Measurement of cesium isotopic ratio by thermal ionization mass spectrometry for neutron capture reaction studies on 135Cs

The measurements of Cs isotopic ratios by TIMS were performed for the sample analysis used to evaluation of the nuclear data of Cs-135. To obtain a high intensity and stable ion beam, the effects of additive agents on the ionization of Cs were examined. The effect of silicotungstic acid on the ionization of Cs was the largest among the additive agents discussed in this study, while this also showed the largest isobaric interference of polyatomic ions. After examining of the analytical conditions, such as the interference effect due to Ba, the sample analysis of two radioactive Cs samples were conducted.