Abstract
The problem considered here is the transition region separating a uniform plasma from its confining magnetic field. The geometry chosen is one-dimensional. A self-consistent solution of Maxwell's equations and the equations of motion of the particles is obtained. This problem was formulated and solved numerically by Tonks. It is the purpose of this paper to present an analytic solution. The most interesting feature of the analysis is that the transition region is finite, the transition taking place entirely within the orbit of the particle of deepest penetration into the confining field.