Cavity loops Influence on the single-bunch Instability thresholds of the CERN PS Booster

The CERN Proton Synchrotron Booster (PSB) delivers a wide variety of high-intensity and high-brightness proton beams to several destinations, including operations at the Large Hadron Collider (LHC) and various fixed-target experiments. Following the Long Shutdown 2 (LS2) upgrades, discrepancies between beam measurements and macro-particle simulations were observed, highlighting the need for a deeper understanding of the longitudinal impedance and related effects in the PSB. To address this, longitudinal single-bunch instability studies have been conducted to evaluate the impedance model through the intensity and energy thresholds across different radio-frequency configurations. This contribution presents experimental results that explore instability mechanisms and the effect of the beam loading compensation feedback system. These results are used to benchmark a new cavity loop simulation, which enables more detailed studies of the accelerator impedance.