Dynamics of a plasma piston in the channel of a rail mass accelerator

The processes taking place in a rail mass accelerator are studied numerically in the approximation of one-dimensional gasdynamics with the equations of electrodynamics in integral form averaged over the channel cross section. It is shown that the so-called H-compressed discharge is not realized and the plasma piston has an extended, complicated structure. Fairly regular oscillations in the gasdynamic parameters and the current density are found to develop with rising current and are damped as the current decays. The structure of the flow depends strongly on the initial state of the plasma.