Structure of a shock front in a three-dimensional complex plasma

A strongly nonlinear density wave transforming into a shock wave in a three-dimensional complex plasma of a direct current gas discharge has been studied using the scientific instrument Plasmakristall-4 under microgravity conditions. The pressure drop of the plasma–dust structure in the wave dominates over the friction against the neutral gas under the chosen experimental conditions. The velocity of the shock wave and the velocities of individual microparticles have been determined. The velocity and concentration profiles of microparticles in the developing shock wave have been reconstructed. Good agreement between the experimental profiles and the results of molecular dynamics simulations has been obtained. The estimates have also shown that the Mach number in the incoming flow is 4.3.