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Cryogenics makes good neighbors

 JLab cryo group  members beginning the process of pulling out the failed unit so they can install the Fermilab unit. Courtesy of JLab.

JLab cryo group members beginning the process of pulling out the failed unit so they can install the Fermilab unit. Courtesy of JLab.

It wasn’t like ringing the door bell and asking to borrow a cup of sugar, but it was close.

In August, Jefferson Lab asked Fermilab to pack up its backup turbine for its cryogenics refrigeration unit and send it halfway across the country. Jefferson Lab’s primary turbine was in Europe for normal wear-and-tear repair, overhaul, and design modification, and its spare turbine had just failed.  The options were to lose countless hours of laboratory experiment time while the backup was sent to Europe for repair, or ask a friend for a favor.

Fermilab agreed to help, running the risk of its own equipment failure while its spare was loaned out.

The loan of the highly delicate and complicated turbine went off as sweetly as if the two national laboratories had been sharing a white picket fence. It serves as  the first success to come from a push for increased collaboration that arose when  the two laboratory’s senior engineers began chatting  about their identical cryogenics refrigerators at the Particle Accelerator Conference in Vancouver in May. It is estimated that a handful or fewer of the  more than three-decade-old refrigerators remain operational across the globe.

“Those turbines are essential for the production of liquid helium and take a long time to repair,” says Ruben Carcagno, Fermilab’s technical division head of tests and instrumentation. “They spin at over 2000 revolutions per second, so you need a very fancy mechanical device to sustain that rate without getting damaged. It is not like it is easy to find a similar machine.”

“I took their request very seriously,” Carcagno says.

Fermilab's spare turbine. Courtesy of JLab.

Fermilab's spare turbine. Courtesy of JLab.

Both laboratories specialize in testing superconducting magnets and cavities, some of which could be used in the proposed International Linear Collider, Project X, or another next-generation accelerator.  Working in the small, specialized field of SRF research and development has brought the laboratories closer. Jefferson Lab tests some of Fermilab’s SRF cavities, and both laboratories use the same rare refrigeration unit model.  Sharing know-how and parts helps both laboratories and saves taxpayers money.

“Fermilab and Jefferson Lab had previously collaborated before with Jefferson Lab providing Fermilab with large helium gas vacuum pumps that support 2-kelvin operation in Fermilab’s test facility," Arenius says. "This is another great example of continued cooperation between our two experienced cryogenic system groups.  Fermilab responded very quickly to our need.”

Within 24-hours of the call for help, Fermilab had crafted a hand-made shipping crate filled with padding, drafted an agreement with Jefferson Lab to get the spare back immediately in the rare chance Fermilab’s cryogenics system failed, too,  and put the turbine in the overnight mail to Virginia.

“Cryogenics is a basic utility, not unlike cooling water or electric power, supporting the research of both laboratories.  The ability to exchange cryogenic technical information and equipment loans in times of need benefits each laboratory and the DOE mission,” said Dana Arenius, Jefferson Lab’s cryogenic engineering group leader.  “We certainly look forward to when we can return the favor.”

Fermilab hopes that Jefferson Lab will do that by offering its advice to help Fermilab upgrade its cryogenics system in the Industrial Building 1 Test Facility to support increased cavity testing.

Jefferson Lab operates and maintains the Central Helium Liquefier, the world's largest 2-kelvin refrigerator. Its cryogenics staff also was lauded by peers in 2006 for innovations that saved the lab $1000 a day on cooling costs. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab and the Spallation Neutron Source (SNS) at Oak Ridge National Lab have already benefited from these innovations through collaborations with Jefferson Lab.

“Jefferson Lab is very experienced and skilled with cryogenics systems, and we thought we could have them critique our plans,” said Carcagno.

As well as upgrading the cryogenics at the cavity test area, Fermilab plans to build a new cryogenics plant near the New Muon Lab onsite to allow for testing of  larger strings of  cryomodules, which contain and cool cavities. Together, these projects  will provide the resources and capacity to position Fermilab to design, test and assemble a steady stream of components for the proposed ILC and Project X, officials have said.

-- Tona Kunz and Kandice Carter