Modeling of the Sulfur Emission in the Asymmetric Pulse Dielectric Barrier Discharge

The asymmetric pulse-periodic dielectric barrier discharge (DBD) in a mixture of argon with sulfur vapor exhibits the emission spectrum of the discharge with intense bands of S-2 molecules (B-3 sigma - > X-3 sigma transition) in the visible region. The modeling of the discharge characteristics in Ar-S-2 mixture within the 1D fluid model is presented showing that during a voltage pulse (150 ns), an electropositive plasma is formed in the entire discharge gap with the electron number density reaching values above 1.5*10(18) m(-3) at the maximum under the mean electron energy of about 3 eV. The high electron number density during the current pulse leads to efficient excitation of sulfur dimers, as a result, their radiative efficiency during the voltage pulse reaches approximately 4%. The discharge is considered as promising one for creating radiation source in visible region of spectrum.