A Toroidal LHC ApparatuS - Definition and Overview

ATLAS (A Toroidal LHC ApparatuS) is one of the two large detector experiments being constructed at the Large Hadron Collider at CERN in Switzerland. It is scheduled to be completed in 2007.

It will investigate several aspects of the Standard Model

• The Higgs mechanism, which gives masses to all elementary particles and demands the existence of a particle called the Higgs boson
• CP-violation, which explains the origin of matter/antimatter symmetry
• Decays of the top quark and more precise determination of its mass

and test two important predictions of Supersymmetry

• The existence of more than one Higgs boson
• Many other new particles at an accessible energy

The ATLAS detector consists of four parts,

Inner Detector

pixel detector, silicon microstrip detector, transition radiation straw detector

Calorimeter

electromagnetic calorimeter,hadronic calorimeter

Muon spectrometer

Resistive plate chambers, monitored drift tube chambers, cathode strip chambers, thin gap chambers

Magnet System