LIGHT-PULSES TO PHOTOMULTIPLIER TUBES FROM EXTENDED SCINTILLATORS

Light pulses seen by photomultiplier tubes (PMTs) after propagation wi thin long scintillator slats or rods, or large disc-shaped scintillato rs are investigated and compared with those from point-like scintillat ors. Results of experimental tests for the disc-shaped configuration, performed with the single photon counting technique, are presented and compared with numerical calculations. These calculations were perform ed describing the light pulse shape by means of a new, quite general a nalytical method based on the geometrical optics concepts of virtual l ight paths and images. The associated electric pulses produced by the PMTs coupled to the scintillators are then discussed with particular e mphasis on their dependence on the distance between light source and p hotocathode.