LASER-STIMULATED 2-STEP RECOMBINATION OF HIGHLY-CHARGED IONS AND ELECTRONS IN A STORAGE-RING

Two-step resonant laser-stimulated recombination of highly charged ion s was performed for the first time. Nd:YAG laser pulses overlapped wit h an Ar18+ beam in the electron cooler of the ESR storage ring at GSI induced transitions from the continuum to the n = 81 state of hydrogen like Ar17+. To avoid reionization in the bending magnet before reachin g the detector, the n = 81 population was transferred to a state well below the reionization threshold by a Ti:sapphire laser. Tuning of thi s laser yielded the n = 81 to 36 and 37 transition-line profiles. The two-step method provides access to detailed Rydberg spectroscopy in an electron beam environment.