Large Hadron Collider is a particle accelerator built at CERN, the European Centre for Nuclear Research, between the Alps and Jura Mountains near Geneva. Construction was completed in May 2008 and cost over three billion pounds. The form of a circle with circumference of 27 km, located 100 m underground. LHC is considered the most powerful particle accelerator in the world. LHC goal is to explore the validity and limitations of the Standard Model, the theoretical model of particle physics base. Theoretically, the accelerator would have to confirm the existence of the Higgs boson, the missing elements covering the Standard Model and explain how elementary particles acquire certain properties such as mass.
Accelerator was put into operation on 10 September 2008. It was built in collaboration with over eight hundred physicists from over eighty-five countries and in partnership with hundreds of major universities and laboratories. After technical difficulties important was reinstated in November 2009.
Although the media have expressed some concerns about the safety of the experiment, there is a consensus in the scientific community about the LHC collisions of particles carried in the sense that they pose no danger to humans / humanity.
Design
LHC is the largest particle accelerator in the world, and reaching the highest energy. Collider is in a circular tunnel with a circumference of 27 km, at a depth between 50-175 m below ground.
Tunnel, wrapped in a layer 3.8 m thick concrete, built between 1983 and 1988, was previously used as host for the Large Electron-Positron Collider. He crosses the border between Switzerland and France at four points, a larger portion of it being in France. Surface buildings housing auxiliary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.
The tunnel is composed of two separate adjacent annular pipe intersect in four points, each pipe containing a proton conduit. They move in contrary directions tunnel. Approximately 1232 magnetic dipoles retain their circular flow path, and 392 quad-pols magnetic flows are used to maintain focus, to maximize the chances of interaction between particles in the four points of intersection of the two streams. In total, over 1,600 superconducting magnet are installed, most weighing over 27 tons. To keep the magnets at their operating temperature of 1.9 K takes approximately 96 tons of liquid helium, making the LHC the largest cryogenic temperature of liquid helium plant. Once or twice a day, while protons are accelerated from 450 GeV up to a maximum of 7 TeV, superconducting electromagnetic dipole magnetic fields are increased from 0.54 to 8.3 tesla (T). Protons can reach each up to 7 TeV energy, bringing the total collision energy to 14 TeV (2.2 μJ). At this energy the protons have a Lorentz factor of about 7,500 and move at speeds of 99.999999% the speed of light. It takes less than 90 is as a proton to make a lap around the main ring – angular speed can reach to 11,000 revolutions per second. Flows are not continuous; protons are gathered in groups or packs 2808, so that interactions between the two streams take place at discrete intervals never shorter than 25 ns. However, the operation is done with fewer groups than was initially established, the interval between proton groups being at least 75 ns.