CMS is one of the two major experiments (CMS and ATLAS) being built for Large Hadron Collider and to become operational in 2006.  Detection of muons will be crucial for discovering new physics phenomena at LHC, and both experiments have muon systems as the focus of their designs.  Muons will play a key role in unveiling Higgs and Supersymmetry, in many exotic physics searches, as well as in studying bottom-quark and top-quark physics. 

     Reliable and precise detection of high rapidity muons, a notoriously difficult task at hadron colliders, will become of great importance as never before.  High efficiency reconstruction of Higgs particle decay products is impossible without excellent muon system coverage at large rapidities, provided by the Endcap Muon System.

     The CMS Endcap Muon System consists of 540 six-plane muon detectors and about 400,000 electronic readout channels. Muon detectors, or Cathode Strip Chambers, are as large as 3.4 x 1.5 m² in size, cover about 6000 m², and have about 2,000,000  50 mm anode wires.  The physics objectives result in a set of challenging requirements on performance of the system, e.g.:

• muons are to be reconstructed with precision of ~100 mm (compare to the overall size of the system);
• at the trigger level, i.e. within first ~300 ns, muon's are to be detected with ~1 mm uncertainty in space and ~4 ns time resolution;
• background rates may be as high as 1000 Hz/cm²