Physicists are Beaming

Full-power circuit means Jefferson Lab now ready for research

NEWPORT NEWS ,VA - The champagne cork was popped just after 7 a.m. Tuesday. A little early for a drink, perhaps, but the physicists had cause to celebrate.

Just three hours before, researchers at the Continuous Electron Beam Accelerator Facility in Newport News had successfully steered a continuous, 4-billion electron volt beam on a five-pass, 4.37-mile journey around their oval-shaped, superconducting particle accelerator.

The milestone, Jefferson Lab officials say, validates a concept born in 1976 in which physicists theorized that a continuous beam of high-speed electrons would, after crashing into targeted atoms, produce particle collisions that would help explore the relationship between subatomic particles known as quarks and gluons.

Now, researchers know it can be done. The first experiments will begin in early summer.

It also means that with the success of Jefferson Lab and two other roughly comparable government physics laboratories, projects which officials say are basically on budget and on schedule, the Department of Energy can begin escaping the giant shadow cast in Texas in 1993 when Congress scrapped the $2.2 billion Superconducting Super Collider.

The breakthrough Tuesday at Jefferson Lab, a $551 million DOE project, was an exercise in the sublime. There was no sound. The beam was invisible. But the physicists were elated. "The best. It's absolutely wonderful," Steve Suhring said.

"Right now, exhausted," said program deputy Lee Harwood. "Other than that, very, very pleased. Folks have been working towards this 10 years; I've been here for eight. To finally have it brings a massive sense of fulfillment, because it's working just like it's supposed to."

The electron beams at Jefferson Lab travel at virtually the speed of light, speeding through a linear series of cryomodules that contain helium cooled to minus 456 degrees Fahrenheit to reduce resistance. But to gain the desired intensity, each beam must be recirculated. At Jefferson Lab, the ideal beam makes five passes around the oval-shaped underground track, steered by powerful magnets.

Two weeks ago, the Jefferson Lab physicists began getting close. They had made the entire circuit at lower power, but had never made five passes, and never with a 4-billion electron volt beam. About 10 days ago, the physicist jokingly known to colleagues as "Attila the Harwood" ordered the team to start from scratch. Methodically, they began again, sending the beam through each section of the underground accelerator, checking for obstructions. "We could taste it," said Harwood. "I wanted it."

The physicists were stuck at the 3 1/2-mile mark - about the end of the the fourth pass. On Monday, after the team had made some corrective changes, the beam shot through. When they inserted a special electron-sensitive wafer into the beam's path, they discovered the beam had gone off-center. When they corrected the path to conform with the proper procedure, the beam was once again partially blocked.

Voila. An obstruction. "We can get around around it," Harwood said.

They tweaked the magnets and deliberately threw the beam off-center. By 1:30 a.m. Tuesday, the full-power beam was halfway through the fifth pass. At 4 a.m., a complete circuit was attained.

The difficulty in attaining the five-pass beam didn't surprise John Domingo, Jefferson Lab's director of physics. "Every machine I've ever been involved with has had `teething problems,'" he said.

Although Tuesday's full-power beam was scheduled for delivery in late March, spokeswoman Linda Ware said the lab is "basically on schedule," saying six weeks off on a milestone project that began in 1987 "is still a remarkable achievement." Coming so close, said Harwood, is a testament to the project's management and the mandatory reviews conducted every six months.

"The thing that killed SSC was not what they were doing technically, but how well they were being managed," he said.

With spending outstripping projected costs on SSC and similar projects, he said, the physics community "was losing credibility with Congress."

The success at Jefferson Lab is being mirrored at two other DOE labs: the Advanced Photon Source at Argonne National Laboratory outside Chicago, about to come on line, and the Advanced Light Source at California's Lawrence Berkeley Laboratory, which began operations last year.

Both have been or are about to be completed on cost and on schedule, said David Nelson, associate director of energy research with DOE.

A meeting in Newport News next week will determine which of the hundreds of researchers already in line to use Jefferson Lab will get priority, Domingo said. "And that, I expect, will be rather heated," he said. But he said that the battle will be over the second place in line, not the first.

"Only an idiot wants to be first," he said, smiling. "That's when you're likely to have trivial problems. But everybody wants to be second."

Daily Press © Article retrieved from the 10 May 95 press