CERN - European Organization for Nuclear Research - Physics Department - NA62

RICH

The RICH detector is required to improve the rejection of background from K+->μ+v decays providing positive identification of the Muon in the background events  and  an identification of the Pion in the signal events.

The RICH Detector is:

  • Separating π+ from μ+ between 15 and 35 GeV/c  momentum providing a muon suppression factor of at least  10-2
  • Measuring the pion crossing time with a resolution of about 100 ps;
  • Producing the L0 trigger for a charged track.

The RICH is situated between the last Straw Station (210m from the target) and the last Large Angle Veto station.   It consists of a cylindrical vessel (Length ~18m,  Ø=3.2 – 3.8m ) with the beam pipe passing in its center. The vessel is filled with Neon (1 atm), at the downstream end a mosaic hexagonal mirrors focuses  the Cherenkov light onto 2x1000 photo detectors situated at the upstream end of the vessel.