We will describe a complete end-to-end simulation of the response of
scintillator counters to charged particles. These counters were extruded
with a titanium dioxide surface coating and two channels for the
embedded wavelength-shifting fibers which are read out by silicon
photomultipliers. The simulation includes the production and propagation
of scintillation and Cerenkov photons, the response of the silicon
photomultipliers, and the generation of the signal waveforms.
Probability lookup tables are used to speed up the simulation of the
photon propagation inside the counters. The simulation was tuned to
match measured data obtained from a test-beam study in the Fermilab
Meson Test Beam Facility using 120 GeV protons. The counters are
intended to be used in the cosmic-ray veto detector for the Mu2e
experiment at Fermilab.