Larmor precession

In physics, Larmor precession (named after Joseph Larmor) refers to the precession of the magnetic moments of electrons, atomic nuclei, and atoms about an external magnetic field. Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. Sir Joseph Larmor ( 11 July 1857 Magheragall, County Antrim, Northern Ireland – 19 May 1942 Holywood Precession refers to a change in the direction of the axis of a rotating object In Physics, Astronomy, Chemistry, and Electrical engineering, the term magnetic moment of a system (such as a loop of Electric current The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J The nucleus of an Atom is the very dense region consisting of Nucleons ( Protons and Neutrons, at the center of an atom History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny In Physics, a magnetic field is a Vector field that permeates space and which can exert a magnetic force on moving Electric charges The magnetic field exerts a torque on the magnetic moment,

$\vec{\Gamma} = \vec{\mu}\times\vec{B}= \gamma\vec{J}\times\vec{B}$

where $\vec{\Gamma}$ is the torque, $\vec{J}$ is the angular momentum vector, $\vec{B}$ is the external magnetic field, $\times$ is the cross product, and $\ \gamma$ is the gyromagnetic ratio which gives the proportionality constant between the magnetic moment and the angular momentum. A torque (τ in Physics, also called a moment (of force is a pseudo- vector that measures the tendency of a force to rotate an object about In Physics, the angular momentum of a particle about an origin is a vector quantity equal to the mass of the particle multiplied by the Cross product of the position In Mathematics, the cross product is a Binary operation on two vectors in a three-dimensional Euclidean space that results in another vector which In Physics, the gyromagnetic ratio (also sometimes known as the magnetogyric ratio in other disciplines of a particle or system is the Ratio of its The angular momentum vector $\vec{J}$ precesses about the external field axis with an angular frequency known as the Larmor frequency,

$\ \omega = \gamma B$

where $\ \omega$ is the angular frequency and B is the magnitude of the magnetic field. Do not confuse with Angular velocity In Physics (specifically Mechanics and Electrical engineering) angular frequency Do not confuse with Angular velocity In Physics (specifically Mechanics and Electrical engineering) angular frequency

A famous 1935 paper published by Lev Landau and Evgeny Lifshitz predicted the existence of ferromagnetic resonance of the Larmor precession, which was verified experimentally and independently by J. Lev Davidovich Landau ( Russian language: Ле́в Дави́дович Ланда́у ( January 22, 1908 &ndash April 1, 1968 Evgeny Mikhailovich Lifshitz (Евгений Михайлович Лифшиц February 21 1915 &ndash October 29 1985) was a leading Soviet Ferromagnetic resonance, or FMR is a Spectroscopic technique to probe the Magnetization of Ferromagnetic materials H. E. Griffiths (UK) and E. K. Zavoiskij (USSR) in 1946.

Larmor precession is important in nuclear magnetic resonance.

Dictionary

-noun

(physics) the precession of the motion of charged particles, or particles having a magnetic moment, in a magnetic field

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