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A Toroidal LHC Apparatus (ATLAS)
Identification
Hosting Legal Entity
European Organization for Nuclear Research
Location
Geneva, PO: CH-1211 (Switzerland)
Structure
Type Of RI
Single-sited
Coordinating Country
Switzerland
Status
Status
Current Status:
Operational
Scientific Description
ATLAS is a particle physics experiment at the Large Hadron Collider at CERN. The ATLAS detector is searching for new discoveries in the head-on collisions of protons of extraordinarily high energy. ATLAS will learn about the basic forces that have shaped our Universe since the beginning of time and that will determine its fate. Among the possible unknowns are the origin of mass, extra dimensions of space, unification of fundamental forces, and evidence for dark matter candidates in the Universe.

The largest volume detector ever constructed for a particle collider, ATLAS has the dimensions of a cylinder, 46m long, 25m in diameter, and sits in a cavern 100m below ground. The ATLAS detector weighs 7,000 tonnes, similar to the weight of the Eiffel Tower.

The detector itself is a many-layered instrument designed to detect some of the tiniest yet most energetic particles ever created on earth. It consists of six different detecting subsystems wrapped concentrically in layers around the collision point to record the trajectory, momentum, and energy of particles, allowing them to be individually identified and measured. A huge magnet system bends the paths of the charged particles so that their momenta can be measured as precisely as possible.

Beams of particles travelling at energies up to seven trillion electron-volts, or speeds up to 99.999999% that of light, from the LHC collide at the centre of the ATLAS detector producing collision debris in the form of new particles which fly out in all directions. Over a billion particle interactions take place in the ATLAS detector every second, a data rate equivalent to 20 simultaneous telephone conversations held by every person on the earth. Only one in a million collisions are flagged as potentially interesting and recorded for further study. The detector tracks and identifies particles to investigate a wide range of physics, from the study of the Higgs boson and top quark to the search for extra dimensions and particles that could make up dark matter.

The four major components of the ATLAS detector are the Inner Detector, the Calorimeter, the Muon Spectrometer and the Magnet System. Integrated with the detector components are: the Trigger and Data Acquisition System, a specialized multi-level computing system, which selects physics events with distinguishing characteristics; and the Computing System, which develops and improves computing software used to store, process and analyse vast amounts of collision data at 130 computing centres worldwide.

Classifications
RI Category
High Energy Physics Facilities
Scientific Domain
Physics, Astronomy, Astrophysics and Mathematics
ESFRI Domain
Physical Sciences and Engineering
Date of last update: 03/11/2017