Speaker
Description
The Time of Propagation (TOP) detector is a novel particle identification system developed for the barrel region of the Belle II experiment at the SuperKEKB collider at KEK in Tsukuba, Japan. The detector is based on reconstructing the emission angle of Cherenkov photons generated in its quartz radiator bars by measuring the propagation time of individual photons to the Micro-Channel Plate PMT sensor plane. The readout electronics for the 8192 channels of the TOP system are built around a switched capacitor array waveform sampling ASIC operating at 2.7GSa/s. Acquired waveforms are processed in real time in the front end electronics, extracting the individual timing of detected photons to better than 100 ps.
After a commissioning run with first beam collisions starting in spring 2018, the final inner tracking system is now installed in the Belle II detector, and the physics programme and luminosity rampup is underway since March 2019.
This talk presents the current experiences and results from commissioning, calibration and operation of the Belle II TOP detector in the first Belle II physics runs up until now.
