The selective production of exotic species (SPES) project aims to construct at Legnaro National Laboratories (LNL) a new facility for the production of radioactive ion beams (RIBs) according to the isotope separation on line (ISOL) technique. In the specific case of the SPES facility, a multi-foil uranium carbide target is impinged by a 40 MeV, 200 µA proton beam generated by a cyclotron proton driver. In these conditions, a fission rate of approximately 10¹³ fissions per second is expected in the target. Then, the ²³⁸U fission fragments are delivered to the ion source: here they can be ionized and subsequently accelerated toward the experimental areas.

On 31 October 2023, the first stable ion beam was produced inside the SPES ISOL bunker. In particular, making use of a FEBIAD Ion Source, the INFN staff produced 400 nA (mainly N1+ and CO1+) @ 50 keV. The ISOL machine proved to be stable and reliable for the entire duration of the tests.

This is the first important step towards reaching the first radioactive beam. The consolidation of the ISOL machine with stable beams will continue during the next months.