# Electron in magnetic field equation

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.

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

vela
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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. is m rest mass?
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.