Fermilab marks a year of Change, Discovery and Safety

by Mike Perricone

Whether or not the end of 1999 officially marks the end of millennium, this year before Y2K marked the beginning of several new eras at Fermilab.

And despite delays in the planned startup for Run II of the Tevatron, the Lab's machines, technicians, engineers and scientists are preparing to use new resources for discoveries that will again push back the frontier of high energy physics.

"We've transformed Fermilab into a much more powerful physics facility--and it's still the world's highest-energy facility for particle physics research," said new Director Michael Witherell.

Witherell, named in March to succeed John Peoples Jr., will preside over a research program that is energized by the addition of a new accelerator, the Main Injector, combined with the unique Antiproton Recycler as its tunnel-mate. Completing an eight-year, $260-million project on time and on budget would be a cause for celebration at any institution, and the Main Injector is at the top of the list of the most important developments at the Lab for 1999.

Dedication: A New Machine

U.S. Secretary of Energy Bill Richardson and U.S. Speaker of the House Dennis Hastert stepped up to the specially-made podium in Ramsey Auditorium, turned ceremonial keys and pushed computer buttons, and officially placed the two-mile circumference Main Injector into operation during ceremonies on June 1.

Hastert, who represents Fermilab's district in Congress and has supported the project from its inception, declared that the Main Injector "ensures that Fermilab is THE place in the world to conduct high-energy physics."

Speaking to a context of increasing sentiment in Congress opposing foreign participation in U.S. science, Richardson pointed to contributions of many foreign-born members of the Lab. "At a time when some may question the value of scientists from other countries and the ways they benefit America," Richardson emphasized, "I say let them visit Fermilab."

Transition: A New Director

Completing and dedicating the Main Injector Project was a fitting climax for Peoples, whose tenure as director (1989-1999) virtually spanned the entire Main Injector-Antiproton Recycler effort from conception to commissioning. He was honored with a symposium in June.

Witherell, a Fermilab experimenter as early as 1978, was named the Lab's fourth director by Universities Research Association, Inc., via a search committee chaired by eminent physicist George Trilling. A former chairman of DOE's High Energy Physics Advisory Panel, Witherell had been a professor at the University of California, Santa Barbara, since 1986.

"We will require new facilities to address pressing scientific questions if the field of particle physics is going to remain vital," Witherell said in his introductory press conference. "I didn't take this job because I thought it would be easy."

Violations: New Asymmetries

The critical glitch between matter and antimatter showed up again, in two new results announced at Fermilab.

In February, scientists at the CDF collaboration cautiously reported finding "tantalizing" evidence of CP violation in neutral B mesons. CP violation, the slight asymmetry in the behavior of matter and antimatter, was discovered in neutral K mesons by James Cronin and Val Fitch in 1964 (see "Nobel '99," Pg. 4). The CDF results were the first evidence in B mesons, and the first results in any particles other than K mesons (kaons).

And just a month later, the KTeV (Kaons at the Tevatron) experiment announced a startlingly large value in the special case called direct CP violation. The value of this key ratio, called epsilon prime over epsilon, underscored with greater precision an effect observed in 1988 by the NA31 experiment at CERN, the European particle physics laboratory in Switzerland.

Groundbreaking: Minos and Auger

The Iron Range of Northeastern Minnesota calls itself the "End of the Road," but a July 20 ceremony represented the next step for the Main Injector Neutrino Oscillation Search.

A half-mile underground in the former iron mine, officials from DOE, Fermilab, and the University of Minnesota swung picks to begin opening a cavern where a 5,000-ton detector will be built. A beam of muon neutrinos will be sent though the earth from Fermilab to the Soudan Mine, 450 miles away; if the beam has a different composition in the detector than it did at its source, that change or oscillation will mean that neutrinos have mass. Neutrinos are so numerous in nature that even a small mass would change our understanding of the composition of the universe.

Far south, in the desert of Argentina, another groundbreaking ceremony in March initiated the construction of 1,600 water-tank detectors (3,000 gallons each) over an area the size of Rhode Island. The Pierre Auger Observatory is investigating the mystery of high-energy cosmic rays, which carry an energy more than 100 million times as great as the Tevatron, the world's highest-energy particle accelerator.

Skygazing: New Quasars

Quasars, or quasi-stellar objects, are another cosmic mystery: they pack the brightness of more than 100 galaxies into a space no bigger than our solar system.

The Sloan Digital Sky Survey, aiming for a high-resolution, three-dimensional mapping of one-fourth of the night sky, was still in shakedown mode when it produced big news just a year ago: it observed the most distant quasar ever recorded.

The telescope at Apache Point, New Mexico, spotted a quasar with a red shift of five, meaning the light had begun its trek when the universe was less than a billion years old and less than a sixth of its present size. Red shift measures the lengthening of light waves as the source recedes from its observer, similar to the lowering in pitch as a sound's source moves away from us.

Computing: Hub for CMS

Fermilab will become a Regional Center for storing and distributing data when the Compact Muon Solenoid experiment begins generating physics results from the Large Hadron Collider at CERN.

In addition to hosting the U.S. collaboration building subassemblies for the CMS detector, Fermilab will also become the collaboration's host laboratory for software, analysis and computing support. As host, Fermilab will have a continually updated copy of all the data used for analysis at CERN, and will make it available to all scientists at all universities and laboratories in the U.S. collaboration of 35 institutions in 19 states.

Computing Division head Matthias Kasemann is the interim manager for the project, which has received initial approval and funding from DOE and the National Science Foundation.

On the Move: CERN Components

The U.S. commitment for LHC accelerator and detector contributions at CERN is $531 million over eight years, and Fermilab is home to two contributing groups.

The US/CMS collaboration, which includes Fermilab, Lawrence Livermore National Lab and Los Alamos National Lab, has gone into production mode with components for the detector. The Fermilab efforts focus on the hadron calorimeter, and on the muon Cathode Strip Chambers.

Another collaboration, coordinating efforts with Fermilab, Lawrence Berkeley National Lab and Brookhaven National Lab, is producing LHC superconducting magnets and their associated systems. Fermilab has delivered a magnet heat exchange test unit; heat exchanger test unit modules have all been delivered to Fermilab from the vendors, and are undergoing final inspection before shipment to CERN. The last in a series of model magnets is being tested, with production due to begin in the spring of 2000.

On the Rise: Lab-Wide Safety

Fermilab's injury rate has improved to the level where it might be the lowest in the Lab's 30-year history. Symbolizing the improvement is the Technical Division's Material Control Department, which has gone more than four years without an injury serious enough to cause an employee to miss a workday.

That record is all the more impressive considering that much of that four-year period was devoted to handling hundreds of magnets for the construction of the Main Injector and the Antiproton Recycler. Those magnets can weigh up to 20 tons each, and even their components are heavy enough to require lifting by crane, sling or forklift, and transport by tractor-trailer.

Said Director Witherell: "Though the numbers are important, it is the people at the Laboratory who really matter. We owe it to each other to keep our Laboratory a safe place to work."

On the Mend: Run II Schedule

Plans to begin Run II of the Tevatron in 2000 have been pushed back to 2001, but collaborations at the CDF and DZero detectors are turning a problem around by turning away from the Lab's historic practice of basing schedules on the most optimistic assumptions.

Competing for manpower and funding has been difficult for the detector groups, whose upgrades incorporate unique systems never designed, built or tested before, requiring extensive research and development. In addition, managing the efforts of 500 independent collaborators has been likened to "herding cats."

But the Lab has made a top priority of completing the upgrades, and both detector groups are paying rigorous attention to new schedules. At CDF, each member of the collaboration must participate in "installation shifts," running through June 2000, as a requirement for authorship on any subsequent results.

The Future: Going Global

Can the world's accelerator-building nations surmount political and economic obstacles, and join forces for a global next step in high-energy physics?

The high-powered International Committee on Future Accelerators, including the directors of the world's major particle physics laboratories, met at Fermilab in October to discuss the challenge. The next-generation machine—whether the Next Linear Collider, the Very Large Hadron Collider, or a muon collider—will require money and resources beyond the reach of any single country, and cooperation beyond the scope of any achieved so far.

The conference made no recommendation on a choice of machine, but clearly saw no doubt about the future of the field.

"We must try to write a global road map, and address regional balances over time," said Jonathan Dorfan, Director of Stanford Linear Accelerator Center. "Intense regionalism is an invitation to extinction."