Neutron fluence in spallation reaction

Dear FLUKA experts and users,

   I am using FLUKA to simulate the Neutron fluence,as a function of position and energy, in Proton induced spallation reaction, I
want to get the Neutron fluence in a Cylindrical system.But,as far as what I have learnd, I found there is no particular card can be
used to estimate directly, both USRBIN and USRYIELD has been considered.The detailed description of the problem is attached.

   Could you please help me with my problem? Thanks!

Guojun Hu