Ah, summer road trips — along with drafting behind semitrailers, you can see things like the world’s largest prairie dog, the world’s largest golf tee, and the world’s largest traveling electromagnet. The latter was special for 2013 and probably won’t happen again, however.
This summer, physicists at Fermilab and Brookhaven National Laboratory sent a 50-foot electromagnet on an unprecedented journey along the eastern seaboard, down around Florida and the Gulf Coast, up the Mississippi River, and onto interstate highways to Chicago. The electromagnet contains fragile coils that could not twist or move more than three millimeters, otherwise it wouldn’t work in a powerful new physics experiment. Thanks in part to this sensitivity, the magnet took 35 days to travel 3,200 miles by truck and barge.
The Big Move was much cheaper than building an entirely new $30 million giant magnet, according to Fermilab. But what is the point of giant magnets like this, anyway? What can you do with them? Actually, a whole lot. A really powerful magnetic field is useful for studying quantum mechanics, how drugs work in the brain, what molecules are in crude oil, and much more, according to the magnet experts at the National High Magnetic Field Laboratory.
Powerful magnets produce magnetic fields of several tesla, which is a lot. Here's a comparison: One tesla is 10,000 gauss. A fridge magnet has about 10 gauss, and the Earth’s magnetic field provides about 0.5 gauss. A magnetic resonance imaging scanner at your doctor’s office has a 1.5 tesla magnet. Last year, scientists at Los Alamos National Lab produced a magnet with a whopping 100 tesla — that’s about 2 million times stronger than Earth’s magnetic field. Scientists have created even greater magnetic fields before, but the magnets are so powerful they literally tear themselves to pieces.
Magnets for physics
The LANL ubermagnet, and other ultra-powerful magnets at Florida-based NHMF facilities, are used for a bunch of experiments. But Fermilab’s new electromagnet is for just one experiment, called Muon g-2 (pronounced "gee minus two"). It will measure the tiny wobbles of subatomic particles called muons. Muons are negatively charged particles, heavier than electrons, that only live 2.2 millionths of a second. They wobble like a spinning top, and they rotate when they’re placed in a magnetic field. The way they rotate provides clues about subatomic quantum effects that could tell physicists interesting things — like whether there are as-yet undiscovered particles zipping around out there.
Brookhaven National Lab built the electromagnet to study this wobbling phenomenon, and in the 1990s, scientists there found some interesting hints of physics beyond what scientists predicted. Now physicists want to try it again using Fermilab’s more powerful equipment. The problem is, short-lived muons need a place to call home — that’s where the electromagnet comes in. It will work like a corral for the particles, herding them around its magnetic field near the speed of light so scientists can examine them.
Fermilab needed a way to get the magnet, and scientists had a few ideas. Coordinators thought about putting it on a truck and driving it across interstate highways. They thought about attaching it to a helicopter, and just choppering it 900 miles as the crow flies. Ultimately, after many months of research, scientists decided the best way was to shrink-wrap it, pluck it up, and put it on a barge at Long Island. Sailing around half the continent meant that for most of its journey, the magnet wouldn’t need roads.
Magnets for medicine and more
Powerful magnets are important for studying future computer technology, including spintronics and quantum mechanics. Not all magnetic fields are about physical science, however. MRI machines revolutionized medicine, but even more powerful magnets could do it again, paving the way for new drugs, protein therapies and more. The LANL 100-tesla beast could be used as a nanoscale microscope, examining protein structures in viruses. In Florida, researchers are using a 45 tesla continuous field magnet to look at enzymes involved in HIV.
Magnets can help agriculture, too. Earlier this summer, researchers at the MagLab reported they might be able to help a key Florida industry: citrus farms. Insects plague orange groves by carrying diseases, notably citrus greening, and by eating the plants themselves. One such pest is the diaprepes root weevil (Diaprepes abbreviatus), which happens to use chemicals called pheromones to communicate. Fatma Kaplan at the University of Florida and Peter E. Teal of the U.S. Department of Agriculture used high-resolution nuclear magnetic resonance at UF to discovered a mating pheromone that male weevils release to attract females. The researchers think they can use it in traps to control insect populations.
So far, all of these applications are for the good of humanity, but we're sure that there are plenty of evil geniuses out there with some different ideas. What would you do with a really powerful magnet?