Energy of particles from heavy ion collisions?

Dear Fluka users,

I'm running lead ion collisions at 100GeV/A. From these collisions, I get
nucleons with E > 100 GeV/A from a USRBDX detector. I understand that it is
kinematically impossible to get particles with energies higher than the
input energy.

Is something wrong with the way I am interpreting the results?

Linked below is a graph of KE vs. frequency of neutrons leaving the
interaction point for both pp and PbPb collisions.

http://i1159.photobucket.com/albums/p624/SCHedges/ppvPbPbneutrons100GeV.png

I have enclosed my .inp file for the heavy ion collisions. Thank you for
your assistance,

Samuel Hedges