Intense relativistic electron beam equilibria in vacuum without a magnetic guide field

Vacuum transport of dense, charged particle beams is investigated as an alternative to plasma neutralization of the beam, which may produce relatively large beam-plasma interaction losses. A solution of the vacuum transport equations, with beam properties invariant in the direction of propagation and without the aid of a magnetic guide field is found and interpreted. The energy required to provide favorable boundary conditions for eliminating beam divergence is shown to be acceptable