Analysis of discharge parameters and optimization study of coaxial DBDs for efficient excimer light sources

In this work, a xenon-filled quartz coaxial dielectric barrier discharge (DBD) tube (ID 6 mm, OD 12 mm) at 400-mbarpressure has been studied at different operating conditions. High-frequency sinusoidal and unipolar pulse-likevoltages are applied at the discharge electrodes for the generation of micro-discharge plasma. Visual images of thedischarge and the electrical waveform confirm the diffused-type discharge. The mechanism that is involved in theignition, development and extinction of DBDs is quantitatively explained by dynamic processes in the discharge. Anequivalent electrical model representing the DBD phenomenon has also been used to validate the characteristicdischarge parameters. The relative intensity analysis of the Xe continuum peak at wavelength 172 nm in the opticalemission spectra of the vacuum ultraviolet region has been carried out for different operating conditions.Approximately three times increment in the radiation is observed in pulse excitation over sinusoidal excitation. Itinfers that the pulsed excitation of DBD sources is advantageous for excimer light sources.

Keywords:

Non-thermal plasma and non-equilibrium plasma , Dielectric barrier discharge (DBD) , Micro-discharges , Diffused discharge , Equivalent electrical circuit