Electric field measurement in the dielectric tube of helium atmospheric pressure plasma jet
Résumé
The results of the electric field measurements in the capillary of the helium plasma jet are presented
in this article. Distributions of the electric field for the streamers are determined for different gas
flow rates. It is found that electric field strength in front of the ionization wave decreases as it
approaches to the exit of the tube. The values obtained under presented experimental conditions are
in the range of 511 kV/cm. It was found that the increase in gas flow above 1500 SCCM could
induce substantial changes in the discharge operation. This is reflected through the formation of the
brighter discharge region and appearance of the electric field maxima. Furthermore, using the
measured values of the electric field strength in the streamer head, it was possible to estimate
electron densities in the streamer channel. Maximal density of 41011cm3 is obtained in the
vicinity of the grounded ring electrode. Similar behaviors of the electron density distributions to the
distributions of the electric field strength are found under the studied experimental conditions.