RECENT ACTIVITIES AT CELSIUS

The CELSIUS ring is used for nuclear and particle phys- ics experiments with stored ion beams interacting with thin internal targets. The target that has been used until now for physics is a cluster-jet target, producing beams of elements from hydrogen to xenon. An electron cooling system is used to accumulate beams that are only deliv- ered with a low intensity from the injector, the Gustaf Werner Cyclotron, and often also to cool the beams after acceleration to improve the conditions for the experi- ments. A target consisting of a stream of frozen hydrogen micro-spheres (pellets) has been installed, and first tests of the interaction between this target and stored and cooled proton beams have been done and are promising. 1 GENERAL