ATLAS experiment
The ATLAS experiment searches 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 extra dimensions of space, unification of fundamental forces, and evidence for dark matter candidates in the Universe. Following the discovery of the Higgs boson, further data will allow in-depth investigation of the boson's properties and thereby of the origin of mass.
The ATLAS detector
(Photo and illustration courtesy of CERN)
ATLAS detector
ATLAS is a "general purpose" detector designed to cover the widest possible range of physics at the LHC. ATLAS is 46 metres long, 25 metres high 25 metres wide and weighs 7,000 tonnes. It has six different detecting subsystems and a huge magnet system that bends the paths of charged particles for momentum measurement.
To get an idea of how each part fits into the whole detector ATLAS has made this video: ATLAS - Episode 1 - A New Hope
To get an idea of how each sub-detector functions ATLAS has made the sequel: ATLAS - Episode 2 - The Particles Strike Back
You can also visit the ATLAS Detector Overview where Episode 2 has been split up into separate sections for each detector module.