  Small-diameter muon drift tube (sMDT) chambers are a cost-effective
technology for high-precision muon tracking. The rate capability of the sMDT
chambers has been extensively tested at the Gamma Irradiation Facility at CERN
in view of expected rates at future high-energy hadron colliders. Results show
that it fulfills the requirements over most of the acceptance of muon
detectors. The optimization of the read-out electronics to further increase the
rate capability of the detectors is discussed. Chambers of this type are under
construction for upgrades of the muon spectrometer of the ATLAS detector at
high LHC luminosities. Design and construction procedures have been optimized
for mass production while providing a precision of better than 10 micrometers
in the sense wire positions and the mechanical stability required to cover
large areas.
