SIMULATION OF ION-BEAM EXTRACTION FROM AN ECR SOURCE

The extraction of ion beams from ECR ion sources is investigated. It i s shown that for high magnetic fields within the extraction region, as in the CAPRICE-type ECR, all different charge states have to be simul ated simultaneously to achieve the correct space charge distribution o f the extracted ion beam. The change of the longitudinal velocity dist ribution for different charge states is taken into account. Beam emitt ance measurements made 280 mm behind the extraction system will be com pared with the results of the simulation. Two possible extraction syst ems which should have influence on the beam characteristics are invest igated.