Cathode strip chambers (CSC) are used in the endcap disks where the magnetic field is uneven and particle rates are higher than in the barrel.
CSCs consist of arrays of positively-charged anode wires crossed with negatively-charged copper cathode strips within a gas volume. When muons pass through, they knock electrons off the gas atoms, which flock to the anode wires creating an avalanche of electrons. Positive ions move away from the wire and towards the copper cathode, also inducing a charge pulse in the strips, at right angles to the wire direction.
Because the strips and the wires are perpendicular, we get two position coordinates for each passing particle.
In addition to providing precise spatial and timing information, the closely spaced wires make the CSCs fast detectors suitable for triggering. Each CSC module contains six layers making it able to accurately identify muons and match their tracks to those in the tracker.
Visit the link for CSC updates: https://cms.cern/tags/csc