title: Rapid breakdown mechanisms of open air nanosecond dielectric barrier discharges.
abstract: The discharge initiation mechanism of nanosecond dielectric barrier discharges in open air has been clarified with time-dependent measurement of the discharge electric field by electric-field-induced coherent Raman scattering and optical emission. Our experimental observations have revealed that, in the prebreakdown phase of a nanosecond dielectric barrier discharge, the externally applied fast-rising electric field is strongly enhanced near the cathode due to large accumulation of space charge, which then strongly enhances ionization near the cathode. Once a sufficiently large number of ionizations take place, the location of peak ionization forms a front and propagates toward the cathode with strong optical emission, which establishes the discharge. This process is essentially different from the well-known Townsend mechanism for slower discharges.
authors: Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Japan. tsuyohito@ppl.eng.osaka-u.ac.jp
authors: Tsuyohito
authors: T
authors: Ito
authors: Tatsuya
authors: T
authors: Kanazawa
authors: Satoshi
authors: S
authors: Hamaguchi