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The Large Hadron Collider (LHC) is the world's largest and most powerful particle collider, the largest, most complex experimental facility ever built, and the largest single machine in the world.〔(【引用サイトリンク】title=The Large Hadron Collider )〕 It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and engineers from over 100 countries, as well as hundreds of universities and laboratories. It lies in a tunnel in circumference, as deep as beneath the France–Switzerland border near Geneva, Switzerland. Its first research run took place from 30 March 2010 to 13 February 2013 at an initial energy of 3.5 teraelectronvolts (TeV) per beam (7 TeV total), almost 4 times more than the previous world record for a collider, rising to 4 TeV per beam (8 TeV total) from 2012.〔(【引用サイトリンク】title=LHC smashes energy record with test collisions )〕 On 13 February 2013 the LHC's first run officially ended, and it was shut down for planned upgrades. 'Test' collisions restarted in the upgraded collider on 5 April 2015,〔 reaching 6.5 TeV per beam on 20 May 2015 (13 TeV total, the current world record for particle collisions). Its second research run commenced on schedule, on 3 June 2015.〔(【引用サイトリンク】title=Large Hadron Collider turns on 'data tap' )〕 The LHC's aim is to allow physicists to test the predictions of different theories of particle physics, high-energy physics and in particular, to further test the properties of the Higgs boson and the large family of new particles predicted by supersymmetric theories, and other unsolved questions of physics, advancing human understanding of physical laws. It contains seven detectors, each designed for certain kinds of research. The proton-proton collision is the primary operation method, but the LHC has also collided protons with lead nuclei for two months in 2013 and used lead–lead collisions for about one month each in 2010, 2011, and 2013 for other investigations. The LHC's computing grid was (and currently is) a world record holder. Data from collisions was anticipated to be produced at an unprecedented rate for the time, of tens of petabytes per year, a major challenge at the time, to be analysed by a grid-based computer network infrastructure connecting 140 computing centers in 35 countries – by 2012 the Worldwide LHC Computing Grid was also the world's largest distributed computing grid, comprising over 170 computing facilities in a worldwide network across 36 countries.〔(【引用サイトリンク】title=Hunt for Higgs boson hits key decision point - Technology & science - Science - NBC News )〕〔(Worldwide LHC Computing Grid main page ) 14 November 2012: ''"() global collaboration of more than 170 computing centres in 36 countries ... to store, distribute and analyse the ~25 Petabytes (25 million Gigabytes) of data annually generated by the Large Hadron Collider"''〕〔(What is the Worldwide LHC Computing Grid? (Public 'About' page) ) 14 November 2012: ''"Currently WLCG is made up of more than 170 computing centers in 36 countries...The WLCG is now the world's largest computing grid"''〕 == Background == The term ''hadron'' refers to composite particles composed of quarks held together by the strong force (as atoms and molecules are held together by the electromagnetic force). The best-known hadrons are the baryons protons and neutrons; hadrons also include mesons such as the pion and kaon, which were discovered during cosmic ray experiments in the late 1940s and early 1950s. A ''collider'' is a type of a particle accelerator with two directed beams of particles. In particle physics colliders are used as a research tool: they accelerate particles to very high kinetic energies and let them impact other particles. Analysis of the byproducts of these collisions gives scientists good evidence of the structure of the subatomic world and the laws of nature governing it. Many of these byproducts are produced only by high energy collisions, and they decay after very short periods of time. Thus many of them are hard or near impossible to study in other ways. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「large hadron collider」の詳細全文を読む スポンサード リンク
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