A miniature electron-beam ion source for in-trap creation of highly charged ions

Measurements of the anomalous magnetic moment of the electron bound in hydrogen-like ions with spinless nuclei have proven to be highly sensitive tests of corresponding calculations based on bound-state quantum electrodynamics. Currently, an experiment on hydrogen-like calcium Ca19+40 is being prepared, which is expected to yield a precision in the 10−9 level for the electronic g factor. This experiment makes use of an in-trap electron-beam ion source with which the charge breeding of the ions is performed by electron-impact ionization.