A Study of the Scintillation Properties of Various Hydrogenous and Non-Hydrogenous Solutes Dissolved in Hexafluorobenzene

To enhance the gamma-ray sensitivity relative to that of fast neutrons, haxafluorobenzene (C6F6), was substituted for the primary solvent in a standard hydrogenous scintillator solution. The solutes used included p-terphenyl, α-NPO, PPO, POPOP, DM-POPOP and decafluorobiphenyl. Optical absorption and emission spectra were measured. The sensitivity relative to NE-211 was determined for Co60 radiation, 14 MeV neutrons and 2.6 MeV neutrons as a function of solute concentration ranging between 0.03 g/liter and 3.0 g/liter. Sensitivity measurements were carried out by measuring the total integrated light output from the scintillators. For all samples studied, the relative sensitivity to Co60 gamma radiation was greater than that for fast neutrons by factors ranging between 5 and 15.