There’s nothing like a fresh coat of paint and the gleam of untrodden floors to get you excited about a new space, especially when they signify the completion of a year-long building renovation to create a mission-critical accelerator R&D facility.
On Jan. 15, roughly 100 Fermilab staff gathered at a ribbon-cutting ceremony at Lab 2 to celebrate the successful conversion of the building from an apprentice machine shop into a facility for the ultraclean assembly of superconducting radio-frequency accelerator cryomodules.
Located in the Fermilab Village, Lab 2 now provides the Technical Division with a much-needed extension for its SRF activities, which have recently expanded thanks to two high-priority projects, SLAC National Accelerator Laboratory’s LCLS-II and Fermilab’s PIP-II.
Over the next several years, one of the primary uses of Lab 2 will be to serve as PIP-II’s cryomodule assembly facility.
“PIP-II represents a big part of the future of Fermilab,” said Fermilab Director Nigel Lockyer at the ribbon-cutting ceremony. He remarked on how the new Lab 2 would advance PIP-II, noting the building’s startling makeover. “The transformation in one year has been remarkable.”
PIP-II is a plan for providing high-intensity proton beams to the laboratory’s experiments. One of its key components is superconducting radio-frequency technology, or SRF, a high-priority R&D area for the laboratory.
Led by Lab 2 Project Director Romesh Sood and Project Manager Sam Posen, employees and contractors created a space where superconducting accelerating cavities – niobium structures used to transfer energy to particle beams as they pass through – could be cleaned and assembled into cryomodules.
To that end, the team demolished a number of Lab 2’s interior walls, tore out old electrical cables and vacuum pipes, filled and covered floor pits, and upgraded the floors via grinding, patching and epoxying.
The work cleared the way for a high-tech cavity production area. About the size of a basketball court, the area comprises spaces for cleaning hardware, degreasing cavities, rinsing cavities with high-pressure water and using nitrogen to blow off equipment.
“We even paid special attention to the nitrogen supply,” Sood said. The nitrogen supply, a large-capacity Dewar flask outside the building, was painted NAL blue to match the Village surroundings. The space around it, once cluttered, was cleared of unnecessary equipment.
Of course, the Dewar installation was more than a cosmetic improvement. At a hefty 900 gallons, the tank only rarely needs to be filled and pipes a continuous supply of nitrogen into the building. Following the theme of repurposing, the Dewar was relocated from the Magnet Storage Building, where it supplied the nitrogen gas that helped protect spare Tevatron magnets from moisture.
The centerpiece of the building is a class 10 cleanroom. Where typical room air contains about 1 billion particles larger than a tenth of a micrometer for every cubic meter, a class 10 cleanroom won’t stand for more than 10,000. Here, gowned-up staff will assemble cavities end to end into strings for the prototype PIP-II cryomodules. Air circulates to prevent particulate matter from entering the cavities during assembly, and the epoxy floor makes for easy cleaning.
“SRF cavities provide extremely efficient acceleration, but they are sensitive to particulates,” Posen said. Particulates can generate stray electrons that degrade cryogenic efficiency, reduce maximum accelerating fields and produce X-rays. “Clean assembly facilities are critical for achieving the best performance possible.”
The other major addition to Lab 2 was the installation of a 12.5-ton-capacity crane. For the PIP-II project, the cavity strings will be installed inside 8-meter-long vacuum vessels. The crane will hoist these massive structures onto trucks for shipping.
Sood and former Technical Division Head Hasan Padamsee, now retired from Fermilab, proposed the Lab 2 renovation over a year ago. Padamsee attended the Jan. 15 ceremony via Skype.
“I’ll admit that when Romesh and Hasan proposed repurposing this building, I was dubious,” said PIP-II Project Manager Steve Holmes at the ribbon-cutting. “But the transformation is pretty astounding.”
At the ceremony, Technical Division Head Sergey Belomestnykh congratulated everyone who worked on Lab 2. He also noted that Lab 2 was the very first building at Fermilab, though in 1968, it looked very different. Resembling an igloo-shaped parachute, the temporary “air building,” as it was called, allowed NAL employees to work on Main Ring magnets. After the air building moved, the permanent Lab 2 was set up in its place. If you visit Lab 2, be sure to look for the racetrack-shaped concrete slab that was part of the original air building.
“Congratulations for completing this facility,” said Pepin Carolan of the Fermi Site Office. “As part of the heart and soul of Fermilab’s future, PIP-II has a strong pulse, and this R&D facility will help keep the blood flowing through that heart.”
Congratulations to Lab 2 Project Director Romesh Sood and Project Manager Sam Posen for a job well done. Thanks also to the following for their contributions to the Lab 2 renovation: the Directorate, Technical Division, PIP-II, SRF Program, Gary Lorenz, Tom Nicol, Miguel Nuñez, Kelly Sedgwick, Bruce Bieritz, Leonardo Ristori, Hasan Padamsee, Sergey Belomestnykh, the Technical Division machine shop, FESS, Procurement and Cryogenic Engineering Department.