Building a magnet test facility on a tight budget

Giorgio Apollinari

Giorgio Apollinari, head of the Technical Division, wrote this column.

“Science is the highest personification of the nation because that nation will remain the first which carries the furthest the works of thought and intelligence.” – Louis Pasteur

It’s challenging to develop new research capabilities when budgets are tight. So I’m pleased to announce that the Technical Division is creating a new magnet test facility here at Fermilab by repurposing existing infrastructure and equipment. With the new facility, we will operate and test a set of large, superconducting solenoid magnets that are being built in China under the leadership of Lawrence Berkeley National Laboratory for the Muon Ionizing Cooling Experiment in the UK. These solenoids represent a major DOE contribution to an international project with high visibility.

MICE, located at the Rutherford Appleton Laboratory, will use these magnets to test the concept of ionization cooling for muon beams. A successful result would represent a major step forward in the development of an intense neutrino factory or muon collider.

It is imperative to test and certify bare, superconducting solenoidal magnetic coils at cryogenic temperatures before installing them in cryostats. At present, no facility exists to test the large solenoids for MICE, about 2 meters in diameter. That’s why members of the Muon Accelerator Program contacted and invited the Technical Division to assist LBNL in the development of such a test facility.

In collaboration with the Fermilab Accelerator Division and the Accelerator Physics Center, we determined that Fermilab has the technical and scientific capabilities to set up such a facility, which will serve Fermilab’s long-term needs as well. We will use the Central Helium Liquefier facility, idle since the Tevatron shutdown, and recycle an unused cryostat from the National High Magnetic Field Lab at Florida State University. We are facing a challenging but achievable schedule – the facility needs to be operational for a first test later this year.

The new facility will then also become available to the entire U.S. particle physics community, including testing solenoids for the planned Mu2e experiment at Fermilab. We will also explore how the Illinois Accelerator Research Center at Fermilab and its industrial partners could use the facility.

TD is also helping with the testing of a second set of coils for MICE, called Spectrometer Solenoids, which were designed and built by a local business in California, under LBNL supervision. TD’s Technology and Instrumentation Department provides the special instrumentation necessary to monitor voltages in the coils and their leads. This system is crucial during operation to detect the loss of superconductivity and protect the magnets from a quench. We are in the process of shipping this system to California, where it will be integrated with the rest of the magnet controls.