Rectilinear transition flow of intense charged particle beams

Charged particle flow in planar geometry is generally classified into two phenomenological regimes. At relatively low current injection densities (less than a critical function of length and potential across the drift space and entrance kinetic energy), all charges propagate across the entire region, and the flow is termed injection limited. Space charge limited flow occurs at supercritical injection densities, and is characterized by partial particle reflection at the plane of minimum kinetic energy. Solutions of the laminar, monoenergetic beam equations demonstrate the existence of a transition region, rather than a single critical current density, in which either flow may exist. (auth)