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 20μm on the location of the individual wires has been achieved and maintained during the five years of construction at 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