Striations in rare gas plasmas

This paper describes the recent progress in understanding the nature of striations in rare gas plasmas. Striations are ionization waves with unique properties determined by transport phenomena, ionization processes and electron kinetics in current-carrying plasmas. Recent progress in understanding the physics of striations is mainly associated with the advances of non-local electron kinetics in spatially inhomogeneous plasmas and the development of computational models of gas discharges. It has been proven that kinetic analysis of electrons is necessary for nearly all types of striations. Most strikingly, the non-hydrodynamic behaviour of electrons reveals itself in kinetic resonances of the electron distribution function in spatially periodic electric fields, resulting in a variety of striations at low pressures. Moving striations in classical dc discharges have been obtained in computer experiments. Renewed interest in striations has been recently generated by the observation of striations inside pixels of plasma display panels and other micro-plasma devices. High sensitivity of striations to the state of electron gas and ionization kinetics makes them an ideal tool for testing discharge models and advanced plasma diagnostics. Further studies of striations in glow discharges could shed light into the physics of different plasma sources used in modern technologies.