The new isotope Cm and new data on Cm and Cf.

The isotopes Cf were produced in irradiations of Pb targets with S ions. At bombarding energies close to the Coulomb barrier two or three neutrons were evaporated from the compound nuclei Cf . Cross-sections were on the order of a few hundred nanobarns. For the isotope Cf a spontaneous fission branching of 0.015±0.002 was determined. The new isotope Cm was produced by $ \alpha$ decay of Cf and identified by $ \alpha$ - $ \alpha$ correlations. It decays with an $ \alpha$ -decay energy of (6954± 20)keV and a half-life of (410±50 s. For the first time, the $ \alpha$ decay of Cf was observed having an energy of (8081±20 keV. For the isotope Cm a half-life of ( 23 s was measured for first time. Spontaneous fission of Cf was confirmed and mass-excess values of the nuclei Cm and Cf were determined. [ABSTRACT FROM AUTHOR]