Cern's Large Hadron Collider makes first collisions

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Cern's Large Hadron Collider makes first collisions​

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Engineers operating the Large Hadron Collider (LHC) have smashed together proton beams in the machine for the very first time.

The step was described as a "great achievement" for those working on the huge physics experiment.

The low-energy collisions came after researchers circulated two beams simultaneously in the LHC's 27km-long tunnel earlier on Monday.

The LHC will smash together beams of protons to shed light on the cosmos.

Operated by the European Organization for Nuclear Research (Cern), the LHC is the world's largest machine and will create similar conditions to those present moments after the Big Bang.

Scientists will search for signs of the Higgs boson, a sub-atomic particle that is crucial to our current understanding of physics.

Although it is predicted to exist, scientists have not yet detected it.

Researchers working on the collider have said they are delighted with the quick progress made since the machine restarted on Friday.

"It's a great achievement to have come this far in so short a time," said Cern's director-general Rolf Heuer.

"But we need to keep a sense of perspective - there's still much to do before we can start the LHC physics programme."

Smashing news

Housed in a tunnel 100m beneath the Franco-Swiss border, the LHC uses some 1,200 "superconducting" magnets to bend proton beams in opposite directions around the tunnel at close to the speed of light.

At allotted points around the "ring", the proton beams cross, smashing into one another with enormous energy.

Large "detector" machines located at these crossing points will scour the wreckage of the collisions for discoveries that could roll back the frontiers of knowledge.

The four main detectors at the LHC are: Atlas, the Compact Muon Solenoid (CMS), Alice and LHCb. Atlas and CMS are so-called multi-purpose detectors, while Alice and LHCb are designed with more specific scientific investigations in mind.

Cern's director of communications, Dr James Gillies, said the first collisions had taken place just as a news conference was underway on Monday to discuss progress following the machine's restart at the weekend.

"We didn't have time to analyse them then. We waited until all four of the (detectors) had seen good candidates (for collisions)," he told BBC News.

Quick progress

The giant Atlas detector was the first to record candidate collisions at 1322 GMT. But CMS failed to see any on the first try. Alice and LHCb saw their first candidate collisions after 1600 GMT.

Operators then went back and adjusted the beam to generate collisions in the Compact Muon Solenoid detector. This time, they were successful, with the first candidates seen at around 1820 GMT.

Fabiola Gianotti, spokesperson for the Atlas scientific team, commented: "This is great news, the start of a fantastic era of physics and hopefully discoveries after 20 years' work by the international community."

The spokesperson for the Alice experiment, Jurgen Schukraft, said cheers erupted with the first collisions.

"This is simply tremendous," he said.

Engineers restarted the LHC on Friday evening after a 14-month hiatus while the machine was being repaired.

It had to be shut down shortly after its inauguration when an electrical fault led to magnets being damaged and to one tonne of liquid helium leaking into the tunnel.

 

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Large Hadron Collider protons circulate in two directions

Beams of protons have started circulating in both directions around the Large Hadron Collider (LHC), a scientist participating in the experiment said on Monday.

Dr. Alexei Ferapontov said LHC detectors had started to pinpoint traces of collisions between particles in the beams and equipment, showing that they are in good working order.

In the next few days, the two beams will be brought together to stage small collisions and lay the groundwork for high-energy collisions for new physics that are expected to take place in January.

On Friday, the first circulating beam of protons successfully made it through the LHC's entirety, the European Organization for Nuclear Research (CERN) said.

Experiments using the LHC were suspended last September shortly after a successful start, due to a malfunction of two superconducting magnets and a subsequent helium leak into the tunnel housing the device.

The collider, located 100 meters under the French-Swiss border with a circumference of 27 km, enables scientists to shoot subatomic particles round an accelerator ring at almost the speed of light, channeled by powerful fields produced by superconducting magnets.

In order to fire beams of protons round the vast underground circular device, the entire ring must be cooled by liquid helium to minus 271 degrees C, just two degrees above absolute zero.

By colliding particles in front of immensely powerful detectors, scientists hope to detect the Higgs boson, nicknamed the "God particle," which was hypothesized in the 1960s to explain how particles acquire mass. Discovering the particle could explain how matter appeared in the split-second after the Big Bang.

The international LHC project has involved more than 2,000 physicists from hundreds of universities and laboratories in 34 countries since 1984. Over 700 Russian physicists from 12 research institutes have taken part.