Hybrid Magnets: Best of Both Worlds
Unlike most of the math that goes on at the Magnet Lab, the equation you need to make a more powerful continuous field magnet is pretty easy. Take a very powerful superconducting magnet say, 11.5 tesla and a very powerful resistive magnet say, 33.5 tesla and put them together. What do you get?
The MagLab’s world-record 45 tesla hybrid magnet.
You get a magnet mutt (although around here we prefer the term hybrid). The combo produces a magnet with the most powerful sustained field in the world: the 45 tesla hybrid magnet designed and operated here at the lab. This 35-ton behemoth is in wide demand among scientists across the globe.
There are almost 4 miles of superconducting cable in the Magnet Lab’s 45 tesla hybrid magnet.
Though designs of hybrid magnets differ, the MagLab hybrid consists of a resistive magnet encircled by a superconducting magnet. Most of the 22-foot tall device is made up of systems that keep the magnet cold enough to operate. Vast amounts of deionized water are used to keep the Bitter magnet cool – about 400 liters a second.
One of only a handful of hybrids in the world, this mighty marvel uses in its superconducting portion enough copper wiring for 80 average homes. And that part of the magnet is kept mighty cold (in the neighborhood of -452 degrees Fahrenheit, or -269 degrees Celsius) almost all the time, even when not in use. If the magnet gets to room temperature, it takes at least six weeks to cool it down to operating temperature!
Cutaway of the 45-tesla hybrid magnet.
As impressive as this tool is, magnet engineers here at the lab, widely recognized as the best in the world at what they do, are already at work creating the next generation of hybrid. The Series Connected Hybrid will generate high magnetic fields while using just one-third the power of traditional “all-resistive” magnets.