:: By Zak Stambor

:: Photo by Fermilab

Chicago Journal ::

Fermi National Accelerator Laboratory looks to the future beyond operating the world's largest particle accelerator.

For more than 20 years Fermi Nat-ional Accelerator Laboratory has housed the Tevatron, the world’s largest particle accelerator. The accelerator, which uses electromagnetic fields to propel and collide electrically charged particles derived from hydrogen gas, has allowed the Batavia, Illinois–based facility to explore the universe’s fundamental building blocks, such as the top quark, the most massive known elementary particle.

Before Fermilab’s planned shutdown of its Tevatron particle accelerator, it replaced a number of the Tevatron’s components, similar to this drift tube that guides particles.

But next May the European Organization for Nuclear Research, also known as CERN, is opening a particle accelerator seven times more powerful than Fermi’s, which the University and the Universities Research Association jointly operate. Having recognized the Tevatron’s high operation and maintenance costs and its inability to compete with the CERN accelerator, the Batavia facility plans to shut down the accelerator in 2009.

In the interim, Roger Dixon, head of Fermi’s accelerator–division, is in a race for the lab to claim a few discoveries. “This is the first time that I have found myself in the strange position where I will no longer be in charge of the most powerful physics tool in the world,” says Dixon, who, combined with Paul Czarapata, deputy division head, has worked at Fermi for 65 years. “The fact that they’re coming along is having a dramatic impact on our mental state. [We’re] driven to get as much out of this machine as we can.”

Among the discoveries Fermi hopes to claim in the next few years is the elusive, theoretical particle called the Higgs boson, the crucial missing piece—or pieces—of particle physics’ Standard Model theory. The theory describes the elementary particles that make up all matter; in the model’s purest form, all particles are massless. But because mass does exist, physicists believe the Higgs field must exist. If it does not, the 37-year-old theory could be overturned.

The more discoveries Fermi can make before the shutdown, the greater the likelihood the global physics community will choose it from a slew of European and Asian competitors to host the International Linear Collider, says Dixon. That project, also known as ILC, is a long-range, worldwide plan to build a $15–$20 billion 35-kilometer accelerator that would piggyback on the CERN facility’s findings to explore such areas as dark matter, the hypothetical matter of unknown composition thought to make up roughly 25 percent of the universe.

Because the ILC may not begin construction until 2015 or later, Fermi is also working on another, shorter-term plan called Project X, a $500 million linear accelerator that could be ready to operate by 2015. A possible stepping-stone to help Fermi compete to host ILC, Project X will explore such fundamental questions as why the universe is made of matter and how it evolved, says Young-Kee Kim, a University physics professor and Fermilab deputy director.

Fermi plans to garner approval and funding for Project X in 2010, around the same time that the facilities’ scientists are winding down their analyses of the Tevatron’s final experiments. By around that time, Fermi also should have a firmer grasp on ILC’s timeline, since CERN’s facility will be fully operational. If Project X is approved and financed, construction could begin later the same year.

Regardless of whether Project X or ILC comes to pass, Fermi will continue to conduct smaller experiments using the facility’s other accelerators. But Project X would help Fermi attract and keep talent, says Dixon, as well as maintain its intellectual energy and institutional knowledge. “If we can build and run [Project X] and get neutrino and other physics research out while we wait to see what happens with ILC we don’t have to wait for approval,” he stresses. “And we don’t lose our momentum.”

Maintaining cutting-edge research at Fermi—and other spots besides CERN—is important for the field, says Dixon. “The world is at a crossroads where we have to ask ourselves whether we want to reduce to one [large-scale] accelerator and not do this research anywhere else. A lot of us feel that is not the direction for the field to go.”