Transformation of the Bennet distribution in a rarefied gas

The usual Bennet distribution of particles in a beam is characterized by a density which decreases comparatively slowly with increasing radius. This is a negative factor in the solution of problems associated with the formation of a thin, powerful, quasistationary, relativistic electron beam. Under sufficiently high pressure of the residual gas the effect of the current of secondary electrons of the plasma, produced by the ionization of the gas by the beam, on the state of the main beam must be taken into account. As a result of this effect, an equilibrium state of the relativistic beam with a drop in the particle density deeper than in the case of the Bennet distribution toward the periphery of the beam can form. For sufficiently high currents in the beam, say in excess of 1 kilo amp, the average Larmor radius of the electrons of the secondary plasma is shorter than the mean-free-path length and the flow of secondary electrons acquires, owing to the magnetization, a longitudinal component which can change the parameters of the beam if the secondary-electron current is comparable to the beam current. This paper examines these phenomena in a kinetic description of the beam and a magnetohydrodynamic description of the plasma