# New High-Precision Drift-Tube Detectors for the ATLAS Muon Spectrometer

## TL;DR

The paper introduces small-diameter muon drift tube detectors with enhanced rate capability and precision, optimized for mass production and upgrade of the ATLAS muon spectrometer for high-luminosity conditions.

## Contribution

Development of high-precision, high-rate capability sMDT detectors with optimized design and construction methods for ATLAS upgrades.

## Key findings

- Achieved 0.005 mm wire positioning accuracy.
- 14 sMDT chambers operational in ATLAS.
- Planned construction of 96 chambers for HL-LHC upgrade.

## Abstract

Small-diameter muon drift tube (sMDT) detectors have been developed for upgrades of the ATLAS muon spectrometer. With a tube diameter of 15 mm, they provide an about an order of magnitude higher rate capability than the present ATLAS muon tracking detectors, the MDT chambers with 30 mm tube diameter. The drift-tube design and the construction methods have been optimised for mass production and allow for complex shapes required for maximising the acceptance. A record sense wire positioning accuracy of 0.005 mm has been achieved with the new design. 14 new sMDT chambers are already operational in ATLAS, further 16 are under construction for installation in the 2019-2020 LHC shutdown. For the upgrade of the barrel muon spectrometer for High-Luminosity LHC, 96 sMDT chambers will be contructed between 2020 and 2024.