The ALICE Experiment Upgrades

TL;DR

The ALICE experiment underwent significant upgrades during the 2019-2021 shutdown, enhancing its detectors and software to improve physics capabilities and prepare for future LHC runs.

Contribution

This paper details the comprehensive upgrades to ALICE's detectors and software, including new silicon trackers, GEM detectors, and trigger systems, to enhance performance and data handling.

Findings

Improved vertexing capabilities with new silicon tracker.

Continuous data taking enabled by GEM detectors.

Enhanced trigger and data reconstruction systems.

Abstract

The ALICE experiment profited of the Long Shutdown during 2019-2021 in order to expand its physics capabilities and fully profit from the increased LHC luminosity in Run 3. The Inner Tracking System has been replaced with a new silicon tracker based on MAPS technology, and a new tracking device has been added in front of the Muon Spectrometer to improve its vertexing capabilities. The wire chambers for TPC readout have been replaced with new GEM detectors which will minimize ion backflow and allow for continuous data taking: moreover, a new detector array dedicated to fast triggering has been installed. On the software side, a new first pass reconstruction was added in order to handle and reduce the data flow and storage. These upgrades will be presented together with an outlook of the future ALICE upgrades in view of the LHC Run 4, which will include the replacement of the ITS inner tracking layers with upgraded silicon devices and a high-granularity electromagnetic and hadronic calorimeter in the forward direction (FOCAL)