Long term experience and performance of COMPASS RICH-1

F Tessarotto , P Abbon (1) , M Alexeev , R Birsa , P Bordalo , F Bradamante , A Bressan , M Büchele , M Chiosso , P Ciliberti , T Dafni (2) , S Dalla Torre , S Dasgupta , E Delagnes (1) , O Denisov , V Duic , Andrea Ferrero (2) , M Finger , M Finger Jr M Finger Jr , H Fischer , C Franco , S Gerassimov , B Gobbo , M Gregori , F Herrmann (3) , B Ketzer , K Königsmann , I Konorov , F Kunne (2) , S Levorato , A Maggiora , N Makke (2) , Arnaud Martin , G Menon , D Neyret (2) , K Novakova , D Panzieri , S Paul , F A Pereira , J Polak , E Rocco , C A Santos , G Sbrizzai , P Schiavon , S Schopferer , M Slunecka , F Sozzi , L Steiger , M Sulc , S Takekawa

1 DEDIP - Département d'Electronique, des Détecteurs et d'Informatique pour la Physique (ex SEDI)
2 DPHN - Département de Physique Nucléaire (ex SPhN)
3 Physikalisches Institut [Freiburg]

COMPASS RICH-1 is a large size gaseous Imaging Cherenkov Detector providing hadron identification in the range from 3 to 55 GeV/c, in the wide acceptance spectrometer of the COMPASS Experiment at CERN SPS. It uses a 3m long C4F10 radiator, a 21m2 large VUV mirror surface and two kinds of photon detectors: MAPMTs and MWPCs with CsI photocathodes, covering a total of 5.5m2. It is in operation since 2002 and its performance increased thanks to progressive optimization and to a major upgrade of its photon detection system, implemented in 2006; a new upgrade is foreseen for 2016, with the use of MPGD-based photon detectors. The main characteristics of COMPASS RICH-1 components are described and the most critical aspects related to the C4F10 radiator gas system, to the mirrors and their alignment, as well as the performance of the photon detectors are presented and discussed. The response of the MWPCs and the observed evolution of the effective quantum efficiency of the CsI photocathodes is analyzed. The properties and performance of the MAPMTs with individual fused lens telescopes are presented together with the readout characteristics. The PID performance of COMPASS RICH-1 is discussed and the future upgrade program is mentioned.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

F Tessarotto, P Abbon, M Alexeev, R Birsa, P Bordalo, et al.. Long term experience and performance of COMPASS RICH-1. INTERNATIONAL CONFERENCE ON INSTRUMENTATION FOR COLLIDING BEAM PHYSICS, Feb 2014, NOVOSIBIRSK, Russia. pp.C09011, ⟨10.1088/1748-0221/9/09/C09011⟩. ⟨hal-01132971⟩