Contribution Contributed Oral
Aerogel RICH counter for the Belle II forward PID
The Belle II spectrometer, a follow up of the very successful Belle experiment, is in the last stages of construction at the SuperKEKB electron-positron collider at KEK in Japan. For the PID system in the forward region of the spectrometer, a proximity focusing RICH counter with aerogel radiator (ARICH) will be employed. The detector will provide a 4σ separation of pions and kaons up to momenta of 3.5 GeV/c, at the kinematic limits of the experiment. ARICH consists of ring-shaped radiator and photon-detector planes, separated by ~20 cm of expansion volume and covering an area of ~3m$^2$. The radiator plane is covered by aerogel tiles and the detector plane is formed by an arrangement of 420 Hybrid Avalanche Photo-Detector (HAPD) modules. HAPD provides high efficiency single photon detection in the high magnetic field of the spectrometer (1.5 T) and withstands high radiation levels expected at the experiment.
The production and quality assurance tests of all detector components were finished in 2016, and their installation into ARICH is largely completed. One sector of fully equipped ARICH is being used for the detector cosmic test. In the talk we will report on the ARICH design, current construction status and recent results from the cosmic test and detector simulation studies.