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Homework Help: Electron in magnetic field equation

  1. Jun 9, 2010 #1
    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. jcsd
  3. Jun 9, 2010 #2
    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})}.
  4. Jun 9, 2010 #3


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    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.
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