Characteristics of Plastic Scintillators

Abstract

Information on the light output of a group of organic solutes in polyvinyltoluene has been obtained. The primary solutes studied are p‐terphenyl and 2‐phenyl‐5‐(4‐biphenylyl)‐1,3,4 oxadiazole (PBD), the latter being the most efficient. Of the secondary solutes studied, 4,4′‐diphenylstilbene and 2,5‐dibiphenylyl oxazole (BBO) are the most efficient. The best plastic scintillator developed contains a combination of 2‐phenyl‐5‐(4‐biphenylyl)‐1,3,4 oxadiazole (PBD) and 4,4′‐diphenylstilbene. The fluorescence spectra of these plastic scintillators were determined. When a secondary solute is added to a plastic scintillator the emitted light is mainly that of the secondary solute. The effect on the light output of the plastic scintillator upon addition of diphenylmercury was also investigated. Regardless of which combination of solutes was used, the mercury compound proved to be a serious quencher of light output.