Tuesday, September 4, 2007

World's Largest Superconducting Magnet Up and Running


The world's largest superconducting magnet has been successfully powered up on its first try and is ready to test some of the most fundamental questions of science, researchers say.

Weighing 110 tons (100 metric tons), the Barrel Toroid—seen here with all eight of its superconducting coils clearly visible in a photo released November 20—is 16 feet (5 meters) wide and 82 feet (25 meters) long, dwarfing the lone technician seen bottom center.

The instrument is a vital component of ATLAS, one of the particle detectors housed at the European Organization for Nuclear Research's (CERN's) Large Hadron Collider (LHC), a new, internationally funded particle accelerator scheduled to begin operation late next year in Geneva, Switzerland. Particle accelerators create and collide beams of speeding, highly energetic atomic or subatomic particles.

The LHC will smash two beams of protons together in some of the most energetic collisions ever created. The goal, physicists say, is to explore the fundamental nature of matter and energy by creating conditions similar to those of the early universe.

At stake are some of science's most difficult puzzles. What is dark matter? Why do things have mass? Why is there so little antimatter? The LHC could provide answers to them all.

The Barrel Toroid will help scientists analyze the proton collisions by generating an enormous magnetic field to bend the paths of charged particles. Scientists can use the angle of deflection along with readings from other instruments to puzzle out what particles were created.

To check that the Barrel Toroid was working, researchers began cooling the instrument to -459 degrees Fahrenheit (-269 degrees Celsius) in July. After six weeks, the device was slowly powered up to an electrical current of 21,000 amps on November 9—more than enough to generate the needed magnetic field.

The instrument was then safely discharged of its stored magnetic energy—1.1 gigajoules, the equivalent of 10,000 cars traveling at 43 miles (75 kilometers) an hour.

Said Herman ten Kate, ATLAS magnet system project leader, in a statement: "We can now say that the ATLAS Barrel Toroid is ready for physics."

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