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A Helmholtz coil Helmholtz coil schematic drawing. A Helmholtz coil is a device for producing a region of nearly uniform magnetic field, named after the German physicist Hermann von Helmholtz. It consists of two electromagnets on the same axis, carrying an equal electric current in the same direction. Besides creating magnetic fields, Helmholtz ...
The Helmholtz equation has a variety of applications in physics and other sciences, including the wave equation, the diffusion equation, and the Schrödinger equation for a free particle. In optics, the Helmholtz equation is the wave equation for the electric field. [1] The equation is named after Hermann von Helmholtz, who studied it in 1860. [2]
The coil cancels the Earth's magnetic field within a central 6-foot (1.8 m) spherical volume. Fluctuations in the ambient field are removed by a servo control, producing stability to half a nanotesla. An artificial magnetic vector can be produced and rotated at a variable rate. 9.42-foot (2.87 m) Helmholtz coils are used for perm/deperm ...
When charged particles move in electric and magnetic fields the following two laws apply: Lorentz force law: = (+),; Newton's second law of motion: = =; where F is the force applied to the ion, m is the mass of the particle, a is the acceleration, Q is the electric charge, E is the electric field, and v × B is the cross product of the ion's velocity and the magnetic flux density.
The Sommerfeld radiation condition is used to solve uniquely the Helmholtz equation. For example, consider the problem of radiation due to a point source in three dimensions, so the function in the Helmholtz equation is () = (), where is the Dirac delta function. This problem has an infinite number of solutions, for example, any function of the ...
Teltron electron beam tube Teltron deflection tube with Helmholtz coils and stand. A teltron tube (named for Teltron Inc., which is now owned by 3B Scientific Ltd.) is a type of cathode ray tube used to demonstrate the properties of electrons.
Helmholtz's polyphonic siren, Hunterian Museum, Glasgow. Hermann Ludwig Ferdinand von Helmholtz (/ ˈ h ɛ l m h oʊ l t s /; German: [ˈhɛʁ.man vɔn ˈhɛlmˌhɔlts]; 31 August 1821 – 8 September 1894; "von" since 1883) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. [2]
The Helmholtz decomposition in three dimensions was first described in 1849 [9] by George Gabriel Stokes for a theory of diffraction. Hermann von Helmholtz published his paper on some hydrodynamic basic equations in 1858, [10] [11] which was part of his research on the Helmholtz's theorems describing the motion of fluid in the vicinity of vortex lines. [11]