Axially-Dependent Equilibrium of an Unneutralized Electron Beam in an Axial Magnetic Field.

摘要

Virtual cathode formation in vacuum-propagating beams may be more widespread than previously recognized. The spin death of parallel beam energy by E sub r x B sub z rotation in front of a density pileup, may assist or steepen the axial density gradient, since the rotation speed tends toward Brillouin flow, omega = omega sub c/2. It may be that the propagation limit (on the beam density) is not omega-squared sub p approx. equal omega-squared sub c in the applied or total magnetic field, but rather omega-squared sub p max (in the presence of self-field pileup) small enough that cE sub r/B sub z