Radioactive Ion Beam Production by Fast-Neutron-Induced Fission in Actinide Targets at EURISOL

In EURISOL, the production of high-intensity RIBs of specific neutron-rich isotopes is obtained by inducing fission in large-mass actinide targets. In our contribution, the use of Uranium
targets is shown to be advantageous to other materials, such as Thorium. Therefore, in order to produce fissions in 238U and reduce the Plutonium inventory, a fast neutron energy spectrum is necessary. The large beam power required to achieve these RIB levels requires the use of a liquid proton-to-neutron converter. This article details the design parameters of the converter, with special attention to the coupled neutronics of the liquid converter and fission target. Calculations performed with the Monte Carlo code FLUKA, suggest the use of a 1 - 2 GeV proton beam and a compact Mercury converter, surrounded by the fission target for efficient use of the spallation neutrons.