Design of a two-ion-source (2-IS) beam transport line for the production of multi charged radioactive ion beams

A “two-ion-source” beam transport line between a surface ionization source and a 6.4 GHz on-line Electron Cyclotron Resonance Ion Source (ECRIS) for the production of multi-charged radioactive ions has been designed. The 1+ ions from the surface ionization source are decelerated and focused onto the ECRIS plasma so that they can be efficiently trapped there and further ionized to charge state q>1+. A scheme for stepwise and gradual deceleration of the 1+ ion beam consisting of a multi-electrode decelerator and a tuning electrode placed before the ECRIS has been optimized. The beam dynamics calculations show that the 1+ beam decelerated to energies of 20–50 eV could be focused to a spot size smaller than the radial dimensions of the ECR plasma zone.