A new application technique of a position-sensitive liquid light guide Cerenkov counter for the simultaneous position detection of 90Sr/90Y and 137Cs radioactivity

A new application of a position-sensitive liquid light guide Cerenkov counter for the simultaneous position detection of 90Sr/90Y and 137Cs radioactivity in a gamma-ray-dominant environment is proposed. β-emitting 90Sr/90Y and γ-emitting 137Cs radioactive point sources were measured using a position-sensitive liquid light guide based on the time-of-flight (TOF) method. We found a clear difference in the count rate ratio between the source position peak and reflection peak of the position histogram. Moreover, simultaneous measurements of the radioactive point sources were performed. The results suggest that the source position and activity of 90Sr/90Y and 137Cs can be simultaneously determined based on the count rate ratio of the source position peak and the reflection peak.