jets operated in the kHz range produce relatively long plasma jets, which
appear continuous to the naked eye, but on micro-second timescales are actually
pulsed. The figure shows a photograph of a cylindrical dielectric barrier
discharge jet. The discharge configuration consists of a glass tube with
internal diameter 4 mm and thickness 1 mm. Tubular copper electrodes surround
the glass tube and are driven at 20 kHz.
The figure above shows time resolved ICCD images of the plasma jet emitted from the
cylindrical dielectric barrier discharge jet illustrating individual plasma
pulses on a nano-second timescale. The jet is operated in helium and the images
are taken for a camera gate of 20 ns and delay of 40 ns between images.