Contribution to the completion of the forward Muon RPC detection system for the CMS experiment at the LHC collider at CERN.

The Compact Muon Solenoid experiment has put emphasis on the detection and identification of muons;the only penetrating charged particle we know. At the LHC, the bunch crossing frequency will be 40 MHz,which, at the nominal luminosity of 10^34 cm-2s-1, leads to 800 million proton-proton collisions per second. Every25 nsec some 1000 particles emerge from the interaction point into the CMS spectrometer. In less than 3 microsec afirst level trigger has to reduce this rate to 100 kHz without losing potentially interesting collisions requiringfurther analysis. This task, without which research at the LHC would be impossible, relies heavily on the muondetection system.The construction of the forward muon RPC system for the CMS phase 1 detector is completed andconsists of 432 chambers. All gas gaps have been produced and tested in Seoul where a gas gap productionfacility has been set up for this project. It is an alternative to the Italian company GT that up to then had theworld monopoly for RPC gas gap production and delivered gaps to L3, Babar, ATLAS and the CMS barrel.Station 1 (144 RPC's) has been produced and tested at CERN with the help of Chinese manpower. Stations 2and 3 (288 RPC's) are assembled in Islamabad and retested at CERN. For the final testing of endcap RPC's, alarge area cosmic hodoscope has been built at CERN in which 10 chambers can be tested together. Thisinfrastructure will remain operational until completion of the entire system. Today all432 RPC detectors of the initial system have been installed on the endcap yokes. The completion of the forward RPC system for CMS phase 2 will require 288 extra chambers for the|eta|<1.6 region and 180 RPC's for the region 1.6

Keywords:HIGH ENERGY INTERACTIONS, LARGE HADRON COLLIDER (LHC), HIGH ENERGY PHYSICS

Disciplines:Elementary particle and high energy physics

Project type:Collaboration project