Measurements of electric field strength in streamer discharges in dry air at atmospheric pressure using intensity ratio of spectral bands of molecular nitrogen

The electric field strength in streamer discharges in dry air at atmospheric pressure was measured using the intensity ratio of spectral bands of molecular nitrogen. The streamer discharges were produced in the needle-plane electrode by applying the positive impulse voltage. It was shown that the reduced electric field strength of the primary streamer was ∼700 Td. It was clarified that the propagation velocity of the streamer was increased with increasing the applied voltage on the electrode, but the reduced electric field strength slightly decreased. The spatial distribution of the reduced electric field strength in the gap was discussed in terms of the secondary streamer near the needle electrode and the photoemission from the plane electrode. © 2016 The Institute of Electrical Engineers of Japan.