In situ powder diagnostics in low temperature plasmas

We present a survey of diagnostics developed for dust particles, present in low pressure, low temperature plasmas. Formation of microscopic particles is an extensively studied phenomenon, and its complexity requires specific experimental methods. The most valuable information about the properties and behaviour of powders is obtained in situ in the plasma. Various interactions of photons with dust particles offer a variety of in situ diagnostic techniques, which allow characterising a wide category of particles. Here we shall concentrate on classification of photoninduced processes in dusty plasmas and demonstrate their diagnostic possibilities. Methods to determine physical and chemical properties of particles, dust density and size from nanometer to micrometer scale, will be described and illustrated with examples.