Home of the Florida Bitter Magnet
The resistive magnets built at the National High Magnetic Field Laboratory are the highest-field resistive magnets in the world. They use a technology called the Florida Bitter magnet, invented right here in Tallahassee. The approach was first done by Francis Bitter in the 1930s, hence the name Bitter magnet. The Florida Bitter magnet, developed in the 1990s, improved the technology dramatically by optimizing the shape and spacing of the cooling holes—increasing efficiency by 40%. Now, 4 out of 5 of the largest magnet labs in the world use the Florida Bitter magnet technology.
How it Works
Florida Bitter magnets use copper sheet metal with lots of cooling holes in it, as well as insulating sheets with the same cooling hole pattern; they are stacked into a helix, then put voltage across the coil; high currents flow through the coil, typically about 40,000 amps; cold water flows through the cooling holes at a speed of about 45 MPH. (If you didn’t have the cooling water, the magnet would melt in a couple hundredths of a second)