Electron in magnetic field equation

1. Jun 9, 2010

ireland01

equation for radius of curvature of relativistic electron in magnetic field?

is this correct:

R = gamma * m * v / e * B

where gamma is lorentz factor, m is electron mass, v is velocity, e is electron charge and B is magnetic field strength.

Last edited: Jun 9, 2010
2. Jun 9, 2010

Rajini

I use this simplified formula (E is electron's energy)
$$R (\textrm {in m})=3.336\;\frac{E (\textrm {in GeV})}{B (\textrm {in T})}.$$

3. Jun 9, 2010

vela

Staff Emeritus
Yes, that's correct. The only difference between the relativistic and non-relativistic formulas is the gamma.

m is the rest mass of the electron. Whenever physicists refer to mass, they almost always mean rest mass. The concept of relativistic mass, while popular with the laypeople, is not a very useful one since it's basically equal to the relativistic energy.