Wave transmission across an interface in a complex plasma

Abstract

Complex plasmas consist of low-temperature plasmas with embedded microparticles. The microparticles acquire electric charges of thousands of electrons and strongly interact with each other. Due to their relatively large size and slow speed, their movement can be recorded with digital cameras and traced from frame to frame. Here, we study the propagation of waves across an interface formed between two subclouds of microparticles of different sizes. For this, we use data recorded under microgravity using the PK-3 Plus Laboratory on board the International Space Station, as well as Langevin dynamics simulations of a complex plasma. Firstly, we study how self-excited waves are transmitted across the interface and demonstrate that a collision zone and a merger zone form. Secondly, we study the propagation of a solitary wave across an interface and demonstrate that at low pressures, reflection at the interface can be observed.