A RICH detector for the CLAS 12GeV Upgrade
Matthias Hoek (KPH Mainz)

The CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLAB) is preparing for a major upgrade of its detector systems by 2014 as part of the accelerator upgrade to deliver electron beams of up to 12GeV, twice the current limit of 6GeV.
The physics program of the upgraded CLAS detector focuses on the investigation of the nucleon structure using semi-inclusive and exclusive deep inelastic reactions.
A good particle identification system is necessary to allow flavour-tagging of the struck quarks, especially in semi-inclusive deep inelastic reactions. Enhanced Pion/kaon separation in the momentum range above 2GeV/c enhances the capabilities of CLAS to deliver outstanding results in the measurement of nucleon structure functions.
The proposed Ring-Imaging Cherenkov detector uses a proximity-imaging configuration with an Aerogel radiator. Mirror optics will reduce the required photon-detection area, which will be instrumented with Multi-Anode PMTs. Currently, detailed Monte-Carlo performance studies and component tests are carried out. The results of these performance studies and component tests as well as preliminary results of a large-scale prototype test experiment at CERN this year will be presented.