Assessment of energetic ion rings versus electron rings for an EBT reactor

This paper summarizes the results of a preliminary assessment of energetic ion rings for use in an ELMO Bumpy Torus (EBT) reactor. The properties of ion rings are compared with those of electron rings. Ion rings appear to require sizable devices and magnetic field strengths for stable, adiabatic confinement. Stable windows for steady-state ion ring operation having acceptable power requirements, determined mainly by Coulomb drag on the background electrons, appear to exist for EBT reactors. Power requirements for ion rings can be quantitatively lower than those for electron rings, provided the ion ring volume does not greatly exceed the electron ring volume. Some stability properties of ion rings are also discussed. Results of parametric trade-off studies for ion rings versus electron rings using an EBT reactor systems code are presented.