STUDY OF TIMING DEGRADATION AND LIGHT ATTENUATION IN LONG PLASTIC SCINTILLATION RODS FROM TIME-OF-FLIGHT COUNTERS IN RELATIVISTIC HEAVY-IONEXPERIMENTS

We have studied the timing and light yield characteristics of long and thin scintillator samples of various sizes. Both the light yield and the time resolution degrade exponentially with respect to the distance from one end; the inverse slope parameters for the time resolutions a re found to be twice those of the light yield. This is interpreted in terms of a photoelectron statistics picture, which can also explain th e observed position dependence of time resolution for time-of-flight c ounters.