On analysis of physical effects on the electrode surface in rail launchers

The paper analyzes the possibility of some physical effects occurring on the electrode surface in plasma-armature rail launchers when the linear current density is higher than the critical values. It is shown the melt on the electrode surface is unstable. An analysis of the possible development of a number of instabilities showed that under experimental conditions, Rayleigh-Taylor and Kelvin-Helmholtz instabilities and magnetohydrodynamic (MHD) instabilities due to the interaction of the flowing current with the self-magnetic field can develop over times much smaller than the discharge time. These instabilities can lead to the entry of the electrode material into the plasma armature and limit acceleration velocities of solids. X-ray recording of the electrode surface confirmed the presence of small-scale inhomogeneity and ejection of the material from the surface. Under certain conditions, the emergence of metal conducting jets from the electrode surface was detected.