Upgraded muon detection system for UA1 based on limited streamer tubes

Abstract We describe the construction and performance of the improved muon detection system of the UA1 experiment. The new position detectors, that complement the original muon detection system based on large planar drift chambers, are limited-streamer chambers for a total surface of 800 m 2 . The coordinate parallel to the wires is readout through the especially developed STAR electronics that integrates and digitizes the signal from the strips. The intrinsic spatial resolution, determined in a test beam, is 400 μm, that achieved so far in the real system is 1.2 mm. The efficiency is evaluated to be (94.9±0.6)%.