Bunched laser cooling of a stored weak Li-7(+) ion beam in a pure triplet state

A preparation scheme for a Li-7(+) ion beam in a storage ring is presented which provides ions in the metastable triplet states with well controlled l ongitudinal phase space properties. For both state selective preparation an d beam cooling, laser- and electron-cooler forces are applied. The spatial- and momentum distributions of the ions are directly detected by a time res olved measurement of the fluorescence light. At low beam intensities, the r emaining heating rate of such a beam is completely determined by residual g as scattering.