The CMS detector is a large general-purpose detector at the LHC,
CERN.
CMS consists of layers of detector material that exploit the
different properties of particles to catch and measure the energy or
momentum of each one.
A particle emerging from the collision and travelling outwards will
first encounter the tracking system, made of silicon pixels and silicon
strip detectors.
The tracker accurately measures the positions of passing charged
particles allowing physicists to reconstruct their tracks.
The CMS magnet is the central device around which the experiment is
built, with a 3.7 Tesla magnetic field.
The magnet’s job is to bend the paths of particles emerging from
high-energy collisions.
The strong magnetic field, combined with high-precision position
measurements in the tracker and muon detectors, this allows accurate
measurement of the momentum of even high-energy particles.
The CMS magnet is a superconducting solenoid.
The tracker and calorimeter detectors (ECAL and HCAL) fit snugly
inside the magnet.