GENEVA – The world's largest atom smasher made another leap forward Monday by circulating beams of protons in opposite directions at the same time in the $10 billion machine after more than a year of repairs, organizers said.
The true test will be in first two months of 2010, when scientists plan to start colliding protons to see what they can discover about the makeup of the universe and its tiniest particles.
The Large Hadron Collider has been advancing faster than expected in its startup phase that began Friday night, said Rolf Heuer, director-general of the European Organization for Nuclear Research, known as CERN."It went much faster than foreseen," said Fabiola Gianotti, who speaks for the Atlas experiment, one of four major detectors in rooms the size of cathedrals about 100 meters (300 feet) underground. "We're all very happy."
It is possible that some unintended proton collisions began Monday or will occur soon at the places where the two beams cross as a side-effect of trying to synchronize the timing of two beams.
Intentional proton collisions could begin within the next 10 days, mainly to check how the machine is working, said spokesman James Gillies.
Ultimately, the collider aims to create conditions like they were 1 trillionth to 2 trillionths of a second after the Big Bang — which scientists think marked the creation of the universe billions of years ago. Physicists also hope the collider will help them see and understand other suspected phenomena, such as dark matter, antimatter and supersymmetry.
The collider was started with great fanfare Sept. 10, 2008, only to be heavily damaged by an electrical fault nine days later. It has taken 14 months to repair and add protection systems to the machine before it was restarted.
The protons on Monday were traveling at almost the speed of light — 11,000 times a second in each direction around the 27-kilometer (17-mile) tunnel under the Swiss-French border at Geneva.
Initial signs are very good, physicists told a news conference. The beam is of superb quality, with the protons tightly packed into hairlike lines and guided by some 1,600 superconducting magnets — some 15 meters (50 feet) long — operating at temperatures colder than outer space for maximum electrical efficiency.
So far the machine is operating at 450 billion electron volts of energy, which is relatively low compared with its design capability of more than 14 times that. It soon will overtake the world's current most powerful accelerator, the Tevatron at Fermilab outside Chicago, which operates at 1 trillion electron volts, or TeV.
Myers said the CERN collider should be ramped up to 1.2 TeV by Christmas. CERN might decide to make the first collisions at the current low energy or at 1.2 TeV, but that will be more for calibration purposes than for making scientific discoveries, he said.
Physicists said the discoveries could begin in the first half of next year when the collider reaches 3.5 TeV. CERN is hoping to have the first collisions at that energy in January or early February, said Gillies.
"That would really mark the start of the research program," he said.
Myers said the collider may even go up to 5 TeV before the end of 2010.
Tejinder S. Virdee, a physicist from London's Imperial College who represents more than 2,000 scientists on CMS, another of the experiments with its own detectors at CERN, said it could take several years before the collider discovers the elusive Higgs boson, a particle that theoretically gives mass to other subatomic particles, and thus everything in the universe.
That is because the Higgs boson is believed to be hard to see and needs powerful energy to be revealed, Virdee said.
"This is going to take a few years," he said.
Director-General Heuer said CERN was being as cautious as a driver would be with the first production model of a new car.
"We'll never accelerate this the first time with a kick-start to its maximum velocity," he said.
Once it is tested out, he added, "we can open windows into new physics and that could happen already next year. It depends on how kind nature is to us."
