Axially symmetric magnetic fields are provided about the longitudinal axis of each beam of a multi-beam electron beam device (MBEBD). A flux equalizer assembly is disposed between the cathodes and the anodes and near the cathodes of a (MBEBD). The assembly includes a ferromagnetic flux plate completely contained within the magnetic focusing circuit of the (MBEBD). The flux plate includes apertures for each beam of the (MBEBD). A flux equalization gap or gaps are disposed in the flux plate to provide a perturbation in the magnetic field in the flux plate which counters the asymmetry induced by the off-axis position of the beam. The gaps (MBEBD) have the effect of producing a locally continuously varying reluctance that locally counters the magnetic field asymmetry. The flux equalizer assembly prevents or substantially reduces beam twist and maintains all of the electron beams of the (MBEBD) as linear beams.