Progress in the visualization of filamentary gas discharges. Part 2: Visualization of DC positive corona discharges

Recently the filamentary gas discharges at atmospheric pressure, such as dielectric-barrier and corona discharges regained their importance due to numerous new applications. These new applications impose a demand of better understanding of the fundamentals of the filamentary discharges. As a consequence, during the last ten years an essential progress in the diagnostics of the filamentary discharges has been made. The recent progress in the investigations of the dielectric-barrier discharges by cross-correlation spectroscopy was described in Part 1 of this paper. Part 2 is a survey of the recent progress in the visualization of DC positive corona discharges.