ATLAS upgrades

Abstract

The ATLAS experiment at CERN has planned many upgrades, in order to cope with the instantaneous luminosity that will be delivered by the Large Hadron Collider (LHC) machine in the next decade. These upgrades will allow the ATLAS experiment to keep or improve its current performance for Run 3, expected to start in 2021, and for the High Luminosity LHC program (HL-LHC) expected to start in ∼2027. For Run 3, we expect an instantaneous luminosity of 2-3 × 1034 cm−2 s−1and an average pileup of ~80 collisions/bunch crossing, while for the HL-LHC phase, an instantaneous luminosity of 7.5 × 1034 cm−2 s−1and an average pileup of ~200 collisions/bunch crossing are foreseen. Although the upgrades are essential to achieve the physics goals, they represent a huge challenge for the detector, trigger and data acquisition (TDAQ) systems. The status of the upgrade activities is presented.