Static exp 3 He/ exp 4 He Gas Mass Spectrometer for Low Level Tritium Concentration Measurements

摘要

A dual collector static gas mass spectrometer designed specifically for measurement of helium-3 and helium-4 was constructed. This instrument will provide a very sensitive means of measuring tritium concentrations from environmental samples by determining the concentration of helium-3, the decay product of tritium. The tritium sample is collected in or converted to an aqueous form, degassed, and stored in a sealed container for at least two weeks to allow helium-3 to accumulate. The sensitivity is a function of the helium-3 accumulation wait time. For samples stored for one month, the predicted sample sensitivity based on the measured source sensitivity is 0.02 pCi/g (tritium in water) for a 3-gram sample. (ERA citation 06:017326)