USRYIELD estimators

Dear FLUKA user,

I am using USRYIELD estimator to score neutron fluence (double
differential) produced from the interaction of 200 MeV (kinetic energy)
proton beam with a thin target of Be-9 (1.2cm). The inputfile is attached.
The result I obtained are not what I expected e.g the neutron spectrum
(see attached file) shows a trend which is opposite of what is expected. I
will be grateful for your input.

Kind Regards,
Buthaina Adam