Correlation of phase resolved current, emission and surface charge measurements in an atmospheric pressure helium jet^*

¹ Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany
² Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald, Germany
³ Iasi Plasma Advanced Research Center (IPARC), Faculty of Physics, Alexandru Ioan Cuza University, Bd. Carol I No. 11, 700506 Iasi, Romania

^a e-mail: gerling@inp-greifswald.de

Received: 30 January 2015
Revised: 23 April 2015
Accepted: 4 May 2015
Published online: 15 July 2015

Abstract

The interaction of an atmospheric pressure plasma jet with two different surfaces (conducting and dielectric) is investigated using a setup with two ring electrodes around a dielectric capillary. For diagnostics, phase resolved ICCD-imaging, current measurements and surface charge measurements are applied. The results show the correlation of plasma dynamics with the deposition of surface charge and electrical current signals. Further, the influence of the distance between surface and jet capillary on the surface charge distribution is presented. A complex discharge dynamic is found with a dielectric barrier discharge between the ring electrodes and back-and-forth bullet propagation outside the capillary. A conducting channel connecting the jet nozzle and the surface is found. This correlates well with the observed charge exchange on the surface. The number of formed channels and the average deposited charge density on the surface is found to be strongly sensitive to the jet distance from the surface.