How many detectors does the lhc have

Modern particle detectors consist of layers of subdetectors, each designed to look for particular properties, or specific types of particle. Tracking devices reveal the paths of electrically charged particles as they pass through and interact with suitable substances. Most tracking devices do not make particle tracks directly visible, but record tiny electrical signals that particles trigger as they move through the device.

A computer program then reconstructs the recorded patterns of tracks. One type of particle, the muon, interacts very little with matter — it can travel through metres of dense material before being stopped.

Muons therefore pass easily through the inner layers of a detector, which is why muon chambers — tracking devices specialised in detecting muons — usually make up the outermost layer of a detector. A calorimeter measures the energy a particle loses as it passes through. Among these were pioneering experiments for electroweak physics, a branch of physics that unifies the electromagnetic and weak fundamental forces.

Then in , the Gargamelle bubble chamber presented first direct evidence of the weak neutral current. Two key scientists behind the discoveries — Carlo Rubbia and Simon van der Meer — received the Nobel prize in physics in Image: CERN.

A Large Ion Collider Experiment. Compact Muon Solenoid. Large Hadron Collider beauty. Total, elastic and diffractive cross-section measurement. Take a virtual walk. Inner Detector.

Muon Spectrometer. The trajectories of charged particle are bent by magnetic fields , and their radius of curvature is used to calculate their momentum: the higher the kinetic energy, the shallower the curvature. For particles with high kinetic energy, therefore, a sufficiently long trajectory must be measured in order to accurately determine the curvature radius. Other important parts of a detector are calorimeters for measuring the energy of particles both charged and uncharged. The calorimeters too have to be large enough to absorb as much particle energy as possible.

These are the two principle reasons why the LHC detectors are so large. The detectors are built to hermetically enclose the interaction region in order to account for the total energy and momentum balance of each event and to reconstruct it in detail.

Combining the information from the different layers of the detector, it is possible to determine the type of particle which has left each trace. Charged particles — electrons, protons and muons — leave traces through ionisation.