In:
Journal of Instrumentation, IOP Publishing, Vol. 19, No. 05 ( 2024-05-01), p. P05063-
Abstract:
The ATLAS detector is installed in its experimental cavern
at Point 1 of the CERN Large Hadron Collider. During Run 2 of the LHC, a luminosity of
ℒ = 2 × 10 34 cm -2 s -1 was
routinely achieved at the start of fills, twice the design luminosity. For Run 3, accelerator improvements, notably luminosity
levelling, allow sustained running at an instantaneous luminosity of ℒ = 2 × 10 34 cm -2 s -1 ,
with an average of up to 60 interactions per bunch crossing. The ATLAS detector has been upgraded to recover Run 1 single-lepton
trigger thresholds while operating comfortably under Run 3 sustained pileup conditions. A fourth pixel layer 3.3 cm from the beam axis
was added before Run 2 to improve vertex reconstruction and b-tagging performance. New Liquid Argon Calorimeter digital
trigger electronics, with corresponding upgrades to the Trigger and Data Acquisition system, take advantage of a factor of 10 finer
granularity to improve triggering on electrons, photons, taus, and hadronic signatures through increased pileup rejection. The inner
muon endcap wheels were replaced by New Small Wheels with Micromegas and small-strip Thin Gap Chamber detectors, providing both precision
tracking and Level-1 Muon trigger functionality. Trigger coverage of the inner barrel muon layer near one endcap region was augmented
with modules integrating new thin-gap resistive plate chambers and smaller-diameter drift-tube chambers. Tile Calorimeter scintillation
counters were added to improve electron energy resolution and background rejection. Upgrades to Minimum Bias Trigger Scintillators
and Forward Detectors improve luminosity monitoring and enable total proton-proton cross section, diffractive physics, and heavy ion
measurements. These upgrades are all compatible with operation in the much harsher environment anticipated after the High-Luminosity
upgrade of the LHC and are the first steps towards preparing ATLAS for the High-Luminosity upgrade of the LHC. This paper describes
the Run 3 configuration of the ATLAS detector.
Type of Medium:
Online Resource
ISSN:
1748-0221
DOI:
10.1088/1748-0221/19/05/P05063
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2024
detail.hit.zdb_id:
2235672-1
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