Scintillator response

Dear Fluka experts,

I would like to calculate the recoil proton energy spectrum in an
organic scintillator, such as BC501-A, NE213 or stilbene after neutron
irradiation (monokinetic beam) between 2 and 15 MeV.

Since the n-p scattering is isotropic in the center of mass system in
this energy range, the energy spectrum of the recoil protons should have
a rectangular shape between 0 and En. Due to edge effects, the spectrum
should have a decreasing slope (without taking into account the
nonlinear light output with energy).

In order to get it, I used the DETECT card to score the energy
deposition in my region of scintillation. But this spectrum showed a
strong peak near the incident energy of neutrons. I can mentioned that
the shape of the spectrum seems to be correct at 70 MeV for example.

Does anybody succeed in this kind of simulation with Fluka ?
Did I misunderstand the results ?

Thanks for your help.
Jean-Emmanuel

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Jean-Emmanuel Groetz
University of Franche-Comte
Laboratoire de Chimie Physique et Rayonnements Alain Chambaudet
UMR CEA E4
16, route de Gray
25030 Besancon Cedex
France
mailto: jegroetz_at_univ-fcomte.fr
phone: +33 3 81 66 65 07
fax: +33 3 81 66 65 22
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