Abstract

The streamer observation and LIF detection of the NO molecules and OH radicals were performed during the steady-state positive DC corona discharge at atmospheric pressure. The time relationship between the regular streamer coronas, laser pulse, LIF signal and laser-induced streamer was explained for no time synchronization LIF measurement. Using the corona radical shower reactor, two-dimensional distributions of ground-state NO (X²II) could be observed not only in the discharge zone but also both in the downstream and the upstream regions of the reactor. The presence of the ground-state OH (X²II) and excited-state OH (A²∑⁺) radicals (EHD) flow on NO profiles n the reactor and ozone interference in OH LIF measurements were discussed. The obtained results showed that the density of NO molecules decreased not only in the plasma region formed by the corona streamers and the downstream regions of the reactor but also in the upstreams region of the reactor. On the other hand, the ground-state OH radicals were generated and stayed mainly in the region where streamers propagated between the electrodes.