6533b86ffe1ef96bd12ce5b2

RESEARCH PRODUCT

Direct high-precision mass measurements onAm241,243,Pu244, andCf249

subject

description

The absolute masses of four long-lived transuranium nuclides, $^{241,243}\mathrm{Am}$, $^{244}\mathrm{Pu}$, $^{244}\mathrm{Pu}$, and $^{249}\mathrm{Cf}$, in the vicinity of the deformed $N=152$ neutron shell closure have been measured directly with the Penning-trap mass spectrometer TRIGA-TRAP. Our measurements confirm the AME2012 mass values of $^{241,243}\mathrm{Am}$ and $^{244}\mathrm{Pu}$ within one standard deviation, which were indirectly determined, by decay spectroscopy studies. In the case of the $^{249}\mathrm{Cf}$ mass, a discrepancy of more than three standard deviations has been observed, affecting absolute masses even in the superheavy element region. The implementation of the mass values into the AME2012 network yields a reduced mass uncertainty for 84 nuclides, particularly for $^{244}\mathrm{Pu}$ and its strongly correlated $\ensuremath{\alpha}$ decay chains.