A passive method to trap an electron beam in a stellatron accelerator

An electron beam can be trapped in a stellatron accelerator with a passive technique by dissipating the energy associated with the poloidal displacement of the beam from its equilibrium position. If the net force on the beam is directed toward the minor center of the vacuum chamber, the beam will spiral toward its equilibrium position. The beam dissipates energy by charging and discharging a conductor that is grounded through a resistor. Numerical solutions in the paraxial approximation illustrate this capture effect, with parameters that show a large enough effect to trap a beam.