Dynamics of acceleration of millimeter-sized pellets in railgun accelerators with external magnetic field

A physical model of the acceleration of small (1–3 mm) solid pellets in a railgun with a plasma piston and an external pulsed magnetic field is proposed. For the typical operating parameters of the railgun, the effect of the erosion of electrodes, drag force, and dimensions of a body on its final velocity has been studied. It is shown that the saturation of velocity of 1- to 2-mm pellets occurs at short distances (15–20 cm) and is mainly governed by the capture of a portion of the erosion mass by the plasma piston.