A new 14 GHz electron-cyclotron-resonance ion source (ECRIS) for the heavy ion accelerator facility ATLAS

A new 14 GHz ECRIS has been designed and built over the last two years. The source design incorporates the latest results from ECR developments to produce intense beams of highly charged ions. An improved magnetic electron confinement is achieved from a large mirror ratio and strong hexapole field. The aluminum plasma chamber and extraction electrode as well as a biased disk on axis at the microwave injection side donate additional electrons to the plasma, making use of the large secondary electron yield from Al/sub 2/O/sub 3/. The source will be capable of ECR plasma heating using two different frequencies simultaneously to increase the electron energy gain. To be able to deliver usable intensities of the heaviest ion beams the design will also allow axial access for metal evaporation ovens and solid material. The main design goal is to produce several e/spl mu/A of at least /sup 238/U/sup 34+/ in order to accelerate the beam to Coulomb-barrier energies without further stripping. First charge state distributions for /sup 16/O and /sup 40/Ar have been measured.