Operations with internal targets and electron cooling at CELSIUS

CELSIUS is a storage ring for intermediate energy nuclear and particle physics with light and heavy ions from the Gustaf Werner cyclotron in Uppsala, Sweden. The ring features extremely thin internal targets and an electron cooling system. The internal target which has been used so far for physics is a cluster-jet target. It has been operated with target beams of hydrogen, deuterium, nitrogen, and argon. An advanced target facility using frozen hydrogen micro-spheres of about 20 μm diameter is under development. Carbon fibres with 7 μm diameter have also been tested as targets. They do, however, give beam lifetimes which are too short to be useful in the physics experiments. Much thinner carbon fibres will be tried in the near future. (author) 14 refs.; 5 figs.; 1 tab