Mass measurements and ion-manipulation techniques applied to the heaviest elements

Abstract

High-precision mass measurements of radionuclides with state-of-the-art mass spectrometry allows us to obtain accurate binding energies. These reflect changes in the nuclear structure. Two-nucleon separation energies, for example, are sensitive indicators of shell closures and the onset of deformation. In addition, masses provide a benchmark for theoretical nuclear models and support their improvement with respect to a better predictive power. In the region of the heaviest elements this enables mapping the strength of shell effects and their extension as recently demonstrated for N = 152. Accurate masses can furthermore provide anchor points to fix decay chains in the mass surface. Moreover, advanced ion-manipulation techniques developed in the context of mass spectrometry pave the way for novel types of experiments such as trap-assisted decay spectroscopy of nuclear state-selected samples. This opens new perspectives for a mass number assignment of decay chains originating from yet unknown superheavy nuclides.