Physics: Electromagnet made of plates of metal rather than coils of wire. This design was created and built in 1933 by Francis Bitter. In his honor the plates are known as Bitter plates. This type of electromagnet is also called a resistive magnet. Francis Bitter stacked alternating Bitter plates and insulators to form the magnet. This magnet requires extensive cooling because of the massive currents involved and usually the plates have holes drilled in them for chilled water to pass.

A field of 33 Tesla can be achieved with these electromagnets but only at the cost of a great deal of energy ( Florida State University does experiments with them that apparently use 10% of the city of Tallahassee's electrical power output when they are on). I sometimes forget and leave an experiment running over the weekend or overnight, good thing I don't work on these things.