Vacuum ultraviolet scintillators: sodium salicylate and p-terphenyl

Abstract

Some of the characteristic properties of sodium salicylate and p-terphenyl have been studied at a convenient incident wavelength of 253.7 nm. These include the fluorescent spectrum, relative quantum efficiency as a function of scintillator thickness, absolute quantum efficiency, and its possible decline with time. It has been shown that the rotary pump and diffusion pump oil vapors in contact with phosphors affect the stability of fluorescence in a marked but complicated manner. The effect of humidity on relative fluorescent quantum efficiency of the phosphors has also been discussed. p-Terphenyl has been found to be a useful alternative to sodium salicylate.