Larmor frequency

Description

In physics, Larmor precession (named after Joseph Larmor) is the precession of the magnetic moment of any object with a magnetic moment about an external magnetic field. Objects with magnetic moments have angular momentum and internal currents of electric charge related to their angular momentum; these include electrons, protons, other fermions, many atomic and nuclear systems, as well as classical macroscopic systems. The magnetic field exerts a torque on the magnetic moment.

The phenomenon is similar to the precession of a tilted classical gyroscope in an external gravitational field. The angular momentum vector precesses about the external field axis with an angular frequency known as the Larmor frequency.

The Larmor frequency is important in NMR spectroscopy.