Isotope ratio analysis of individual plutonium and uranium-plutonium mixed oxide particles by thermal ionization mass spectrometry with a continuous heating method

Suzuki, Daisuke   ; Kokubu, Yoko   ; Lee, C. G.; Esaka, Fumitaka  ; Magara, Masaaki  ; Kimura, Takaumi 

In conventional isotope ratio analysis of individual plutonium particles, the analytical procedure is complicated, because the particles have to be dissolved prior to the measurement. The chemical treatments may cause contamination of U existing in the environment. This makes it difficult to obtain accurate Pu/Pu isotope ratio. In the present work, an analytical method by a combination of single particle transfer and thermal ionization mass spectrometry with a continuous heating method is examined for individual plutonium particles, namely the particles are measured without any chemical treatments. In addition, the technique is applied to the analysis of individual uranium-plutonium mixed oxide (MOX) particles. The results of analysis of individual particles produced from standard solutions indicate that all isotope ratios are consistent with the certified values. There is no effect of isobaric interference on the results. In conclusion, the proposed analytical method is a useful tool for the isotope ratio analysis of plutonium and MOX particles without any chemical treatments.