By all reasonable standards, the Fermi National Accelerator Laboratory has been a roaring success.
The research base for scientists from more than 100 universities in the United States, Fermilab houses the Tevatron, which for most of the past two decades has been the world’s most powerful particle collider. Its groundbreaking discoveries include things that can’t be seen but are essential building blocks of our material world: subatomic particles called the bottom quark, the top quark, and the tau neutrino. “It’s had a brilliant history,” says Fermilab’s director, Piermaria J. Oddone.
Yet all good things must come to an end. The Tevatron faces a scheduled shutdown this year. The European science agency CERN has spent billions to build an even larger machine, the 17-mile-long Large Hadron Collider, outside Geneva. And Congress—which already pumps nearly $1-billion each year into high-energy physics research—seems increasingly reluctant to keep spending money on the smaller and older Tevatron.
To cope with the loss, Fermilab officials and the 1,500 university scientists who work here are banking on two new strategies to keep U.S. high-energy physics relevant and competitive. One is to produce record numbers of particles under a scheme called Project X, increasing the potential rate of new discoveries. The other is to add far-flung telescopes and ground-based cosmic-particle detectors to their repertoire, allowing them to observe the super-powered—and free—atom-smashing device known as the universe.
The options are creating some hope among young scientists who might otherwise be buying plane tickets to Switzerland. Zachary L. Marshall, who recently completed his doctorate in physics at the California Institute of Technology while working at CERN, says Project X would be an attractive asset for him and would allow types of particle-physics studies that even the Large Hadron Collider “is simply not capable of doing.”
Universities get major benefits from Fermilab. Those using it—led by the University of Chicago, the University of Rochester, and the University of Virginia—can let faculty and students use the federally financed facility without charge. That includes use of the Tevatron, a four-mile-long underground racetrack that is lined with magnets to steer particle beams into one another and is studded with advanced detectors to track new particles produced when the beams collide.
The job of keeping the facility world class has become tougher as economic worries weigh on Congress. Most federal support for high-energy physics comes through an allocation, now about $800-million a year, to the Department of Energy. Fermilab gets about $400-million, a level that has had little or no increase in recent years, prompting layoffs. Scientists have asked the federal government for a three-year reprieve for the Tevatron so it can hunt one last prized particle, the never-seen Higgs boson, but the appeal faces major hurdles in an era of federal budget cutbacks.
In that discouraging environment, Fermilab’s leadership, drawn primarily from the University of Chicago, is hoping to maintain scientific relevance by emphasizing high-volume particle generation and heavenly observations.
‘Intensity Frontier’
Project X is key to the particle-generation strategy, which Fermilab officials call “the intensity frontier.” If approved by Congress, the program would have as its focal point an array of 48 high-precision particle generators that would triple the output of the particle generator now feeding the Tevatron and other projects at Fermilab. Project X would shoot out the world’s most intense beams of protons and other subatomic particles used in a variety of experiments.
But unlike a major new particle collider, covering miles of ground and costing billions of dollars, Project X would carry a price tag in the range of hundreds of millions of dollars. Its ability to generate intense streams of particles would greatly help researchers exploring subjects such as neutrinos, “probably the least well understood particles in the known universe,” says Mr. Marshall.
Then there is the cosmic-exploration strategy. The idea is that researchers would be able to look to the sky in search of extremely high-speed particle collisions and other phenomena that behemoths like the Large Hadron Collider are merely trying to replicate. It’s a matter of knowing how and where to look, says Craig J. Hogan, a professor of astronomy and astrophysics at Chicago. “Nature,” he says, “actually does more extreme things than we could do in the lab.”
One of Mr. Hogan’s projects is a $50-million overhaul of the 40-year-old Cerro Tololo Inter-American Observatory, in Chile. There he is leading a 120-scientist team from Fermilab that’s designing and installing a 20,000-pound camera that can search the galaxies for signs of dark matter and dark energy—the unseen majority of matter and energy lurking in space. A series of efforts by Fermilab, such as the overhaul of the Chilean telescope, are aimed at figuring out what the invisible material is made of.
Other Fermilab projects are much smaller. Another one led by Mr. Hogan, costing about $2-million in federal money, is his creation of a “holometer.” Basically an empty tube through which lasers are fired, the new instrument is intended to precisely measure light moving through a vacuum to see whether space and time flow smoothly or, as Mr. Hogan suspects, become grainy and pixilated at extremely small scales.
Fermilab’s ability to probe such major unanswered questions about the universe is proving attractive to researchers, says Marvin L. Marshak, a professor of physics at the University of Minnesota who studies neutrinos at Fermilab. “My colleagues look at a sector full of surprises and hope they can come up with the next surprise to discover,” he says.
Big Mysteries
The number of scientists at Fermilab shows that the facility is still attractive to many researchers, even though CERN is clearly the hot new destination. As the Large Hadron Collider’s activity was ramped up, the U.S. contingent working at CERN ballooned, jumping 146 percent, to 1,609 staff members, from 2005 to 2010. CERN’s total registered users increased 55 percent during that period to 9,923. Fermilab had a 2-percent increase in users during the same period, to 2,311, with growth from overseas canceling a 6-percent decline from American universities.
The continuing appeal reflects scientists’ confidence in Fermilab’s strategies for doing cutting-edge work on big mysteries without the high-speed collisions of the Tevatron. In addition to questions about dark matter, there are conundrums about the cause behind gravity. And there are questions about how matter itself came to dominate over its functional opposite, antimatter.
Particles and antiparticles give off energy when combined, and they are believed to have formed in equal amounts at the formation of the universe in the Big Bang. But matter now dominates in the universe, and it’s not clear why. Neutrinos, nearly massless particles created naturally from radioactive decay or nuclear reactions, may hold a clue. Their neutral charge raises the possibility that neutrinos and antineutrinos are the same thing, since a particle carries the opposite charge of its antiparticle. If matter does include all forms of neutrinos—even the antiversions—that might help explain why matter is dominant.. Lacking any better explanation, and given the difficulty of capturing neutrinos, they remain a major suspect in efforts to explain the dominance of matter.
Mr. Marshak is involved in at least three existing and planned systems for creating neutrinos at Fermilab and firing them north and west into sophisticated detectors in Minnesota and South Dakota. The lengthy distance is necessary because neutrinos come in three main varieties and can apparently change from one to another. The hundreds of miles of travel gives neutrinos time—if only milliseconds—to make the transformation, ideally helping scientists derive clues to how and why the neutrinos act as they do.
Even researchers who do not study neutrinos directly benefit from a greater understanding of their properties, because the uncertainties surrounding neutrinos can greatly complicate the calculations of physicists trying to analyze the debris of a high-speed particle collision.
This offers an example of how the pursuit of high-energy physics can lead to solutions beyond the question at hand. One of the best-known benefits has been the development of the World Wide Web, created by researchers at CERN to share information about their particle chases with scientists around the world. Other examples are the development of scanner technologies used in medicine and security equipment, irradiation technologies used to scrub drinking water and smokestack emissions, and confinement technologies used in the development of nuclear fusion as an energy source.
But to the research community, spinoffs are not the essential point. As the lone federal lab dedicated to high-energy particle physics, Fermilab is for many researchers a critical component of science-based strategies to ensure the nation’s educational and economic competitiveness.
This explains the current lobbying of Congress for money to build the Project X machine. With less hope, researchers are also pushing for a proposed “international linear accelerator” that would collide extremely tiny particles such as electrons. The price tag for this, nearly $7-billion, makes it unlikely that the proposed accelerator would end up in Illinois.
Which makes other, smaller projects even more important. “It’s crucial to develop a viable program for Fermilab,” says Barry C. Barish, a professor emeritus of physics at Caltech. “If the whole U.S. program became dependent on offshore facilities, in time it wouldn’t be very viable.”
