Laser spectroscopy of hyperfine structure in highly charged ions: a test of QED at high fields

An overview is presented of laser spectroscopy experiments with cold, trapped, highly charged ions, which will be performed at the HITRAP facility at GSI in Darmstadt (Germany). These high-resolution measurements of ground-state hyperfine splittings will be three orders of magnitude more precise than previous measurements. Moreover, from a comparison of measurements of the hyperfine splittings in hydrogen-like and lithium-like ions of the same isotope, QED effects at high electromagnetic fields can be determined within a few percent. Several candidate ions suited for these laser spectroscopy studies are presented.PACS Nos.: 12.20.Fv, 21.10.Ky, 32.10.Fn, 32.30.–r