Tunnel of the Large Hadron Collider (LHC) with magnets

Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator. It first started up on 10 September 2008, and remains the latest addition to CERN’s accelerator complex. The LHC consists of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way.

CERN, the particle physics lab near Geneva where the Higgs boson was discovered in 2012

Tour the Large Hadron Collider and other CERN experiments in 360-degree photo panoramas online. Virtual visitors can “walk” through a tunnel housing part of the collider’s 27-kilometer-long particle accelerator. Or you can explore brightly painted particle detectors such as the Compact Muon Solenoid experiment more…

Meet the people in CERN Engineering

  • Fabiola Gianotti – On January 1, 2016, Gianotti became director general of CERN, the first woman ever named to the position. For the next five years, she’ll help select the experiments performed at the world’s most famous particle collider. A noted lover of the font Comic Sans, Gianotti helped lead the team that discovered the Higgs boson.

What’s the problem?
LHC consists of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way.

  • Ask – Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. What are some ways to get the particle beams to travel fast enough to produce these collisions?
  • Imagine – The beams travel in opposite directions in separate beam pipes – two tubes kept at ultrahigh vacuum. They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets. How can these speeds be maintained? How can resistance be reduced?
  • Design, Build – The electromagnets are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy. This requires chilling the magnets to ‑271.3°C – a temperature colder than outer space.
  • Improve – Much of the accelerator is connected to a distribution system of liquid helium, which cools the magnets, as well as to other supply services.

That’s engineering

  • cryogenics – the study of the production and behavior of materials at very low temperatures (below −150 °C, −238 °F or 123 K).
  • absolute temperature scales – Kelvin (SI units) or Rankine scale (Imperial and US units).
  • relative temperature scales – Celsius and Fahrenheit

Engineering ideas

  • cryogenics, temperature, electromagnet, vacuum, radiofrequency cavities, particle accelerator

Learn more…