Presented are the main design features of the large Cathode Strip Chambers
(CSCs) for the CMS endcap muon system as well as the performance results ob
tained with the first large-scale prototype. The 3.4 x 1.2 m(2) six-plane p
rototype has been reliably operated over one year and the cosmic-ray tests
showed that it was capable of detecting muons with similar to 80 mu m spati
al and similar to 5 ns time resolutions. (C) 1998 Elsevier Science B.V. All
rights reserved.