ATLAS Tile Calorimeter

ATLAS Tile Calorimeter
Name	Tile Calorimeter
Detector	Calorimeter
Experiment	ATLAS
Facility	Large Hadron Collider
Location	CERN
Status	Operational

ATLAS Tile Calorimeter

The ATLAS Tile Calorimeter is a hadronic sampling calorimeter used in the ATLAS experiment at the Large Hadron Collider at CERN. It provides measurements of hadron and jet energies and contributes to missing transverse energy reconstruction and triggering for searches such as those by ATLAS Collaboration and analyses related to the Higgs boson, Top quark, and searches for Supersymmetry. The detector interfaces with systems including the Inner Detector (ATLAS), Muon Spectrometer, and the ATLAS trigger system.

Overview

The Tile Calorimeter forms the central hadronic calorimeter of the ATLAS experiment and is positioned between the Electromagnetic Calorimeter (ATLAS) and the Muon Spectrometer. Its role impacts measurements relevant to the Standard Model tests, precision studies of the Higgs boson, and new-physics searches such as those inspired by Supersymmetry and Extra dimensions. The design follows principles used in prior experiments like UA1 and UA2 and complements technologies deployed in the CMS experiment and historical detectors such as LEP experiments. Operations coordinate with accelerator campaigns like LHC Run 1 and LHC Run 2 under oversight by CERN management and the ATLAS Collaboration governance.

Design and Components

The calorimeter is a steel–scintillator sampling device segmented into a central barrel and two extended barrels, each subdivided into modules and readout cells. Mechanical supports and module integration reference construction practices from projects at facilities including CERN Meyrin Site and institutions collaborating across countries such as University of Oxford, Universidad de Zaragoza, University of Bern, and Brookhaven National Laboratory. Scintillating tiles couple via wavelength-shifting fibers to photomultiplier tubes developed with partners including Hamamatsu and custom electronics groups from University of Manchester and LPNHE. The absorber steel and segmentation scheme were informed by calorimetry principles applied in Fermilab and DESY test beams. The module assembly used tooling and quality control comparable to systems built for the ATLAS Tile Calorimeter Upgrade collaborations.

Readout and Electronics

Photomultiplier tubes convert light from wavelength-shifting fibers into analogue signals, which are amplified, shaped, and digitized by front-end electronics designed by teams from CERN and collaborating laboratories such as KEK and TRIUMF. Signals propagate to back-end readout cards in the ATLAS trigger and data acquisition system where zero suppression, data formatting, and integration with the Level-1 trigger (ATLAS) and High-Level Trigger occur. Electronics design took account of radiation tolerance standards used at LHCb and employed testing methodologies similar to those at SLAC National Accelerator Laboratory. Calibration sources such as charge injection systems and laser distribution networks are integrated into the readout chain, coordinated with monitoring frameworks developed by groups at IFIC Valencia and Instituto de Física Corpuscular.

Performance and Calibration

Energy resolution, linearity, and uniformity are characterized via test-beam campaigns at facilities like CERN PS and CERN SPS, with Monte Carlo validations using toolkits from GEANT4 and simulation frameworks maintained by the ATLAS computing group. Calibration employs multiple complementary systems: radioactive source scans analogous to methods used at SPS experiments, laser calibration traces referenced to photomultiplier response studies at IHEP, and charge injection calibrations similar to procedures at DESY. Performance metrics feed into physics object calibrations for jets, missing energy, and tau leptons in analyses by teams drawn from institutions such as University of Athens, University of Melbourne, and University of Tokyo.

Operation and Data Quality

Operation spans coordination with LHC fills managed by the CERN accelerator complex and shift teams from the ATLAS Collaboration. Data quality monitoring systems flag issues using software stacks developed in collaboration with computing centers including CERN IT and regional WLCG partners at GridKa and BNL RHIC & ATLAS Computing Facility. Detector stability during high-luminosity runs was maintained using procedures influenced by experience from Tevatron operations and newer protocols adopted for LHC Run 3. Studies of noise, time alignment, and channel failures are reported to ATLAS working groups and archived in databases maintained by the ATLAS Conditions Database teams.

Upgrades and Maintenance

Planned and implemented upgrades address radiation tolerance, readout bandwidth, and maintenance accessibility ahead of high-luminosity phases guided by the High-Luminosity LHC program and coordinated with upgrade efforts across subsystems such as the ATLAS Liquid Argon Calorimeter Upgrade. Upgrade projects involved collaborations among national laboratories including CERN, Brookhaven National Laboratory, Lawrence Berkeley National Laboratory, and university groups from Iowa State University and University College London. Maintenance campaigns leverage protocols from detector refurbishment projects at SLAC and integrate quality assurance methods from ISO standards used in large-scale scientific instrumentation projects.

Category:ATLAS detector