M. Rendel | Searcharxiv

arXiv2026

Construction and Performance of the sMDT Precision Muon Tracking Chambers for ATLAS at the HL-LHC

In order to improve the muon trigger efficiency and the rate capability of the ATLAS muon detectors for operation at the high luminosity upgrade of the Large Hadron Collider (HL-LHC), the Monitored Drift Tube (MDT) tracking chambers in the inner barrel layer of the ATLAS Muon Spectrometer will be replaced by small-diameter Muon Drift Tube (sMDT) chambers integrated with new thin-gap RPC trigger chambers. The sMDT chambers are in serial production since January 2021. This documentation provides insight into the drift tube production and every step performed in the chamber construction at the MPI Munich. The serial production involves a stringent quality control program to assure the reliability and high mechanical precision of the chambers. This program consists of tests of the individual drift tubes, measurements of the chamber geometry and proof of gas tightness. Final certification at the production site is provided using cosmic rays. The dedicated quality control database and monitoring Web interface that is used commonly for both production sites of the sMDT chambers is presented

hep-ex↗

arXiv2021

Commissioning and installation of the new small-Diameter Muon Drift Tube (sMDT) detectors for the Phase-I upgrade of the ATLAS Muon Spectrometer

The Monitored Drift Tubes, as a part of the ATLAS muon spectrometer, are precision drift chambers designed to provide excellent spatial resolution and high tracking efficiency independent of the track angle. Through the life of the LHC and ATLAS experiment, this detector has already demonstrated that they provide precise tracking over large areas. The aim of the ATLAS muon spectrometer upgrade is to increase the muon trigger efficiency, precise muon momentum measurement and to improve the rate capability of the muon system in the high-background regions during the High-Luminosity LHC runs. To meet these requirements, the proposed solution is based on the small (15 mm) diameter Muon Drift Tube chamber (sMDT) technology. The new detector provides about an order of magnitude higher rate capability and allows for the installation of additional new triplet Resistive Plate Chambers (RPCs) trigger detectors in the barrel inner layer of the muon system. A pilot project for the barrel inner layer upgrade is underway during the 2019/21 LHC shutdown. For this reason, the Max-Planck-Institute for Physics in Munich has built 16 sMDT chambers, each will cover an area of about 2.5 $m^{2}$. To ensure their proper operation in the experiment, the sMDT detectors have to pass a set of stringent tests both at the production site and after their delivery at CERN. After their installation in the ATLAS muon spectrometer, the muon stations are further tested and commissioned with cosmic rays. The author will describe the detector design, the quality assurance and certification path, as well as will present the experience with the chamber tests, the integration procedure and installation of the muon stations in the ATLAS experiment.

physics.ins-det↗