Self-pulsing $104Acm−2$ current density discharges in dielectric barrier $Al/Al2O3$ microplasma devices Available to Purchase

Excitation of $Al/Al2O3$ microplasma devices with $50μs$⁠, 800 V pulses produces, in $Ar/H2$ gas mixtures at 600 Torr, $∼6A$ current pulses with a duration of $∼30ns$⁠. Corresponding to peak current and power densities of $∼104A/cm2$ and $∼2.5GW/cm3$⁠, respectively, these pulses are generated in a $10μs$ burst in which the voltage self-pulses at a repetition frequency of $∼3MHz$⁠. Analysis of the $Hα$⁠, $Hβ$⁠, and $ArII$ emission line profiles yields a plasma density of $∼1017cm−3$⁠, and the emission of $OIV$ ions suggests the presence of energetic electrons. Images of the microplasma indicate that the plasma is initiated by surface flashover and extends $∼200μm$ outside the microcavity.