Perspectives de mesure de la masse du quark Top avec le détecteur ATLAS

This document presents the work done to instrument the "Super-Drawer", supports of the fronend electronics of the Tile Calorimeter, as well as the preparatory analysis of the Top quark mass measurement with ATLAS detector. Initially the instrumental part exposes the various stages having led to the instrumentation. This required upstream a phase caved integration, where methods were developed to cope with space and ergonomic constraints during the assembly of the Super-Drawers. The experience accumulated in this fast phase allowed the drafting of the protocol of assembly of the Super-Drawers and the installation of the two assembly lines. The first ten Super-Drawers were thus produced for the 2001 test- beam period, and the continuous production of the 260 remaining SuperDrawers must start in June 2002. In the analysis part, this thesis deals with the precise measurement of the Top quark mass in the lepton plus jets channel. It is initially shown that systematic uncertainties will dominate the precision on the measurement, in particular the knowledge of the jet energy scale as well as the final state radiations, leading to a total error of approximately 2 GeV. It is then shown that the same events can be used for the energy calibration of the light jets to better than 1%. Finally, the use of a kinematic fit should make it possible to reduce the impact of the effects due to the knowledge of the light jets energy scale like to the final state radiations. A total uncertainty to the measurement of the Top mass less than 1 GeV appears possible in one year of data taking at low luminosity, this uncertainty being dominated by the knowledge of the b-quark jet energy scale, supposed known at 1% level.