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Timeline: Major events for CERN and particle physics

(Reuters) - The European Organisation for Nuclear Research, known as CERN, is the world’s largest particle physics laboratory.

Following is a brief history of CERN and its advances in particle physics:

1954 - CERN was founded as one of Europe’s first joint ventures, partly as a way to share the rising costs of running nuclear physics facilities. Its 12 founding members were Belgium, Britain, Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Sweden, Switzerland and Yugoslavia.

1957 - The 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, with the later-developed Proton Synchrotron dedicated to particle physics. That machine accelerated protons for the first time in November 1959.

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.

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

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.

1976 - The Super Proton Synchrotron, with a circumference of 7 km (4.4 miles) 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.

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. It was closed in 2000 to allow for the construction of the Large Hadron Collider in the same tunnel.

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 ($9 billion). At full power, trillions of protons can race around its ring at 11,245 times a second -- some 99.99 percent the speed of light.

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.

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.

September 2008 - 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.

September 2008 - 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.

November 2009 - CERN restarts the Large Hadron Collider after more than a year of repairs. Within a day they succeed in circulating particle beams in both directions in the tunnel, taking the experiment well beyond where it was when shut down in September 2008, and two days later achieves its first low-power collisions.

November 30, 2009 - CERN scores a world first by accelerating beams to the highest energy ever achieved in a particle collider.

March 1, 2010 - CERN restarts the LHC after a technical break over the Christmas holiday.

March 8, 2010 - CERN says the experiment could detect dark matter, believed to make up 25 percent of the universe but whose existence has never been proven.

March 30, 2010 - CERN due to start attempt to collide particles at the highest energy level so far -- 7 tera-electron volts (TeV)

Compiled by Laura MacInnis and Jonathan Lynn; editing by David Stamp

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