Fermilab's legendary atom-smasher is shut down

A legendary tool in scientists' attempts to explain the universe was laid to rest Friday in Batavia.

The Tevatron particle accelerator at Fermilab was turned off after 26 years of supplying data about the nature of subatomic particles that build our universe.

The once most powerful accelerator in the world had its title usurped by the Large Hadron Collider in Europe in 2009. And when Fermilab couldn't get enough federal funding to keep running the Tevatron a few more years as well as build new experiments, lab officials decided to focus on the future.

"We need to move on to the most productive (thing)," laboratory director Pier Oddone said after a ceremony Friday. "So it is a natural thing to shut (the Tevatron) down."

Fermilab officials marked the end of the accelerator's life with a party - including food, souvenir lapel pins, posters and special T-shirts. Former laboratory directors Leon Lederman - on whose watch the Tevatron was built and fired up - and Mike Witherell attended.

Employees watched the shutdown via video feed from their offices or with Oddone in Fermilab's Ramsey Auditorium. Bob Mau, the former head of Tevatron operations, was on hand for the ceremony, pointing out how the controls worked.

It took about 40 minutes, cutting from the main control room to the control rooms for the Collider Detector at Fermilab and the DZero experiments, the two detectors on the Main Ring. Workers in those rooms saved the last bits of data before shutting them to protect the sensitive detectors from errant particles.

Then came the final moment - complete with large push buttons installed for the occasion.

Helen Edwards, the lead scientist for the design and construction of the Tevatron in the early 1970s, had the honor of powering down the accelerator. Her work on the Tevatron won her and three others the National Medal of Technology in 1989.

Edwards first directed the remaining beams of protons and antiprotons left in the accelerator to a metal detector. Then she turned off the power to the 1,000 magnets that steered the proton and antiproton beams around the 4-mile ring accelerator.

The crowd in Ramsey laughed when the power button had to be pushed a second time because it apparently didn't work the first time.

The Tevatron began experiments in 1983. In 1994, it helped scientists find the last of six quarks - the top quark. That heavy particle had been sought for more than 18 years and helped to explain how matter obtained mass, especially at the beginning of the universe. The postulation of the existence of the top quark won two Japanese scientists the 2008 Nobel Prize in Physics.

It will take about a week to warm up the superconducting magnets, which were normally chilled to -450 degrees Fahrenheit. After that, Fermilab workers will begin removing the cooling fluids and gases, work that is expected to take through the end of the year.

Lab officials estimate it will take a month to shut down the Collider Detector and three months for DZero.

The button incident wasn't the only laugh of the day. Oddone wrapped up the event by telling of a dream he had Thursday night. Noting there is "a certain spirit of rebelliousness" at Fermilab, he said he dreamed that when he gave the command to Mau to shut it down, "they actually barricade the door and he says, 'Make me. Tell me why I should do this.'"

But he had given the reason a moment before: The future.

"After more than 25 years at the forefront of the energy frontier, Fermilab has now staked its claim at the intensity frontier of particle physics, where the currency is not the highest energies but the greatest number of particles," Oddone said.

That includes two new projects: the Long-Baseline Neutrino Experiment, where neutrinos will be shot to a detector in South Dakota, and Project X. Fermilab also will continue work on the cosmic frontier, studying dark matter particles.

It has a big new task at hand, too, after researchers using equipment at CERN, the European Organization for Nuclear Research, revealed their finding that cast doubt on Einstein's theory of relativity, which holds no particle can move faster than the speed of light. Fermilab is one of only two other labs in the world that could try to replicate CERN's work. The other, in Japan, has been slowed by the earthquake and tsunami.

Fermilab saw similar faster-than-light results in 2007 while shooting a beam of neutrinos to a lab in northern Minnesota. But the scientific significance of that observation was undercut by a large margin of error. Now the lab hopes to upgrade its own "clock" to see if it can confirm or debunk the European findings.

The Tevatron

Circumference: The main ring is 4 miles around.

Depth: The tunnel is 25 feet below grade. There is a berm on top.

Temperature: The cable inside the superconducting magnets is cooled to -450 degrees Fahrenheit.

What's in it: A lot of stuff, but the stars are the 1,000 superconducting magnets that conduct electrical current without resistance. That extra strength enables acceleration to a higher energy.

Energy: 1.8 trillion volts.

Particle detectors: Two, the DZero and CDF. Each weighs about 5,000 pounds.

Initial cost: $120 million when completed in 1983 — but lab officials point out it built on existing facilities, and would have cost more to build from scratch.SOURCE: Fermi National Accelerator Laboratory