Wave Phenomena in a Stratified Complex Plasma

PK-4 is a plasma facility that uses a dc discharge inside a glass tube for experiments on complex (dusty) plasmas in microgravity onboard the International Space Station. It was launched in October 2014. During development, several models of PK-4 were built. The experiments described here took place in the engineering model of PK-4. During a test run, we injected particles with different diameters. They formed a stratified complex plasma where an instability generated waves inside the strata. The analysis of the video data is shown and the type and the cause of the instability are discussed here.