High-Current Discharge in a Limited Volume Projectile of a Railgun

A theoretical study of plasma parameters of a high-current discharge in a limited volume (in the discharge chamber) of a body moving in an electrodynamic accelerator (railgun) has been performed. The experiments have shown that in the case of a cylindrical chamber the accelerated body is destroyed. Calculations made it possible to determine factors that are responsible for the destruction; these are a rapid burnout of chamber walls and a high pressure of the plasma. A series of simulations of the parameters of the plasma in the discharge chamber with a rectangular cross section have been carried out. It has been shown that, at a ratio of the sides of the rectangle greater than $2.5$, the burnout of the walls is less than $2$ mm. However, the plasma pressure remains high ($\sim10^5$ atm), which requires the chamber walls to be reinforced by a strong carcass.