An Etymological Dictionary of Astronomy and Astrophysics

The radius of the circular motion of a → charged particle moving in a → uniform magnetic field. Same as → gyroradius, → radius of gyration, → cyclotron radius. The Larmor radius (r_L) is obtained by equating the → Lorentz force with the → centripetal force: qvB = mv²/r_L, which leads to r_L = p/(ZeB), where p is → momentum, Z is → atomic number, e is the → electron charge, and B is → magnetic induction. The frequency of this circular motion is known as the → gyrofrequency.

See also: → Larmor frequency; → radius.