Wednesday 11 June 2008

Speaker: Antonis Papanestis   (Rutherford Appleton Laboratory, Particle Physics Department)

Title: The LHCb RICH detectors

Abstract: The success of the LHCb experiment depends heavily on particle identification over the momentum
range 2-100 GeV/c. To meet this challenge, LHCb uses a Ring Imaging Cherenkov (RICH)
system composed of two detectors with three radiators. RICH1 has both aerogel and gas (C4F10)
radiators, while RICH2 has only a gas (CF4) radiator. RICH-2 is already fully operational
in the LHCb experimental area, while the installation of RICH-1 is almost complete.
 
Novel Hybrid Photon Detectors (HPDs) have been developed in collaboration with industry to
detect the Cherenkov photons. A silicon pixel detector bump-bonded to a readout chip is
encapsulated in a vacuum tube with a bi-alkali photocathode. The HPDs are enclosed in iron
shielding and Mumetal cylinders surround the individual detectors to protect them from magnetic
fields within the external shielding of up to 50 mT. The mass production of a total of 484
HPDs required for the two RICH detectors has been a big success.
 
The latest news from the commissioning of the RICH detectors and the LHCb experiment will be
presented.