The Balmer spectrum of H-like uranium produced by radiative recombination at low velocities

For radiative recombination occurring during electron cooling of highly charged ions the associated Balmer spectrum has been observed for the first time. The experiment has been performed for bare uranium ions at the ESR storage ring at GSI, Darmstadt. Also the recombination into the L-shell sublevels j=1/2 and 3/2 could be observed. The spectrum is compared to a cascade simulation taking into account capture into high-Rydberg states.