Equilibrium of a high current electron ring in a modified betatron accelerator. Memorandum report

This paper addresses the dynamics of an ultra-high current electron ring in a modified betatron configuration. Our studies include analytical and numerical results for both 'cold' and 'hot' rings. It has been found that the walls surrounding the ring and toroidal effects (hoop stresses) play a very important role in the dynamics of the ring, even when the wall conductivity is infinite. For finite wall conductivity, the diffusion of the ring's self magnetic field profoundly impacts its dynamics in general the equilibrium could be lost if means are not provided to compensate for this effect. In addition, it has been found that the Grad B drift is not important, except when the bounce frequency is very small. The general conclusion of these studies is that equilibrium states of ultra-high current rings in a modified betatron configuration exist over a wide range of parameters. These states are accessible and within the realm of existing pulsed power technology.