Fermilab's new accelerator work enters next phase

Fermilab has started the second phase of construction on a facility tied into the next generation of particle accelerators, preparing for the eventual day its old workhorse, the legendary Tevatron, is shut down.

Two above-ground buildings are being constructed next to the New Muon building, which is being converted into the Superconducting Radio-Frequency (SRF) accelerator test facility. Work is nearly complete on a tunnel extension off one end of New Muon that will help house a linear accelerator.

The interior of the New Muon building's test hall was gutted starting in March, and the first length of "test cave" was built. That cave will extend into the new tunnel, for a total length of 460 feet.

The cave will house six cryogenic modules. Electrons will be shot into the accelerator, and will receive bumps of energy from radio-frequency waves along the way. At the end of the tunnel, they will smash into a pile of water-cooled copper, graphite and aluminum.

The modules' cavities will be chilled to -456 degree Fahrenheit, several degrees shy of absolute zero, to eliminate electrical resistance. The less resistance there is, the shorter the accelerator can be, said Jerry Leibfritz, the project's leader.

The idea is to test equipment in the modules for construction of other cryogenic accelerators, including those for the proposed Project X experiment at the Batavia-based federal laboratory and the International Linear Collider. The SRF will also test the capabilities of U.S. companies to manufacture products for such accelerators.

"We had to start planning for the future of Fermilab" for once its famed Tevatron synchronous accelerator is abandoned, Leibfritz said. "We always had big plans of what we wanted to do out here." The circular Tevatron is tentatively scheduled to be shut in 2011, now that the bigger, more powerful CERN accelerator in Europe is operational.

Electrons aren't the only thing about the project being speeded up.

It's being paid for with $52.7 million of money released through the American Recovery and Reinvestment Act.

The first phase is expected to cost $2.8 million. Construction of the cryogenic support buildings is estimated at $4.2 million. Those support buildings store the refrigerating compressors and the chemicals used to cool the cryomodules. About 200 Chicago-area tradesmen have been involved in the construction, doing work for contractor Barton Malow of Minnesota. The rest of the money is going for infrastructure and equipment. Leibfritz expects the work to be finished next fall.

That infusion of ARRA cash moved the project out of a standstill, according to Leibfritz.

Some infrastructure for the test facility was installed in 2007. But then the recession hit, and funding for Fermilab was cut. Employees were forced to take furlough days, and work on the project slowed.

"We would have gotten here eventually," Leibfritz said. "We probably would have done this, but at a much slower pace."