Beam test of FARICH prototype with digital photon counter

• DOI: 10.1016/j.nima.2013.07.068
• Publication Date: 2013-07-26T15:40:44Z
• Authors: A.Yu. Barnyakov; M.Yu. Barnyakov; V.S. Bobrovnikov; A.R. Buzykaev; A.F. Danilyuk; C. Degenhardt; R. Dorscheid; D.A. Finogeev; T. Frach; V.V. Gulevich; T.L. Karavicheva; S.A. Kononov; E.A. Kravchenko; A.B. Kurepin; I.A. Kuyanov; O. Muelhens; A.P. Onuchin; I.V. Ovtin; V.I. Razin; A.I. Reshetin; R. Schulze; A.A. Talyshev; E.A. Usenko; B. Zwaans
• Keywords: Momentum (technical analysis); Particle identification; Radiator (engine cooling); Cherenkov detector

Abstract In June 2012 we tested a Focusing Aerogel RICH detector prototype based on Digital Photon Counters (DPC) by Philips at the CERN PS T10 beam line with a particle momentum up to 6 GeV/c. The prototype comprises a 20×20 cm2 photon detector with 48×48 DPC pixels. In order to reduce the dark count rate, the photon detector was cooled to −40 °C in addition to disabling individual DPC's microcells. A four layer focusing aerogel radiator with 200 mm focal distance was studied. We obtained a Cherenkov angle resolution of 3.61±0.04 mrad. The mean number of photoelectrons in a ring is 12. Directly measured π / K separation at 6 GeV/c momentum is 3.5 σ , μ / π separation is 5.3 σ at 1 GeV/c. A comparison with a Monte Carlo simulation is presented as well.