Simulation study of the wavelength shifter fiber readout of plastic scintillator

The light yield (LY) of a wavelength shifter (WLS) fiber embedded in a plastic scintillator plate was studied by the MC simulation using the Mathematica package to find its optimum length and fiber density in the shashlik mode. It was identified whether or not the light absorbed in a fiber has been once reflected at any surface. The partial LY with reflections at upper and lower surfaces as well as without reflections have a tendency to saturate at around 100 mm of the scintillator length. The behavior of increasing LY with the density of WLS fibers also was confirmed by comparing the simulation with the past measurement.