Quenching Effects of Several Compounds in Naphthalene Scintillators

Abstract

Fluorescence quenching of solution scintillators with molten naphthalene as a solvent is studied with excitation by gamma-rays and uv light. The material used as fluorescent solutes are anthracene, PPO, BBO, POPOP, QP, DPH and DPS. The qnenchers used are carbon tetrachloride, phenyl halides, and organic compounds of lead and boron. The experimental results are analyzed according to the Stern-Volmer equation. The rates of quenching by carbon tetrachloride and iodobenzene are comparable to those of energy transfer as given on usual liquid scintillators. The effects of phenyl halides except iodobenzene are quite slight. The rates of quenching are higher by 20-60% under excitation by gamma-rays than by 254 mµ light. Other results obtained for both modes of excitation show that addition of a lead compound tends to increase the sensitivity of the scintillators to gamma-rays.