Luminescence in a Scintillation Solution Excited by α and β Particles and Related Studies in Quenching

Abstract

The relative intensity of the light pulses produced by α and β particles in a scintillating solution of 2,5‐diphenyloxazole (PPO) in xylene has been investigated as a function of the concentration of the solute. The α/β ratio is substantially smaller than that found in organic plastic scintillators. From the data the dynamic quenching parameter has been calculated. Several independent experiments, i.e., measurements pertaining to mean lifetime of fluorescence, uv excitation, and pulse heights, were undertaken to study the mechanisms of quenching by oxygen in a scintillating solution. The best interpretation of the oxygen effect is consistent with the existence of dynamic quenching of the solvent and of the solute.