Optical diagnostics of dusty plasmas

Abstract

Particle-containing (complex or dusty) plasmas offer and require the development of sophisticated diagnostic techniques to measure their properties such as particle motion, particle density, particle size and demixing properties. Here, an overview of selected optical diagnostic techniques for dusty plasmas and some recent applications are given. As examples, angle-resolved optical tomography reveals the spatially resolved particle density in dense dust systems as well as the size distribution of particles trapped in the plasma. Phase separation of binary mixtures of dust particles can be studied by exploiting the fluorescence of dyed particles. There, the dynamics of the demixing process can be measured in terms of an effective diffusion coefficient. Finally, three-dimensional trajectories of particles are determined from stereoscopy allowing to study the motion of hundreds of particles in a restricted volume.