Improvement of Electrical Measurement of a Dielectric Barrier Discharge Plasma Jet

The effects of the position of the current probe on electrical measurements as well as those of typical materials on the current of a He plasma jet during the interaction of the plasma jet with surface materials were investigated using a dielectric barrier discharge reactor, in which the two electrodes were isolated from ambient air by electrical insulating oil. Here, we demonstrate accurate discharge power measurement obtained by positioning the current probe between the two electrodes rather than on the ground wire. The emission current of the plasma jet increased sharply upon the interaction with a ground-connected metal surface, because in this case, the surface functioned as a second ground electrode. Similarly, important is that the average velocity of a plasma bullet can be estimated from the phase shift of the current waveforms at different positions. The phase shift can be monitored by an oscilloscope using a cursor tool during the plasma discharge process. The average velocity of the plasma bullets in this paper ranged from 56 to 266 km/s.