Excitation of Al/ Al2 O3 microplasma devices with 50 μs, 800 V pulses produces, in Ar/ H2 gas mixtures at 600 Torr, ∼6 A current pulses with a duration of ∼30 ns. Corresponding to peak current and power densities of ∼ 104 A/ cm2 and ∼2.5 GW/ cm3, respectively, these pulses are generated in a 10 μs burst in which the voltage self-pulses at a repetition frequency of ∼3 MHz. Analysis of the Hα, HΒ, and Ar II emission line profiles yields a plasma density of ∼ 1017 cm-3, and the emission of O IV ions suggests the presence of energetic electrons. Images of the microplasma indicate that the plasma is initiated by surface flashover and extends ∼200 μm outside the microcavity.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)