At CERN's Large Hadron Collider (LHC), protons are accelerated to extremely high speeds and energies before they collide with each other. The LHC is a circular particle accelerator located in a 27-kilometer underground tunnel. It uses a complex system of superconducting magnets to steer and accelerate protons to nearly the speed of light.
Here's a simplified description of the process:
Proton acceleration: Protons are obtained from hydrogen gas and stripped of their electrons. Electric fields are used to accelerate the protons to high energies in a linear accelerator (LINAC). The protons are then injected into a circular accelerator called the Proton Synchrotron (PS) and further accelerated.
Booster acceleration: After the Proton Synchrotron, the protons are injected into the Super Proton Synchrotron (SPS), which increases their energy even more.
Final acceleration: The protons are finally injected into the main LHC ring, where they are accelerated to their maximum energy using a series of radiofrequency cavities and superconducting magnets.
Collision points: The LHC consists of two beam pipes in opposite directions, each containing a stream of accelerated protons. These two beams are brought into collision at four specific interaction points around the LHC ring, where large particle detectors are located.
Proton collisions: When two protons collide head-on at extremely high speeds and energies, several things can happen:
a. Elastic scattering: The protons can scatter off each other at small angles, changing direction but not undergoing any significant interactions.
b. Inelastic scattering: The collision can result in the production of new particles and jets of particles. Energy is transferred from the colliding protons to create a shower of secondary particles.
c. Production of exotic particles: The high energies achieved at the LHC can sometimes result in the creation of exotic particles that are short-lived and not commonly observed in nature.
d. Searches for new physics: One of the primary goals of the LHC is to search for new physics beyond the Standard Model. By colliding protons at high energies, scientists hope to discover new particles or phenomena that could help unravel mysteries of the universe.
Detection: The collision products and secondary particles are detected by large and complex particle detectors, such as ATLAS and CMS, located at the collision points. These detectors measure the properties and trajectories of the produced particles, allowing scientists to analyze the collision events.
By studying the collision products and their properties, scientists can gain insights into the fundamental structure of matter, the nature of particles, and the fundamental forces of the universe. The LHC has been instrumental in the discovery of the Higgs boson and continues to push the boundaries of our understanding of particle physics.