The ILIAS-project at the University of Vienna was initiated in 2010 to explore isobar suppression by selective laser photodetachment for AMS applications. A gas-filled radio frequency quadrupole (RFQ) is used to decelerate and cool negative atomic and molecular ion beams from a cesium sputter source and extend the ion-laser interaction time, thereby substantially increasing the efficiency of photodetachment and isobar suppression. Following successful development and characterization at a purpose-built test bench, the RFQ cooler is currently moved to a new injector beamline at VERA for first applications of this novel technique at a state-of-the-art AMS facility.
This talk will give an overview of the project, with highlights on the experimental results including the suppression of a 63Cu− test beam by more than 99.999% with a 532nm laser, optical filtering of MgO− and AlO− beams, and comprehensive measurements of the ion residence time inside the RFQ cooler.