Gyroradius

The gyroradius (also known as radius of gyration, Larmor radius or cyclotron radius) is the radius of the circular motion of a charged particle in the presence of a uniform magnetic field.

where

  • is the gyroradius,
  • is the mass of the charged particle,
  • is the velocity component perpendicular to the direction of the magnetic field,
  • is the charge of the particle, and
  • is the constant magnetic field.

(All units are in SI)

Similarly, the frequency of this circular motion is known as the gyrofrequency or cyclotron frequency, and is given in radian/second by:

and in Hz by:

For electrons, this works out to be

Read more about Gyroradius:  Relativistic Case, Derivation