- Bitter electromagnet
A Bitter electromagnet or Bitter solenoid is a type of
electromagnet made of circularmetal plates and insulating spacers stacked in a helical configuration, rather than coils of wire. This design was invented and built in 1933 by American physicistFrancis Bitter . In his honor the plates are known as "Bitter plates".Bitter electromagnets are used to produce extremely strong
magnetic field s (up to 60 Tesla as of2006 ). The stacked plate design is mechanically very sturdy, to withstand the outward pressure produced byLorentz force s, which increase as the square of the magnetic field strength. Additionally, water circulates through holes in the plates as acoolant , as resistive heating also increases as the square of the magnetic field strength.Despite the drawback of resistive heating, Bitter electromagnets are used where extremely strong fields are required because superconducting electromagnets cannot operate above the field strength at which the magnet materials cease to be superconducting (typically on the order of 10 to 20 Tesla, due to flux creep, though theoretical limits are higher).
External links
* [http://www.magnet.fsu.edu/magnettechnology/research/magnetprojects/index.html National High Magnetic Field Laboratory Magnet Projects Page] at
Florida State University
* [http://www.hfml.ru.nl/magnets.shtml Magnets at Nijmegen High Field Magnet Laboratory]
* [http://www.hfml.ru.nl/froglev.html Levitating frog] and a ball of water inside a Bitter solenoid at the [http://www.hfml.ru.nl High Field Magnet Laboratory]
* [http://www.hfml.ru.nl/20t-magnet.html Diagrams and description] of the Bitter solenoid used in the frog levitation demonstrationee also
*
superconducting magnet
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