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

CEDAR

CEDAR: existing Cherenkov counter at CERN

• Adapted to NA62 need : H2 instead of Nitrogen & New photo detector and electronics
• Vary gas pressure and diaphragm aperture to select Kaons

Kaon rate = 50 MHz and ~100 photons per Kaon on 8 spots of 10x30 mm² each

photon rate = ~ 2 MHz / mm² (rate of singles from accidentals, after-pulses, dark noise not included)

Key points for the new detector

• Single photon counting application
• Stand very high photon rate / unit area (occupancy in time and space)
• Reduced active area (beam activity)(minimum ~150 mm² / spot due to optics phase space)
• UV/Blue light sensitivity with the highest efficiency (PDE)
• Excellent timing resolution (100 ps)
• Exposition to the halo of intense hadron beam (radiation damage)