High-precision X-ray tomograph for quality control of the ATLAS muon monitored drift chambers

For the Large Hadron Collider (LHC), ATLAS, a large general-purpose detector for physics experiment, is under construction. The muon spectrometer of ATLAS is on the scale of a very large industrial project: 1200 large monitored drift tubes (MDT) chambers will be built aiming at an exceptional quality in terms of mechanical accuracy, material reliability, assembly, and monitoring. For Quality Control, an X-ray tomograph, monitored by a set of interferometers, has been developed and built at CERN. The tomograph provides an accuracy below 10 μm in the determination of the position of each MDT drift tube. First, results have been obtained on MDT prototypes.