RECOMBINATION STUDIES OF HIGHLY-CHARGED IONS IN THE COOLER RING CRYRING

Cooler-storage ring facilities offer unique experimental possibilities for studies of electron-ion recombination processes at low relative e nergies by employing the electron cooler as a target. Through the use of an adiabatically expanded electron beam in the cooler of CRYRING, c ollisions down to 10(-4)eV relative energies were measured with highly charged ions stored in the ring at around 15MeV/amu energies. Example s of recombination measurements for C4+ and Ar15+ ions at an energy re solution of as low as 10(-2)eV FWHM are presented and compared with ca lculations of the energies and resonance strength for dielectronic rec ombination using multiconfiguration Breit-Pauli approximations. They a gree in spectral shape and absolute cross section but show some deviat ion for lower n in the Rydberg series.