An apparatus and method for controlling a plasma in a plasma processing system. In the above Chemical Formula 1, R is the same as described in the detailed description. A plate glass distances the original from the opposing member. The invention also relates to a process for transporting a continuous web around the apparatus whereby the distance between adjacent web support plates is greater than the minimum distance, and wherein the web is transported around the circular path so that a web loop is formed when the distance between adjacent web support plates decreases towards the minimum distance.