The Large Hadron Collider [LHC] is a particle accelerator and collider located at CERN [Center for Nuclear Energy Research], near Generva, Switzerland.  Currently under construction, the LHC is presently scheduled to begin operation [at reduced energies] in May, 2008.  The LHC would be expected to become the world's largest and highest energy particle collider if commissioning at 7 TeV [trillion electron volts] is completed. The LHC is being funded and built in collaboration with over two thousand physicists from thirty-four countries, universities and laboratories.  The numerous superconducting magnets that line the length of the collider rings were funded by the US DOE and built by Fermilab at Chicago, Illinois, using off-the-shelf technology developed by Fermilab.

If switched on, it is theorized that the collider will produce the elusive "Higgs boson" particle — often dubbed the God Particle — the detection of which might possibly help explain how other fundamental particles gain mass and fill in some of the gaps in the "Standard Model" theory.  Other theoretical particles that have been predicted might be created include  "strangelets", minature black holes [MBH], magnetic monopoles, etc. 

Strangelets are theorized to be a more stable form of nuclear matter, containing an equal number of up, down and strange quarks, compared to normal nuclear matter composed of only up and down quarks.  Its greater stability would result in a fusion capability with normal nuclei, releasing energy.  Minature black holes are theorized to evaporate quickly by "Hawking radiation", though such mechansm of evaporation is also only theorized and not proven.  Magnetic monopoles were first theorized by P.A.M. Dirac, who also correctly predicted the existence of positrons.  Analogous to particles that carry a single electric charge [positive or negative], a magnetic monopole would be a particle carrying a single magnetic charge [north or south] of strengnth 137-fold of an electric charge.

The collider is contained in a 27 kilometer [17 mile] circumference tunnel located underground at a depth ranging from 50 to 150 meters below the surrounding countryside.  The tunnel was formerly used to house the LEP, a lower-energy electron-positron collider.

The three-meter-diameter, concrete-lined tunnel actually crosses the border between Switzerland and France at four points, although the majority of its length is inside France. The collider itself is located underground, with many surface buildings holding ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.

The collider tunnel contains two evacuated pipes enclosed within the numerous superconducting magnets cooled by liquid Helium.  The magnets would cause the beam to curve into a circular path, joining head to the tail as they were threaded in.  Into  each pipe it is planned to thread a proton [Hydrogen nucleus] beam or Lead nucleus beam. The two beams would travel in opposite directions around the ring. Additional magnets would be used to direct the beams to four intersection points where high-energy head-on collisions between them would take place.

The protons would each have an energy of 7 TeV [trillion electron-volts], giving a total collision energy of 14 TeV. It would take around 90 microseconds [0.090 milliseconds] for an individual atomic nucleus [Hydrogen nucleus, or proton; or Lead nucleus] to travel once around the collider, traveling at roughly 99.99% the speed of light. Rather than continuous beams, the atomic nuclei would be "bunched" together into approximately 2,800 bunches, so that collisions between the two beams would take place repeatedly at separate short intervals, never shorter than 25 nanoseconds [0.025 microseconds] apart.  If the collider is first commissioned, it would be operated with fewer bunches, to give a bunch crossing interval of 75 nanoseconds. The number of bunches would later be increased to give a final bunch crossing interval of 25 nanoseconds.

Prior to being injected into the main accelerator, the atomic nuclei would be prepared through a series of systems that successively increase the nucleus energy levels [increasing speed]. The first system is the linear accelerator [Linac2] generating 50 MeV protons which would feed the Proton Synchrotron Booster [PSB]. Protons would then injected at 1.4 GeV into the Proton Synchrotron [PS at 26 GeV. The Low-Energy Injector Ring [LEIR] would be used as an ion storage and cooler unit.  Finally the Super Protron Synchrotron [SPS] could be used to increase the energy of the protons up to 450 GeV.

Six detectors are being constructed at the LHC. They are located underground, in large caverns excavated at the LHC's intersection points. Two of them, ATLAS and CMS are large, "general purpose" particle detectors. The other four [LHCb, ALICE, TOTEM, and LHCf] are smaller and more specialized.

The LHC would also be used to collide heavy atomic nuclei such as Lead [Pb] with a much greater collision energy of 1,150 TeV due to the much greater mass of the Lead nucleus compared to the Hydrogen nucleus.

The size of the LHC constitutes an exceptional engineering challenge with unique safety issues. While running, the total energy stored in the magnets would be 10 GJ [gigaJoules], and in the beam, 725 MJ [megaJoules].  The Beam Dump must absorb an energy equivalent to a standard military bomb. For comparison, 725 MJ is equivalent to the detonation energy of approximately 157 kg [347 pounds] of TNT, and 10 GJ is about 2.5 metric tons of TNT.