.eps|attachment (110.0 KB)

Dear @danipuerta ,

Thank you for your question. I will review your inquiry and respond as soon as possible.

Best regards,
Tommaso