Resonance Ionization Laser Ion Source - Off-line tests at TRIUMF Original Research Article

Resonance ionization laser ion sources (RILIS) developed into the most powerful tool for radioactive ion beam production at on-line facilities, as they provide a selective ionization process with inherent suppression of unwanted isobaric contaminations at the ion source. While typical tunable laser systems for these applications are based on dye lasers, we developed an all solid state laser system which consists of three pulsed titanium:sapphire (ti:sa) lasers pumped by a single high repetition rate Nd:YAG laser. Each ti:sa laser provides up to 2.5 W average output power at 12 kHz repetition rate in the wavelength region of 700-950 nm with optional frequency doubling in BBO crystals. This laser system developed at the University of Mainz, was transferred to TRIUMF, Canada, to perform feasibility studies on stable isotopes at an off-line mass separator as preparation for the construction of a RILIS at the isotope separator and accelerator (ISAC). Additionally, the introduction of repelling potentials for decoupling of the hot ion source cavity from the laser ionization location was tested and resulted in a further decrease of surface ions and therefore isobaric contaminations in the ion beam.