Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=223049
Story Retrieval Date: 3/1/2015 12:53:37 AM CST
What’s 50 feet across, 110,000 pounds and so fragile it cannot be tilted more than 2 millimeters?
If you guessed a giant magnetic ring—you’re right. But this superconducting electromagnet could be the key to unlocking the mysteries of the Big Bang.
“The ring is this perfect magnet that you would never want to try to replicate,” said Brendan Casey, a physicist at the Fermi National Accelerator Laboratory in Batavia. It is designed to measure the magnetic “wobble” of subatomic particles called muons—a heavier cousin of the electron that exist for only 2.2 millionths of a second.
Fermilab’s accelerators happen to be the best in the U.S. at creating muons, making it a match made in heaven for the magnetic ring, a gift from Brookhaven National Laboratory. So, on June 16, the ring will depart on a 3,200-mile journey from Brookhaven in New York to Fermilab.
Once the machines are united, scientists will deep-freeze the ring (also known as the cryostat), and shoot muons into it. Muons decay into a positron (an antimatter electron) and two neutrinos. The chargeless neutrinos will fly off, undetected and untouched. But the remaining positively charged positron will spin in the direction the short-lived muon was taking in reaction to the magnets inside the ring. Scientists will measure and analyze the frequency at which the positron spins, “like the revolving light on a lighthouse,” Casey said.
This frequency will determine the accuracy of the existing Standard Model predictions about matter, which physicists have used to identify all known forces and particles. If the experiment finds the existing model to be correct, it will provide a more rigid structure for existing physics and could push scientists to study unknowns such as dark matter and supersymmetry.
The Big Bang theory itself is based on the Standard Model of physics.
However, if the scientists disprove the model, all bets are off—it will usher in an entirely new era of particle physics.
But marrying the accelerators and cryostat turns out to be no small feat.
The ring’s 50-foot diameter requires it to cruise by waterway: down the Atlantic coast, around the tip of Florida, through the Gulf of Mexico and up the Mississippi. There simply aren’t enough roads between New York and Illinois wide enough to accommodate the massive structure.
Adding another layer of complexity to the task, this diva of a machine cannot be tilted more than two millimeters in any direction during the move. If deflected more than a few degrees, the magnets within the cryostat could shift, disrupting the inner workings.
“The ring is one big monolithic thing, to find the exact spot where it was broken and to repair it would add a pretty significant delay,” Casey said.
Even given the complications, headaches and price tag in excess of $3 million, the move is the only viable option. Creating a new particle storage ring from scratch would cost about 10 times more than moving the existing one.
So who does a physicist call to move something as enormous and delicate as the cryostat?
Emmert International, a heavy rigging and transport company, is accustomed to difficult cargo. Their average freight is oil drilling equipment, wind turbines, generators, transformers, and “basically anything specialized that won’t fit on your average truck,” according to Terry Emmert, Emmert International’s executive vice president and founder. But their claim to fame was moving a 340 ton boulder 110 miles from Riverside, Calif. to Los Angeles to be displayed as a permanent art fixture.
Though the company is accustomed to safely delivering difficult packages, the ring provided an unprecedented set of challenges. Emmert’s team of 12, working alongside Fermilab’s scientists, spent six months engineering a transport fixture that could prevent any deflections the magnet might encounter along the way.
“We needed something that wouldn’t twist,” Emmert said of the red frame, which is made of steel and weighs more than 25,000 pounds in itself. The ring will be suspended inside the frame by three wires that in effect allow the ring to float. As the ocean waves knock into it or the transport vehicle hits potholes, the frame absorbs the shock and the wires within tighten or loosen as needed so that the electromagnet hovers undisturbed.
The hardest part of the planning was figuring out the logistics, according to Emmert. In case of hurricanes or tropical storms, the cryostat must be docked until the weather passes. And, if the roadways aren’t wide enough, Emmert’s crew will take out street signs and light poles to accommodate the load, immediately replacing them after passing. So each township or city driven through as well as every port passed had to be informed of the move.
“Over the last year the engineering has been thought out and discussed,” Emmert said, “So right now is kind of the easy part.”
Despite a year of planning, there will still be game-time decisions. For example, the crew may take the Tennessee-Tombigbee Waterway instead of the Mississippi depending on river traffic. And once it arrives in Lemont via the Des Plaines River, the team is still unsure of exactly which roadways to take from there.
“Everything is still preliminary,” according to a representative from the Illinois Tollway Association working with Emmert. Though it is expected to arrive in about five weeks, they still haven’t decided between the Interstate 88 or Warrenville Road.
“It’s going to be a tight fit through the Boughton Road exit on Interstate 355,” said the representative, “This thing takes up four lanes and we only have three. So with the shoulder we’ve only got about a foot on both sides.”
Since the ring can only move at most 10 miles per hour, the travel will take place in the middle of the night, most likely sometime between midnight and 4 a.m. However, movers should be able to go the entire way from where Interstate 355 crosses the Des Plaines River in Lemont to Fermilab in one night.