Laser Ionization and Penning Trap Mass Spectrometry – A Fruitful Combination for Isomer Separation and High-precision Mass Measurements

Abstract

We have demonstrated for the first time that element-selective laser ionization in combination with ultra-high resolution mass spectrometry can be used to prepare isomerically pure ion ensembles. Together with β–γ coincidence studies this method allowed a determination of the low-energy structure and the unambiguous identification of triple β-decaying isomerism in 70Cu. By selective resonant ionization and measurement of the masses of these three states using ISOLTRAP at ISOLDE/CERN with a relative uncertainty of δm/m ≈ 5 ⋅ 10−8 a clear state-to-mass assignment was possible which resolved the assignment puzzle in 70Cu.