Study of fast gases, resolutions and contaminants in the DØ muon system

Abstract Studies of the operating parameters of the DO muon chambers are reported. The choice of operating gas was such to find a nonexplosive gas with properties similar to those of argon-ethane. Faster gases were also studied. The resolutions of the chambers in two coordinates were determined. Finally, systematic effects due to variations in voltage, gas mix, O 2 contamination and H 2 O contamination were determined.