We have built a full scale prototype of the precision tracking chambers (Monitored Drift Tubes, MDT) for the muon spectrometer of the Atlas Experiment at the LHC collider. This article describes in detail the procedures used in constructing the drift tubes and in assembling the chamber. It presents data showing that the required mechanical precision has been achieved as well as test beam results displaying the over all chamber performance. The article presents data demonstrating the derivation of the space-time relation of the drift tubes by the autocalibration procedure using real data from the tracks crossing the chamber. Autocalibration is the procedure which must be used during run time.

We present a full-scale MDT prototype for the Atlas Muon Spectrometer. The chamber consists of two multilayers made of three layers of 96 drift tubes each. The main feature of this chamber is the very accurate mechanical construction (20μm accuracy on single wire positioning) together with a very good individual tube spatial resolution. In this paper we present results both on the mechanical accuracy of the chamber, and on the performances obtained on the H8 test beam at CERN. In particular, we present an autocalibration method that allows to obtain the space-to-time relation of the tubes with a systematic error less than 20μm, the space resolution and the efficiency of the chamber.