DYNAMICS OF A DIVERGENT PLASMA BEAM INJECTED INTO A TRANSVERSE MAGNETIC-FIELD

A divergent two-dimensional plasma beam propagating in vacuum across a magnetic field was studied. The beam was shown to self-focus over a l ength about similar to min(a/alpha, root a rho(ci)), where alpha is th e divergence angle, and rho(ci) is the Larmor radius. A sharp gradient of the plasma density, a step, was found to be formed at the beam edg e opposite the direction of the Larmor deviation of ions. Beam dynamic s were simulated. Ion-plasma and electron oscillations were determined ; the electron oscillation frequency appeared to be about similar to o mega(pe)(2)/omega(ce).