2D-resolved electric field development in helium coplanar DBD: spectrally filtered ICCD camera approach
| Authors | |
|---|---|
| Year of publication | 2018 |
| Type | Article in Periodical |
| Magazine / Source | Plasma Sources Science and Technology |
| MU Faculty or unit | |
| Citation | |
| Web | http://dx.doi.org/10.1088/1361-6595/aade41 |
| Doi | http://dx.doi.org/10.1088/1361-6595/aade41 |
| Keywords | coplanar discharge; electric field; 2D; imaging; helium; ICCD |
| Description | Electric field strength in diffuse coplanar barrier discharge in helium at atmospheric pressure, driven by AC voltage amplitude 1.5 kV, frequency 10 kHz), was measured by optical emission spectroscopy. Two helium singlet lines at 667.8 nm (He I) and 728.1 nm (He I) were recorded within the discharge space and period with a high spatial (20µm) and temporal (50ns) resolution and analysed with the line intensity ratio method developed by Ivković et al 2014. A novel experimental approach, based on a direct observation of the discharge by ICCD camera through two interference filters, was developed to obtain 2D spatially resolved distributions of the electric field. The obtained results proved the existence of several developing regions of high electric field, namely the cathode-directed and anode ionization waves. Electric field in the cathode directed wave peaked at 32kV/cm during the first contact of the wave with the cathode’s dielectrics, followed by decrease to values of 15–25kV/cm above the electrode. The electric field in anode directed wave was lower, reading some 15kV/cm. The performed ‘sensitivity analysis’ pointed out the crucial importance of precise temporal and spatial synchronization for the techniques based on intensity ratio of two spectral lines. Artificially introduced 50ns misalignment between the measured data of both spectral lines resulted in the substantial distortion of the electric field map. Reduction of the temporal resolution from 50ns to 100ns led to the decrease of electric field maxima by the 30 %. Reduction of the spatial resolution from 20µm to 40µm decreased the maximal field value by 10%. |
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