Rare isotope beam tuning in FRIB

The Facility for Rare Isotope Beams (FRIB) provides rare-isotope beams for user experiments in nuclear physics, nuclear astrophysics, fundamental symmetries, etc. A superconducting driver-linac accelerates heavy-ion beams onto the production target, and the Advanced Rare Isotope Separator (ARIS) collects and purifies the rare isotope fragments of interest. Subsequently, the transfer hall beamlines deliver isotopes to user setups at experiment stations. The isotope beam condition from ARIS strongly depends on the fragment of interest. Therefore, the beamline settings are optimized for each experiment based on various users’ requirements on the fly. Two new beamlines in the transfer hall were commissioned in 2025, bringing the total number of available end stations to five. Since the first user experiments in 2022, ongoing beam tests and operations have continued to improve operational efficiency and user satisfaction. Results and findings of beam tuning obtained from the commissioning and recent operations will be reported.