World’s largest atom smasher in Geneva ramps up collisions before year-end break

Atom smasher ramps up collisions before year end

GENEVA — The world’s largest atom smasher produced 50,000 proton collisions at the highest energy level ever recorded, the operators said Monday.

The weekend run demonstrated how well the Large Hadron Collider is working in preparation for going to even higher energy level next year for experiments to delve further into the makeup of matter, said Rolf Heuer, director-general of the European Organization for Nuclear Research, or CERN.

The new $10 billion machine, which has made a nearly flawless comeback after being heavily damaged during a startup collapse a year ago, was built to examine suspected phenomena such as dark matter, antimatter and ultimately the creation of the universe billions of years ago, which many theorize occurred as a massive explosion known as the Big Bang.

“After only three weeks of running it almost felt like routine operation in the CERN control center,” said Heuer.

The LHC provided well over 1 million lower-energy collisions to each of the major “experiments” — massive detectors in cathedral-sized rooms along the 27-kilometer (17-mile) circular accelerator in a tunnel 300 feet (100 meters) underground near Geneva, on the Swiss-French border.

The low energy collisions enabled operators to calibrate the machine and detectors with showers of particles already discovered so that there will be a solid basis for understanding what happens when higher energy experiments start in the first half of next year.

Heuer said all experiments got “a very good set of data” from long periods of stable beams.

Two beams of circulating particles traveling in opposite directions at 1.18 trillion electron volts produced the collisions, about 20 percent higher than the previous record set by the Tevatron collider at Fermilab outside Chicago.

The particle beams travel at nearly the speed of light, circling the tunnel in fire-hose-sized pipes 11,000 times a second until powerful, superconducting magnets force the beams to collide to see what will occur.

“The experiments saw about 50,000 collisions” at the higher energy, said Heuer. “With only three days of operation to go before the end-of-the-year technical stop, the experiments have many events to look at in the new year, and the LHC operators have learned a lot about their machine, which is running more smoothly than anyone could have expected.”

Major new scientific discoveries are expected after the beams are ramped up still higher, to 3.5 TeV, probably by February.

The collider was started with great fanfare Sept. 10, 2008, only to be heavily damaged by an electrical fault nine days later. It took 14 months to repair and add protection systems to the machine before it was restarted. The overall price of repairs and improvements is expected to cost $40 million, according to CERN.

The long-term goal, after more modifications, will be to run the proton beams at 7 TeV in each direction — with seven times the energy for collisions that is available at Fermilab.

The higher the energy and the greater the number of protons in the beam, the more likely it will be that the scientists will discover particles and forces.

Still, 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. It is believed the Higgs boson is hard to see and needs powerful energy to be revealed.

Physicists have used smaller, room-temperature colliders for decades to study the atom. They once thought protons and neutrons were the smallest components of the atom’s nucleus, but the colliders showed that they are made of quarks and gluons and that there are other forces and particles.

The LHC operates at nearly absolute zero temperature, colder than outer space, which allows some 2,000 superconducting magnets to guide the protons most efficiently.

More than 8,000 physicists from labs around the world also have work planned for the Large Hadron Collider. The organization is run by its 20 European member nations, with support from other countries, including observers from Japan, India, Russia and the United States, which have made big contributions.