Speaker
Description
The electron affinity (EA) is the energy released when an additional electron is bound to a neutral atom, creating a negative ion. Due to a lack of long-range Coulomb attraction, the EA is dominated by electron-electron interactions, making negative ions excellent systems to probe these effects. A particular example is the determination of the specific mass shift, which is of importance when extracting nuclear charge radii from laser-spectroscopy experiments. However, only very few isotope shifts of the EA have been measured to date.
Berzinsh et al. [1] investigated the isotope shift of the EA of the two stable chlorine isotopes, 35Cl and 37Cl both experimentally and theoretically. A discrepancy in their experimental and theoretical results was then solved by Carette and Goodefroid in 2013, increasing the precision of their calculations beyond the uncertainty of the experimental value.
Consequently, a study of the isotope shift of a large mass range of chlorine isotopes was proposed at the radioactive ion beam facility CERN-ISOLDE and performed in 2024 using the GANDALPH spectrometer [3], which was successfully used to determine EAs of radioisotopes previously [3,4].
Here, we will present the results of this measurement campaign and give an outlook on future experiments using the charge exchange process to produce negative ions.
References:
[1] Berzinsh et al. Phys. Rev. A 51, (1995) 231
[2] Carette and Godefroid, J. Phys. B 46 (2013)
[3] Rothe et al., J. Phys. G (2017)
[4] D. Leimbach et al. Nat. Comm 11, 3824 (2020)
