Comprehensive mass measurement study of Cf fission fragments with MRTOF-MS and detailed study of masses of neutron-rich Ce isotopes

MRTOF-MSを用いたCf核分裂片の包括的な質量測定研究と中性子過剰Ce同位体の質量の精密研究

木村 創大*; 伊藤 由太   ; 他8名*

Kimura, Sota*; Ito, Yuta; 8 of others*

We report the mass measurements of neutron-rich isotopes produced via spontaneous fission of Cf using a multireflection time-of-flight mass spectrograph. The mass of Ce is determined experimentally for the first time. A discrepancy between the experimental and literature values was found for the mass of Sb, which was previously deduced through indirect measurements. In comparison with several theoretical predictions, both the values and the trend of the mass excesses of Ce cannot be consistently explained. The wide-range and simultaneous mass measurements of the multireflection time-of-flight mass spectrograph enable us to crosscheck the existing mass data, and the conflict between the measured time-of-flight ratio and the extracted mass would imply the necessity of re-examining them.