Enhanced corona discharge: I-V characterization and ion density measurements

Summary form only given, as follows. Attachment of electrons to the oxygen molecules can be a problem for corona discharge at atmospheric pressure in air. We have found a way to enhance the discharge by reducing or avoiding the attachment. The enhancement is achieved by replacing the air around the limited corona points with non-electronegative gases such as argon, helium, and nitrogen as shown in the figure below. The configuration of such electrode is made of a line of pins fastened to a brass pipe at one end and protrudes from the other end through tiny holes. The feed gas escapes through the holes and provides a local atmosphere around the corona points. By proper biasing a pair of such electrodes separated by a distance, we are able to produce both positive and negative ions that migrate into the bulk plasma to overcome the previous density limitation that occurred because of space charge in a single species corona discharge. We will present the I-V characteristics, the local ion density measurement and the spatial ion density profile of our enhanced corona discharge apparatus. Ozone detection will also be discussed.