Magnetic attraction. Hundreds of people have come out to see the Muon g-2 ring along its 5000-kilometer route to Fermilab in Illinois.

Reidar Hahn

After 6-Week Journey, Giant Magnet Arrives at Fermilab

Physicists breathed a sigh of relief early this morning as a 15-meter-wide superconducting magnet rolled through the gates of Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois. It was the last step of a nail-biting 5000-kilometer journey that moved the delicate ring-shaped magnet from Brookhaven National Laboratory in Upton, New York, to its new home on the prairie.

The ring is part of an experiment called Muon g-2, which hopes to precisely measure the magnetic moment of an elementary particle called the muon in hopes of detecting long-sought-after hints of new physics. An earlier experiment at Brookhaven produced a result that didn’t agree with the standard model; now, the Fermilab team hopes to conclusively confirm or refute that result by repeating the experiment with an improved muon beam.

The ring’s trip began on 22 June, after bad weather delayed the magnet’s initial departure by 1 week. A truck towed the ring along Long Island’s William Floyd Parkway, arriving at a Long Island port in the wee hours of Monday, 24 June. Then, workers secured the magnet on a barge, which set sail down the Eastern Seaboard. A storm forced a 5-day pause near Norfolk, Virginia, then the barge raced around Florida and across the Gulf of Mexico just ahead of Tropical Storm Chantal. A tugboat named Miss Katie pushed it up a total of three rivers on its way to Lemont, Illinois, where it arrived on Saturday, 20 July.

The magnet has spent the last 3 nights creeping across shuttered Illinois roads on its way to its final destination. At every stop, “the streets [were] just lined with people,” reports Brendan Casey, a Fermilab physicist. The laboratory is hosting a public event to welcome the ring today.

Throughout its journey, the ring was held steady by a 40-ton fixture designed by the heavy haul transportation company Emmert International. The fixture was designed to prevent the magnet from bending or twisting by more than 2 millimeters, which could damage the superconducting coils inside.

Fermilab scientists plan to start testing the magnet within the next few weeks, but won’t know for sure whether the ring survived its journey unscathed until 1 year from now, when they try to cool its coils back down to superconducting temperatures. The team hopes to start taking data in 2016.