Improvement of ozone producing coaxial reactor by tensioned inner wire electrode in using nanosecond pulsed power

Nanosecond pulsed power has been introduced to produce ozone efficiently and we attempted to increase concentration by adopting a thin coaxial reactor with a short electrode separation. However, temporal downturn of ozone concentration had been observed. This was because the inner wire electrode of coaxial reactor was curved and spark discharges frequently occurred around where the electrodes separation narrowed. Two approaches were employed to suppress this phenomenon. One was an adoption of tensioned inner wire electrode by a spring. The curvature of inner electrode was constrained and the downturn of ozone concentration was not observed. As a result, the concentration increased and steadily stayed. Another was an adoption of a thicker inner electrode, of which diameter was 1, 8, or 14 mm. Although the curvature of inner electrode was constrained, ozone concentration decreased. This would be because electric field strength on the electrode surface reduced occurrence of streamer discharges on the electrode surface. There was, however, a room of study because decreasing of ozone concentration was small in spite of the low electric field in using 8-mm electrode.