Optimization of Light Yield and Timing of Extruded Plastic Scintillator

High energy physics experiments often use extruded plastic scintillator with wavelength-shifting (WLS) fiber coupled to silicon photomultiplier (SIPM) readout. Using cosmic ray, we studied factors, such as the fiber's diameter, the extrusion dimension, and the type of fiber, that can affect the light yield and timing resolution of plastic extruded scintillator read out with WLSs and SiPMs. We also studied the decay time of the different types of fiber using a 405nm laser diode to excite the fiber directly as well as a 260nm LED to excite the extruded scintillator, where the scintillation is then carried by the fiber to the SiPM. Our results suggest that increasing the thickness of the extrusion and increasing the fiber diameter increases the light yield. Furthermore, BCF-92 fiber produces a lower light yield than Y-11 but has a significantly faster decay time and better timing resolution.