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Here's a traffic alert well in advance for drivers outside Chicago. A 50-foot metallic donut wrapped in plastic and traveling 3 to 4 miles an hour threatens to block your path later this month. It's an electromagnetic particle storage ring. This $20-million piece of equipment is just starting its 3,200-mile journey. It's leaving the East Coast. And by late July, it will be well on its way, carried up the Des Plaines River. Finally, it will take to the street on its way to the Fermi National Laboratory. From member station WSHU, Charles Lane explains.
CHARLES LANE, BYLINE: It looks almost like the Millennium Falcon, creeping ever so slowing, taking up the entire roadway on New York's Long Island. A team of spotters walks along side calling out trees that need cutting and road signs that need to be taken down.
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LANE: Its name is the Muon g-2, and Chris Polly is the lead scientist for the ring's experiments.
CHRIS POLLY: It's an electromagnet, a very powerful electromagnet capable of carrying 5,200 amps of current. It creates a very strong magnetic field that allows us to store a special particle called a muon.
LANE: Muons are a sort of phantom particle that only exist for a very short time after a particle collision. The g-2 traps them and then uses them to probe for evidence of other new particles no one has ever seen before. Back in 2001, Brookhaven scientists found hints of new particles, but to be sure, scientists need more muons.
Fermi National Lab, outside of Chicago, has a big accelerator that can produce loads of them, but no ring. So you just have to get the ring to the accelerator.
POLLY: The weight is really not a problem. It weighs 15 tons, and so, you know, that's sort of the equivalent of, you know, six or seven cars. The difficult part is really the fact that it's 50 feet in diameter. It doesn't come apart, and we don't want it to flex by more than three millimeters.
LANE: The easiest way to Chicago for a 50-foot ring is by sea barge. It'll go down the East Coast, around Florida, through the Gulf of Mexico and up the Tombigbee, Missouri, and Des Plaines rivers. But even getting to the barge is difficult. They thought about airlifting it by helicopter, but...
POLLY: It turns out you can't just pick up a 15-ton ring and fly it over people's houses without asking them first. And that might have been possible through six miles of Long Island, but it was impossible over 30 miles of Chicago suburbs.
LANE: So on land, it moves at night in a rolling barricade on a 64-wheel tractor-trailer. Terry Emmert is in charge of the move. He had lights strung on the ring that make it look like it's levitating through town.
TERRY EMMERT: Probably 1,000 people out alongside the road, cheering on and sitting in lounge chairs, drinking their coffee at 2 o'clock in the morning. It was amazing to see that many people out at that time of the morning.
LANE: Once it reaches the shoreline, a crane lifts the g-2. It slowly hovers through the sky, swaying gently in the breeze as seagulls dance about. After a soft touchdown, workers start bolting it to a special hydro dampening system.
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EMMERT: It did look like a big flying saucer coming across there, a big white one. And it looked like it was just floating across from the trailer over to the barge.
LANE: Emmert had the ring shrink-wrapped in plastic to protect it from the sun and salt water. Weather is his biggest fear, so it will head to port at the first sign of rough seas. The logistics will be far more complicated once it reaches Chicago the last week of July. There, crews will have to take down utility poles and toll plazas to cut the 50-foot wide path needed. The move is costing about $3 million, but scientists say that's far cheaper than building a brand-new particle ring. For NPR News, I'm Charles Lane.