Perhaps I’m biased, but Fermilab is one of my favorite places. Not only is it home to the biggest kind of Big Science — the Tevatron — but it also manages to be the quirkiest of the National Labs. I went there for the first time as a science writing intern in the summer of 2005 and, as this trip should make clear, never really looked back.
Fermilab was built on a green field site, meaning that there was almost nothing there before the lab. Since building where there is no existing infrastructure is so much more expensive than upgrading (or simply repurposing) existing lab space and equipment, it is rarely done anymore. The Superconducting Super Collider’s green field construction contributed significantly to its burgeoning cost estimates and thus played a role in its cancellation. By contrast, Brookhaven’s Relativistic Heavy Ion Collider makes use of a myriad of pre-existing accelerator components and the Large Hadron Collider is housed in the tunnel formerly used by CERN’s Large Electron-Positron Collider.
Fermilab was almost singlehandedly designed by the legendary physicist Robert Wilson, who managed to complete his pet project ahead of schedule and under budget by exerting an extraordinary degree of personal control over its construction details. His efficiency, along with the 1960s’ tremendous respect for physics, gave him the freedom to do things his way. In most instances, this freedom resulted in some seriously idiosyncratic architecture.
Additional construction at Fermilab has stayed very close to Wilson’s vision and steps have been taken to preserve the laboratory’s past. The pi poles are scrupulously, if laboriously, protected from woodpecker damage, and the original bubble chamber now serves as a sculpture that looks like something out of Willy Wonka’s factory.
The lab is also home to a herd of bison. In the past, one was killed at the end of every summer for a barbeque, and a stuffed bison head still hangs above the pool table in the lab’s Users’ Center. Today, the bison are left to peacefully make their home in part of the lab’s prairie preserve.
If Wilson could afford to build his weird dream lab because he stuck to the budget, Fermilab can afford to remain this quirky and strange because it is home to the Tevatron, which has been the world’s most powerful particle accelerator since 1983. The machine’s most important discovery was the 1995 observation of the top quark, which filled in the last missing piece in the Standard Model’s prediction of six quarks. (The fifth quark to be observed, the bottom quark, was discovered at Fermilab, too, but using fixed target experiments in 1977.) The Tevatron has been the heart of particle physics for the last 25+ years, and its presence has defined Fermilab since it was built.
Even when the data doesn’t shake the foundations of physics, the Tevatron provides a view into an aspect of reality that was previously accessible only to theory and imagination. As the most powerful collider in the world for so long, it remains the only place in the world — indeed, perhaps the only place in the universe since shortly after the Big Bang — where certain conditions and types of matter exist.
The Tevatron has two detectors: the Collider Detector Facility (CDF) and DZero, which is named for its position on the accelerator ring. We visited CDF on this visit:
Of course, once can’t talk about the Tevatron these days without talking about the LHC. Once it gets up and running, the LHC will produce collisions that are seven times more powerful than the ones at the Tevatron — essentially leaving the older accelerator in the dust when it comes to the search for the Higgs boson, supersymmetry, and other fields of Beyond the Standard Model physics that require higher energy machines. So what happens to the Tevatron? What happens to Fermilab? And more importantly, what happens to the thousands of scientists who have built their careers (and often, their lives) around Fermilab’s accelerator?
When I worked at Fermilab four years ago, I never heard anything but enthusiasm for and excitement about the prospect of the LHC. But it was clearly difficult for the lab to imagine itself playing second-highest-energy fiddle to CERN. Wilson Hall is even home to a remote LHC control room, so scientists at Fermilab can monitor the machine while their CERN counterparts are sleeping. A practical move, but one that seems to scream, “Don’t forget about us!”
In 2005, the Tevatron was scheduled to be shut down in 2009. Now they’re talking about running through 2011, and given how difficult starting up the LHC is proving to be, the shut down date could be pushed back even further. When I asked CDF’s Gene Flannagan when he thought we’d be saying goodbye to the machine, he said, “They’ve been talking about turning the Tevatron off since I came here in 1999, so I have no idea.”
The Tevatron is now running better than ever. The machine’s luminosity (number of collisions) has increased so much in the last few years that it’s actually been difficult for the experiments to keep up. CDF expects to double its data sets in the next two years, and after decades of operation, the scientists have a pretty good idea of where to look for the most exciting results. It’s even possible the Tevatron experiments could detect the Higgs, if they get lucky and the particle has a low enough mass.
No matter how many low-mass Higgs searches the detectors run or how many remote control rooms Fermilab builds, the Tevatron will never be the LHC. But that doesn’t mean it’s automatically obsolete. In fact, as long as the LHC remains mired in technical difficulties, the Tevatron’s independence may prove to be its greatest strength. Shiny new machines dominate news about Big Science, but often older means wiser. I was struck by how smoothly everything runs at CDF — they actually manage to take date 24 hours a day when the machine is running, and many of the youngest collaborators have never even seen the detector because things need to be fixed so rarely. After 25 years, the Tevatron and the scientists who work with it know what they’re doing.
I have no doubt that the Tevatron will remain a vital part of high energy physics for many years, whether in its current capacity or serving a new and unexpected purpose. If Oak Ridge can find use for an 8-track player, Fermilab should be able to keep the second most powerful particle accelerator in the world alive.
Stay tuned for more about Fermilab’s neutrino research and the development of the International Linear Collider (ILC), the postulated successor to the LHC.