m and the best resolution of 110 m is for the 5.5 mm chevron with the
Ar-isobutane mixture. It appears to be rather straightforward to achieve the
resolution requirements imposed on the muon tracking chambers and still
maintain an economical readout system. If the readout is placed at 1 cm
intervals we expect to obtain 100 m resolution.We believe that three high resolution cathodes per station is sufficient to adequately determine the muon bend coordinate with adequate redundancy to insure high tracking efficiency. A minimal system would include two high resolution cathodes. The radial coordinate can be obtained from reading out the anode or the second cathode or both in a hit/nohit fashion at 1- or 2-cm intervals. Two planes with a coarse hit/nohit readout are necessary to determine the radial coordinate with adequate redundancy for good efficiency. For a 1-cm read out scheme and three planes we estimate that 15,000 high resolution channels are needed. For the hit/nohit anode or cathode and two planes per station, 10,000 channels are required at 1-cm read out and 5000 at 2-cm read out. The best solution would be to read out each plane, a high resolution cathode, a hit/nohit anode, and a stereo hit/nohit cathode. These three measurements would uniquely determine the space point on each plane and aid in track reconstruction when high occupancy leads to many potential ghost points. Our simulations (see separate report) have used three high resolution cathodes and three hit/nohit cathodes at 1-cm spacing. Other configurations are being simulated.
Figure 4.1.1: Measured resolutions for different gas mixtures and cathode configurations: (a) floating 5.5 mm strips with Ar-C_4H_10, (b) floating 5.5 mm strips with CF_4-C_4H_10, (c) 11 mm chevrons with CF_4-C_4H_10, and (d) floating 11 mm chevrons with CF_4-C_4H_10.