Measurement of neutron flux produced by proton

Dear Fluka experts:
In my simulation, I’m using 218MeV proton to hit a 303030cm^2 water phantom through a universal range shifter(PMMA) to see the neutron information.
x+.flair (6.4 KB)

According to previous studies, there should be three peaks in the neutron flux spectrum(Thermal, Evaporation, Direct).

But, I can only see the thermal peak in my simulation.

It’s there something wrong with my configurations?

Dear Nicolas

You compare two different quantities. The role model plot shows the result in something which is called lethargy presentations, which is consistent with Fluence *E. In your plot you show differential fluence (particles/cm2 per MeV). If you chose in Flair the following parameter <X>*Y for printing your histogram to show your result in lethargy representation, then the resulting plot will be much more similar to your role model plot and higher energies will appear.

I hope this helps a bit

Best regards


Dear Vincke:
Problem soved! Thanks!