Force-Free Configuration of a High-Intensity Electron Beam

The equilibrium configuration of a neutralized electron beam is calculated, including the self-field (parallel to the beam) generated by the beam itself. The resultant equilibrium configuration allows an arbitrary current to be carried by the beam, the motion of electrons being unimpeded by the self-magnetic field. Electrons in this configuration travel almost parallel to the magnetic field; thus, the synchrotron radiation can be minimized. It is suggested that this type of configuration opens up the possibility of low-loss electron coils and, in particular, is useful for fusion reactors.