Electron shakeoff following the β+ decay of +19Ne and +35Ar trapped ions

The electron shakeoff of ¹⁹F and ³⁵Cl atoms resulting from the β⁺ decay of ⁺¹⁹Ne and ⁺³⁵Ar ions has been investigated using a Paul trap coupled to a time of flight recoil-ion spectrometer. The charge-state distributions of the recoiling daughter nuclei were compared to theoretical calculations based on the sudden approximation and accounting for subsequent Auger processes. The excellent agreement obtained for ³⁵Cl is not reproduced in ¹⁹F. The shortcoming is attributed to the inaccuracy of the independent particle model employed to calculate the primary shakeoff probabilities in systems with rather low atomic numbers. This calls for more elaborate calculations, including explicitly the electron-electron correlations.