docs: def calc_nu_b(b):
      """Calculate the cyclotron frequency in Hz given a magnetic field strength in Gauss.
  
      This is in cycles per second not radians per second; i.e. there is a 2π in
      the denominator: ν_B = e B / (2π m_e c)
  
      """
      return cgs.e * b / (2 * cgs.pi * cgs.me * cgs.c)