Sub-nanosecond timing studies with plastic scintillation studies

Systematic studies on fast timing with plastic scintillation detectors and constant fraction pulse-height triggers, have been carried out. Using the leading-edge fast discriminators, the optimum triggering fraction C/R for NE111 scintillators coupled to RCA 8575 photomultipliers has been found to be approximately 20%. Further the time resolution for NE102A is observed to be 20% worse than NE111 scintillators using XP1021 phototubes. Effect of scintillator thickness and the utilized photocathode area on time resolution and is investigated with NE111 and XP1021 combinations. The variation of time resolution as a function of energy for this combination has also been studied. (author)