The ALICE fast interaction trigger performance and upgrade

The ALICE setup for LHC Run 3 aims to collect all minimum bias data at the targeted 1[Formula: see text]MHz interaction rate for protons and 50[Formula: see text]kHz for heavy-ion collisions. The projected maximum ALICE data rate will be [Formula: see text]3[Formula: see text]TB/s, two orders of magnitude higher than in Run 1 and Run 2. ALICE detectors, front-end readout electronics and data processing systems were upgraded to meet these challenges. One of the upgrades is the Fast Interaction Trigger (FIT). The custom-designed front-end electronics (FEE) process the detectors’ signals in [Formula: see text]200[Formula: see text]ns. The three main detectors of FIT are FT0, FV0 and FDD. These detectors provide trigger generation, luminosity monitoring, online vertex determination, collision time measurement, multiplicity detection, event plane and centrality determination and diffractive event measurements. This contribution will present an overview of the FIT and its performance based on the p–p and Pb–Pb collisions collected in 2022 and 2023, respectively. The FIT FEE upgrade, planned for the LHC Run 4, will also be discussed.