OODR-LIF experiments on N$_{2}$(A$^{3}\Sigma $u$^{ +})$ in volume and in surface atmospheric pressure DBDs

A calibrated optical double resonance laser induced fluorescence, OODR-LIF, has been used to measure N$_{2}$(A$^{3}\Sigma _{u}^{+})$ metastable density at high pressure in the voltage cycle of volume and surface atmospheric DBDs. OODR{\_}LIF excitation-detection scheme is: N$_{2}$(A$^{3}\Sigma _{u}^{+}$, v) + h$\nu _{L1 }\to $ N$_{2}$(B$^{3}\Pi _{g}$, v') + h$\nu _{L2 }\to $ N$_{2}$(C$^{3}\Pi _{g}$, v'') $\to \quad _{ }$ N$_{2}$(C$^{3}\Pi _{g}$, v'')+ h$\nu _{E }$. The two exciting photons (\textit{red-}$\nu _{L1}$ and\textit{ UV-}$\nu _{L2})$ are generated by two independently tunable and synchronized lasers. In volume DBD, N$_{2}$(A) is measured in the discharge gap ( d=1.5 mm, voltage 10 kV$_{pp}$ at 1.8 kHz) pulsed at T$_{ON}$=5ms and T$_{OFF}$=10ms. In surface DBD, N$_{2}$(A) is measured in the gas layer over a comb electrode deposited over a ceramic plate back covered by a metallic large background electrode. The current and the applied voltage are monitored by a digitizing oscilloscope. The measured time-resolved emissions of N$_{2}$ SPS and NO-$\gamma $ bands allows exploring the correlations between emissions, LIF and discharge current and implementing a calibration of OODR-LIF. The measured density is about 10$^{13}$cm$^{-3}$ in volume DBD while lower in a surface DBD.