Key points are not available for this paper at this time.
The Time-Of-Propagation (TOP) counter is a ring-imaging Cherenkov detector designed to identify the charged hadrons in the barrel region of the Belle II detector. The Belle II experiment collected data delivered by the SuperKEKB accelerator from March 2019 to June 2022. After the first run period (Run1), a long shutdown (LS1) was dedicated to implement several accelerator and detector upgrades. The second collision period (Run2) was started in January 2024. The components of the TOP detector and the performance during the Run1 will be reported and the detector upgrade during LS1 and future upgrades will be described.
E. Torassa (Fri,) studied this question.