000001697 001__ 1697
000001697 005__ 20190926085548.0
000001697 037__ $$aBELLE2-TALK-CONF-2019-130
000001697 041__ $$aeng
000001697 100__ $$aMartin Bessner
000001697 245__ $$aPerformance of the Belle II imaging Time-Of-Propagation (iTOP) detector in first collisions
000001697 260__ $$aVCI2019$$c2019-02-22
000001697 300__ $$a21
000001697 500__ $$a20 minutes
000001697 520__ $$aThe iTOP detector is a novel Cherenkov detector developed for particle identification at Belle II, an upgrade of the previous Belle experiment at KEK. The SuperKEKB accelerator, an upgrade of KEKB, collides electrons and positrons with a design luminosity of 8*10^(35)/(cm^2 s). In order to exploit the high collision rate Belle II has a trigger rate of up to 30 kHz. The iTOP detector uses quartz bars as source of Cherenkov photons. The photons are reflected inside the bars until they hit photomultipliers at one end. The spatial distribution and precise arrival times of the detected photons are used to reconstruct the Cherenkov angle. To achieve a good pion-kaon separation the photon arrival times have to be measured with a resolution better than 100 ps. Microchannel plate photomultipliers together with dedicated high-speed electronics for 2.7 GSa/s waveform sampling are used to achieve this timing resolution. The iTOP detector consists of 16 modules with 512 channels each, in total the detector has 8192 channels. First collisions were recorded in Spring 2018. A phase of physics operation with a ramp up to full luminosity starts March 2019. In this talk the design of the iTOP detector will be shown and experience and results from initial operation will be discussed together with an outlook on future running conditions.
000001697 6531_ $$aTOP
000001697 8560_ $$fmartin.bessner@desy.de
000001697 8564_ $$uhttps://docs.belle2.org/record/1697/files/BELLE2-TALK-CONF-2019-130.pdf