Design and performance of the PHENIX muon tracking systems

The PHENIX muon spectrometers at RHIC incorporates cathode strip chambers (CSC) as the tracking detectors. The design requirements for the spectrometers was such that the mass resolution for the vector mesons would allow for a clear separation of the individual states. This lead to the requirement that the CSC´s have a resolution of 100 μm and the intermediate detector station have a radiation length less than 0.1% The octant shaped chambers were constructed of a honeycomb panel structure for the first and last station and the middle station used etched 25 μm metallized mylar foils held under tension by thick aluminum frames. The largest chambers, 3.5 m × 3.5 m, are at station 3. Both spectrometers have now been fully instrumented and data taking has been very successful. We have shown that the chambers have met design requirements. A description of the design and performance of the chambers for both cosmic rays and real data is given.