LSC background prediction using three-dimensional modelling

A general 3-D surface B(Q, V) is proposed to describe, in liquid scintillation counting, the dependence of the background count rate B, on both the quenching level and the volume of sample, which avoids the need for preparing and measuring blank vials for each problem sample. The analytical function has four parameters which have been determined for Optiphase-Hisafe II® scintillator volumes between 2 and 20 mL and sample quench ranging from 25–50% 3H-equivalent efficiency. It has been successfully tested with 3H standard samples of activity down to 0.24 Bq, with significant background corrections, between 30 and 95% of the raw count rate.