Development of the RF-IGISOL at CYRIC

An rf ion guide for mass separation of fission fragments has been developed as a new type of the ion-source of an ion guide isotope separator on-line (IGISOL). Fission fragments from an uranium target are thermalized in a large helium gas cell and extracted by a combination of dc and inhomogeneous rf electric fields. They are subsequently mass separated by an electromagnetic mass separator. Test experiments with a radioactive α-source and with fission fragments produced in the proton-induced fission of 238U reveal that the yields of mass-separated radioactive ion beams are enhanced, due to the dc and rf electric fields in the gas cell.