International audienceOn-line ion sources at ISOL facilities normally produce only singly charged ions but efficient accelerators require high charge states. Therefore, for the post acceleration of radioactive ions, charge state breeding is being used or planned to use at most of these facilities. For ISAC at TRIUMF the acceptance of the accelerator requires a maximum A/q value of 30 and if further stripping should be avoided A/q<7. To investigate the charge state breeding process an ECRIS (14 GHz PHOENIX from Pantechnik) has been set-up on a test bench. Singly charged ions have been produced with several ion sources typical for the on-line operation and were injected into the charge breeder. The main purpose of the tests has been the optimization of the efficiency for the charge breeding into the desired charge state. The maximum efficiencies reached so far are up to about 6% for noble gas ions and about 3.5% for alkalines. As ion optics simulations show these values may be improved by further optimization of the injection of the singly charged ions into the ECR plasma. In order to meet the velocity acceptance of the accelerator at different A/q values a two gap acceleration system for the highly charged ions has been installed to allow the source to run at different voltages. As the radioactive ions are produced only in small quantities (single ions up to $10^{10}$ per second) background from ions of the support gas or from residual gas should be minimized. Therefore, clean helium gas has been chosen as a support gas. A good mass resolution is essential for the separation of the desired highly charged ions from background peaks. A combination of magnetic and electrostatic sector fields ensures this and separates scattered or charge exchanged ions from the beam. For the further beam transport to the accelerator cross sections for charge exchange of the highly charged ions with the residual gas have been determined. The results of the test measurements and the planning for the on-line installation will be presented
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