A dish for determining tritium content with liquid radiometer

The results of experimental studies on selecting material and optimum geometrical dimensions of a measuring dish of a high-sensitivity liquid radiometer designed for mass analysis of tritium in the form of tritiated water in environmental aquatic objects at the 104 Bq/m3 level are presented. The experiments are carried out in the detection unit using the FEhU-118 photomultiplier with semitransparent antimony-potassium-sodium-cesium photocathodes characterized by light sensitivity of (1-2)x10-4 A/lm and measurement stability. It is shown that a dish made of polytetrafluorethylene with wall thickness of 0.8-1.0 mm and useful capacity of 45 cm3 (5 cm3 of tritiated water and 40 cm3 of liquid scintillator ZhS-8I) is chosen as an optimum one