Taking a closer look at LHC


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Major events for CERN.

1949 - During the European Cultural Conference at Lausanne, the French physicist and Nobel prize-winner Louis de Broglie proposes the creation of a European science laboratory.

1950 -  At the 5th General Conference of UNESCO held in Florence, the American physicist and Nobel prize-winner Isidore Rabi puts forward a resolution, which is unanimously adopted, authorising the Director General of UNESCO, "to assist and encourage the formation and organization of regional centres and laboratories in order to increase and make more fruitful the international collaboration of scientists ...".

1952 -  After two UNESCO Conferences are held on the subject, 11 European governments sign an agreement setting up a provisional ‘Conseil européen pour la Recherche nucléaire' (CERN). At a meeting of the CERN council in Amsterdam, a site near Geneva is selected for the planned laboratory.

1954 - The European Organization for Nuclear Research is formally created on 29 September. Its 12 founding members were Belgium, Britain, Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Sweden, Switzerland and Yugoslavia. Austria and Spain join CERN in 1959 and 1961 respectively.Yugoslavia leaves the Organization in 1961 for financial reasons. Spain leaves the Organization in 1969 but rejoins in 1983. Finland and Poland join in 1991, Hungary in 1992, the Czech and Slovak Republics in 1993, and Bulgaria in 1999 bringing the number of Member States to 20.

1957 - The 600 MeV Synchrocyclotron, CERN's first accelerator, was built to provide beams for particle and nuclear physics experiments. It was subsequently used in nuclear physics, astrophysics and medical physics.

1959 - Proton Synchrotron (PS) -28 GeV- dedicated to particle physics accelerated protons for the first time in November 1959.

1963 - First bubble chamber pictures of neutrino interactions are taken. Neutrino physics benefits greatly from fast ejection of protons from the Synchrotron, which is achieved for the first time ever during May this year.

1965 - Agreement with French authorities is signed in September on extending the CERN site over the French border. In December, the Council approves the construction of the Intersecting Storage Rings (ISR) on this extension of the site.

1967 - CERN commissions one of the world's finest facilities for the study of very short-lived nuclei-the Isotope Separator On-line (ISOLDE). An agreement between CERN, France and Germany covers the construction of a 3.7 metre hydrogen bubble chamber equipped with the largest superconducting magnet in the world. During its working life from 1973 to 1984, the ‘Big European Bubble Chamber' (BEBC) takes over 6 million photographs.

1968 - CERN scientist Georges Charpak develops a gas-filled box known as a "multiwire proportional chamber" that counted particles one thousand times better than previous detectors. Georges Charpak is awarded the Nobel Prize for Physics in 1992 for this invention. 

1971 - The Intersecting Storage Rings produced the first-ever proton-proton collisions, a precursor to CERN's colliding-beam projects.

1972 -   A four ring 800 MeV Booster is completed to increase the injection energy of the PS. With the booster and a new Linac, which starts operation in 1978, the PS machine exceeds its design intensity by more than a thousand times.

1973 - CERN announces an experiment in its Gargamelle bubble chamber shows the existence of neutral currents, a major advance in understanding the particles of matter and how they interact. In particular, it gives strong support to the theory that attempts to unite our understanding of the weak force-governing such phenomena as radioactivity-with the familiar electromagnetic force.

1976 - The Super Proton Synchrotron, with a circumference of 7 km is built, providing beams to large experimental areas of CERN. Scientists using those beams in 1983 discover the two charged particles, called W, and their neutral counterpart Z. The Super Proton Synchrotron is now the last link in the chain providing beams for the Large Hadron Collider.

1978 - Experiments at CERN show how beam quality and intensity can be improved using the ‘stochastic cooling technique', enabling intense beams of antiprotons to be accelerated and stored.

1981 -   Conversion of the SPS into a proton-antiproton collider and the building of two experimental areas (UA-1 and UA-2) where data from the collisions can be taken. From then on, the operation of the SPS is divided between this collider mode and fixed-target physics. The first proton-antiproton collisions at an energy of 2 x 270 GeV are seen in July 1981, a few months after the start-up of the new Antiproton Accumulator ring (AA), where stochastic cooling is applied to produce the antiproton beam.

1981 - The Member States authorise construction of the Large Electron-Positron collider (LEP) for an initial operating energy of 50 GeV per beam.

1983 - Scientists using beams from SPS discover the two charged particles, called W± and their neutral counterpart Z (the carriers of the weak nuclear force). These discoveries confirmed the Electroweak Theory.

1984 -  Carlo Rubbia and Simon van der Meer receive the Nobel Prize for Physics for their experimental work on proton-antiproton collisions that culminated in the discovery of the W boson and Z boson at CERN in 1983.

1989 - The Large Electron-Positron collider (LEP) is the largest electron-positron accelerator ever built with a circumference of 27 km (16.8 miles). The excavation of the tunnel to house it was Europe's largest civil engineering project before the Channel Tunnel. Its experiments proved there are three generations of particles of matter. The four LEP detectors are ALEPH, DELPHI, L3 and OPAL.

1990 - CERN scientist Tim Berners-Lee invents the worldwide web to meet demands for information-sharing between scientists. Berners-Lee defined basic concepts like the URL, http and html and also wrote the first browser and server software.

1994 - The CERN governing Council approves construction of the Large Hadron Collider, the world's largest particle accelerator with an eventual project cost of 10 billion Swiss francs (€ 7,4 billion).

1995 - Team at CERN's Low Energy Antiproton Ring facility creates atoms of anti-hydrogen, the first time that anti-matter particles were brought together to make complete atoms, helping explain the universe's asymmetry between matter and anti-matter.

1996 - LEP is upgraded to run at the W pair production threshold of 163 GeV. Further upgrades will take LEP energy to 200 GeV by 1999.

1997 - After agreeing to provide significant financial contributions to the LHC, the USA becomes an observer at CERN Council.

2000 - LEP was closed in 2000, after running for 11 years, to allow for the construction of the Large Hadron Collider in the same tunnel. A final burst of excitement occurred a few months prior to the scheduled shut down when one collaboration reported findings of a Higgs boson signal; however, it was not enough evidence to keep LEP in operation.

2001 -  The European DataGrid project (EDG) is launched two years after the idea was born in Annapolis, USA. The project tests a networking infrastructure for the future computing grid. The Grid must connect tens of thousands of computers worldwide to serve scientific projects like the LHC.

2002 - Two CERN experiments create and trap thousands of atoms of anti-matter in a "cold" state, meaning the atoms are slow-moving and can exist for long enough to be studied before they meet ordinary matter and annihilate.

2002 - The first octupole correction magnet is delivered. In addition to the 1232 main dipole magnets that will curve the trajectory of the protons and the 400 focussing quadrupoles, the LHC will be equipped with some 5000 corrector magnets. The last piece of LEP goes up to the surface. In 14 months of dismantling, 40000 tonnes of material were removed from the 27-kilometre tunnel.

2003 -2008 - The assembly of LHC machine and its detectors takes place.

2008 September  - The Large Hadron Collider starts up. Its experiments are expected to address questions such as what gives matter its mass, why nature prefers matter to anti-matter, and how matter evolved from the first instants of the universe's existence.

2008 September - Nine days after it is switched on, the LHC is shut down because of overheating due to problems in the super-conducting cable connecting two cooling magnets. Repairs cost up to $30 million.

2009 November - After restarting the Large Hadron Collider after more than a year of repairs, LHC sets new world record. CERN‟s Large Hadron Collider has become the world‟s highest energy particle accelerator, having accelerated its twin beams of protons to an energy of 1.18 TeV in the early hours of the morning. This exceeds the previous world record of 0.98 TeV, which had been held by the US Fermi National Accelerator Laboratory‟s Tevatron collider since 2001.

March 2010 - LHC sets new record. Two 3.5 TeV proton beams successfully circulated in the Large Hadron Collider for the first time. This is the highest energy yet achieved in a particle accelerator, and an important step on the way to the start of the LHC research programme.

November 2010 - Four days is all it took for the LHC operations team at CERN to complete the transition from protons to lead ions in the LHC. After extracting the final proton beam first collisions were recorded on 7 November.

December 2011 -Standard Model Higgs boson mass constrained to the range 115-130 GeV. In a seminar held at CERN On December 13th, the ATLAS and CMS experiments presented the status of their searches for the Standard Model Higgs boson.

2012.  LHC are running with a beam energy of 4 TeV. The strategy is to optimise LHC running to deliver the maximum possible amount of data in 2012 before the LHC goes into a long shutdown to prepare for higher energy running. The schedule is to run beams through to November. There will then be a long technical stop of around 20 months, with the LHC restarting close to its full design energy late in 2014 and operating for physics at the new high energy in early 2015.

A Particle consistent with Higgs boson. The ATLAS and CMS experiments see strong indications for the presence of a new particle, which could be the Higgs boson, in the mass region around 126 gigaelectronvolts (GeV).

The LHCb experiment discovered two excited states for the Λb beauty particle, and measured of one of the rarest processes so far observed in particle physics, the decay of a Bs  meson into two muons. ALICE performed detailed studies of the quark-gluon plasma, the matter of the primordial universe, and measurements from the TOTEM experiment are giving insights on the structure of the proton and provide input to the analyses of the other LHC experiments.

There were also exciting results from the antimatter hall as ALPHA made the first spectroscopic measurements of antihydrogen; and CERN celebrated several anniversaries: the Proton Synchrotron Booster celebrated its 40th birthday and to mark 100 years of research in cosmic rays
 the laboratory welcomed the astronauts who placed the Alpha Magnetic Spectrometer on the International Space Station.

Jan/Feb 2013. LHC run for 4 weeks with p-Pb collisions Shutdown

2013/14. Long Shutdown (LS) for the whole accelerator complex (LS1) LS1 was started as the project for the repair of the magnet interconnects to allow operating LHC at 14 TeV cms.

© Xabier Cid Vidal & Ramon Cid - rcid@lhc-closer.es  | SANTIAGO (SPAIN) | Original Design by Gabriel Morales Rey