Determination of 135Cs by accelerator mass spectrometry

Abstract The ratio of anthropogenic 135 Cs and 137 Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying 135 Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn 2 , and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10 −3 and 1.7 × 10 −7 respectively. This quantification of 135 Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.