Equilibrium theory of an electron spiral torus in a neutral background gas

Summary form only given, as follows. The radial equilibrium for an infinite aspect-ratio electron spiral (EST) has been analyzed. In the EST, a thin (typically one electron layer thick) toroidal electron shell surrounds a toroidal ion cloud of constant density. The ions provide a radial equilibrium force for the electrons. An ambient gas pressure is assumed, and is required for ion equilibrium. We consider the case where the electrons have only an poloidal velocity /spl upsi//sub e/spl phi//. Under the general constraint of conservation of poloidal current, the product n/sub e/r/spl upsi//sub e/spl phi//. must be constant as a function of poloidal position. Under certain assumptions for the electron and ion density distributions, the electron and ion force equations decouple and can be solved separately. We compare the resulting ion density and velocity solutions with energy density predictions from the virial theorem.