LHC tunnel. The LHC (large hadron collider) in its tunnel at CERN (the European particle physics laboratory) near Geneva, Switzerland. The LHC is a 27-kilometre-long underground ring of superconducting magnets housed in this pipe-like structure (blue), or cryostat. The cryostat is cooled by liquid helium to keep it at an operating temperature just above absolute zero. It will accelerate two counter-rotating beam of protons to an energy of 7 tera electron volts (TeV) and then bring them to collide head on. Several detectors are being built around the LHC to detect the various particles produced by the collision. A pilot run of the LHC is scheduled for summer 2007.