Spectral diagnostics of high-pressure gliding discharges

Spectral methods allow to determine the vibrational, rotational and electron temperatures of gliding arc type discharges excited in air at the pressure of (0.1-1.2) MPa. AC discharges of 50 Hz were excited in screaming air (10-50) l/min on horn-shaped Cu electrodes. The vibrational structure of N2 and OH radicals was observed only up to pressures of (0.3-0.4) MPa. The vibrational temperatures determined from the 2nd positive system of N2 in air were Tvx ∼ (2-4) · 103 K and the rotational temperature TR1 ∼ (3-6) · 103 K. The rotational temperature from the rotational structure of OH radicals of branch Q1 of the vibrational band 0-0 of 306.4 nm was TRN ∼ (0.7-1.4) · 103 K. The electron excitation temperature TE determined by means of the relative intensities of the Cu atomic lines was ∼ (7-12) · 103 K up to 1.2 MPa. (author)