Characteristics of an Overstressed Nanosecond Discharge Between Copper Electrodes and Zinc Electrodes in Argon


Purpose. Study of the characteristics of an overstressed nanosecond discharge between a copper electrode and a zinc electrode in high-pressure argon (p=50 kPa). The spatial, electrical, and optical characteristics of the discharge were investigated for the distance between the electrodes d=2 and 7 mm.

Methods. The study of the characteristics of an overstressed bipolar nanosecond discharge was carried out on an experimental stand. An intense nanosecond discharge between a copper electrode and a zinc electrode was ignited in a sealed Plexiglas chamber. The distance between the electrodes was d=2 or 7 mm. To ignite the discharge, bipolar high-voltage pulses with a duration of 50-100 ns and an amplitude of ±(20-40) kV were applied to the electrodes of the discharge cell. Plasma radiation was recorded in the spectral range λ=196-663 nm.

Results. The study of the spectral characteristics of plasma based on vapor-gas mixtures “copper-zincargon” showed that the most intense were the resonance spectral lines of the copper atom (λ=324.75 and 327.39 nm CuI) of the lines of a singly charged copper ion in the range 200-330 nm, the most intense was the line λ=227.62 nm CuII. A line with λ=618.86 nm Cu11 was distinguished from ionic spectral lines in the visible region of the spectrum. The introduction of zinc vapor into the discharge made it possible to shift the short-wavelength edge of the emission spectrum to 202-207 nm due to the intense ionic lines of zinc and to enrich the spectrum of UV radiation of the plasma with intense spectral lines 258.24; 268.41; 271.24 and 275.64 nm ZnI.

Conclusions. The study of the emission spectra of the discharge plasma made it possible to establish the main excited products that were formed in the plasma. The presence in the plasma radiation spectra of intense spectral lines of atoms and singly charged ions, both copper and zinc, creates the prerequisites for the synthesis of thin bimetallic films based on the copper-zinc composition from the products of sputtering of the electrode material in argon.

Keywords: overstressed nanosecond discharge, argon, copper, zinc, plasma