The construction and the quality assurance–quality control of the 112 MDT-Barrel Inner Small precision chambers of the ATLAS Muon Spectrometer

The construction of the 112 BIS monitored drift-tube chambers (MDT) for the ATLAS muon spectrometer is described, with emphasis on the quality assurance–quality control procedures. The required mechanical precision of 20 μ m on the location of the individual wires has been achieved and maintained during the five years of construction at the University of Thessaloniki. A sample of 12% of the chambers, randomly selected over the entire production period, has been scanned at the X-ray tomograph facility at CERN. The agreement between the quality assurance–quality control measurements during the assembly and the X-ray tomograph results is also presented.