The background and¹⁴C detection efficiency of a liquid scintillation counter

Abstract

Experiments with scintillation counters using p-terphenyl in benzene are described. By the use of a combination of steel screening, coincidence counting and pulse height selection the total background is reduced to 30 c.p.m. at room temperature for a counting volume of 20 ml. The 14C detection efficiency under these conditions is approximately 40%. Light interaction between the photomultipliers used is almost eliminated by the use of a suitable filter.