made of plates of metal rather than coil
s 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
s to form the magnet
. This magnet
requires extensive cooling
because of the massive current
s 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.