A Bitter electromagnet or Bitter solenoid is a type of electromagnet made of metal plates and insulating spacers stacked in a helix configuration, 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. Image File history File links Frog_diamagnetic_levitation. ... Image File history File links Frog_diamagnetic_levitation. ... An electromagnet is a type of magnet in which the magnetic field is produced by a flow of electric current. ... Hot metal work from a blacksmith Look up Metal in Wiktionary, the free dictionary. ... // Definition An Insulator is a material or object which resists the flow of electric charge. ... A helix (pl: helices), from the Greek word έλικας/έλιξ, is a twisted shape like a spring, screw or a spiral staircase. ... Francis Bitter (July 22, 1902 - July 26, 1967) was an American physicist. ...

Bitter electromagnets are used to produce extremely strong magnetic fields (up to 60 teslas as of 2006). The stacked plate design is mechanically very sturdy, to withstand the outward pressure produced by Lorentz forces, which increase as the square of the magnetic field strength. Additionally, water circulates through holes in the plates as a coolant, as resistive heating also increases as the square of the magnetic field strength. It has been suggested that Magnetic field density be merged into this article or section. ... The tesla (symbol T) is the SI derived unit of magnetic flux density (or magnetic induction). ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... In physics, the Lorentz force is the force exerted on a charged particle in an electromagnetic field. ... A coolant, or heat transfer fluid, is a fluid which flows through a device in order to prevent its overheating, transferring the heat produced by the device to other devices that utilize or dissipate it. ... In electronics, and in physics more broadly, Joule heating refers to the increase in temperature of a conductor as a result of resistance to an electrical current flowing through it. ...

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 teslas, due to flux creep, though theoretical limits are higher). A magnet levitating above a high-temperature superconductor (with boiling liquid nitrogen underneath) demonstrates the Meissner effect. ... Flux pinning is the phenomenon where a magnets lines of force (called flux) become trapped or pinned inside a superconducting material. ...

External links

• National High Magnetic Field Laboratory Core Projects Page at Florida State University
• Levitating frog and a ball of water inside a Bitter solenoid at the High Field Magnet Laboratory
• Diagrams and description of the Bitter solenoid used in the frog levitation demonstration